From ada92746b7084d3bf181b1f477e0eaf385dd6676 Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Fri, 14 Mar 2014 17:38:42 -0300
Subject: [PATCH 01/22] selectUnspent function and tests

---
 Transaction.js           | 50 ++++++++++++++++++++++++++++++++++++++++
 test/data/unspends.json  | 24 +++++++++++++++++++
 test/test.Transaction.js | 29 +++++++++++++++++++++++
 test/testdata.js         |  3 +++
 4 files changed, 106 insertions(+)
 create mode 100644 test/data/unspends.json

diff --git a/Transaction.js b/Transaction.js
index 37d2ad8..1da4964 100644
--- a/Transaction.js
+++ b/Transaction.js
@@ -679,6 +679,56 @@ Transaction.prototype.parse = function (parser) {
   this.calcHash();
 };
 
+/*
+ * selectUnspent
+ *
+ *  Selects some unspend outputs for later usage in tx inputs
+ *
+ * @unspentArray: unspent array (UTXO) avaible on the form:
+ * [{
+ *       address: "mqSjTad2TKbPcKQ3Jq4kgCkKatyN44UMgZ",
+ *       hash: "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1",
+ *       scriptPubKey: "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ac",
+ *       vout: 1,
+ *       amount: 0.01,                
+ *       }, [...]
+ * ]
+ * This is compatible con insight's /utxo API. 
+ * NOTE that amount is in BTCs! (as returned in insight and bitcoind.
+ *
+ * @totalNeededAmount: output transaction amount in BTC, including fee
+ *
+ *
+ * Return the selected outputs or null if there are not enough funds.
+ * It does not check for confirmations. The unspendArray should be filtered.
+ *
+ */
+Transaction.selectUnspent = function (unspentArray, totalNeededAmount) {
+
+  // TODO we could randomize or select the selection
+  
+  var selected = [];
+  var l = unspentArray.length;
+  var totalSat = bignum(0);
+  var totalNeededAmountSat = bignum(totalNeededAmount * util.COIN);
+  var fullfill  = false;
+
+  for(var i = 0; i<l; i++) {
+    var u = unspentArray[i];
+    var sat = bignum(u.amount * util.COIN);
+    totalSat = totalSat.add(sat);
+    selected.push(u);
+    if(totalSat.cmp(totalNeededAmountSat) >= 0) {
+      fullfill = true;
+      break;
+    }
+  }
+  if (!fullfill) return [];
+  return selected;
+}
+
+
+
 var TransactionInputsCache = exports.TransactionInputsCache =
 function TransactionInputsCache(tx)
 {
diff --git a/test/data/unspends.json b/test/data/unspends.json
new file mode 100644
index 0000000..d9fac53
--- /dev/null
+++ b/test/data/unspends.json
@@ -0,0 +1,24 @@
+[
+  {
+    "address": "mqSjTad2TKbPcKQ3Jq4kgCkKatyN44UMgZ",
+    "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1",
+    "scriptPubKey": "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ac",
+    "vout": 1,
+    "amount": 0.01
+  },
+  {
+    "address": "mqSjTad2TKbPcKQ3Jq4kgCkKatyN44UMgZ",
+    "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc2",
+    "scriptPubKey": "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ad",
+    "vout": 1,
+    "amount": 0.1
+  },
+  {
+    "address": "mqSjTad2TKbPcKQ3Jq4kgCkKatyN44UMgZ",
+    "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc3",
+    "scriptPubKey": "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ae",
+    "vout": 3,
+    "amount": 1
+  }
+]
+
diff --git a/test/test.Transaction.js b/test/test.Transaction.js
index ff2dc4b..c8bf0b0 100644
--- a/test/test.Transaction.js
+++ b/test/test.Transaction.js
@@ -25,11 +25,40 @@ describe('Transaction', function() {
     should.exist(In);
     should.exist(Out);
   });
+
+
   it('should be able to create instance', function() {
     var t = new Transaction();
     should.exist(t);
   });
 
+
+  it('should be able to select unspents', function() {
+    var u = Transaction.selectUnspent(testdata.dataUnspends,1.0);
+    u.length.should.equal(3);
+    u = Transaction.selectUnspent(testdata.dataUnspends,0.5);
+    u.length.should.equal(3);
+    u = Transaction.selectUnspent(testdata.dataUnspends,0.1);
+    u.length.should.equal(2);
+    u = Transaction.selectUnspent(testdata.dataUnspends,0.05);
+    u.length.should.equal(2);
+    u = Transaction.selectUnspent(testdata.dataUnspends,0.015);
+    u.length.should.equal(2);
+    u = Transaction.selectUnspent(testdata.dataUnspends,0.01);
+    u.length.should.equal(1);
+    should.exist(u[0].amount);
+    should.exist(u[0].txid);
+    should.exist(u[0].scriptPubKey);
+    should.exist(u[0].vout);
+  });
+
+
+  it.skip('should be able to create instance thru #create', function() {
+    var t = Transaction.create({
+    });
+    should.exist(t);
+  });
+
   // Read tests from test/data/tx_valid.json
   // Format is an array of arrays
   // Inner arrays are either [ "comment" ]
diff --git a/test/testdata.js b/test/testdata.js
index dd05be7..6eef35a 100644
--- a/test/testdata.js
+++ b/test/testdata.js
@@ -7,6 +7,8 @@ var dataTxValid = JSON.parse(fs.readFileSync('test/data/tx_valid.json'));
 var dataTxInvalid = JSON.parse(fs.readFileSync('test/data/tx_invalid.json'));
 var dataScriptValid = JSON.parse(fs.readFileSync('test/data/script_valid.json'));
 var dataScriptInvalid = JSON.parse(fs.readFileSync('test/data/script_invalid.json'));
+var dataUnspends = JSON.parse(fs.readFileSync('test/data/unspends.json'));
+ 
 
 module.exports.dataValid = dataValid;
 module.exports.dataInvalid = dataInvalid;
@@ -16,3 +18,4 @@ module.exports.dataTxInvalid = dataTxInvalid;
 module.exports.dataScriptValid = dataScriptValid;
 module.exports.dataScriptInvalid = dataScriptInvalid;
 module.exports.dataScriptAll = dataScriptValid.concat(dataScriptInvalid);
+module.exports.dataUnspends = dataUnspends;

From 671d372c199d94b75e66fb18ba8ef48c27843f30 Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sat, 15 Mar 2014 03:27:06 -0300
Subject: [PATCH 02/22] tx creation working. more tests needed

---
 Address.js               |  16 ++++
 Transaction.js           | 175 +++++++++++++++++++++++++++++++--------
 test/test.Transaction.js |  24 ++++--
 util/util.js             |   3 +
 4 files changed, 180 insertions(+), 38 deletions(-)

diff --git a/Address.js b/Address.js
index 07333da..f8dcf8e 100644
--- a/Address.js
+++ b/Address.js
@@ -1,6 +1,7 @@
 'use strict';
 var imports = require('soop').imports();
 var parent  = imports.parent || require('./util/VersionedData');
+var networks= imports.networks || require('./networks');
 
 function Address() {
   Address.super(this, arguments);
@@ -22,4 +23,19 @@ Address.prototype.isValid = function() {
   return answer;
 };
 
+Address.prototype.network = function() {
+  var version = this.version();
+
+  var livenet = networks.livenet;
+  var testnet = networks.testnet;
+
+  var answer;
+  if (version === livenet.addressPubkey || version === livenet.addressScript)
+    answer = livenet;
+  else if (version === testnet.addressPubkey || version === testnet.addressScript)
+    answer = testnet;
+
+  return answer;
+};
+
 module.exports = require('soop')(Address);
diff --git a/Transaction.js b/Transaction.js
index 1da4964..5e04e13 100644
--- a/Transaction.js
+++ b/Transaction.js
@@ -11,8 +11,10 @@ var Parser             = imports.Parser || require('./util/BinaryParser');
 var Step               = imports.Step || require('step');
 var buffertools        = imports.buffertools || require('buffertools');
 var error              = imports.error || require('./util/error');
+var networks           = imports.networks || require('./networks');
 
 var COINBASE_OP = Buffer.concat([util.NULL_HASH, new Buffer('FFFFFFFF', 'hex')]);
+var DEFAULT_FEE = 0.0001;
 
 function TransactionIn(data) {
   if ("object" !== typeof data) {
@@ -605,36 +607,7 @@ Transaction.prototype.fromObj = function fromObj(obj) {
   txobj.ins = [];
   txobj.outs = [];
 
-  obj.inputs.forEach(function(inputobj) {
-    var txin = new TransactionIn();
-    txin.s = util.EMPTY_BUFFER;
-    txin.q = 0xffffffff;
-
-    var hash = new Buffer(inputobj.txid, 'hex');
-    hash = buffertools.reverse(hash);
-    var vout = parseInt(inputobj.vout);
-    var voutBuf = new Buffer(4);
-    voutBuf.writeUInt32LE(vout, 0);
-
-    txin.o = Buffer.concat([hash, voutBuf]);
-
-    txobj.ins.push(txin);
-  });
-
-  var keys = Object.keys(obj.outputs);
-  keys.forEach(function(addrStr) {
-    var addr = new Address(addrStr);
-    var script = Script.createPubKeyHashOut(addr.payload());
-
-    var valueNum = bignum(obj.outputs[addrStr]);
-    var value = util.bigIntToValue(valueNum);
-
-    var txout = new TransactionOut();
-    txout.v = value;
-    txout.s = script.getBuffer();
-
-    txobj.outs.push(txout);
-  });
+  var tx = new Transaction(txobj);
 
   this.lock_time = txobj.lock_time;
   this.version = txobj.version;
@@ -694,7 +667,8 @@ Transaction.prototype.parse = function (parser) {
  *       }, [...]
  * ]
  * This is compatible con insight's /utxo API. 
- * NOTE that amount is in BTCs! (as returned in insight and bitcoind.
+ * NOTE that amount is in BTCs! (as returned in insight and bitcoind)
+ * amountSat can be given to provide amount in satochis.
  *
  * @totalNeededAmount: output transaction amount in BTC, including fee
  *
@@ -705,17 +679,27 @@ Transaction.prototype.parse = function (parser) {
  */
 Transaction.selectUnspent = function (unspentArray, totalNeededAmount) {
 
+  // TODO implement bidcoind heristics
+  //  A-
+  //  1) select utxos with 6+ confirmations
+  //  2) if not 2) select utxos with 1+ confirmations
+  //  3) if not select unconfirmed.
+  //
+  //  B-
+  //  Select smaller utxos first.
+  //
+  //
   // TODO we could randomize or select the selection
   
   var selected = [];
   var l = unspentArray.length;
   var totalSat = bignum(0);
-  var totalNeededAmountSat = bignum(totalNeededAmount * util.COIN);
+  var totalNeededAmountSat = util.parseValue(totalNeededAmount);
   var fullfill  = false;
 
   for(var i = 0; i<l; i++) {
     var u = unspentArray[i];
-    var sat = bignum(u.amount * util.COIN);
+    var sat = u.amountSat || util.parseValue(u.amount);
     totalSat = totalSat.add(sat);
     selected.push(u);
     if(totalSat.cmp(totalNeededAmountSat) >= 0) {
@@ -727,7 +711,132 @@ Transaction.selectUnspent = function (unspentArray, totalNeededAmount) {
   return selected;
 }
 
+/*
+ * _scriptForAddress
+ * 
+ *  Returns a scriptPubKey for the given address type
+ */
 
+Transaction._scriptForAddress = function (addressString) {
+
+  var livenet = networks.livenet;
+  var testnet = networks.testnet;
+  var address = new Address(addressString);
+
+  var version = address.version();
+  var script;
+  if (version == livenet.addressPubkey || version == testnet.addressPubkey)
+    script = Script.createPubKeyHashOut(address.payload());
+  else if (version == livenet.addressScript || version == testnet.addressScript)
+    script = Script.createP2SH(address.payload());
+  else
+    throw new Error('invalid output address');
+
+  return script;
+};
+
+/*
+ * create
+ *
+ *  creates a transaction
+ *
+ *  @ins 
+ *    a selected set of utxos, as described on selectUnspent
+ *  @outs
+ *    an array of [{
+ *      address: xx, 
+ *      amount:0.001
+*     },...]
+ *  @opts
+ *    { 
+ *      remainderAddress: null,
+ *      fee: 0.001,
+ *      lockTime: null,
+ *    }
+ *
+ *  Amounts are in BTC. instead of fee and amount; feeSat and amountSat can be given, 
+ *  repectively, to provide amounts in satoshis.
+ *
+ *  (TODO: should we use uBTC already?)
+ *
+ *  If not remainderAddress is given, and there is a remainderAddress
+ *  first in address will be used. (TODO: is this is reasoable?)
+ *
+ *  TODO add exceptions for validations:
+ *  out address - ins amount > out amount - fees < maxFees
+ *  + more?
+ */
+
+Transaction.create = function (ins, outs, opts) {
+  opts = opts || {};
+
+  var feeSat = opts.feeSat || util.parseValue(opts.fee || DEFAULT_FEE);
+  var txobj = {};
+  txobj.version = 1;
+  txobj.lock_time = opts.lockTime || 0;
+  txobj.ins     = [];
+  txobj.outs    = [];
+
+  var l = ins.length;
+  var valueInSat = bignum(0);
+  for(var i=0; i<l; i++) {
+    valueInSat = valueInSat.add(util.parseValue(ins[i].amount));
+
+    var txin = {};
+    txin.s = util.EMPTY_BUFFER;
+    txin.q = 0xffffffff;
+
+    var hash = new Buffer(ins[i].txid, 'hex');
+    var hashReversed = buffertools.reverse(hash);
+
+    var vout = parseInt(ins[i].vout);
+    var voutBuf = new Buffer(4);
+    voutBuf.writeUInt32LE(vout, 0);
+
+    txin.o = Buffer.concat([hashReversed, voutBuf]);
+    txobj.ins.push(txin); 
+  }
+
+
+  var valueOutSat = bignum(0);
+  l = outs.length;
+
+  for(var i=0;i<outs.length;i++) {
+    var sat = outs[i].amountSat || util.parseValue(outs[i].amount);
+    valueOutSat = valueOutSat.add(sat);
+  }
+
+  if (valueInSat.cmp(valueOutSat)<0) {
+    throw new Error('transaction inputs sum less than outputs');
+  }
+
+  var remainderSat = valueInSat.sub(valueOutSat);
+
+  if (remainderSat.cmp(0)>0) {
+    var remainderAddress = opts.remainderAddress || ins[0].address;
+
+    outs.push({
+      address: remainderAddress,
+      amountSat: remainderSat,
+    });
+  }
+
+  for(var i=0;i<outs.length;i++) {
+    var amountSat = outs[i].amountSat || util.parseValue(outs[i].amount);
+    var value = util.bigIntToValue(amountSat);
+    var script = Transaction._scriptForAddress(outs[i].address);
+
+    var txout = {
+      v: value,
+      s: script.getBuffer(),
+    };
+
+    txobj.outs.push(txout);
+  }
+
+
+  return new Transaction(txobj);
+};
 
 var TransactionInputsCache = exports.TransactionInputsCache =
 function TransactionInputsCache(tx)
diff --git a/test/test.Transaction.js b/test/test.Transaction.js
index c8bf0b0..64a7270 100644
--- a/test/test.Transaction.js
+++ b/test/test.Transaction.js
@@ -10,6 +10,7 @@ var Transaction;
 var In;
 var Out;
 var Script = bitcore.Script;
+var util = bitcore.util;
 var buffertools = require('buffertools');
 var testdata = testdata || require('./testdata');
 
@@ -33,7 +34,7 @@ describe('Transaction', function() {
   });
 
 
-  it('should be able to select unspents', function() {
+  it('should be able to select utxos', function() {
     var u = Transaction.selectUnspent(testdata.dataUnspends,1.0);
     u.length.should.equal(3);
     u = Transaction.selectUnspent(testdata.dataUnspends,0.5);
@@ -52,11 +53,24 @@ describe('Transaction', function() {
     should.exist(u[0].vout);
   });
 
+  it('should return null if not enough utxos', function() {
+    var u = Transaction.selectUnspent(testdata.dataUnspends,1.12);
+    u.length.should.equal(0);
+  });
 
-  it.skip('should be able to create instance thru #create', function() {
-    var t = Transaction.create({
-    });
-    should.exist(t);
+
+  it('should be able to create instance thru #create', function() {
+    var utxos = Transaction.selectUnspent(testdata.dataUnspends,0.1);
+    var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
+    var tx = Transaction.create(utxos, outs, 
+                                {remainderAddress:'3CMNFxN1oHBc4R1EpboAL5yzHGgE611Xou'});
+    should.exist(tx);
+    tx.version.should.equal(1);
+    tx.ins.length.should.equal(2);
+    tx.outs.length.should.equal(2);
+    util.valueToBigInt(tx.outs[0].v).cmp(8000000).should.equal(0);
+    // TODO remainder is 0.03 here because unspend just select utxos in order
+    util.valueToBigInt(tx.outs[1].v).cmp(3000000).should.equal(0);
   });
 
   // Read tests from test/data/tx_valid.json
diff --git a/util/util.js b/util/util.js
index d90cb25..2b78394 100644
--- a/util/util.js
+++ b/util/util.js
@@ -188,6 +188,9 @@ function parseWholeValue(res)
 
 exports.parseValue = function parseValue(valueStr)
 {
+  if (typeof valueStr !== 'string') 
+    valueStr = valueStr.toString();
+
   var res = valueStr.match(reFullVal);
   if (res)
     return parseFullValue(res);

From 706162e2ba29c094cf42065e967f2e1dbe15abee Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sat, 15 Mar 2014 12:21:59 -0300
Subject: [PATCH 03/22] #create for Transaction and tests

---
 Transaction.js           | 93 +++++++++++++++++++++++++---------------
 test/data/unspends.json  |  7 ++-
 test/test.Transaction.js | 64 +++++++++++++++++++++------
 3 files changed, 115 insertions(+), 49 deletions(-)

diff --git a/Transaction.js b/Transaction.js
index 5e04e13..4fcccb1 100644
--- a/Transaction.js
+++ b/Transaction.js
@@ -652,6 +652,47 @@ Transaction.prototype.parse = function (parser) {
   this.calcHash();
 };
 
+/*
+ * _selectUnspent
+ *
+ *  Selects some unspend outputs for later usage in tx inputs
+ *
+ * @unspentArray: unspent array (UTXO) avaible on the form (see selectUnspent)
+ * @totalNeededAmount: output transaction amount in BTC, including fee
+ * @minConfirmations: 0 by default.
+ *
+ *
+ * Returns the selected outputs or null if there are not enough funds.
+ * The utxos are selected in the order they appear in the original array. 
+ * Sorting must be done previusly.
+ *
+ */
+Transaction._selectUnspent = function (unspentArray, totalNeededAmount, minConfirmations) {
+  minConfirmations = minConfirmations || 0;
+
+  var selected = [];
+  var l = unspentArray.length;
+  var totalSat = bignum(0);
+  var totalNeededAmountSat = util.parseValue(totalNeededAmount);
+  var fullfill  = false;
+
+  for(var i = 0; i<l; i++) {
+    var u = unspentArray[i];
+    if ( (u.confirmations||0) < minConfirmations) 
+      continue;
+
+    var sat = u.amountSat || util.parseValue(u.amount);
+    totalSat = totalSat.add(sat);
+    selected.push(u);
+    if(totalSat.cmp(totalNeededAmountSat) >= 0) {
+      fullfill = true;
+      break;
+    }
+  }
+  if (!fullfill) return [];
+  return selected;
+}
+
 /*
  * selectUnspent
  *
@@ -664,51 +705,31 @@ Transaction.prototype.parse = function (parser) {
  *       scriptPubKey: "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ac",
  *       vout: 1,
  *       amount: 0.01,                
+ *       confirmations: 3
  *       }, [...]
  * ]
  * This is compatible con insight's /utxo API. 
- * NOTE that amount is in BTCs! (as returned in insight and bitcoind)
+ * That amount is in BTCs. (as returned in insight and bitcoind)
  * amountSat can be given to provide amount in satochis.
  *
  * @totalNeededAmount: output transaction amount in BTC, including fee
+ * @allowUnconfirmed:false (allow selecting unconfirmed utxos)
  *
  *
- * Return the selected outputs or null if there are not enough funds.
- * It does not check for confirmations. The unspendArray should be filtered.
+ * Note that the sum of the selected unspent is >= the desired amount.
  *
  */
-Transaction.selectUnspent = function (unspentArray, totalNeededAmount) {
 
-  // TODO implement bidcoind heristics
-  //  A-
-  //  1) select utxos with 6+ confirmations
-  //  2) if not 2) select utxos with 1+ confirmations
-  //  3) if not select unconfirmed.
-  //
-  //  B-
-  //  Select smaller utxos first.
-  //
-  //
-  // TODO we could randomize or select the selection
-  
-  var selected = [];
-  var l = unspentArray.length;
-  var totalSat = bignum(0);
-  var totalNeededAmountSat = util.parseValue(totalNeededAmount);
-  var fullfill  = false;
+Transaction.selectUnspent = function (unspentArray, totalNeededAmount, allowUnconfirmed) {
+  var answer = Transaction._selectUnspent(unspentArray, totalNeededAmount, 6);
 
-  for(var i = 0; i<l; i++) {
-    var u = unspentArray[i];
-    var sat = u.amountSat || util.parseValue(u.amount);
-    totalSat = totalSat.add(sat);
-    selected.push(u);
-    if(totalSat.cmp(totalNeededAmountSat) >= 0) {
-      fullfill = true;
-      break;
-    }
-  }
-  if (!fullfill) return [];
-  return selected;
+  if (!answer.length) 
+    answer = Transaction._selectUnspent(unspentArray, totalNeededAmount, 1);
+
+  if (!answer.length && allowUnconfirmed)
+    answer = Transaction._selectUnspent(unspentArray, totalNeededAmount, 0);
+
+  return answer;
 }
 
 /*
@@ -805,9 +826,13 @@ Transaction.create = function (ins, outs, opts) {
     var sat = outs[i].amountSat || util.parseValue(outs[i].amount);
     valueOutSat = valueOutSat.add(sat);
   }
+  valueOutSat = valueOutSat.add(feeSat);
 
   if (valueInSat.cmp(valueOutSat)<0) {
-    throw new Error('transaction inputs sum less than outputs');
+    var inv = valueInSat.toString();
+    var ouv = valueOutSat.toString();
+    throw new Error('transaction input amount is less than outputs: ' + 
+                    inv + ' < '+ouv + ' [SAT]');
   }
 
   var remainderSat = valueInSat.sub(valueOutSat);
diff --git a/test/data/unspends.json b/test/data/unspends.json
index d9fac53..9c818a8 100644
--- a/test/data/unspends.json
+++ b/test/data/unspends.json
@@ -4,13 +4,15 @@
     "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1",
     "scriptPubKey": "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ac",
     "vout": 1,
-    "amount": 0.01
+    "amount": 0.01,
+    "confirmations":7
   },
   {
     "address": "mqSjTad2TKbPcKQ3Jq4kgCkKatyN44UMgZ",
     "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc2",
     "scriptPubKey": "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ad",
-    "vout": 1,
+    "vout": 0,
+    "confirmations": 1,
     "amount": 0.1
   },
   {
@@ -18,6 +20,7 @@
     "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc3",
     "scriptPubKey": "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ae",
     "vout": 3,
+    "confirmations": 0,
     "amount": 1
   }
 ]
diff --git a/test/test.Transaction.js b/test/test.Transaction.js
index 64a7270..bf0671d 100644
--- a/test/test.Transaction.js
+++ b/test/test.Transaction.js
@@ -34,18 +34,18 @@ describe('Transaction', function() {
   });
 
 
-  it('should be able to select utxos', function() {
-    var u = Transaction.selectUnspent(testdata.dataUnspends,1.0);
+  it('#_selectUnspent should be able to select utxos', function() {
+    var u = Transaction._selectUnspent(testdata.dataUnspends,1.0);
     u.length.should.equal(3);
-    u = Transaction.selectUnspent(testdata.dataUnspends,0.5);
+    u = Transaction._selectUnspent(testdata.dataUnspends,0.5);
     u.length.should.equal(3);
-    u = Transaction.selectUnspent(testdata.dataUnspends,0.1);
+    u = Transaction._selectUnspent(testdata.dataUnspends,0.1);
     u.length.should.equal(2);
-    u = Transaction.selectUnspent(testdata.dataUnspends,0.05);
+    u = Transaction._selectUnspent(testdata.dataUnspends,0.05);
     u.length.should.equal(2);
-    u = Transaction.selectUnspent(testdata.dataUnspends,0.015);
+    u = Transaction._selectUnspent(testdata.dataUnspends,0.015);
     u.length.should.equal(2);
-    u = Transaction.selectUnspent(testdata.dataUnspends,0.01);
+    u = Transaction._selectUnspent(testdata.dataUnspends,0.01);
     u.length.should.equal(1);
     should.exist(u[0].amount);
     should.exist(u[0].txid);
@@ -53,26 +53,64 @@ describe('Transaction', function() {
     should.exist(u[0].vout);
   });
 
-  it('should return null if not enough utxos', function() {
+  it('#selectUnspent should return null if not enough utxos', function() {
     var u = Transaction.selectUnspent(testdata.dataUnspends,1.12);
     u.length.should.equal(0);
   });
 
 
-  it('should be able to create instance thru #create', function() {
+  it('#selectUnspent should check confirmations', function() {
+    var u = Transaction.selectUnspent(testdata.dataUnspends,0.9);
+    u.length.should.equal(0);
+    var u = Transaction.selectUnspent(testdata.dataUnspends,0.9,true);
+    u.length.should.equal(3);
+
+    var u = Transaction.selectUnspent(testdata.dataUnspends,0.11);
+    u.length.should.equal(2);
+    var u = Transaction.selectUnspent(testdata.dataUnspends,0.111);
+    u.length.should.equal(0);
+  });
+
+
+  var opts = {remainderAddress: 'mwZabyZXg8JzUtFX1pkGygsMJjnuqiNhgd'};
+  it('#create should be able to create instance', function() {
     var utxos = Transaction.selectUnspent(testdata.dataUnspends,0.1);
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
-    var tx = Transaction.create(utxos, outs, 
-                                {remainderAddress:'3CMNFxN1oHBc4R1EpboAL5yzHGgE611Xou'});
+    var tx = Transaction.create(utxos, outs, opts);
     should.exist(tx);
+
     tx.version.should.equal(1);
     tx.ins.length.should.equal(2);
     tx.outs.length.should.equal(2);
     util.valueToBigInt(tx.outs[0].v).cmp(8000000).should.equal(0);
-    // TODO remainder is 0.03 here because unspend just select utxos in order
-    util.valueToBigInt(tx.outs[1].v).cmp(3000000).should.equal(0);
+    // remainder is 0.0299 here because unspend select utxos in order
+    util.valueToBigInt(tx.outs[1].v).cmp(2990000).should.equal(0);
   });
 
+
+  it('#create should fail if not enough inputs ', function() {
+    var utxos = Transaction.selectUnspent(testdata.dataUnspends,1);
+    var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
+    Transaction
+      .create
+      .bind(utxos, outs, opts)
+      .should.throw();
+  });
+
+
+  it('#create should create same output as bitcoind createrawtransaction ', function() {
+    var utxos = Transaction.selectUnspent(testdata.dataUnspends,0.1);
+    var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
+    var tx = Transaction.create(utxos, outs, opts); 
+    tx.serialize().toString('hex').should.equal('0100000002c1cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0100000000ffffffffc2cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0000000000ffffffff0200127a00000000001976a914774e603bafb717bd3f070e68bbcccfd907c77d1388acb09f2d00000000001976a914b00127584485a7cff0949ef0f6bc5575f06ce00d88ac00000000');
+
+    outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
+    tx = Transaction.create(utxos, outs, {fee:0.03} ); 
+    tx.serialize().toString('hex').should.equal('0100000002c1cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0100000000ffffffffc2cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0000000000ffffffff0100127a00000000001976a914774e603bafb717bd3f070e68bbcccfd907c77d1388ac00000000');
+
+  });
+  
+
   // Read tests from test/data/tx_valid.json
   // Format is an array of arrays
   // Inner arrays are either [ "comment" ]

From 35f5c9c57015a0910927de0411cedac14dcd91ca Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sat, 15 Mar 2014 12:22:15 -0300
Subject: [PATCH 04/22] #create for Transaction and tests

---
 test/test.Transaction.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/test/test.Transaction.js b/test/test.Transaction.js
index bf0671d..b6fa09a 100644
--- a/test/test.Transaction.js
+++ b/test/test.Transaction.js
@@ -104,6 +104,7 @@ describe('Transaction', function() {
     var tx = Transaction.create(utxos, outs, opts); 
     tx.serialize().toString('hex').should.equal('0100000002c1cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0100000000ffffffffc2cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0000000000ffffffff0200127a00000000001976a914774e603bafb717bd3f070e68bbcccfd907c77d1388acb09f2d00000000001976a914b00127584485a7cff0949ef0f6bc5575f06ce00d88ac00000000');
 
+    // no remainder
     outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
     tx = Transaction.create(utxos, outs, {fee:0.03} ); 
     tx.serialize().toString('hex').should.equal('0100000002c1cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0100000000ffffffffc2cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0000000000ffffffff0100127a00000000001976a914774e603bafb717bd3f070e68bbcccfd907c77d1388ac00000000');

From 128662ceeeaaecd5a325d2ba96b916d48d2f29b7 Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sat, 15 Mar 2014 12:22:36 -0300
Subject: [PATCH 05/22] #create for Transaction and tests

---
 test/test.Transaction.js | 1 -
 1 file changed, 1 deletion(-)

diff --git a/test/test.Transaction.js b/test/test.Transaction.js
index b6fa09a..47dd752 100644
--- a/test/test.Transaction.js
+++ b/test/test.Transaction.js
@@ -108,7 +108,6 @@ describe('Transaction', function() {
     outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
     tx = Transaction.create(utxos, outs, {fee:0.03} ); 
     tx.serialize().toString('hex').should.equal('0100000002c1cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0100000000ffffffffc2cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0000000000ffffffff0100127a00000000001976a914774e603bafb717bd3f070e68bbcccfd907c77d1388ac00000000');
-
   });
   
 

From ced6c91b69bdda002bfcbd55317591fe237846c5 Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sat, 15 Mar 2014 17:44:29 -0300
Subject: [PATCH 06/22] add comment to generate hardcoded dara

---
 test/test.Transaction.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/test/test.Transaction.js b/test/test.Transaction.js
index 47dd752..bed43d9 100644
--- a/test/test.Transaction.js
+++ b/test/test.Transaction.js
@@ -102,11 +102,17 @@ describe('Transaction', function() {
     var utxos = Transaction.selectUnspent(testdata.dataUnspends,0.1);
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
     var tx = Transaction.create(utxos, outs, opts); 
+
+
+    // string output generated from: bitcoind createrawtransaction '[{"txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1","vout":1},{"txid":"2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc2","vout":0}  ]' '{"mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE":0.08,"mwZabyZXg8JzUtFX1pkGygsMJjnuqiNhgd":0.0299}'
     tx.serialize().toString('hex').should.equal('0100000002c1cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0100000000ffffffffc2cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0000000000ffffffff0200127a00000000001976a914774e603bafb717bd3f070e68bbcccfd907c77d1388acb09f2d00000000001976a914b00127584485a7cff0949ef0f6bc5575f06ce00d88ac00000000');
 
     // no remainder
     outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
     tx = Transaction.create(utxos, outs, {fee:0.03} ); 
+
+    // string output generated from: bitcoind createrawtransaction '[{"txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1","vout":1},{"txid":"2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc2","vout":0}  ]' '{"mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE":0.08}'
+    //
     tx.serialize().toString('hex').should.equal('0100000002c1cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0100000000ffffffffc2cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0000000000ffffffff0100127a00000000001976a914774e603bafb717bd3f070e68bbcccfd907c77d1388ac00000000');
   });
   

From d473b400deea730e970bfdf0a8c97eafb6193dd1 Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sat, 15 Mar 2014 17:58:38 -0300
Subject: [PATCH 07/22] remove outdated example

---
 examples/createTx.js     | 205 ---------------------------------------
 test/test.Transaction.js |   9 +-
 2 files changed, 8 insertions(+), 206 deletions(-)
 delete mode 100644 examples/createTx.js

diff --git a/examples/createTx.js b/examples/createTx.js
deleted file mode 100644
index e9cc25a..0000000
--- a/examples/createTx.js
+++ /dev/null
@@ -1,205 +0,0 @@
-
-
-
-var bitcore = require('../bitcore');
-
-var priv    = 'cTgGUrcro89yUtKeG6gHBAS14r3qp25KwTTxG9d4kEzcFxecuZDm';
-var amt     = '0.005';
-var toAddress = 'myuAQcCc1REUgXGsCTiYhZvPPc3XxZ36G1';
-var changeAddressString = 'moDz3jEo9q7CxjBDjmb13sL4SKkgo2AACE';
-var feeString = '0.0001';
-
-var safeUnspent = [
-{
-address: "mqSjTad2TKbPcKQ3Jq4kgCkKatyN44UMgZ",
-hash: "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1",
-vout: 1,
-ts: 1394719301,
-scriptPubKey: "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ac",
-amount: 0.01,
-confirmations: 2
-}
-]
-;
-
-console.log('TX Data: BTC:' + amt + ' => '+ toAddress + ', change To:' + changeAddressString ) ;
-console.log('Unspends:', safeUnspent);
-
-var wk  = new bitcore.WalletKey({
-  network: bitcore.networks.testnet
-});
-wk.fromObj({ priv: priv, });
-
-var wkObj= wk.storeObj();
-var keyPairs = [{
-  key: wkObj.priv,
-  address: wkObj.addr,
-}];
-console.log('KEY DB IS:', keyPairs); 
-
-var Address = bitcore.Address;
-var Transaction = bitcore.Transaction;
-var Script = bitcore.Script;
-var nets = bitcore.networks;
-var z = bitcore.bignum(0);
-var amt = bitcore.util.parseValue(amt);
-
-if(z.cmp(amt) === 0 )
-  throw "spend amount must be greater than zero";
-
-if(!changeAddressString)
-  throw "change address was not provided";
-
-var fee = bitcore.util.parseValue(feeString || '0');
-var total = bitcore.bignum(0).add(amt).add(fee);
-var address = new Address(toAddress);
-var sendTx = new Transaction();
-var i;
-
-var unspent = [];
-var unspentAmt = bitcore.bignum(0);
-
-
-for(i=0;i<safeUnspent.length;i++) {
-  unspent.push(safeUnspent[i]);
-
-      var amountSatoshiString = new bitcore.bignum(safeUnspent[i].amount * Math.pow(10,8)).toString();
-
-      unspentAmt = unspentAmt.add(new bitcore.bignum(amountSatoshiString));
-
-      // If > -1, we have enough to send the requested amount
-      if(unspentAmt.cmp(total) > -1) {
-        break;
-      }
-    }
-
-    if(unspentAmt.cmp(total) < 0) {
-      throw "you do not have enough bitcoins to send this amount";
-    }
-
-    var txobj = {};
-    txobj.version = 1;
-    txobj.lock_time = 0;
-    txobj.ins = [];
-    txobj.outs = [];
-    
-    for(i=0;i<unspent.length;i++) {
-      var txin = {};
-
-      txin.s = bitcore.util.EMPTY_BUFFER;
-      txin.q = 0xffffffff;
-
-      var hash = new bitcore.Buffer(unspent[i].hash, 'hex');
-      var hashReversed = bitcore.buffertools.reverse(hash);
-      var vout = parseInt(unspent[i].vout);
-      var voutBuf = new bitcore.Buffer(4);
-      voutBuf.writeUInt32LE(vout, 0);
-
-      txin.o = bitcore.Buffer.concat([hashReversed, voutBuf]);
-      txobj.ins.push(txin); 
-    }
-
-
-    // This is not used really, but we keep it for the future.
-    var version = address.version();
-    var script;
-    if (version == nets.livenet.addressPubkey || version == nets.testnet.addressPubkey)
-      script = Script.createPubKeyHashOut(address.payload());
-    else if (version == nets.livenet.addressScript || version == nets.testnet.addressScript)
-      script = Script.createP2SH(address.payload());
-    else
-      throw new Error('invalid output address');
-
-    var value = bitcore.util.bigIntToValue(amt);
-    var txout = {
-      v: value,
-      s: script.getBuffer(),
-    };
-    txobj.outs.push(txout);
-    var remainder = unspentAmt.sub(total);
-
-    if(z.cmp(amt) !== 0 ) {
-      var changeAddress = new Address(changeAddressString);
-      var changeValue = bitcore.util.bigIntToValue(remainder);
-
-      // This is not used really, but we keep it for the future.
-      var cversion = changeAddress.version();
-      var cscript;
-      if (cversion == nets.livenet.addressPubkey || cversion == nets.testnet.addressPubkey)
-        cscript = Script.createPubKeyHashOut(changeAddress.payload());
-      else if (cversion == nets.livenet.addressScript || cversion == nets.testnet.addressScript)
-        cscript = Script.createP2SH(changeAddress.payload());
-      else
-        throw new Error('invalid change output address');
-
-      var change = {
-        v: changeValue,
-        s: cscript.getBuffer(),
-      };
-      txobj.outs.push(change);
-    }
-
-    var tx = new Transaction(txobj);
-    var anypay = false;
-    var l = unspent.length;
-    var allFound = l;
-
-    // Here will be the beginning of your signing for loop
-    for(i=0;i < l;i++) {
-      var scriptBuf = new bitcore.Buffer(unspent[i].scriptPubKey, 'hex');
-
-      var s = new Script(scriptBuf);
-      if (s.classify() !==  Script.TX_PUBKEYHASH) {
-        throw new Error('input script type '+ s.getRawOutType() +' not supported yet');
-      }
-      var txSigHash = tx.hashForSignature(s, i,
-                anypay ? Transaction.SIGHASH_ANYONECANPAY : Transaction.SIGHASH_ALL);
-
-
-//      txSigHash = bitcore.buffertools.reverse(txSigHash);
-
-      for(var j=0;j<keyPairs.length;j++) {
-        var kp = keyPairs[j];
-        if(kp.address === unspent[i].address) {
-console.log('[wallet.js.409:address:] SIGNING With...', kp.key); //TODO
-
-console.log('[kk.js.168:txSigHash:] HASH TO SIGN: ',bitcore.buffertools.toHex(txSigHash)); //TODO
-          var wKey = new bitcore.WalletKey({network: bitcore.networks.testnet});
-          wKey.fromObj({
-            priv: kp.key,
-          });
-
-console.log('[kk2.js.169] PRIV KEY', bitcore.buffertools.toHex(wKey.privKey.private )); //TODO
-console.log('[kk2.js.169] PUB KEY', bitcore.buffertools.toHex(wKey.privKey.public )); //TODO
-
-          var sigRaw = wKey.privKey.signSync(txSigHash);
-console.log('[kk.js.168:txSigHash:] SIGNATURE: ',bitcore.buffertools.toHex(sigRaw)); //TODO
-
-//VERIFY          
-console.log('[kk.js.168:txSigHash:] VERIFY: ',wKey.privKey.verifySignatureSync(txSigHash, sigRaw)); //TODO
-
-          var sigType = new bitcore.Buffer(1);
-          sigType[0] = anypay ? Transaction.SIGHASH_ANYONECANPAY : Transaction.SIGHASH_ALL;
-          var sig = bitcore.Buffer.concat([sigRaw, sigType]);
-
-          var scriptSig = new Script();
-          scriptSig.chunks.push(sig);
-          scriptSig.chunks.push(wKey.privKey.public);
-          scriptSig.updateBuffer();
-          tx.ins[i].s = scriptSig.getBuffer();
-          allFound--;
-          break;
-        }
-      }
-    }
-
-    if (allFound !== 0)  {
-      throw new Error('could not find priv key for some inputs');
-    }
-
-var txHex = tx.serialize().toString('hex');
-console.log('[kk.js.188:ret:] OUT IS: ', txHex);
-
-
-////
-
diff --git a/test/test.Transaction.js b/test/test.Transaction.js
index bed43d9..835b918 100644
--- a/test/test.Transaction.js
+++ b/test/test.Transaction.js
@@ -115,7 +115,14 @@ describe('Transaction', function() {
     //
     tx.serialize().toString('hex').should.equal('0100000002c1cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0100000000ffffffffc2cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0000000000ffffffff0100127a00000000001976a914774e603bafb717bd3f070e68bbcccfd907c77d1388ac00000000');
   });
-  
+ 
+  it.skip('#sign should sign a tx', function() {
+    var utxos = Transaction.selectUnspent(testdata.dataUnspends,0.1);
+    var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
+    var tx = Transaction.create(utxos, outs, opts); 
+  });
+
+
 
   // Read tests from test/data/tx_valid.json
   // Format is an array of arrays

From 97209540b65fc9fb2b3ee8c96ddf5ec91a6aad7f Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sat, 15 Mar 2014 18:10:46 -0300
Subject: [PATCH 08/22] add example to createKey

---
 examples/CreateKey.js | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 examples/CreateKey.js

diff --git a/examples/CreateKey.js b/examples/CreateKey.js
new file mode 100644
index 0000000..91f5aa9
--- /dev/null
+++ b/examples/CreateKey.js
@@ -0,0 +1,42 @@
+'use strict';
+
+
+var run = function() {
+  // Replace '../bitcore' with 'bitcore' if you use this code elsewhere.
+  var bitcore = require('../bitcore');
+  var networks = require('../networks');
+  var WalletKey = bitcore.WalletKey;
+
+
+  function print(wk) {
+
+    console.log('\n## Network: ' + wk.network.name);
+    console.log ('\t * Hex Representation');
+    console.log ('\tPrivate: ' + bitcore.buffertools.toHex(wk.privKey.private));
+    console.log ('\tPublic : ' + bitcore.buffertools.toHex(wk.privKey.public));
+    console.log ('\tPublic Compressed : ' + (wk.privKey.compressed?'Yes':'No'));
+
+    var wkObj = wk.storeObj();
+    console.log ('\n * WalletKey Store Object');
+    console.log ('\tPrivate: ' + wkObj.priv);
+    console.log ('\tPublic : ' + wkObj.pub);
+    console.log ('\tAddr   : ' + wkObj.addr);
+  };
+
+  //Generate a new one
+  var wk = new WalletKey({network: networks.testnet});
+  wk.generate();
+  print(wk);
+
+  //Generate from private Key WIF
+  var wk2 = new WalletKey({network: networks.testnet});
+  wk2.fromObj({priv:'cS62Ej4SobZnpFQYN1PEEBr2KWf5sgRYYnELtumcG6WVCfxno39V'});
+  print(wk2);
+
+
+};
+
+module.exports.run = run;
+if (require.main === module) {
+  run();
+}

From b6e6ad28eb681ac5739b6d070c4a12ba9ceb31f4 Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sat, 15 Mar 2014 18:21:59 -0300
Subject: [PATCH 09/22] fix variable names

---
 test/data/{unspends.json => unspent.json} |  0
 test/data/unspentSign.json                | 34 +++++++++++++++++++++++
 test/test.Transaction.js                  | 32 ++++++++++-----------
 test/testdata.js                          |  6 ++--
 4 files changed, 54 insertions(+), 18 deletions(-)
 rename test/data/{unspends.json => unspent.json} (100%)
 create mode 100644 test/data/unspentSign.json

diff --git a/test/data/unspends.json b/test/data/unspent.json
similarity index 100%
rename from test/data/unspends.json
rename to test/data/unspent.json
diff --git a/test/data/unspentSign.json b/test/data/unspentSign.json
new file mode 100644
index 0000000..ce2fa69
--- /dev/null
+++ b/test/data/unspentSign.json
@@ -0,0 +1,34 @@
+{ 
+  "unspent": [
+    {
+      "address": "n4g2TFaQo8UgedwpkYdcQFF6xE2Ei9Czvy",
+      "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1",
+      "scriptPubKey": "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ac",
+      "vout": 1,
+      "amount": 1.01,
+      "confirmations":7
+    },
+    {
+      "address": "mhNCT9TwZAGF1tLPpZdqfkTmtBkY282YDW",
+      "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc2",
+      "scriptPubKey": "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ad",
+      "vout": 0,
+      "confirmations": 1,
+      "amount": 10
+    },
+    {
+      "address": "n44hn28zAooZpn8mpWKzATbabqaHDK9oNJ",
+      "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc3",
+      "scriptPubKey": "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ae",
+      "vout": 3,
+      "confirmations": 0,
+      "amount": 5
+    }
+  ],
+  "keyStrings": [
+    "cSq7yo4fvsbMyWVN945VUGUWMaSazZPWqBVJZyoGsHmNq6W4HVBV",
+    "cPa87VgwZfowGZYaEenoQeJgRfKW6PhZ1R65EHTkN1K19cSvc92G",
+    "cPQ9DSbBRLva9av5nqeF5AGrh3dsdW8p2E5jS4P8bDWZAoQTeeKB"
+  ]
+}
+
diff --git a/test/test.Transaction.js b/test/test.Transaction.js
index 835b918..926bf1a 100644
--- a/test/test.Transaction.js
+++ b/test/test.Transaction.js
@@ -35,17 +35,17 @@ describe('Transaction', function() {
 
 
   it('#_selectUnspent should be able to select utxos', function() {
-    var u = Transaction._selectUnspent(testdata.dataUnspends,1.0);
+    var u = Transaction._selectUnspent(testdata.dataUnspent,1.0);
     u.length.should.equal(3);
-    u = Transaction._selectUnspent(testdata.dataUnspends,0.5);
+    u = Transaction._selectUnspent(testdata.dataUnspent,0.5);
     u.length.should.equal(3);
-    u = Transaction._selectUnspent(testdata.dataUnspends,0.1);
+    u = Transaction._selectUnspent(testdata.dataUnspent,0.1);
     u.length.should.equal(2);
-    u = Transaction._selectUnspent(testdata.dataUnspends,0.05);
+    u = Transaction._selectUnspent(testdata.dataUnspent,0.05);
     u.length.should.equal(2);
-    u = Transaction._selectUnspent(testdata.dataUnspends,0.015);
+    u = Transaction._selectUnspent(testdata.dataUnspent,0.015);
     u.length.should.equal(2);
-    u = Transaction._selectUnspent(testdata.dataUnspends,0.01);
+    u = Transaction._selectUnspent(testdata.dataUnspent,0.01);
     u.length.should.equal(1);
     should.exist(u[0].amount);
     should.exist(u[0].txid);
@@ -54,27 +54,27 @@ describe('Transaction', function() {
   });
 
   it('#selectUnspent should return null if not enough utxos', function() {
-    var u = Transaction.selectUnspent(testdata.dataUnspends,1.12);
+    var u = Transaction.selectUnspent(testdata.dataUnspent,1.12);
     u.length.should.equal(0);
   });
 
 
   it('#selectUnspent should check confirmations', function() {
-    var u = Transaction.selectUnspent(testdata.dataUnspends,0.9);
+    var u = Transaction.selectUnspent(testdata.dataUnspent,0.9);
     u.length.should.equal(0);
-    var u = Transaction.selectUnspent(testdata.dataUnspends,0.9,true);
+    var u = Transaction.selectUnspent(testdata.dataUnspent,0.9,true);
     u.length.should.equal(3);
 
-    var u = Transaction.selectUnspent(testdata.dataUnspends,0.11);
+    var u = Transaction.selectUnspent(testdata.dataUnspent,0.11);
     u.length.should.equal(2);
-    var u = Transaction.selectUnspent(testdata.dataUnspends,0.111);
+    var u = Transaction.selectUnspent(testdata.dataUnspent,0.111);
     u.length.should.equal(0);
   });
 
 
   var opts = {remainderAddress: 'mwZabyZXg8JzUtFX1pkGygsMJjnuqiNhgd'};
   it('#create should be able to create instance', function() {
-    var utxos = Transaction.selectUnspent(testdata.dataUnspends,0.1);
+    var utxos = Transaction.selectUnspent(testdata.dataUnspent,0.1);
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
     var tx = Transaction.create(utxos, outs, opts);
     should.exist(tx);
@@ -83,13 +83,13 @@ describe('Transaction', function() {
     tx.ins.length.should.equal(2);
     tx.outs.length.should.equal(2);
     util.valueToBigInt(tx.outs[0].v).cmp(8000000).should.equal(0);
-    // remainder is 0.0299 here because unspend select utxos in order
+    // remainder is 0.0299 here because unspent select utxos in order
     util.valueToBigInt(tx.outs[1].v).cmp(2990000).should.equal(0);
   });
 
 
   it('#create should fail if not enough inputs ', function() {
-    var utxos = Transaction.selectUnspent(testdata.dataUnspends,1);
+    var utxos = Transaction.selectUnspent(testdata.dataUnspent,1);
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
     Transaction
       .create
@@ -99,7 +99,7 @@ describe('Transaction', function() {
 
 
   it('#create should create same output as bitcoind createrawtransaction ', function() {
-    var utxos = Transaction.selectUnspent(testdata.dataUnspends,0.1);
+    var utxos = Transaction.selectUnspent(testdata.dataUnspent,0.1);
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
     var tx = Transaction.create(utxos, outs, opts); 
 
@@ -117,7 +117,7 @@ describe('Transaction', function() {
   });
  
   it.skip('#sign should sign a tx', function() {
-    var utxos = Transaction.selectUnspent(testdata.dataUnspends,0.1);
+    var utxos = Transaction.selectUnspent(testdata.dataUnspentign.unspent,0.1);
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
     var tx = Transaction.create(utxos, outs, opts); 
   });
diff --git a/test/testdata.js b/test/testdata.js
index 6eef35a..6460c23 100644
--- a/test/testdata.js
+++ b/test/testdata.js
@@ -7,7 +7,8 @@ var dataTxValid = JSON.parse(fs.readFileSync('test/data/tx_valid.json'));
 var dataTxInvalid = JSON.parse(fs.readFileSync('test/data/tx_invalid.json'));
 var dataScriptValid = JSON.parse(fs.readFileSync('test/data/script_valid.json'));
 var dataScriptInvalid = JSON.parse(fs.readFileSync('test/data/script_invalid.json'));
-var dataUnspends = JSON.parse(fs.readFileSync('test/data/unspends.json'));
+var dataUnspent = JSON.parse(fs.readFileSync('test/data/unspent.json'));
+var dataUnspentSign = JSON.parse(fs.readFileSync('test/data/unspentSign.json'));
  
 
 module.exports.dataValid = dataValid;
@@ -18,4 +19,5 @@ module.exports.dataTxInvalid = dataTxInvalid;
 module.exports.dataScriptValid = dataScriptValid;
 module.exports.dataScriptInvalid = dataScriptInvalid;
 module.exports.dataScriptAll = dataScriptValid.concat(dataScriptInvalid);
-module.exports.dataUnspends = dataUnspends;
+module.exports.dataUnspent = dataUnspent;
+module.exports.dataUnspentSign = dataUnspentSign;

From 7d1df2602ce7922bb1871547aa0ebddf29227e40 Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sat, 15 Mar 2014 18:39:51 -0300
Subject: [PATCH 10/22] add test for #network in Address

---
 test/test.Address.js | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/test/test.Address.js b/test/test.Address.js
index 21d1534..3e0441f 100644
--- a/test/test.Address.js
+++ b/test/test.Address.js
@@ -47,4 +47,24 @@ describe('Address', function() {
       s.should.equal(a.toString()); // check that validation doesn't change data
     });
   });
+  it('should be able to detect network from an address', function() {
+    var a = new Address('1KfyjCgBSMsLqiCbakfSdeoBUqMqLUiu3T');
+    a.network().name.should.equal('livenet');
+    var a = new Address('1dice8EMZmqKvrGE4Qc9bUFf9PX3xaYDp');
+    a.network().name.should.equal('livenet');
+    //p2sh
+    var a = new Address('3QRhucKtEn5P9i7YPxzXCqBtPJTPbRFycn');
+    a.network().name.should.equal('livenet');
+
+    //testnet
+    var a = new Address('mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE');
+    a.network().name.should.equal('testnet');
+    var a = new Address('n2ekxibY5keRiMaoKFGfiNfXQCS4zTUpct');
+    a.network().name.should.equal('testnet');
+
+    //p2sh
+    var a = new Address('2NBSBcf2KfjPEEqVusmrWdmUeNHRiUTS3Li');
+    a.network().name.should.equal('testnet');
+  });
+ 
 });

From 5bf652dcb69870cb38bc595570209d0a52680d44 Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sat, 15 Mar 2014 18:46:59 -0300
Subject: [PATCH 11/22] add uncompressed key generation example

---
 examples/CreateKey.js | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/examples/CreateKey.js b/examples/CreateKey.js
index 91f5aa9..5bc7196 100644
--- a/examples/CreateKey.js
+++ b/examples/CreateKey.js
@@ -1,12 +1,14 @@
 'use strict';
 
 
+
 var run = function() {
   // Replace '../bitcore' with 'bitcore' if you use this code elsewhere.
   var bitcore = require('../bitcore');
   var networks = require('../networks');
   var WalletKey = bitcore.WalletKey;
 
+  var opts = {network: networks.livenet};
 
   function print(wk) {
 
@@ -17,19 +19,26 @@ var run = function() {
     console.log ('\tPublic Compressed : ' + (wk.privKey.compressed?'Yes':'No'));
 
     var wkObj = wk.storeObj();
-    console.log ('\n * WalletKey Store Object');
+    console.log ('\n\t * WalletKey Store Object');
     console.log ('\tPrivate: ' + wkObj.priv);
     console.log ('\tPublic : ' + wkObj.pub);
     console.log ('\tAddr   : ' + wkObj.addr);
   };
 
-  //Generate a new one
-  var wk = new WalletKey({network: networks.testnet});
+  //Generate a new one (compressed public key, compressed WIK flag)
+  var wk = new WalletKey(opts);
   wk.generate();
   print(wk);
 
+  //Generate a new one (uncompressed public key, uncompressed WIK flag)
+  var wk = new WalletKey(opts);
+  wk.generate();
+  wk.privKey.compressed = false;
+  wk.privKey.regenerateSync();
+  print(wk);
+
   //Generate from private Key WIF
-  var wk2 = new WalletKey({network: networks.testnet});
+  var wk2 = new WalletKey(opts);
   wk2.fromObj({priv:'cS62Ej4SobZnpFQYN1PEEBr2KWf5sgRYYnELtumcG6WVCfxno39V'});
   print(wk2);
 

From 807a72666ceee93d81c9824d0e0e5a6d61ae5c54 Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sat, 15 Mar 2014 18:49:48 -0300
Subject: [PATCH 12/22] add network detection in private key and tests

---
 PrivateKey.js           | 16 ++++++++++++++++
 test/test.PrivateKey.js | 20 ++++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/PrivateKey.js b/PrivateKey.js
index c9a811c..9e2eac6 100644
--- a/PrivateKey.js
+++ b/PrivateKey.js
@@ -1,6 +1,7 @@
 var imports            = require('soop').imports();
 
 var parent = imports.parent || require('./util/VersionedData');
+var networks= imports.networks || require('./networks');
 
 //compressed is true if public key is compressed; false otherwise
 function PrivateKey(version, buf, compressed) {
@@ -61,4 +62,19 @@ PrivateKey.prototype.compressed = function(compressed) {
   }
 };
 
+PrivateKey.prototype.network = function() {
+  var version = this.version();
+
+  var livenet = networks.livenet;
+  var testnet = networks.testnet;
+
+  var answer;
+  if (version === livenet.keySecret)
+    answer = livenet;
+  else if (version === testnet.keySecret)
+    answer = testnet;
+
+  return answer;
+};
+
 module.exports = require('soop')(PrivateKey);
diff --git a/test/test.PrivateKey.js b/test/test.PrivateKey.js
index f6508e5..3d41de7 100644
--- a/test/test.PrivateKey.js
+++ b/test/test.PrivateKey.js
@@ -29,4 +29,24 @@ describe('PrivateKey', function() {
 
     privkey.as('base58').should.equal('cTpB4YiyKiBcPxnefsDpbnDxFDffjqJob8wGCEDXxgQ7zQoMXJdH');
   });
+
+  it('should be able to detect network from privatekey', function() {
+    var a = new PrivateKey('cMu64LfQqrPC83SjJqde4mZ5jzC48zyeKbUZbTjQdh6pa1h48TdM');
+    a.network().name.should.equal('testnet');
+    var a = new PrivateKey('cS62Ej4SobZnpFQYN1PEEBr2KWf5sgRYYnELtumcG6WVCfxno39V');
+    a.network().name.should.equal('testnet');
+
+    //compress flag = on
+    var a = new PrivateKey('KwHXRTLNWKzxy2NUnnhFtxricC3Dod4Dd3D7RKzVkKDtWrZhuDHs');
+    a.network().name.should.equal('livenet');
+    var a = new PrivateKey('KwaLX8oyJNNCL9tcyYakQHJDTnrPAmZ2M1YK7NhEcT9j55LWqMZz');
+    a.network().name.should.equal('livenet');
+
+    //compress flag = off
+    var a = new PrivateKey('5KS4jw2kT3VoEFUfzgSpX3GVi7qRYkTfwTBU7qxPKyvbGuiVj33');
+    a.network().name.should.equal('livenet');
+    var a = new PrivateKey('5JZsbYcnYN8Dz2YeSLZr6aswrVevedMUSFWxpie6SPpYRb2E4Gi');
+    a.network().name.should.equal('livenet');
+  });
+ 
 });

From a6463a3835d0003d61372192a03e47cc489261ec Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sat, 15 Mar 2014 21:04:56 -0300
Subject: [PATCH 13/22] ignore tags file

---
 .gitignore | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.gitignore b/.gitignore
index 44f3737..4c15f13 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,3 +8,4 @@ node_modules/
 *~
 .project
 README.html
+tags

From a2041d5790a2f9157fc6d439ef386f61c703c51c Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sat, 15 Mar 2014 21:12:23 -0300
Subject: [PATCH 14/22] add TX signing. Support to p2pubkeyhash

---
 Transaction.js             | 117 +++++++++++++++++++++++++++++++++++--
 test/data/unspentSign.json |   6 +-
 test/test.Transaction.js   |  33 ++++++++++-
 3 files changed, 145 insertions(+), 11 deletions(-)

diff --git a/Transaction.js b/Transaction.js
index 4fcccb1..3b58233 100644
--- a/Transaction.js
+++ b/Transaction.js
@@ -12,6 +12,8 @@ var Step               = imports.Step || require('step');
 var buffertools        = imports.buffertools || require('buffertools');
 var error              = imports.error || require('./util/error');
 var networks           = imports.networks || require('./networks');
+var WalletKey          = imports.WalletKey || require('./WalletKey');
+var PrivateKey         = imports.PrivateKey || require('./PrivateKey');
 
 var COINBASE_OP = Buffer.concat([util.NULL_HASH, new Buffer('FFFFFFFF', 'hex')]);
 var DEFAULT_FEE = 0.0001;
@@ -780,12 +782,12 @@ Transaction._scriptForAddress = function (addressString) {
  *
  *  (TODO: should we use uBTC already?)
  *
- *  If not remainderAddress is given, and there is a remainderAddress
- *  first in address will be used. (TODO: is this is reasoable?)
+ *  If no remainderAddress is given, and there is a remainderAddress
+ *  first in address will be used. (TODO: is this is reasonable?)
+ *
+ *  The address from the inputs will be added to the Transaction object 
+ *  for latter signing
  *
- *  TODO add exceptions for validations:
- *  out address - ins amount > out amount - fees < maxFees
- *  + more?
  */
 
 Transaction.create = function (ins, outs, opts) {
@@ -798,6 +800,8 @@ Transaction.create = function (ins, outs, opts) {
   txobj.ins     = [];
   txobj.outs    = [];
 
+  var inputMap = [];
+
   var l = ins.length;
   var valueInSat = bignum(0);
   for(var i=0; i<l; i++) {
@@ -816,6 +820,10 @@ Transaction.create = function (ins, outs, opts) {
 
     txin.o = Buffer.concat([hashReversed, voutBuf]);
     txobj.ins.push(txin); 
+    inputMap[i]= {
+      address: ins[i].address, 
+      scriptPubKey: ins[i].scriptPubKey
+    };
   }
 
 
@@ -860,9 +868,106 @@ Transaction.create = function (ins, outs, opts) {
   }
 
 
-  return new Transaction(txobj);
+  var tx =  new Transaction(txobj);
+  tx.inputMap = inputMap;
+  return tx;
 };
 
+/*
+ * sign
+ *
+ *  signs the transaction
+ *
+ *  @keypairs
+ *    an array of strings representing private keys to sign the 
+ *    transaction in WIF private key format OR WalletKey objects
+ *
+ *  @opts
+ *    signhash: Transaction.SIGHASH_ALL
+ *
+ *  Return the 'completeness' status of the tx (i.e, if all inputs are signed).
+ *
+ *  To sign a TX, the TX must contain .inputMap to match private keys 
+ *  with inputs and scriptPubKey
+ */
+
+Transaction.prototype.sign = function (keys, opts) {
+  var self = this;
+  var complete = false;
+  var m = keys.length;
+  opts = opts || {};
+  var signhash = opts.signhash || SIGHASH_ALL;
+
+  if (!self.inputMap) {
+    throw new Error('this TX does not have information about input address, cannot be signed');
+  }
+
+  //prepare keys
+  var walletKeyMap = {};
+  var l = keys.length;
+  var wk;
+  for(var i=0; i<l; i++) {
+    var k = keys[i];
+
+    if (typeof k === 'string') {
+      var pk = new PrivateKey(k);
+      wk = new WalletKey({network: pk.network()});
+      wk.fromObj({priv:k});
+    }
+    else if (k instanceof WalletKey) {
+      wk = k;
+    }
+    else {
+      throw new Error('argument must be an array of strings (WIF format) or WalletKey objects');
+    }
+    walletKeyMap[wk.storeObj().addr] = wk;
+  }
+
+  var inputSigned = 0;
+  l = self.ins.length;
+  for(var i=0;i<l;i++) {
+    var aIn = self.ins[i];
+    var wk = walletKeyMap[self.inputMap[i].address];
+
+    if (typeof wk === 'undefined') {
+      if ( buffertools.compare(aIn.s,util.EMPTY_BUFFER)!==0 ) 
+        inputSigned++;
+      continue;
+    }
+    var scriptBuf = new Buffer(self.inputMap[i].scriptPubKey, 'hex');
+    var s = new Script(scriptBuf);
+    if (s.classify() !==  Script.TX_PUBKEYHASH) {
+      throw new Error('input:'+i+' script type:'+ s.getRawOutType() +' not supported yet');
+    }
+
+    var txSigHash = self.hashForSignature(s, i, signhash);
+
+    var sigRaw;
+    do {
+      sigRaw = wk.privKey.signSync(txSigHash);
+    } while ( wk.privKey.verifySignatureSync(txSigHash, sigRaw) === false );
+
+
+    var sigType = new Buffer(1);
+    sigType[0] = signhash;
+    var sig = Buffer.concat([sigRaw, sigType]);
+
+    var scriptSig = new Script();
+    scriptSig.chunks.push(sig);
+    scriptSig.chunks.push(wk.privKey.public);
+    scriptSig.updateBuffer();
+    self.ins[i].s = scriptSig.getBuffer();
+    inputSigned++;
+  }
+
+  var complete = inputSigned === l;
+
+  return complete;
+};
+
+
+
+
 var TransactionInputsCache = exports.TransactionInputsCache =
 function TransactionInputsCache(tx)
 {
diff --git a/test/data/unspentSign.json b/test/data/unspentSign.json
index ce2fa69..f03e40e 100644
--- a/test/data/unspentSign.json
+++ b/test/data/unspentSign.json
@@ -3,7 +3,7 @@
     {
       "address": "n4g2TFaQo8UgedwpkYdcQFF6xE2Ei9Czvy",
       "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1",
-      "scriptPubKey": "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ac",
+      "scriptPubKey": "76a914fe021bac469a5c49915b2a8ffa7390a9ce5580f988ac",
       "vout": 1,
       "amount": 1.01,
       "confirmations":7
@@ -11,7 +11,7 @@
     {
       "address": "mhNCT9TwZAGF1tLPpZdqfkTmtBkY282YDW",
       "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc2",
-      "scriptPubKey": "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ad",
+      "scriptPubKey": "76a9141448534cb1a1ec44665b0eb2326e570814afe3f188ac",
       "vout": 0,
       "confirmations": 1,
       "amount": 10
@@ -19,7 +19,7 @@
     {
       "address": "n44hn28zAooZpn8mpWKzATbabqaHDK9oNJ",
       "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc3",
-      "scriptPubKey": "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ae",
+      "scriptPubKey": "76a914f753f58b1fb1daaa5534b10af85ca9210f3445d288ac",
       "vout": 3,
       "confirmations": 0,
       "amount": 5
diff --git a/test/test.Transaction.js b/test/test.Transaction.js
index 926bf1a..8755592 100644
--- a/test/test.Transaction.js
+++ b/test/test.Transaction.js
@@ -116,13 +116,42 @@ describe('Transaction', function() {
     tx.serialize().toString('hex').should.equal('0100000002c1cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0100000000ffffffffc2cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0000000000ffffffff0100127a00000000001976a914774e603bafb717bd3f070e68bbcccfd907c77d1388ac00000000');
   });
  
-  it.skip('#sign should sign a tx', function() {
-    var utxos = Transaction.selectUnspent(testdata.dataUnspentign.unspent,0.1);
+  it('#sign should sign a tx', function() {
+    var utxos = Transaction.selectUnspent(testdata.dataUnspentSign.unspent,0.1);
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
     var tx = Transaction.create(utxos, outs, opts); 
+    tx.sign(testdata.dataUnspentSign.keyStrings).should.equal(true);
+
+    var utxos2 = Transaction.selectUnspent(testdata.dataUnspentSign.unspent,16, true);
+    var outs2 = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
+    var tx2 = Transaction.create(utxos2, outs2, opts); 
+    tx2.sign(testdata.dataUnspentSign.keyStrings).should.equal(true);
   });
+  it('#sign should fail to sign a tx', function() {
+    var utxos = Transaction.selectUnspent(testdata.dataUnspentSign.unspent,0.1);
+    var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
+    var tx = Transaction.create(utxos, outs, opts); 
+    tx.sign(['cNpW8B7XPAzCdRR9RBWxZeveSNy3meXgHD8GuhcqUyDuy8ptCDzJ']).should.equal(false);
+  });
+  it('#sign should sign a tx in multiple steps', function() {
+    var utxos = Transaction.selectUnspent(testdata.dataUnspentSign.unspent,13, true);
+    var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
 
+    var tx = Transaction.create(utxos, outs, opts); 
+    var k1 = testdata.dataUnspentSign.keyStrings.slice(0,1);
+    var k23 = testdata.dataUnspentSign.keyStrings.slice(1,3);
+    tx.sign(k1).should.equal(false);
+    tx.sign(k23).should.equal(true);
 
+    var tx2 = Transaction.create(utxos, outs, opts); 
+    var k1 = testdata.dataUnspentSign.keyStrings.slice(0,1);
+    var k2 = testdata.dataUnspentSign.keyStrings.slice(1,2);
+    var k3 = testdata.dataUnspentSign.keyStrings.slice(2,3);
+    tx2.sign(k1).should.equal(false);
+    tx2.sign(k2).should.equal(false);
+    tx2.sign(k3).should.equal(true);
+ 
+  });
 
   // Read tests from test/data/tx_valid.json
   // Format is an array of arrays

From 530f05f87602c2cf078955ad46b8b182ff9b12ee Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sat, 15 Mar 2014 21:15:10 -0300
Subject: [PATCH 15/22] add limit to try-verify loop

---
 Transaction.js | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Transaction.js b/Transaction.js
index 3b58233..874183d 100644
--- a/Transaction.js
+++ b/Transaction.js
@@ -943,10 +943,15 @@ Transaction.prototype.sign = function (keys, opts) {
     var txSigHash = self.hashForSignature(s, i, signhash);
 
     var sigRaw;
+    var triesLeft = 10;
     do {
       sigRaw = wk.privKey.signSync(txSigHash);
-    } while ( wk.privKey.verifySignatureSync(txSigHash, sigRaw) === false );
+    } while ( wk.privKey.verifySignatureSync(txSigHash, sigRaw) === false && triesLeft-- );
 
+    if (!triesLeft) {
+      log.debug('could not sign input:'+i +' verification failed');
+      continue;
+    }
 
     var sigType = new Buffer(1);
     sigType[0] = signhash;

From 242f4381ae117ba9fd3271a6eb4e63a30d807d74 Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sat, 15 Mar 2014 22:00:58 -0300
Subject: [PATCH 16/22] fix error in commit

---
 Transaction.js | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/Transaction.js b/Transaction.js
index 874183d..1c55c78 100644
--- a/Transaction.js
+++ b/Transaction.js
@@ -609,7 +609,36 @@ Transaction.prototype.fromObj = function fromObj(obj) {
   txobj.ins = [];
   txobj.outs = [];
 
-  var tx = new Transaction(txobj);
+  obj.inputs.forEach(function(inputobj) {
+    var txin = new TransactionIn();
+    txin.s = util.EMPTY_BUFFER;
+    txin.q = 0xffffffff;
+
+    var hash = new Buffer(inputobj.txid, 'hex');
+    hash = buffertools.reverse(hash);
+    var vout = parseInt(inputobj.vout);
+    var voutBuf = new Buffer(4);
+    voutBuf.writeUInt32LE(vout, 0);
+
+    txin.o = Buffer.concat([hash, voutBuf]);
+
+    txobj.ins.push(txin);
+  });
+
+  var keys = Object.keys(obj.outputs);
+  keys.forEach(function(addrStr) {
+    var addr = new Address(addrStr);
+    var script = Script.createPubKeyHashOut(addr.payload());
+
+    var valueNum = bignum(obj.outputs[addrStr]);
+    var value = util.bigIntToValue(valueNum);
+
+    var txout = new TransactionOut();
+    txout.v = value;
+    txout.s = script.getBuffer();
+
+    txobj.outs.push(txout);
+  });
 
   this.lock_time = txobj.lock_time;
   this.version = txobj.version;

From aac13a8817bdd6ec844a7c81177adab6445318ee Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sun, 16 Mar 2014 07:09:46 -0300
Subject: [PATCH 17/22] remove uncompressed key example

---
 examples/CreateKey.js | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/examples/CreateKey.js b/examples/CreateKey.js
index 5bc7196..8b162cf 100644
--- a/examples/CreateKey.js
+++ b/examples/CreateKey.js
@@ -25,19 +25,12 @@ var run = function() {
     console.log ('\tAddr   : ' + wkObj.addr);
   };
 
-  //Generate a new one (compressed public key, compressed WIK flag)
+  //Generate a new one (compressed public key, compressed WIF flag)
   var wk = new WalletKey(opts);
   wk.generate();
   print(wk);
 
-  //Generate a new one (uncompressed public key, uncompressed WIK flag)
-  var wk = new WalletKey(opts);
-  wk.generate();
-  wk.privKey.compressed = false;
-  wk.privKey.regenerateSync();
-  print(wk);
-
-  //Generate from private Key WIF
+  //Generate from private Key WIF. Compressed status taken from WIF.
   var wk2 = new WalletKey(opts);
   wk2.fromObj({priv:'cS62Ej4SobZnpFQYN1PEEBr2KWf5sgRYYnELtumcG6WVCfxno39V'});
   print(wk2);

From 42d30f44a844e9609fd481e4fed17b71e447bf8d Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sun, 16 Mar 2014 19:18:46 -0300
Subject: [PATCH 18/22] better utxo selection, combining inputs different
 confimations steps

---
 Transaction.js           | 91 ++++++++++++++++++----------------------
 test/test.Transaction.js | 36 +++++++++-------
 2 files changed, 61 insertions(+), 66 deletions(-)

diff --git a/Transaction.js b/Transaction.js
index 1c55c78..3393f36 100644
--- a/Transaction.js
+++ b/Transaction.js
@@ -683,51 +683,12 @@ Transaction.prototype.parse = function (parser) {
   this.calcHash();
 };
 
-/*
- * _selectUnspent
- *
- *  Selects some unspend outputs for later usage in tx inputs
- *
- * @unspentArray: unspent array (UTXO) avaible on the form (see selectUnspent)
- * @totalNeededAmount: output transaction amount in BTC, including fee
- * @minConfirmations: 0 by default.
- *
- *
- * Returns the selected outputs or null if there are not enough funds.
- * The utxos are selected in the order they appear in the original array. 
- * Sorting must be done previusly.
- *
- */
-Transaction._selectUnspent = function (unspentArray, totalNeededAmount, minConfirmations) {
-  minConfirmations = minConfirmations || 0;
 
-  var selected = [];
-  var l = unspentArray.length;
-  var totalSat = bignum(0);
-  var totalNeededAmountSat = util.parseValue(totalNeededAmount);
-  var fullfill  = false;
-
-  for(var i = 0; i<l; i++) {
-    var u = unspentArray[i];
-    if ( (u.confirmations||0) < minConfirmations) 
-      continue;
-
-    var sat = u.amountSat || util.parseValue(u.amount);
-    totalSat = totalSat.add(sat);
-    selected.push(u);
-    if(totalSat.cmp(totalNeededAmountSat) >= 0) {
-      fullfill = true;
-      break;
-    }
-  }
-  if (!fullfill) return [];
-  return selected;
-}
 
 /*
  * selectUnspent
  *
- *  Selects some unspend outputs for later usage in tx inputs
+ *  Selects some unspent outputs for later usage in tx inputs
  *
  * @unspentArray: unspent array (UTXO) avaible on the form:
  * [{
@@ -739,28 +700,56 @@ Transaction._selectUnspent = function (unspentArray, totalNeededAmount, minConfi
  *       confirmations: 3
  *       }, [...]
  * ]
- * This is compatible con insight's /utxo API. 
- * That amount is in BTCs. (as returned in insight and bitcoind)
- * amountSat can be given to provide amount in satochis.
+ * This is compatible con insight's utxo API. 
+ * That amount is in BTCs (as returned in insight and bitcoind).
+ * amountSat (instead of amount) can be given to provide amount in satochis.
  *
  * @totalNeededAmount: output transaction amount in BTC, including fee
- * @allowUnconfirmed:false (allow selecting unconfirmed utxos)
- *
+ * @allowUnconfirmed: false (allow selecting unconfirmed utxos)
  *
  * Note that the sum of the selected unspent is >= the desired amount.
+ * Returns the selected unspent outputs if the totalNeededAmount was reach. 
+ * 'null' if not.
+ *
+ * TODO: utxo selection is not optimized to minimize mempool usage.
  *
  */
 
 Transaction.selectUnspent = function (unspentArray, totalNeededAmount, allowUnconfirmed) {
-  var answer = Transaction._selectUnspent(unspentArray, totalNeededAmount, 6);
 
-  if (!answer.length) 
-    answer = Transaction._selectUnspent(unspentArray, totalNeededAmount, 1);
+  var minConfirmationSteps = [6,1];
+  if (allowUnconfirmed) minConfirmationSteps.push(0);
 
-  if (!answer.length && allowUnconfirmed)
-    answer = Transaction._selectUnspent(unspentArray, totalNeededAmount, 0);
+  var ret = [];
+  var l = unspentArray.length;
+  var totalSat = bignum(0);
+  var totalNeededAmountSat = util.parseValue(totalNeededAmount);
+  var fulfill  = false;
+  var maxConfirmations = null;
 
-  return answer;
+  do {
+    var minConfirmations = minConfirmationSteps.shift();
+    for(var i = 0; i<l; i++) {
+      var u = unspentArray[i];
+
+      var c = u.confirmations || 0;
+
+      if ( c  < minConfirmations || (maxConfirmations && c >=maxConfirmations) ) 
+        continue;
+
+
+      var sat = u.amountSat || util.parseValue(u.amount);
+      totalSat = totalSat.add(sat);
+      ret.push(u);
+      if(totalSat.cmp(totalNeededAmountSat) >= 0) {
+        fulfill = true;
+        break;
+      }
+    }
+    maxConfirmations = minConfirmations;
+  } while( !fulfill && minConfirmationSteps.length);
+
+  return fulfill ? ret : null;
 }
 
 /*
diff --git a/test/test.Transaction.js b/test/test.Transaction.js
index 8755592..3631f04 100644
--- a/test/test.Transaction.js
+++ b/test/test.Transaction.js
@@ -34,41 +34,47 @@ describe('Transaction', function() {
   });
 
 
-  it('#_selectUnspent should be able to select utxos', function() {
-    var u = Transaction._selectUnspent(testdata.dataUnspent,1.0);
+  it('#selectUnspent should be able to select utxos', function() {
+    var u = Transaction.selectUnspent(testdata.dataUnspent,1.0, true);
     u.length.should.equal(3);
-    u = Transaction._selectUnspent(testdata.dataUnspent,0.5);
-    u.length.should.equal(3);
-    u = Transaction._selectUnspent(testdata.dataUnspent,0.1);
-    u.length.should.equal(2);
-    u = Transaction._selectUnspent(testdata.dataUnspent,0.05);
-    u.length.should.equal(2);
-    u = Transaction._selectUnspent(testdata.dataUnspent,0.015);
-    u.length.should.equal(2);
-    u = Transaction._selectUnspent(testdata.dataUnspent,0.01);
-    u.length.should.equal(1);
+
     should.exist(u[0].amount);
     should.exist(u[0].txid);
     should.exist(u[0].scriptPubKey);
     should.exist(u[0].vout);
+
+    u = Transaction.selectUnspent(testdata.dataUnspent,0.5, true);
+    u.length.should.equal(3);
+
+    u = Transaction.selectUnspent(testdata.dataUnspent,0.1, true);
+    u.length.should.equal(2);
+
+    u = Transaction.selectUnspent(testdata.dataUnspent,0.05, true);
+    u.length.should.equal(2);
+
+    u = Transaction.selectUnspent(testdata.dataUnspent,0.015, true);
+    u.length.should.equal(2);
+
+    u = Transaction.selectUnspent(testdata.dataUnspent,0.01, true);
+    u.length.should.equal(1);
   });
 
   it('#selectUnspent should return null if not enough utxos', function() {
     var u = Transaction.selectUnspent(testdata.dataUnspent,1.12);
-    u.length.should.equal(0);
+    should.not.exist(u);
   });
 
 
   it('#selectUnspent should check confirmations', function() {
     var u = Transaction.selectUnspent(testdata.dataUnspent,0.9);
-    u.length.should.equal(0);
+    should.not.exist(u);
     var u = Transaction.selectUnspent(testdata.dataUnspent,0.9,true);
     u.length.should.equal(3);
 
     var u = Transaction.selectUnspent(testdata.dataUnspent,0.11);
     u.length.should.equal(2);
     var u = Transaction.selectUnspent(testdata.dataUnspent,0.111);
-    u.length.should.equal(0);
+    should.not.exist(u);
   });
 
 

From 0c83ecf5fb8e1eda5e675bc83576172dd85f7f9f Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sun, 16 Mar 2014 20:50:49 -0300
Subject: [PATCH 19/22] new interfase for create TX (select + prepare + sign)

---
 Transaction.js           | 203 ++++++++++++++++++++++++---------------
 test/test.Transaction.js |  66 +++++++------
 2 files changed, 163 insertions(+), 106 deletions(-)

diff --git a/Transaction.js b/Transaction.js
index 3393f36..fb7a8f7 100644
--- a/Transaction.js
+++ b/Transaction.js
@@ -16,7 +16,7 @@ var WalletKey          = imports.WalletKey || require('./WalletKey');
 var PrivateKey         = imports.PrivateKey || require('./PrivateKey');
 
 var COINBASE_OP = Buffer.concat([util.NULL_HASH, new Buffer('FFFFFFFF', 'hex')]);
-var DEFAULT_FEE = 0.0001;
+var DEFAULT_FEE = 0.001;
 
 function TransactionIn(data) {
   if ("object" !== typeof data) {
@@ -690,20 +690,7 @@ Transaction.prototype.parse = function (parser) {
  *
  *  Selects some unspent outputs for later usage in tx inputs
  *
- * @unspentArray: unspent array (UTXO) avaible on the form:
- * [{
- *       address: "mqSjTad2TKbPcKQ3Jq4kgCkKatyN44UMgZ",
- *       hash: "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1",
- *       scriptPubKey: "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ac",
- *       vout: 1,
- *       amount: 0.01,                
- *       confirmations: 3
- *       }, [...]
- * ]
- * This is compatible con insight's utxo API. 
- * That amount is in BTCs (as returned in insight and bitcoind).
- * amountSat (instead of amount) can be given to provide amount in satochis.
- *
+ * @utxos 
  * @totalNeededAmount: output transaction amount in BTC, including fee
  * @allowUnconfirmed: false (allow selecting unconfirmed utxos)
  *
@@ -715,13 +702,13 @@ Transaction.prototype.parse = function (parser) {
  *
  */
 
-Transaction.selectUnspent = function (unspentArray, totalNeededAmount, allowUnconfirmed) {
+Transaction.selectUnspent = function (utxos, totalNeededAmount, allowUnconfirmed) {
 
   var minConfirmationSteps = [6,1];
   if (allowUnconfirmed) minConfirmationSteps.push(0);
 
   var ret = [];
-  var l = unspentArray.length;
+  var l = utxos.length;
   var totalSat = bignum(0);
   var totalNeededAmountSat = util.parseValue(totalNeededAmount);
   var fulfill  = false;
@@ -730,7 +717,7 @@ Transaction.selectUnspent = function (unspentArray, totalNeededAmount, allowUnco
   do {
     var minConfirmations = minConfirmationSteps.shift();
     for(var i = 0; i<l; i++) {
-      var u = unspentArray[i];
+      var u = utxos[i];
 
       var c = u.confirmations || 0;
 
@@ -776,39 +763,18 @@ Transaction._scriptForAddress = function (addressString) {
   return script;
 };
 
-/*
- * create
- *
- *  creates a transaction
- *
- *  @ins 
- *    a selected set of utxos, as described on selectUnspent
- *  @outs
- *    an array of [{
- *      address: xx, 
- *      amount:0.001
-*     },...]
- *  @opts
- *    { 
- *      remainderAddress: null,
- *      fee: 0.001,
- *      lockTime: null,
- *    }
- *
- *  Amounts are in BTC. instead of fee and amount; feeSat and amountSat can be given, 
- *  repectively, to provide amounts in satoshis.
- *
- *  (TODO: should we use uBTC already?)
- *
- *  If no remainderAddress is given, and there is a remainderAddress
- *  first in address will be used. (TODO: is this is reasonable?)
- *
- *  The address from the inputs will be added to the Transaction object 
- *  for latter signing
- *
- */
+Transaction._sumOutputs = function(outs) {
+  var valueOutSat = bignum(0);
+  var l = outs.length;
 
-Transaction.create = function (ins, outs, opts) {
+  for(var i=0;i<outs.length;i++) {
+    var sat = outs[i].amountSat || util.parseValue(outs[i].amount);
+    valueOutSat = valueOutSat.add(sat);
+  }
+  return valueOutSat;
+}
+
+Transaction.prepare = function (ins, outs, opts) {
   opts = opts || {};
 
   var feeSat = opts.feeSat || util.parseValue(opts.fee || DEFAULT_FEE);
@@ -818,7 +784,6 @@ Transaction.create = function (ins, outs, opts) {
   txobj.ins     = [];
   txobj.outs    = [];
 
-  var inputMap = [];
 
   var l = ins.length;
   var valueInSat = bignum(0);
@@ -838,20 +803,9 @@ Transaction.create = function (ins, outs, opts) {
 
     txin.o = Buffer.concat([hashReversed, voutBuf]);
     txobj.ins.push(txin); 
-    inputMap[i]= {
-      address: ins[i].address, 
-      scriptPubKey: ins[i].scriptPubKey
-    };
   }
 
-
-  var valueOutSat = bignum(0);
-  l = outs.length;
-
-  for(var i=0;i<outs.length;i++) {
-    var sat = outs[i].amountSat || util.parseValue(outs[i].amount);
-    valueOutSat = valueOutSat.add(sat);
-  }
+  var valueOutSat = Transaction._sumOutputs(outs);
   valueOutSat = valueOutSat.add(feeSat);
 
   if (valueInSat.cmp(valueOutSat)<0) {
@@ -886,38 +840,54 @@ Transaction.create = function (ins, outs, opts) {
   }
 
 
-  var tx =  new Transaction(txobj);
-  tx.inputMap = inputMap;
-  return tx;
+  return  new Transaction(txobj);
 };
 
+Transaction.prototype.isComplete = function () {
+  var l = this.ins.length;
+
+  var ret = true;
+  for (var i=0; i<l; i++) {
+    if ( buffertools.compare(this.ins[i].s,util.EMPTY_BUFFER)===0 )  {
+      ret = false;
+      break;
+    }
+  };
+  return ret;
+};
+ 
+
 /*
  * sign
  *
  *  signs the transaction
  *
+ *  @ utxos
  *  @keypairs
- *    an array of strings representing private keys to sign the 
- *    transaction in WIF private key format OR WalletKey objects
- *
  *  @opts
  *    signhash: Transaction.SIGHASH_ALL
  *
  *  Return the 'completeness' status of the tx (i.e, if all inputs are signed).
  *
- *  To sign a TX, the TX must contain .inputMap to match private keys 
- *  with inputs and scriptPubKey
  */
 
-Transaction.prototype.sign = function (keys, opts) {
+Transaction.prototype.sign = function (selectedUtxos, keys, opts) {
   var self = this;
   var complete = false;
   var m = keys.length;
   opts = opts || {};
   var signhash = opts.signhash || SIGHASH_ALL;
 
-  if (!self.inputMap) {
-    throw new Error('this TX does not have information about input address, cannot be signed');
+  if (selectedUtxos.length !== self.ins.length) 
+    throw new Error('given selectedUtxos do not match tx inputs');
+
+  var inputMap = [];
+  var l = selectedUtxos.length;
+  for(var i=0; i<l; i++) {
+    inputMap[i]= {
+      address: selectedUtxos[i].address, 
+      scriptPubKey: selectedUtxos[i].scriptPubKey
+    };
   }
 
   //prepare keys
@@ -945,14 +915,14 @@ Transaction.prototype.sign = function (keys, opts) {
   l = self.ins.length;
   for(var i=0;i<l;i++) {
     var aIn = self.ins[i];
-    var wk = walletKeyMap[self.inputMap[i].address];
+    var wk = walletKeyMap[inputMap[i].address];
 
     if (typeof wk === 'undefined') {
       if ( buffertools.compare(aIn.s,util.EMPTY_BUFFER)!==0 ) 
         inputSigned++;
       continue;
     }
-    var scriptBuf = new Buffer(self.inputMap[i].scriptPubKey, 'hex');
+    var scriptBuf = new Buffer(inputMap[i].scriptPubKey, 'hex');
     var s = new Script(scriptBuf);
     if (s.classify() !==  Script.TX_PUBKEYHASH) {
       throw new Error('input:'+i+' script type:'+ s.getRawOutType() +' not supported yet');
@@ -991,6 +961,87 @@ Transaction.prototype.sign = function (keys, opts) {
 
 
 
+
+/*
+ * create
+ *
+ *  creates and signs a transaction
+ *
+ *  @utxos 
+ *    unspent outputs array (UTXO), using the following format:
+ *    [{
+ *       address: "mqSjTad2TKbPcKQ3Jq4kgCkKatyN44UMgZ",
+ *       hash: "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1",
+ *       scriptPubKey: "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ac",
+ *       vout: 1,
+ *       amount: 0.01,                
+ *       confirmations: 3
+ *       }, ...
+ *    ]
+ * This is compatible con insight's utxo API. 
+ * That amount is in BTCs (as returned in insight and bitcoind).
+ * amountSat (instead of amount) can be given to provide amount in satochis.
+ *
+
+ *  @outs
+ *    an array of [{
+ *      address: xx, 
+ *      amount:0.001
+ *     },...]
+ *
+ *  @keys
+ *     an array of strings representing private keys to sign the 
+ *    transaction in WIF private key format OR WalletKey objects
+ *
+ *  @opts
+ *    { 
+ *      remainderAddress: null,
+ *      fee: 0.001,
+ *      lockTime: null,
+ *      allowUnconfirmed: false,
+ *      signhash: SIGHASH_ALL
+ *    }
+ *
+ *  Amounts are in BTC. instead of fee and amount; feeSat and amountSat can be given, 
+ *  repectively, to provide amounts in satoshis.
+ *
+ *  If no remainderAddress is given, and there is a remainderAddress
+ *  first in address will be used. (TODO: is this is reasonable?)
+ *
+ *  if not keys are provided, the transaction will no be signed. .sign can be used to
+ *  sign it later.
+ *
+ *  The Transaction creation is handled in 3 steps:
+ *    .selectUnspent
+ *    .prepare
+ *    .sign
+ *
+ */
+
+
+Transaction.create = function (utxos, outs, keys, opts) {
+
+    var valueOutSat = Transaction
+      ._sumOutputs(outs)
+      .add(DEFAULT_FEE * util.COIN);
+
+    var selectedUtxos = Transaction
+      .selectUnspent(utxos,valueOutSat / util.COIN, opts.allowUnconfirmed);
+
+    if (!selectedUtxos) {
+      throw new Error(
+        'the given UTXOs dont sum up the given outputs: ' 
+        + valueOutSat.toString() 
+        + ' SAT'
+      );
+    }
+
+    var tx = Transaction.prepare(selectedUtxos, outs, opts);
+    //TODO interate with the new TX fee
+    if (keys) tx.sign(selectedUtxos, keys);
+    return tx;
+};
+
 var TransactionInputsCache = exports.TransactionInputsCache =
 function TransactionInputsCache(tx)
 {
diff --git a/test/test.Transaction.js b/test/test.Transaction.js
index 3631f04..f1cfce2 100644
--- a/test/test.Transaction.js
+++ b/test/test.Transaction.js
@@ -78,44 +78,49 @@ describe('Transaction', function() {
   });
 
 
-  var opts = {remainderAddress: 'mwZabyZXg8JzUtFX1pkGygsMJjnuqiNhgd'};
+  var opts = {
+    remainderAddress: 'mwZabyZXg8JzUtFX1pkGygsMJjnuqiNhgd',
+    allowUnconfirmed: true,
+  };
+
   it('#create should be able to create instance', function() {
-    var utxos = Transaction.selectUnspent(testdata.dataUnspent,0.1);
+    var utxos =testdata.dataUnspent;
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
-    var tx = Transaction.create(utxos, outs, opts);
+    var tx = Transaction.create(utxos, outs, null, opts);
     should.exist(tx);
 
     tx.version.should.equal(1);
     tx.ins.length.should.equal(2);
     tx.outs.length.should.equal(2);
+
     util.valueToBigInt(tx.outs[0].v).cmp(8000000).should.equal(0);
     // remainder is 0.0299 here because unspent select utxos in order
-    util.valueToBigInt(tx.outs[1].v).cmp(2990000).should.equal(0);
+    util.valueToBigInt(tx.outs[1].v).cmp(2900000).should.equal(0);
+    tx.isComplete().should.equal(false);
   });
 
-
   it('#create should fail if not enough inputs ', function() {
-    var utxos = Transaction.selectUnspent(testdata.dataUnspent,1);
-    var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
+    var utxos =testdata.dataUnspent;
+    var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:80}];
     Transaction
       .create
-      .bind(utxos, outs, opts)
+      .bind(utxos, outs, null, opts)
       .should.throw();
   });
 
 
   it('#create should create same output as bitcoind createrawtransaction ', function() {
-    var utxos = Transaction.selectUnspent(testdata.dataUnspent,0.1);
+    var utxos =testdata.dataUnspent;
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
-    var tx = Transaction.create(utxos, outs, opts); 
+    var tx = Transaction.create(utxos, outs, null, opts); 
 
 
     // string output generated from: bitcoind createrawtransaction '[{"txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1","vout":1},{"txid":"2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc2","vout":0}  ]' '{"mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE":0.08,"mwZabyZXg8JzUtFX1pkGygsMJjnuqiNhgd":0.0299}'
-    tx.serialize().toString('hex').should.equal('0100000002c1cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0100000000ffffffffc2cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0000000000ffffffff0200127a00000000001976a914774e603bafb717bd3f070e68bbcccfd907c77d1388acb09f2d00000000001976a914b00127584485a7cff0949ef0f6bc5575f06ce00d88ac00000000');
+    tx.serialize().toString('hex').should.equal('0100000002c1cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0100000000ffffffffc2cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0000000000ffffffff0200127a00000000001976a914774e603bafb717bd3f070e68bbcccfd907c77d1388ac20402c00000000001976a914b00127584485a7cff0949ef0f6bc5575f06ce00d88ac00000000');
 
     // no remainder
     outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
-    tx = Transaction.create(utxos, outs, {fee:0.03} ); 
+    tx = Transaction.create(utxos, outs, null, {fee:0.03} ); 
 
     // string output generated from: bitcoind createrawtransaction '[{"txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1","vout":1},{"txid":"2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc2","vout":0}  ]' '{"mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE":0.08}'
     //
@@ -123,39 +128,40 @@ describe('Transaction', function() {
   });
  
   it('#sign should sign a tx', function() {
-    var utxos = Transaction.selectUnspent(testdata.dataUnspentSign.unspent,0.1);
+    var utxos =testdata.dataUnspentSign.unspent;
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
-    var tx = Transaction.create(utxos, outs, opts); 
-    tx.sign(testdata.dataUnspentSign.keyStrings).should.equal(true);
+    var tx = Transaction.create(utxos, outs, testdata.dataUnspentSign.keyStrings, opts); 
+    tx.isComplete().should.equal(true);
 
-    var utxos2 = Transaction.selectUnspent(testdata.dataUnspentSign.unspent,16, true);
-    var outs2 = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
-    var tx2 = Transaction.create(utxos2, outs2, opts); 
-    tx2.sign(testdata.dataUnspentSign.keyStrings).should.equal(true);
+    var outs2 = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:16}];
+    var tx2 = Transaction.create(utxos, outs2, testdata.dataUnspentSign.keyStrings, opts); 
+    tx2.isComplete().should.equal(true);
   });
-  it('#sign should fail to sign a tx', function() {
-    var utxos = Transaction.selectUnspent(testdata.dataUnspentSign.unspent,0.1);
+
+  it('#sign should sign an incomplete tx ', function() {
+    var keys = ['cNpW8B7XPAzCdRR9RBWxZeveSNy3meXgHD8GuhcqUyDuy8ptCDzJ'];
+    var utxos =testdata.dataUnspentSign.unspent;
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
-    var tx = Transaction.create(utxos, outs, opts); 
-    tx.sign(['cNpW8B7XPAzCdRR9RBWxZeveSNy3meXgHD8GuhcqUyDuy8ptCDzJ']).should.equal(false);
+    var tx = Transaction.create(utxos, outs, keys, opts); 
+    tx.isComplete().should.equal(false);
   });
   it('#sign should sign a tx in multiple steps', function() {
     var utxos = Transaction.selectUnspent(testdata.dataUnspentSign.unspent,13, true);
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
 
-    var tx = Transaction.create(utxos, outs, opts); 
+    var tx = Transaction.prepare(utxos, outs, opts); 
     var k1 = testdata.dataUnspentSign.keyStrings.slice(0,1);
     var k23 = testdata.dataUnspentSign.keyStrings.slice(1,3);
-    tx.sign(k1).should.equal(false);
-    tx.sign(k23).should.equal(true);
+    tx.sign(utxos, k1).should.equal(false);
+    tx.sign(utxos, k23).should.equal(true);
 
-    var tx2 = Transaction.create(utxos, outs, opts); 
+    var tx2 = Transaction.prepare(utxos, outs, opts); 
     var k1 = testdata.dataUnspentSign.keyStrings.slice(0,1);
     var k2 = testdata.dataUnspentSign.keyStrings.slice(1,2);
     var k3 = testdata.dataUnspentSign.keyStrings.slice(2,3);
-    tx2.sign(k1).should.equal(false);
-    tx2.sign(k2).should.equal(false);
-    tx2.sign(k3).should.equal(true);
+    tx2.sign(utxos, k1).should.equal(false);
+    tx2.sign(utxos, k2).should.equal(false);
+    tx2.sign(utxos, k3).should.equal(true);
  
   });
 

From 041f06aae1595bcd2e5906731c5b4f59adb3ba64 Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sun, 16 Mar 2014 23:47:01 -0300
Subject: [PATCH 20/22] dynamic fee

---
 Transaction.js             | 103 +++++++++++++++++++++++++++----------
 test/data/unspentSign.json |   2 +-
 test/test.Transaction.js   |  62 +++++++++++++++++++++-
 3 files changed, 136 insertions(+), 31 deletions(-)

diff --git a/Transaction.js b/Transaction.js
index fb7a8f7..c16a252 100644
--- a/Transaction.js
+++ b/Transaction.js
@@ -16,7 +16,7 @@ var WalletKey          = imports.WalletKey || require('./WalletKey');
 var PrivateKey         = imports.PrivateKey || require('./PrivateKey');
 
 var COINBASE_OP = Buffer.concat([util.NULL_HASH, new Buffer('FFFFFFFF', 'hex')]);
-var DEFAULT_FEE = 0.001;
+var FEE_PER_1000B_SAT = parseInt(0.0001 * util.COIN); 
 
 function TransactionIn(data) {
   if ("object" !== typeof data) {
@@ -777,7 +777,7 @@ Transaction._sumOutputs = function(outs) {
 Transaction.prepare = function (ins, outs, opts) {
   opts = opts || {};
 
-  var feeSat = opts.feeSat || util.parseValue(opts.fee || DEFAULT_FEE);
+  var feeSat = opts.feeSat || (opts.fee? util.parseValue(opts.fee) : FEE_PER_1000B_SAT );
   var txobj = {};
   txobj.version = 1;
   txobj.lock_time = opts.lockTime || 0;
@@ -815,27 +815,27 @@ Transaction.prepare = function (ins, outs, opts) {
                     inv + ' < '+ouv + ' [SAT]');
   }
 
-  var remainderSat = valueInSat.sub(valueOutSat);
-
-  if (remainderSat.cmp(0)>0) {
-    var remainderAddress = opts.remainderAddress || ins[0].address;
-
-    outs.push({
-      address: remainderAddress,
-      amountSat: remainderSat,
-    });
-  }
-
   for(var i=0;i<outs.length;i++) {
     var amountSat = outs[i].amountSat || util.parseValue(outs[i].amount);
     var value = util.bigIntToValue(amountSat);
     var script = Transaction._scriptForAddress(outs[i].address);
-
     var txout = {
       v: value,
       s: script.getBuffer(),
     };
+    txobj.outs.push(txout);
+  }
 
+  // add remainder (without modifiying outs[])
+  var remainderSat = valueInSat.sub(valueOutSat);
+  if (remainderSat.cmp(0)>0) {
+    var remainderAddress = opts.remainderAddress || ins[0].address;
+    var value = util.bigIntToValue(remainderSat);
+    var script = Transaction._scriptForAddress(remainderAddress);
+    var txout = {
+      v: value,
+      s: script.getBuffer(),
+    };
     txobj.outs.push(txout);
   }
 
@@ -843,6 +843,31 @@ Transaction.prepare = function (ins, outs, opts) {
   return  new Transaction(txobj);
 };
 
+Transaction.prototype.calcSize = function () {
+  var totalSize = 8; // version + lock_time
+  totalSize += util.getVarIntSize(this.ins.length); // tx_in count
+  this.ins.forEach(function (txin) {
+    totalSize += 36 + util.getVarIntSize(txin.s.length) +
+      txin.s.length + 4; // outpoint + script_len + script + sequence
+  });
+
+  totalSize += util.getVarIntSize(this.outs.length);
+  this.outs.forEach(function (txout) {
+    totalSize += util.getVarIntSize(txout.s.length) +
+      txout.s.length + 8; // script_len + script + value
+  });
+  this.size = totalSize;
+  return totalSize;
+};
+
+Transaction.prototype.getSize = function getHash() {
+  if (!this.size) {
+    this.size = this.calcSize();
+  }
+  return this.size;
+};
+
+
 Transaction.prototype.isComplete = function () {
   var l = this.ins.length;
 
@@ -1021,23 +1046,45 @@ Transaction.prototype.sign = function (selectedUtxos, keys, opts) {
 
 Transaction.create = function (utxos, outs, keys, opts) {
 
-    var valueOutSat = Transaction
-      ._sumOutputs(outs)
-      .add(DEFAULT_FEE * util.COIN);
+    //starting size estimation
+    var size    = 500;
+    var opts    = opts || {};
 
-    var selectedUtxos = Transaction
-      .selectUnspent(utxos,valueOutSat / util.COIN, opts.allowUnconfirmed);
-
-    if (!selectedUtxos) {
-      throw new Error(
-        'the given UTXOs dont sum up the given outputs: ' 
-        + valueOutSat.toString() 
-        + ' SAT'
-      );
+    var givenFeeSat;
+    if (opts.fee || opts.feeSat) {
+      givenFeeSat = opts.fee ? opts.fee * util.COIN : opts.feeSat;
     }
 
-    var tx = Transaction.prepare(selectedUtxos, outs, opts);
-    //TODO interate with the new TX fee
+    do {
+      // based on https://en.bitcoin.it/wiki/Transaction_fees
+      maxSizeK     = parseInt(size/1000) + 1;
+      var feeSat  = givenFeeSat
+        ? givenFeeSat : maxSizeK * FEE_PER_1000B_SAT ;
+
+      var valueOutSat = Transaction
+        ._sumOutputs(outs)
+        .add(feeSat);
+
+      var selectedUtxos = Transaction
+        .selectUnspent(utxos,valueOutSat / util.COIN, opts.allowUnconfirmed);
+
+      if (!selectedUtxos) {
+        throw new Error(
+          'the given UTXOs dont sum up the given outputs: ' 
+          + valueOutSat.toString() 
+          + ' (fee is ' + feeSat
+          + ' )SAT'
+        );
+      }
+      var tx = Transaction.prepare(selectedUtxos, outs, {
+        feeSat: feeSat,
+        remainderAddress: opts.remainderAddress,
+        lockTime: opts.lockTime,
+      });
+
+      size = tx.getSize();
+    } while (size > (maxSizeK+1)*1000 );
+
     if (keys) tx.sign(selectedUtxos, keys);
     return tx;
 };
diff --git a/test/data/unspentSign.json b/test/data/unspentSign.json
index f03e40e..5826f4c 100644
--- a/test/data/unspentSign.json
+++ b/test/data/unspentSign.json
@@ -5,7 +5,7 @@
       "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1",
       "scriptPubKey": "76a914fe021bac469a5c49915b2a8ffa7390a9ce5580f988ac",
       "vout": 1,
-      "amount": 1.01,
+      "amount": 1.0101,
       "confirmations":7
     },
     {
diff --git a/test/test.Transaction.js b/test/test.Transaction.js
index f1cfce2..6de6b26 100644
--- a/test/test.Transaction.js
+++ b/test/test.Transaction.js
@@ -94,8 +94,9 @@ describe('Transaction', function() {
     tx.outs.length.should.equal(2);
 
     util.valueToBigInt(tx.outs[0].v).cmp(8000000).should.equal(0);
+
     // remainder is 0.0299 here because unspent select utxos in order
-    util.valueToBigInt(tx.outs[1].v).cmp(2900000).should.equal(0);
+    util.valueToBigInt(tx.outs[1].v).cmp(2990000).should.equal(0);
     tx.isComplete().should.equal(false);
   });
 
@@ -106,6 +107,12 @@ describe('Transaction', function() {
       .create
       .bind(utxos, outs, null, opts)
       .should.throw();
+
+    var outs2 = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.5}];
+    should.exist( Transaction.create(utxos, outs2, null, opts));
+
+    // do not allow unconfirmed
+    Transaction.create.bind(utxos, outs2).should.throw();
   });
 
 
@@ -116,7 +123,7 @@ describe('Transaction', function() {
 
 
     // string output generated from: bitcoind createrawtransaction '[{"txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1","vout":1},{"txid":"2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc2","vout":0}  ]' '{"mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE":0.08,"mwZabyZXg8JzUtFX1pkGygsMJjnuqiNhgd":0.0299}'
-    tx.serialize().toString('hex').should.equal('0100000002c1cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0100000000ffffffffc2cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0000000000ffffffff0200127a00000000001976a914774e603bafb717bd3f070e68bbcccfd907c77d1388ac20402c00000000001976a914b00127584485a7cff0949ef0f6bc5575f06ce00d88ac00000000');
+    tx.serialize().toString('hex').should.equal('0100000002c1cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0100000000ffffffffc2cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0000000000ffffffff0200127a00000000001976a914774e603bafb717bd3f070e68bbcccfd907c77d1388acb09f2d00000000001976a914b00127584485a7cff0949ef0f6bc5575f06ce00d88ac00000000');
 
     // no remainder
     outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
@@ -132,10 +139,14 @@ describe('Transaction', function() {
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
     var tx = Transaction.create(utxos, outs, testdata.dataUnspentSign.keyStrings, opts); 
     tx.isComplete().should.equal(true);
+    tx.ins.length.should.equal(1);
+    tx.outs.length.should.equal(2);
 
     var outs2 = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:16}];
     var tx2 = Transaction.create(utxos, outs2, testdata.dataUnspentSign.keyStrings, opts); 
     tx2.isComplete().should.equal(true);
+    tx2.ins.length.should.equal(3);
+    tx2.outs.length.should.equal(2);
   });
 
   it('#sign should sign an incomplete tx ', function() {
@@ -143,6 +154,8 @@ describe('Transaction', function() {
     var utxos =testdata.dataUnspentSign.unspent;
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
     var tx = Transaction.create(utxos, outs, keys, opts); 
+    tx.ins.length.should.equal(1);
+    tx.outs.length.should.equal(2);
     tx.isComplete().should.equal(false);
   });
   it('#sign should sign a tx in multiple steps', function() {
@@ -165,6 +178,51 @@ describe('Transaction', function() {
  
   });
 
+  it('#create: should generate dynamic fee and readjust (and not) the selected UTXOs', function() {
+    //this cases exceeds the input by 1mbtc AFTEr calculating the dynamic fee,
+    //so, it should trigger adding a new 10BTC utxo
+    var utxos =testdata.dataUnspentSign.unspent;
+    var outs = [];
+    var n =101;
+    for (var i=0; i<n; i++) {
+      outs.push({address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.01});
+    }
+
+    var tx = Transaction.create(utxos, outs, testdata.dataUnspentSign.keyStrings, opts); 
+    tx.getSize().should.equal(3560);
+
+    // ins = 11.0101 BTC (2 inputs: 1.0101 + 10 );
+    tx.ins.length.should.equal(2);
+    // outs = 101 outs:
+    // 101 * 0.01 = 1.01BTC; + 0.0004 fee = 1.0104btc
+    // remainder = 11.0101-1.0104 = 9.9997
+    tx.outs.length.should.equal(102);
+    util.valueToBigInt(tx.outs[n].v).cmp(999970000).should.equal(0);
+    tx.isComplete().should.equal(true);
+
+
+    //this is the complementary case, it does not trigger a new utxo
+    var utxos =testdata.dataUnspentSign.unspent;
+    var outs = [];
+    var n =100;
+    for (var i=0; i<n; i++) {
+      outs.push({address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.01});
+    }
+
+    var tx = Transaction.create(utxos, outs, testdata.dataUnspentSign.keyStrings, opts); 
+    tx.getSize().should.equal(3485);
+
+    // ins = 1.0101 BTC (1 inputs: 1.0101);
+    tx.ins.length.should.equal(1);
+    // outs = 100 outs:
+    // 100 * 0.01 = 1BTC; + 0.0004 fee = 1.0004btc
+    // remainder = 1.0101-1.0004 = 0.0097
+    tx.outs.length.should.equal(101);
+    util.valueToBigInt(tx.outs[n].v).cmp(970000).should.equal(0);
+    tx.isComplete().should.equal(true);
+  });
+
+
   // Read tests from test/data/tx_valid.json
   // Format is an array of arrays
   // Inner arrays are either [ "comment" ]

From eb8763ac9f4e5e2f170576782882bc6e7296f8d4 Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sun, 16 Mar 2014 23:51:35 -0300
Subject: [PATCH 21/22] add comment regarding coins selection

---
 Transaction.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Transaction.js b/Transaction.js
index c16a252..f9c8e69 100644
--- a/Transaction.js
+++ b/Transaction.js
@@ -736,6 +736,10 @@ Transaction.selectUnspent = function (utxos, totalNeededAmount, allowUnconfirmed
     maxConfirmations = minConfirmations;
   } while( !fulfill && minConfirmationSteps.length);
 
+  //TODO(?): sort ret and check is some inputs can be avoided.
+  //If the initial utxos are sorted, this step would be necesary only if
+  //utxos were selected from different minConfirmationSteps.
+
   return fulfill ? ret : null;
 }
 

From aab52ad2291c5cb9a2d8ad9a196907e4c29f8844 Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Tue, 18 Mar 2014 11:32:31 -0300
Subject: [PATCH 22/22] updated interfase to create: create and createAndSign

---
 README.md                   |  83 ++++++++-------
 Transaction.js              | 145 +++++++++++++++-----------
 examples/CreateAndSignTx.js | 201 ++++--------------------------------
 test/test.Transaction.js    |  91 +++++++++++-----
 4 files changed, 212 insertions(+), 308 deletions(-)

diff --git a/README.md b/README.md
index de7b466..4802d4e 100644
--- a/README.md
+++ b/README.md
@@ -130,54 +130,53 @@ var bitcore = require('bitcore');
 var networks = bitcore.networks;
 var Peer = bitcore.Peer;
 var Transaction = bitcore.Transaction;
-var Address = bitcore.Address;
-var Script = bitcore.Script;
-var coinUtil = bitcore.util;
 var PeerManager = require('soop').load('../PeerManager', {
   network: networks.testnet
 });
 
-var createTx = function() {
-  var TXIN = 'd05f35e0bbc495f6dcab03e599c8f5e32a07cdb4bc76964de201d06a2a7d8265';
-  var TXIN_N = 0;
-  var ADDR = 'muHct3YZ9Nd5Pq7uLYYhXRAxeW4EnpcaLz';
-  var VAL = '0.001';
-
-  var txobj = {
-    version: 1,
-    lock_time: 0,
-    ins: [],
-    outs: []
-  };
-
-  var txin = {
-    s: coinUtil.EMPTY_BUFFER, // Add signature
-    q: 0xffffffff
-  };
-
-  var hash = new Buffer(TXIN.split('').reverse(), 'hex');
-  var vout = parseInt(TXIN_N);
-  var voutBuf = new Buffer(4);
-
-  voutBuf.writeUInt32LE(vout, 0);
-  txin.o = Buffer.concat([hash, voutBuf]);
-  txobj.ins.push(txin);
-
-  var addr = new Address(ADDR);
-  var script = Script.createPubKeyHashOut(addr.payload());
-  var valueNum = coinUtil.parseValue(VAL);
-  var value = coinUtil.bigIntToValue(valueNum);
-
-  var txout = {
-    v: value,
-    s: script.getBuffer(),
-  };
-  txobj.outs.push(txout);
-
-  return new Transaction(txobj);
-
+// this can be get from insight.bitcore.io API o blockchain.info
+var utxos = { 
+  "unspent": [
+    {
+      "address": "n4g2TFaQo8UgedwpkYdcQFF6xE2Ei9Czvy",
+      "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1",
+      "scriptPubKey": "76a914fe021bac469a5c49915b2a8ffa7390a9ce5580f988ac",
+      "vout": 1,
+      "amount": 1.0101,
+      "confirmations":7
+    },
+    {
+      "address": "mhNCT9TwZAGF1tLPpZdqfkTmtBkY282YDW",
+      "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc2",
+      "scriptPubKey": "76a9141448534cb1a1ec44665b0eb2326e570814afe3f188ac",
+      "vout": 0,
+      "confirmations": 1,
+      "amount": 10
+    },
 };
 
+//private keys in WIF format (see Transaction.js for other options)
+var keys = [
+  "cSq7yo4fvsbMyWVN945VUGUWMaSazZPWqBVJZyoGsHmNq6W4HVBV",
+  "cPa87VgwZfowGZYaEenoQeJgRfKW6PhZ1R65EHTkN1K19cSvc92G",
+  "cPQ9DSbBRLva9av5nqeF5AGrh3dsdW8p2E5jS4P8bDWZAoQTeeKB"
+];
+
+function createTx() {
+  var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
+
+  var ret = Transaction.createAndSign(utxos, outs, keys); 
+
+  / * create and signing can be done in 2 steps using:
+    *       var ret = Transaction.create(utxos,outs);
+    * and later:
+    *       ret.tx.sign(ret.tx.selectedUtxos, outs, keys); 
+    */
+
+  return ret.tx.serialize().toString('hex');
+};
+
+
 var peerman = new PeerManager();
 peerman.addPeer(new Peer('127.0.0.1', 18333));
 
diff --git a/Transaction.js b/Transaction.js
index f9c8e69..6d28741 100644
--- a/Transaction.js
+++ b/Transaction.js
@@ -778,10 +778,16 @@ Transaction._sumOutputs = function(outs) {
   return valueOutSat;
 }
 
-Transaction.prepare = function (ins, outs, opts) {
-  opts = opts || {};
+/*
+ * createWithFee 
+ *  Create a TX given ins (selected already), outs, and a FIXED fee
+ *  details on the input on .create
+ */
+
+Transaction.createWithFee = function (ins, outs, feeSat, opts) {
+  opts = opts || {};
+  feeSat = feeSat ||  0;
 
-  var feeSat = opts.feeSat || (opts.fee? util.parseValue(opts.fee) : FEE_PER_1000B_SAT );
   var txobj = {};
   txobj.version = 1;
   txobj.lock_time = opts.lockTime || 0;
@@ -981,18 +987,74 @@ Transaction.prototype.sign = function (selectedUtxos, keys, opts) {
     self.ins[i].s = scriptSig.getBuffer();
     inputSigned++;
   }
-
   var complete = inputSigned === l;
-
   return complete;
 };
 
+/*
+ * create
+ *
+ *  creates a transaction without signing it.
+ *
+ *   @utxos
+ *   @outs
+ *   @opts
+ *
+ *  See createAndSign for documentation on the inputs
+ *
+ *   Returns:
+ *     { tx: {}, selectedUtxos: []}
+ *   see createAndSign for details
+ *
+ */
 
+Transaction.create = function (utxos, outs, opts) {
 
+    //starting size estimation
+    var size    = 500;
+    var opts    = opts || {};
+
+    var givenFeeSat;
+    if (opts.fee || opts.feeSat) {
+      givenFeeSat = opts.fee ? opts.fee * util.COIN : opts.feeSat;
+    }
+
+    var selectedUtxos;
+    do {
+      // based on https://en.bitcoin.it/wiki/Transaction_fees
+      maxSizeK     = parseInt(size/1000) + 1;
+      var feeSat  = givenFeeSat
+        ? givenFeeSat : maxSizeK * FEE_PER_1000B_SAT ;
+
+      var valueOutSat = Transaction
+        ._sumOutputs(outs)
+        .add(feeSat);
+
+      selectedUtxos = Transaction
+        .selectUnspent(utxos,valueOutSat / util.COIN, opts.allowUnconfirmed);
+
+      if (!selectedUtxos) {
+        throw new Error(
+          'the given UTXOs dont sum up the given outputs: ' 
+          + valueOutSat.toString() 
+          + ' (fee is ' + feeSat
+          + ' )SAT'
+        );
+      }
+      var tx = Transaction.createWithFee(selectedUtxos, outs, feeSat, {
+        remainderAddress: opts.remainderAddress,
+        lockTime: opts.lockTime,
+      });
+
+      size = tx.getSize();
+    } while (size > (maxSizeK+1)*1000 );
+
+    return {tx: tx, selectedUtxos: selectedUtxos};
+};
 
 
 /*
- * create
+ * createAndSign
  *
  *  creates and signs a transaction
  *
@@ -1031,66 +1093,33 @@ Transaction.prototype.sign = function (selectedUtxos, keys, opts) {
  *      signhash: SIGHASH_ALL
  *    }
  *
+ *
+ *   Retuns:
+ *   { 
+ *      tx: The new created transaction,
+ *      selectedUtxos: The UTXOs selected as inputs for this transaction
+ *   }
+ *
  *  Amounts are in BTC. instead of fee and amount; feeSat and amountSat can be given, 
  *  repectively, to provide amounts in satoshis.
  *
- *  If no remainderAddress is given, and there is a remainderAddress
- *  first in address will be used. (TODO: is this is reasonable?)
+ *  If no remainderAddress is given, and there are remainder coins, the
+ *  first IN address will be used to return the coins. (TODO: is this is reasonable?)
  *
- *  if not keys are provided, the transaction will no be signed. .sign can be used to
- *  sign it later.
- *
- *  The Transaction creation is handled in 3 steps:
- *    .selectUnspent
- *    .prepare
+ *  The Transaction creation is handled in 2 steps:
+ *    .create
+ *      .selectUnspent
+ *      .createWithFee
  *    .sign
  *
+ *  If you need just to create a TX and not sign it, use .create  
+ *
  */
 
-
-Transaction.create = function (utxos, outs, keys, opts) {
-
-    //starting size estimation
-    var size    = 500;
-    var opts    = opts || {};
-
-    var givenFeeSat;
-    if (opts.fee || opts.feeSat) {
-      givenFeeSat = opts.fee ? opts.fee * util.COIN : opts.feeSat;
-    }
-
-    do {
-      // based on https://en.bitcoin.it/wiki/Transaction_fees
-      maxSizeK     = parseInt(size/1000) + 1;
-      var feeSat  = givenFeeSat
-        ? givenFeeSat : maxSizeK * FEE_PER_1000B_SAT ;
-
-      var valueOutSat = Transaction
-        ._sumOutputs(outs)
-        .add(feeSat);
-
-      var selectedUtxos = Transaction
-        .selectUnspent(utxos,valueOutSat / util.COIN, opts.allowUnconfirmed);
-
-      if (!selectedUtxos) {
-        throw new Error(
-          'the given UTXOs dont sum up the given outputs: ' 
-          + valueOutSat.toString() 
-          + ' (fee is ' + feeSat
-          + ' )SAT'
-        );
-      }
-      var tx = Transaction.prepare(selectedUtxos, outs, {
-        feeSat: feeSat,
-        remainderAddress: opts.remainderAddress,
-        lockTime: opts.lockTime,
-      });
-
-      size = tx.getSize();
-    } while (size > (maxSizeK+1)*1000 );
-
-    if (keys) tx.sign(selectedUtxos, keys);
-    return tx;
+Transaction.createAndSign = function (utxos, outs, keys, opts) {
+    var ret = Transaction.create(utxos, outs, opts);
+    ret.tx.sign(ret.selectedUtxos, keys);
+    return ret;
 };
 
 var TransactionInputsCache = exports.TransactionInputsCache =
diff --git a/examples/CreateAndSignTx.js b/examples/CreateAndSignTx.js
index aa8a746..0e34252 100644
--- a/examples/CreateAndSignTx.js
+++ b/examples/CreateAndSignTx.js
@@ -8,195 +8,34 @@ var run = function() {
   var amt     = '0.005';
   var toAddress = 'myuAQcCc1REUgXGsCTiYhZvPPc3XxZ36G1';
   var changeAddressString = 'moDz3jEo9q7CxjBDjmb13sL4SKkgo2AACE';
-  var feeString = '0.0001';
 
-  var safeUnspent = [
-  {
-  address: "mqSjTad2TKbPcKQ3Jq4kgCkKatyN44UMgZ",
-  hash: "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1",
-  vout: 1,
-  ts: 1394719301,
-  scriptPubKey: "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ac",
-  amount: 0.01,
-  confirmations: 2
-  }
-  ]
-  ;
+  var utxos = [{
+    address: "mqSjTad2TKbPcKQ3Jq4kgCkKatyN44UMgZ",
+    txid: "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1",
+    vout: 1,
+    ts: 1394719301,
+    scriptPubKey: "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ac",
+    amount: 0.01,
+    confirmations: 2
+  }];
 
   console.log('TX Data: BTC:' + amt + ' => '+ toAddress + ', change To:' + changeAddressString ) ;
-  console.log('Unspends:', safeUnspent);
-
-  var wk  = new bitcore.WalletKey({
-    network: bitcore.networks.testnet
-  });
-  wk.fromObj({ priv: priv, });
-
-  var wkObj= wk.storeObj();
-  var keyPairs = [{
-    key: wkObj.priv,
-    address: wkObj.addr,
-  }];
-  console.log('KEY DB IS:', keyPairs); 
-
-  var Address = bitcore.Address;
-  var Transaction = bitcore.Transaction;
-  var Script = bitcore.Script;
-  var nets = bitcore.networks;
-  var z = bitcore.bignum(0);
-  var amt = bitcore.util.parseValue(amt);
-
-  if(z.cmp(amt) === 0 )
-    throw "spend amount must be greater than zero";
-
-  if(!changeAddressString)
-    throw "change address was not provided";
-
-  var fee = bitcore.util.parseValue(feeString || '0');
-  var total = bitcore.bignum(0).add(amt).add(fee);
-  var address = new Address(toAddress);
-  var sendTx = new Transaction();
-  var i;
-
-  var unspent = [];
-  var unspentAmt = bitcore.bignum(0);
+  console.log('Unspends Outputs:', utxos);
 
 
-  for(i=0;i<safeUnspent.length;i++) {
-    unspent.push(safeUnspent[i]);
+  var outs = [{address:toAddress, amount:amt}];
+  var keys = [priv];
 
-        var amountSatoshiString = new bitcore.bignum(safeUnspent[i].amount * Math.pow(10,8)).toString();
+  var ret = bitcore.Transaction.createAndSign(utxos, outs, keys,
+                {remainderAddress: changeAddressString}); 
 
-        unspentAmt = unspentAmt.add(new bitcore.bignum(amountSatoshiString));
+   /* create and signing can be done in 2 steps using:
+    *       var ret = Transaction.create(utxos,outs);
+    * and later:
+    *       ret.tx.sign(ret.tx.selectedUtxos, outs, keys); 
+    */
 
-        // If > -1, we have enough to send the requested amount
-        if(unspentAmt.cmp(total) > -1) {
-          break;
-        }
-      }
-
-      if(unspentAmt.cmp(total) < 0) {
-        throw "you do not have enough bitcoins to send this amount";
-      }
-
-      var txobj = {};
-      txobj.version = 1;
-      txobj.lock_time = 0;
-      txobj.ins = [];
-      txobj.outs = [];
-      
-      for(i=0;i<unspent.length;i++) {
-        var txin = {};
-
-        txin.s = bitcore.util.EMPTY_BUFFER;
-        txin.q = 0xffffffff;
-
-        var hash = new bitcore.Buffer(unspent[i].hash, 'hex');
-        var hashReversed = bitcore.buffertools.reverse(hash);
-        var vout = parseInt(unspent[i].vout);
-        var voutBuf = new bitcore.Buffer(4);
-        voutBuf.writeUInt32LE(vout, 0);
-
-        txin.o = bitcore.Buffer.concat([hashReversed, voutBuf]);
-        txobj.ins.push(txin); 
-      }
-
-
-      // This is not used really, but we keep it for the future.
-      var version = address.version();
-      var script;
-      if (version == nets.livenet.addressPubkey || version == nets.testnet.addressPubkey)
-        script = Script.createPubKeyHashOut(address.payload());
-      else if (version == nets.livenet.addressScript || version == nets.testnet.addressScript)
-        script = Script.createP2SH(address.payload());
-      else
-        throw new Error('invalid output address');
-
-      var value = bitcore.util.bigIntToValue(amt);
-      var txout = {
-        v: value,
-        s: script.getBuffer(),
-      };
-      txobj.outs.push(txout);
-      var remainder = unspentAmt.sub(total);
-
-      if(z.cmp(amt) !== 0 ) {
-        var changeAddress = new Address(changeAddressString);
-        var changeValue = bitcore.util.bigIntToValue(remainder);
-
-        // This is not used really, but we keep it for the future.
-        var cversion = changeAddress.version();
-        var cscript;
-        if (cversion == nets.livenet.addressPubkey || cversion == nets.testnet.addressPubkey)
-          cscript = Script.createPubKeyHashOut(changeAddress.payload());
-        else if (cversion == nets.livenet.addressScript || cversion == nets.testnet.addressScript)
-          cscript = Script.createP2SH(changeAddress.payload());
-        else
-          throw new Error('invalid change output address');
-
-        var change = {
-          v: changeValue,
-          s: cscript.getBuffer(),
-        };
-        txobj.outs.push(change);
-      }
-
-      var tx = new Transaction(txobj);
-      var anypay = false;
-      var l = unspent.length;
-      var allFound = l;
-
-      // Here will be the beginning of your signing for loop
-      for(i=0;i < l;i++) {
-        var scriptBuf = new bitcore.Buffer(unspent[i].scriptPubKey, 'hex');
-
-        var s = new Script(scriptBuf);
-        if (s.classify() !==  Script.TX_PUBKEYHASH) {
-          throw new Error('input script type '+ s.getRawOutType() +' not supported yet');
-        }
-        var txSigHash = tx.hashForSignature(s, i,
-                  anypay ? Transaction.SIGHASH_ANYONECANPAY : Transaction.SIGHASH_ALL);
-
-
-  //      txSigHash = bitcore.buffertools.reverse(txSigHash);
-
-        for(var j=0;j<keyPairs.length;j++) {
-          var kp = keyPairs[j];
-          if(kp.address === unspent[i].address) {
-            console.log('SIGNING With...', kp.key); //TODO
-            console.log('HASH TO SIGN: ',bitcore.buffertools.toHex(txSigHash)); //TODO
-            var wKey = new bitcore.WalletKey({network: bitcore.networks.testnet});
-            wKey.fromObj({
-              priv: kp.key,
-            });
-
-            console.log('PRIV KEY', bitcore.buffertools.toHex(wKey.privKey.private )); //TODO
-            console.log('PUB KEY', bitcore.buffertools.toHex(wKey.privKey.public )); //TODO
-
-            var sigRaw = wKey.privKey.signSync(txSigHash);
-            console.log('SIGNATURE: ',bitcore.buffertools.toHex(sigRaw)); //TODO
-
-            console.log('VERIFY: ',wKey.privKey.verifySignatureSync(txSigHash, sigRaw)); //TODO
-
-            var sigType = new bitcore.Buffer(1);
-            sigType[0] = anypay ? Transaction.SIGHASH_ANYONECANPAY : Transaction.SIGHASH_ALL;
-            var sig = bitcore.Buffer.concat([sigRaw, sigType]);
-
-            var scriptSig = new Script();
-            scriptSig.chunks.push(sig);
-            scriptSig.chunks.push(wKey.privKey.public);
-            scriptSig.updateBuffer();
-            tx.ins[i].s = scriptSig.getBuffer();
-            allFound--;
-            break;
-          }
-        }
-      }
-
-      if (allFound !== 0)  {
-        throw new Error('could not find priv key for some inputs');
-      }
-
-  var txHex = tx.serialize().toString('hex');
+  var txHex =  ret.tx.serialize().toString('hex');
   console.log('TX HEX IS: ', txHex);
 };
 
diff --git a/test/test.Transaction.js b/test/test.Transaction.js
index 6de6b26..094dd0b 100644
--- a/test/test.Transaction.js
+++ b/test/test.Transaction.js
@@ -86,8 +86,13 @@ describe('Transaction', function() {
   it('#create should be able to create instance', function() {
     var utxos =testdata.dataUnspent;
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
-    var tx = Transaction.create(utxos, outs, null, opts);
-    should.exist(tx);
+
+    var ret = Transaction.create(utxos, outs, opts);
+    should.exist(ret.tx);
+    should.exist(ret.selectedUtxos);
+    ret.selectedUtxos.length.should.equal(2);
+
+    var tx = ret.tx;
 
     tx.version.should.equal(1);
     tx.ins.length.should.equal(2);
@@ -105,11 +110,11 @@ describe('Transaction', function() {
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:80}];
     Transaction
       .create
-      .bind(utxos, outs, null, opts)
+      .bind(utxos, outs, opts)
       .should.throw();
 
     var outs2 = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.5}];
-    should.exist( Transaction.create(utxos, outs2, null, opts));
+    should.exist( Transaction.create(utxos, outs2, opts));
 
     // do not allow unconfirmed
     Transaction.create.bind(utxos, outs2).should.throw();
@@ -119,66 +124,96 @@ describe('Transaction', function() {
   it('#create should create same output as bitcoind createrawtransaction ', function() {
     var utxos =testdata.dataUnspent;
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
-    var tx = Transaction.create(utxos, outs, null, opts); 
-
+    var ret = Transaction.create(utxos, outs, opts); 
+    var tx = ret.tx;
 
     // string output generated from: bitcoind createrawtransaction '[{"txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1","vout":1},{"txid":"2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc2","vout":0}  ]' '{"mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE":0.08,"mwZabyZXg8JzUtFX1pkGygsMJjnuqiNhgd":0.0299}'
     tx.serialize().toString('hex').should.equal('0100000002c1cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0100000000ffffffffc2cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0000000000ffffffff0200127a00000000001976a914774e603bafb717bd3f070e68bbcccfd907c77d1388acb09f2d00000000001976a914b00127584485a7cff0949ef0f6bc5575f06ce00d88ac00000000');
 
+  });
+
+  it('#create should create same output as bitcoind createrawtransaction wo remainder', function() {
+    var utxos =testdata.dataUnspent;
     // no remainder
-    outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
-    tx = Transaction.create(utxos, outs, null, {fee:0.03} ); 
+    var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
+    var ret = Transaction.create(utxos, outs, {fee:0.03} ); 
+    var tx = ret.tx;
 
     // string output generated from: bitcoind createrawtransaction '[{"txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1","vout":1},{"txid":"2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc2","vout":0}  ]' '{"mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE":0.08}'
     //
     tx.serialize().toString('hex').should.equal('0100000002c1cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0100000000ffffffffc2cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0000000000ffffffff0100127a00000000001976a914774e603bafb717bd3f070e68bbcccfd907c77d1388ac00000000');
   });
  
-  it('#sign should sign a tx', function() {
+  it('#createAndSign should sign a tx', function() {
     var utxos =testdata.dataUnspentSign.unspent;
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
-    var tx = Transaction.create(utxos, outs, testdata.dataUnspentSign.keyStrings, opts); 
+    var ret = Transaction.createAndSign(utxos, outs, testdata.dataUnspentSign.keyStrings, opts); 
+    var tx = ret.tx;
     tx.isComplete().should.equal(true);
     tx.ins.length.should.equal(1);
     tx.outs.length.should.equal(2);
 
     var outs2 = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:16}];
-    var tx2 = Transaction.create(utxos, outs2, testdata.dataUnspentSign.keyStrings, opts); 
+    var ret2 = Transaction.createAndSign(utxos, outs2, testdata.dataUnspentSign.keyStrings, opts); 
+    var tx2 = ret2.tx;
     tx2.isComplete().should.equal(true);
     tx2.ins.length.should.equal(3);
     tx2.outs.length.should.equal(2);
   });
 
-  it('#sign should sign an incomplete tx ', function() {
+  it('#createAndSign should sign an incomplete tx ', function() {
     var keys = ['cNpW8B7XPAzCdRR9RBWxZeveSNy3meXgHD8GuhcqUyDuy8ptCDzJ'];
     var utxos =testdata.dataUnspentSign.unspent;
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
-    var tx = Transaction.create(utxos, outs, keys, opts); 
+    var ret = Transaction.createAndSign(utxos, outs, keys, opts); 
+    var tx = ret.tx;
     tx.ins.length.should.equal(1);
     tx.outs.length.should.equal(2);
-    tx.isComplete().should.equal(false);
   });
-  it('#sign should sign a tx in multiple steps', function() {
-    var utxos = Transaction.selectUnspent(testdata.dataUnspentSign.unspent,13, true);
+  it('#isComplete should return TX signature status', function() {
+    var keys = ['cNpW8B7XPAzCdRR9RBWxZeveSNy3meXgHD8GuhcqUyDuy8ptCDzJ'];
+    var utxos =testdata.dataUnspentSign.unspent;
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
+    var ret = Transaction.createAndSign(utxos, outs, keys, opts); 
+    var tx = ret.tx;
+    tx.isComplete().should.equal(false);
+    tx.sign(ret.selectedUtxos, testdata.dataUnspentSign.keyStrings);
+    tx.isComplete().should.equal(true);
+  });
+
+  it('#sign should sign a tx in multiple steps (case1)', function() {
+    var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:1.08}];
+    var ret = Transaction.create(testdata.dataUnspentSign.unspent, outs, opts); 
+    var tx            = ret.tx;
+    var selectedUtxos = ret.selectedUtxos;
 
-    var tx = Transaction.prepare(utxos, outs, opts); 
     var k1 = testdata.dataUnspentSign.keyStrings.slice(0,1);
-    var k23 = testdata.dataUnspentSign.keyStrings.slice(1,3);
-    tx.sign(utxos, k1).should.equal(false);
-    tx.sign(utxos, k23).should.equal(true);
 
-    var tx2 = Transaction.prepare(utxos, outs, opts); 
+    tx.isComplete().should.equal(false);
+
+    tx.sign(selectedUtxos, k1).should.equal(false);
+
+    var k23 = testdata.dataUnspentSign.keyStrings.slice(1,3);
+    tx.sign(selectedUtxos, k23).should.equal(true);
+    tx.isComplete().should.equal(true);
+  });
+
+  it('#sign should sign a tx in multiple steps (case2)', function() {
+    var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:16}];
+    var ret = Transaction.create(testdata.dataUnspentSign.unspent, outs, opts); 
+    var tx            = ret.tx;
+    var selectedUtxos = ret.selectedUtxos;
+
     var k1 = testdata.dataUnspentSign.keyStrings.slice(0,1);
     var k2 = testdata.dataUnspentSign.keyStrings.slice(1,2);
     var k3 = testdata.dataUnspentSign.keyStrings.slice(2,3);
-    tx2.sign(utxos, k1).should.equal(false);
-    tx2.sign(utxos, k2).should.equal(false);
-    tx2.sign(utxos, k3).should.equal(true);
+    tx.sign(selectedUtxos, k1).should.equal(false);
+    tx.sign(selectedUtxos, k2).should.equal(false);
+    tx.sign(selectedUtxos, k3).should.equal(true);
  
   });
 
-  it('#create: should generate dynamic fee and readjust (and not) the selected UTXOs', function() {
+  it('#createAndSign: should generate dynamic fee and readjust (and not) the selected UTXOs', function() {
     //this cases exceeds the input by 1mbtc AFTEr calculating the dynamic fee,
     //so, it should trigger adding a new 10BTC utxo
     var utxos =testdata.dataUnspentSign.unspent;
@@ -188,7 +223,8 @@ describe('Transaction', function() {
       outs.push({address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.01});
     }
 
-    var tx = Transaction.create(utxos, outs, testdata.dataUnspentSign.keyStrings, opts); 
+    var ret = Transaction.createAndSign(utxos, outs, testdata.dataUnspentSign.keyStrings, opts); 
+    var tx = ret.tx;
     tx.getSize().should.equal(3560);
 
     // ins = 11.0101 BTC (2 inputs: 1.0101 + 10 );
@@ -209,7 +245,8 @@ describe('Transaction', function() {
       outs.push({address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.01});
     }
 
-    var tx = Transaction.create(utxos, outs, testdata.dataUnspentSign.keyStrings, opts); 
+    var ret = Transaction.createAndSign(utxos, outs, testdata.dataUnspentSign.keyStrings, opts); 
+    var tx = ret.tx;
     tx.getSize().should.equal(3485);
 
     // ins = 1.0101 BTC (1 inputs: 1.0101);