From bfd570e204b3ea7dda294cb55523587fbf07d07d Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Fri, 12 Feb 2016 04:18:01 -0800
Subject: [PATCH] coin selection. misc.

---
 lib/bcoin/tx.js     | 39 +++++++++++++++++++++++++++------------
 test/wallet-test.js |  2 +-
 2 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/lib/bcoin/tx.js b/lib/bcoin/tx.js
index ae09b575..b2a1beee 100644
--- a/lib/bcoin/tx.js
+++ b/lib/bcoin/tx.js
@@ -1024,10 +1024,17 @@ TX.prototype.getInputs = function getInputs(unspent, options) {
     };
   }
 
-  // Oldest unspents first
-  unspent = unspent.slice().sort(function(a, b) {
-    return a.height - b.height;
-  });
+  if (!options.selection || options.selection === 'age') {
+    // Oldest unspents first
+    unspent = unspent.slice().sort(function(a, b) {
+      return a.height - b.height;
+    });
+  } else if (options.selection === 'random' || options.selection === 'all') {
+    // Random unspents
+    unspent = unspent.slice().sort(function(a, b) {
+      return Math.random() > 0.5 ? 1 : -1;
+    });
+  }
 
   function total() {
     if (options.subtractFee)
@@ -1053,6 +1060,9 @@ TX.prototype.getInputs = function getInputs(unspent, options) {
       if (options.wallet)
         options.wallet.scriptInputs(tx, index);
 
+      if (options.selection === 'all')
+        continue;
+
       // Stop once we're full.
       if (isFull())
         break;
@@ -1083,6 +1093,11 @@ TX.prototype.getInputs = function getInputs(unspent, options) {
       // Calculate max possible size after signing.
       size = tx.maxSize(options.m, options.n);
 
+      // if (newkb == null && tx.isFree(size)) {
+      //   fee = new bn(0);
+      //   break;
+      // }
+
       newkb = Math.ceil(size / 1024) - totalkb;
       fee.iaddn(newkb * minFee);
       totalkb += newkb;
@@ -1140,7 +1155,7 @@ TX.prototype.fill = function fill(unspent, options) {
 
   result = this.getInputs(unspent, options);
 
-  this.total = result.total;
+  this.requiredFunds = result.total;
 
   if (!result.inputs)
     return result;
@@ -1599,8 +1614,8 @@ TX.prototype.isStandardInputs = function isStandardInputs(flags) {
   return true;
 };
 
-TX.prototype.getPriority = function getPriority() {
-  var size, sum, i, input, age, height;
+TX.prototype.getPriority = function getPriority(size) {
+  var sum, i, input, age, height;
 
   height = this.height;
 
@@ -1610,7 +1625,7 @@ TX.prototype.getPriority = function getPriority() {
   if (!this.hasPrevout())
     return new bn(0);
 
-  size = this.maxSize();
+  size = size || this.maxSize();
   sum = new bn(0);
 
   for (i = 0; i < this.inputs.length; i++) {
@@ -1633,13 +1648,13 @@ TX.prototype.getPriority = function getPriority() {
   return sum.divn(size);
 };
 
-TX.prototype.isFree = function isFree() {
-  var size, priority;
+TX.prototype.isFree = function isFree(size) {
+  var priority;
 
   if (!this.hasPrevout())
     return false;
 
-  size = this.maxSize();
+  size = size || this.maxSize();
 
   if (size >= constants.tx.maxFreeSize)
     return false;
@@ -1735,7 +1750,7 @@ TX.prototype.inspect = function inspect() {
     copy.block = this.block;
   delete copy._raw;
   delete copy._chain;
-  delete copy.total;
+  delete copy.requiredFunds;
   copy.hash = this.hash('hex');
   copy.rhash = this.rhash;
   copy.rblock = this.rblock;
diff --git a/test/wallet-test.js b/test/wallet-test.js
index 600bdbb5..126af919 100644
--- a/test/wallet-test.js
+++ b/test/wallet-test.js
@@ -170,7 +170,7 @@ describe('Wallet', function() {
     // Create new transaction
     var t3 = bcoin.tx().out(w2, 15000);
     assert(!w1.fill(t3));
-    assert.equal(t3.total.toString(10), 25000);
+    assert.equal(t3.requiredFunds.toString(10), 25000);
 
     cb();
   });