/**
 * tx.js - transaction object for bcoin
 * Copyright (c) 2014-2015, Fedor Indutny (MIT License)
 * https://github.com/indutny/bcoin
 */

var bn = require('bn.js');

var bcoin = require('../bcoin');
var utils = bcoin.utils;
var assert = utils.assert;
var constants = bcoin.protocol.constants;

/**
 * TX
 */

function TX(data, block) {
  if (!(this instanceof TX))
    return new TX(data, block);

  if (!data)
    data = {};

  this.type = 'tx';
  this.version = data.version || 1;
  this.inputs = [];
  this.outputs = [];
  this.locktime = data.locktime || 0;
  this.ts = data.ts || 0;
  this.block = data.block || null;
  this._hash = null;

  this._raw = data._raw || null;
  this._size = data._size || 0;
  this._offset = data._offset || 0;

  this.height = data.height != null ? data.height : -1;
  this.relayedBy = data.relayedBy || '0.0.0.0';

  this._chain = data.chain;

  if (data.inputs) {
    assert(this.inputs.length === 0);
    data.inputs.forEach(function(input) {
      this.addInput(input);
    }, this);
  }

  if (data.outputs) {
    assert(this.outputs.length === 0);
    data.outputs.forEach(function(output) {
      this.addOutput(output);
    }, this);
  }

  this._init(block);
}

TX.prototype._init = function _init(block) {
  if (block && this.ts === 0) {
    if (block.type === 'merkleblock') {
      if (block.hasTX(this.hash('hex')))
        this.setBlock(block);
    } else {
      this.setBlock(block);
    }
  }

  if (!this._raw)
    this._raw = this.render();

  if (!this._size)
    this._size = this._raw.length;
};

TX.prototype.setBlock = function setBlock(block) {
  this.relayedBy = block.relayedBy;
  this.ts = block.ts;
  this.block = block.hash('hex');
  this.height = block.height;
};

TX.prototype.clone = function clone() {
  var tx = new TX(this);

  tx.inputs = tx.inputs.map(function(input) {
    input.script = input.script.slice();
    return input;
  });

  tx.outputs = tx.outputs.map(function(output) {
    output.script = output.script.slice();
    return output;
  });

  delete tx._raw;
  delete tx._size;

  return tx;
};

TX.prototype.hash = function hash(enc) {
  var hash;

  if (this._hash)
    return enc === 'hex' ? utils.toHex(this._hash) : this._hash;

  hash = utils.dsha256(this._raw);

  this._hash = hash;

  return enc === 'hex' ? utils.toHex(hash) : hash;
};

TX.prototype.render = function render() {
  if (this._raw)
    return this._raw;
  return bcoin.protocol.framer.tx(this);
};

TX.prototype.getSize = function getSize() {
  return this._size || this.render().length;
};

TX.prototype.addInput = function addInput(input) {
  assert(input.prevout);

  input = bcoin.input(input);

  this.inputs.push(input);
};

TX.prototype._inputIndex = function _inputIndex(hash, index) {
  var i, ex;

  for (i = 0; i < this.inputs.length; i++) {
    ex = this.inputs[i];
    if (ex.prevout.hash === hash && ex.prevout.index === index)
      return i;
  }

  return -1;
};

TX.prototype.addOutput = function addOutput(output) {
  output = bcoin.output(output);

  this.outputs.push(output);
};

TX.prototype.getSubscript = function getSubscript(index) {
  var script;

  if (typeof index !== 'number')
    index = this.outputs.indexOf(index);

  assert(this.outputs[index]);

  script = this.outputs[index].script;

  return bcoin.script.getSubscript(script);
};

TX.prototype.signatureHash = function signatureHash(index, s, type) {
  var copy = this.clone();
  var i, msg, hash;

  if (typeof index !== 'number')
    index = this.inputs.indexOf(index);

  if (typeof type === 'string')
    type = constants.hashType[type];

  assert(index >= 0 && index < copy.inputs.length)
  assert(Array.isArray(s));

  // Disable this for now. We allow null hash types
  // because bitcoind allows empty signatures. On
  // another note, we allow all weird sighash types
  // if strictenc is not enabled.
  // assert(utils.isFinite(type));

  // Remove all signatures.
  for (i = 0; i < copy.inputs.length; i++)
    copy.inputs[i].script = [];

  // Set our input to previous output's script
  copy.inputs[index].script = s;

  if ((type & 0x1f) === constants.hashType.none) {
    // Drop all outputs. We don't want to sign them.
    copy.outputs = [];

    // Allow input sequence updates for other inputs.
    for (i = 0; i < copy.inputs.length; i++) {
      if (i !== index)
        copy.inputs[i].sequence = 0;
    }
  } else if ((type & 0x1f) === constants.hashType.single) {
    // Bitcoind used to return 1 as an error code:
    // it ended up being treated like a hash.
    if (index >= copy.outputs.length)
      return new Buffer(constants.oneHash);

    // Drop all the outputs after the input index.
    copy.outputs.length = index + 1;

    // Null outputs that are not the at current input index.
    for (i = 0; i < copy.outputs.length; i++) {
      if (i !== index) {
        copy.outputs[i].script = [];
        copy.outputs[i].value = new bn('ffffffffffffffff', 'hex');
      }
    }

    // Allow input sequence updates for other inputs.
    for (i = 0; i < copy.inputs.length; i++) {
      if (i !== index)
        copy.inputs[i].sequence = 0;
    }
  }

  // Only sign our input. Allows anyone to add inputs.
  if (type & constants.hashType.anyonecanpay) {
    copy.inputs[0] = copy.inputs[index];
    copy.inputs.length = 1;
  }

  copy = bcoin.protocol.framer.tx(copy);

  msg = new Buffer(copy.length + 4);
  utils.copy(copy, msg, 0);
  utils.writeU32(msg, type, copy.length);

  hash = utils.dsha256(msg);

  return hash;
};

TX.prototype.tbsHash = function tbsHash(enc, force) {
  var copy = this.clone();
  var i;

  if (this.isCoinbase())
    return this.hash(enc);

  if (!this._tbsHash || force) {
    for (i = 0; i < copy.inputs.length; i++) {
      if (!copy.inputs[i].isCoinbase())
        copy.inputs[i].script = [];
    }

    copy = bcoin.protocol.framer.tx(copy);
    this._tbsHash = utils.dsha256(copy);
  }

  return enc === 'hex'
    ? utils.toHex(this._tbsHash)
    : this._tbsHash.slice();
};

TX.prototype.verify = function verify(index, force, flags) {
  // Valid if included in block
  if (!force && this.ts !== 0)
    return true;

  if (this.inputs.length === 0)
    return false;

  if (index && typeof index === 'object')
    index = this.inputs.indexOf(index);

  if (index != null)
    assert(this.inputs[index]);

  if (this.isCoinbase())
    return true;

  return this.inputs.every(function(input, i) {
    if (index != null && i !== index)
      return true;

    if (!input.output) {
      utils.debug('Warning: Not all outputs available for tx.verify().');
      return false;
    }

    return bcoin.script.verify(input.script, input.output.script, this, i, flags);
  }, this);
};

TX.prototype.isCoinbase = function isCoinbase() {
  return this.inputs.length === 1 && +this.inputs[0].prevout.hash === 0;
};

TX.prototype.getFee = function getFee() {
  if (!this.hasPrevout())
    return new bn(0);

  return this.getInputValue().sub(this.getOutputValue());
};

TX.prototype.getInputValue = function getInputValue() {
  var acc = new bn(0);

  if (this.inputs.length === 0)
    return acc;

  if (!this.hasPrevout())
    return acc;

  return this.inputs.reduce(function(acc, input) {
    return acc.iadd(input.output.value);
  }, acc);
};

TX.prototype.getOutputValue = function getOutputValue() {
  var acc = new bn(0);

  if (this.outputs.length === 0)
    return acc;

  return this.outputs.reduce(function(acc, output) {
    return acc.iadd(output.value);
  }, acc);
};

TX.prototype.getFunds = function getFunds(side) {
  var acc = new bn(0);

  if (side === 'in' || side === 'input')
    return this.getInputValue();

  return this.getOutputValue();
};

TX.prototype.testInputs = function testInputs(addressTable, index, collect) {
  var inputs = [];
  var i, input;

  if (typeof addressTable === 'string')
    addressTable = [addressTable];

  if (Array.isArray(addressTable)) {
    addressTable = addressTable.reduce(function(out, address) {
      out[address] = true;
      return out;
    }, {});
  }

  if (index && typeof index === 'object')
    index = this.inputs.indexOf(index);

  if (index != null)
    assert(this.inputs[index]);

  for (i = 0; i < this.inputs.length; i++) {
    if (index != null && i !== index)
      continue;

    input = this.inputs[i];

    if (input.test(addressTable)) {
      if (!collect)
        return true;
      inputs.push(input);
    }
  }

  if (!collect)
    return false;

  if (inputs.length === 0)
    return false;

  return inputs;
};

TX.prototype.testOutputs = function testOutputs(addressTable, index, collect) {
  var outputs = [];
  var i, output;

  if (typeof addressTable === 'string')
    addressTable = [addressTable];

  if (Array.isArray(addressTable)) {
    addressTable = addressTable.reduce(function(out, address) {
      out[address] = true;
      return out;
    }, {});
  }

  if (index && typeof index === 'object')
    index = this.outputs.indexOf(index);

  if (index != null)
    assert(this.outputs[index]);

  for (i = 0; i < this.outputs.length; i++) {
    if (index != null && i !== index)
      continue;

    output = this.outputs[i];

    if (output.test(addressTable)) {
      if (!collect)
        return true;
      outputs.push(output);
    }
  }

  if (!collect)
    return false;

  if (outputs.length === 0)
    return false;

  return outputs;
};

TX.prototype.hasPrevout = function hasPrevout() {
  if (this.inputs.length === 0)
    return false;

  return this.inputs.every(function(input) {
    return !!input.output;
  });
};

TX.prototype.fillPrevout = function fillPrevout(txs, unspent) {
  var inputs;

  if (txs instanceof TX) {
    txs = [txs];
    unspent = null;
  } else if (txs instanceof bcoin.coin) {
    unspent = [tx];
    txs = null;
  } else if (txs instanceof bcoin.txpool) {
    unspent = txs._unspent;
    txs = txs._all;
  } else if (txs instanceof bcoin.wallet) {
    unspent = txs.tx._unspent;
    txs = txs.tx._all;
  }

  if (Array.isArray(txs)) {
    txs = txs.reduce(function(out, tx) {
      out[tx.hash('hex')] = tx;
      return out;
    }, {});
  }

  if (Array.isArray(unspent)) {
    unspent = unspent.reduce(function(out, coin) {
      out[coin.hash + '/' + coin.index] = coin;
      return out;
    }, {});
  }

  inputs = this.inputs.filter(function(input) {
    var key;

    if (!input.output) {
      key = input.prevout.hash + '/' + input.prevout.index;
      if (unspent && unspent[key])
        input.output = unspent[key];
      else if (txs && txs[input.prevout.hash])
        input.output = bcoin.coin(txs[input.prevout.hash], input.prevout.index);
    }

    return !!input.output;
  }, this);

  return inputs.length === this.inputs.length;
};

TX.prototype.isFinal = function isFinal(height, ts) {
  var threshold = constants.locktimeThreshold;
  var i;

  if (this.locktime === 0)
    return true;

  if (this.locktime < (this.locktime < threshold ? height : ts))
    return true;

  for (i = 0; i < this.inputs.length; i++) {
    if (this.inputs[i].sequence !== 0xffffffff)
      return false;
  }

  return true;
};

TX.prototype.getSigops = function getSigops(scriptHash, accurate) {
  var n = 0;
  this.inputs.forEach(function(input) {
    var prev;
    n += bcoin.script.getSigops(input.script, accurate);
    if (scriptHash && !this.isCoinbase()) {
      prev = input.output ? input.output.script : null;
      n += bcoin.script.getScripthashSigops(input.script, prev);
    }
  }, this);
  this.outputs.forEach(function(output) {
    n += bcoin.script.getSigops(output.script, accurate);
  }, this);
  return n;
};

TX.prototype.isStandard = function isStandard(flags) {
  var i, input, output, type;
  var nulldata = 0;

  if (flags == null)
    flags = constants.flags.STANDARD_VERIFY_FLAGS;

  if (this.version > constants.tx.version || this.version < 1)
    return false;

  if (this.getSize() > constants.tx.maxSize)
    return false;

  for (i = 0; i < this.inputs.length; i++) {
    input = this.inputs[i];

    if (bcoin.script.getSize(input.script) > 1650)
      return false;

    // Not accurate?
    if (this.isCoinbase())
      continue;

    if (flags & constants.flags.VERIFY_SIGPUSHONLY) {
      if (!bcoin.script.isPushOnly(input.script))
        return false;
    }
  }

  for (i = 0; i < this.outputs.length; i++) {
    output = this.outputs[i];
    type = bcoin.script.getType(output.script);

    if (!bcoin.script.isStandard(output.script))
      return false;

    if (type === 'unknown')
      return false;

    if (type === 'nulldata') {
      nulldata++;
      continue;
    }

    if (type === 'multisig' && !constants.tx.bareMultisig)
      return false;

    if (output.value.cmpn(constants.tx.dustThreshold) < 0)
      return false;
  }

  if (nulldata > 1)
    return false;

  return true;
};

TX.prototype.isStandardInputs = function isStandardInputs(flags) {
  var i, input, args, stack, res, redeem, targs;
  var maxSigops = constants.script.maxScripthashSigops;

  if (flags == null)
    flags = constants.flags.STANDARD_VERIFY_FLAGS;

  if (this.isCoinbase())
    return true;

  for (i = 0; i < this.inputs.length; i++) {
    input = this.inputs[i];

    if (!input.output)
      return false;

    args = bcoin.script.getArgs(input.output.script);

    if (args < 0)
      return false;

    stack = [];

    res = bcoin.script.execute(input.script, stack, this, i, flags);

    if (!res)
      return false;

    if ((flags & constants.flags.VERIFY_P2SH)
        && bcoin.script.isScripthash(input.output.script)) {
      if (stack.length === 0)
        return false;

      redeem = bcoin.script.getRedeem(stack);

      if (!redeem)
        return false;

      // Not accurate?
      if (bcoin.script.getSize(redeem) > 520)
        return false;

      // Also consider scripthash "unknown"?
      if (bcoin.script.getType(redeem) === 'unknown') {
        if (bcoin.script.getSigops(redeem, true) > maxSigops)
          return false;
        continue;
      }

      targs = bcoin.script.getArgs(redeem);
      if (targs < 0)
        return false;
      args += targs;
    }

    if (stack.length !== args)
      return false;
  }

  return true;
};

TX.prototype.maxSize = function maxSize() {
  return this.getSize();
};

TX.prototype.getPriority = function getPriority(size) {
  var sum, i, input, age, height;

  height = this.height;

  if (height === -1)
    height = null;

  if (!this.hasPrevout())
    return new bn(0);

  size = size || this.maxSize();
  sum = new bn(0);

  for (i = 0; i < this.inputs.length; i++) {
    input = this.inputs[i];

    if (!input.output)
      return new bn(0);

    age = input.output.getConfirmations(height);

    if (age === -1)
      age = 0;

    if (age !== 0)
      age += 1;

    sum.iadd(input.output.value.muln(age));
  }

  return sum.divn(size);
};

TX.prototype.isFree = function isFree(size) {
  var priority;

  if (!this.hasPrevout())
    return false;

  size = size || this.maxSize();

  if (size >= constants.tx.maxFreeSize)
    return false;

  priority = this.getPriority();

  return priority.cmp(constants.tx.freeThreshold) > 0;
};

TX.prototype.getHeight = function getHeight() {
  if (this.height !== -1)
    return this.height;

  if (!this.chain)
    return -1;

  return this.block ? this.chain.getHeight(this.block) : -1;
};

TX.prototype.getConfirmations = function getConfirmations(height) {
  var top, height;

  if (height == null) {
    if (!this.chain)
      return 0;

    top = this.chain.height;
  } else {
    top = height;
  }

  height = this.height;

  if (height === -1)
    return 0;

  if (top < height)
    return 1;

  return top - height + 1;
};

TX.prototype.getValue = function getValue() {
  return this.getOutputValue();
};

TX.prototype.hasType = function hasType(type) {
  for (var i = 0; i < this.inputs.length; i++) {
    if (bcoin.script.getInputType(this.inputs[i].script) === type)
      return true;
  }
  for (var i = 0; i < this.outputs.length; i++) {
    if (bcoin.script.getType(this.outputs[i].script) === type)
      return true;
  }
  return false;
};

TX.prototype.__defineGetter__('chain', function() {
  return this._chain || bcoin.chain.global;
});

TX.prototype.__defineGetter__('rblock', function() {
  return this.block
    ? utils.revHex(this.block)
    : null;
});

TX.prototype.__defineGetter__('rhash', function() {
  return utils.revHex(this.hash('hex'));
});

TX.prototype.__defineGetter__('fee', function() {
  return this.getFee();
});

TX.prototype.__defineGetter__('value', function() {
  return this.getValue();
});

TX.prototype.__defineGetter__('confirmations', function() {
  return this.getConfirmations();
});

TX.prototype.__defineGetter__('priority', function() {
  return this.getPriority();
});

TX.prototype.inspect = function inspect() {
  var copy = this.clone();
  copy.__proto__ = null;
  delete copy._raw;
  delete copy._chain;
  copy.hash = this.hash('hex');
  copy.rhash = this.rhash;
  copy.rblock = this.rblock;
  copy.value = utils.btc(this.getValue());
  copy.fee = utils.btc(this.getFee());
  copy.confirmations = this.getConfirmations();
  copy.priority = this.getPriority().toString(10);
  copy.date = new Date((copy.ts || 0) * 1000).toISOString();
  return copy;
};

TX.prototype.toCompact = function toCompact(coins) {
  return {
    type: 'tx',
    block: this.block,
    height: this.height,
    ts: this.ts,
    relayedBy: this.relayedBy,
    coins: coins ? this.inputs.map(function(input) {
      return input.output ? input.output.toRaw('hex') : null;
    }) : null,
    tx: utils.toHex(this.render())
  };
};

TX._fromCompact = function _fromCompact(json) {
  var raw, data, tx;

  assert.equal(json.type, 'tx');

  raw = new Buffer(json.tx, 'hex');
  data = new bcoin.protocol.parser().parseTX(raw);

  data.height = json.height;
  data.block = json.block;
  data.ts = json.ts;
  data.relayedBy = json.relayedBy;

  if (json.coins) {
    json.coins.forEach(function(output, i) {
      if (!output)
        return;

      data.inputs[i].output = bcoin.coin._fromRaw(output, 'hex');
    });
  }

  return data;
};

TX.fromCompact = function fromCompact(json) {
  return new TX(TX._fromCompact(json));
};

TX.prototype.toJSON = function toJSON() {
  return {
    type: 'tx',
    hash: utils.revHex(this.hash('hex')),
    height: this.height,
    block: this.block ? utils.revHex(this.block) : null,
    ts: this.ts,
    relayedBy: this.relayedBy,
    version: this.version,
    inputs: this.inputs.map(function(input) {
      return input.toJSON();
    }),
    outputs: this.outputs.map(function(output) {
      return output.toJSON();
    }),
    locktime: this.locktime
  };
};

TX._fromJSON = function fromJSON(json) {
  return {
    block: json.block ? utils.revHex(json.block) : null,
    height: json.height,
    ts: json.ts,
    relayedBy: json.relayedBy,
    version: json.version,
    inputs: json.inputs.map(function(input) {
      return bcoin.input._fromJSON(input);
    }),
    outputs: json.outputs.map(function(output) {
      return bcoin.output._fromJSON(output);
    }),
    locktime: json.locktime
  };
};

TX.fromJSON = function fromJSON(json) {
  return new TX(TX._fromJSON(json));
};

TX.prototype.toRaw = function toRaw(enc) {
  var data = this.render();

  if (enc === 'hex')
    data = utils.toHex(data);

  return data;
};

TX._fromRaw = function _fromRaw(data, enc) {
  var parser = new bcoin.protocol.parser();

  if (enc === 'hex')
    data = new Buffer(data, 'hex');

  return parser.parseTX(data);
};

TX.fromRaw = function fromRaw(data, enc) {
  return new bcoin.tx(TX._fromRaw(data, enc));
};

/**
 * Expose
 */

module.exports = TX;