'use strict';

var BaseModule = require('../module');
var inherits = require('util').inherits;
var async = require('async');
var chainlib = require('chainlib');
var log = chainlib.log;
var errors = chainlib.errors;
var bitcore = require('bitcore');
var PublicKey = bitcore.PublicKey;
var Address = bitcore.Address;

var AddressModule = function(options) {
  BaseModule.call(this, options);

  this.txSubscriptions = {};
  this.balanceSubscriptions = {};
};

inherits(AddressModule, BaseModule);

AddressModule.PREFIXES = {
  OUTPUTS: 'outs'
};

AddressModule.prototype.getAPIMethods = function() {
  return [
    ['getBalance', this, this.getBalance, 2],
    ['getOutputs', this, this.getOutputs, 2],
    ['getUnspentOutputs', this, this.getUnspentOutputs, 2],
    ['isSpent', this, this.isSpent, 2]
  ];
};

AddressModule.prototype.getEvents = function() {
  return [
    ['transaction', this, this.subscribeTransaction, this.unsubscribeTransaction],
    ['balance', this, this.subscribeBalance, this.unsubscribeBalance]
  ];
};

AddressModule.prototype.blockHandler = function(block, addOutput, callback) {
  var txs = this.db.getTransactionsFromBlock(block);

  log.debug('Updating output index');

  var action = 'put';
  if (!addOutput) {
    action = 'del';
  }

  var operations = [];

  for (var i = 0; i < txs.length; i++) {

    var tx = txs[i];
    var txid = tx.id;
    var inputs = tx.inputs;
    var outputs = tx.outputs;

    for (var j = 0; j < outputs.length; j++) {
      var output = outputs[j];

      var script = output.script;
      if(!script) {
        log.debug('Invalid script');
        continue;
      }

      if (!script.isPublicKeyHashOut() && !script.isScriptHashOut() && !script.isPublicKeyOut()) {
        // ignore for now
        log.debug('script was not pubkeyhashout, scripthashout, or pubkeyout');
        continue;
      }

      var address;

      if(script.isPublicKeyOut()) {
        var pubkey = script.chunks[0].buf;
        address = Address.fromPublicKey(new PublicKey(pubkey), this.db.network);
      } else {
        address = output.script.toAddress(this.db.network);
      }

      var outputIndex = j;

      var timestamp = block.timestamp.getTime();
      var height = block.__height;

      operations.push({
        type: action,
        key: [AddressModule.PREFIXES.OUTPUTS, address, timestamp, txid, outputIndex].join('-'),
        value: [output.satoshis, script, height].join(':')
      });

      if(self.txSubscriptions[address]) {
        var subscriptions = self.txSubscriptions[address];
        for(var i = 0; i < subscriptions.length; i++) {
          subscriptions[i].emit('transaction', tx);
        }
      }

      if(self.balanceSubscriptions[address]) {
        var emitters = self.balanceSubsriptions[address];
        self.getBalance(address, true, function(err, balance) {
          if(err) {
            return self.emit(err);
          }

          for(var i = 0; i < subscriptions.length; i++) {
            emitters[i].emit('balance', address, balance, block);
          }
        });
      }
    }

    if(tx.isCoinbase()) {
      continue;
    }

  }

  setImmediate(function() {
    callback(null, operations);
  });
};

AddressModule.prototype.subscribeTransaction = function(emitter, addresses) {
  for(var i = 0; i < addresses.length; i++) {
    if(!this.txSubscriptions[addresses[i]]) {
      this.txSubscriptions[addresses[i]] = [];
    }

    this.txSubscriptions[addresses[i]].push(emitter);
  }
};

AddressModule.prototype.subscribeBalance = function(emitter, addresses) {
  for(var i = 0; i < addresses.length; i++) {
    if(!this.balanceSubscriptions[addresses[i]]) {
      this.balanceSubscriptions[addresses[i]] = [];
    }

    this.balanceSubscriptions[addresses[i]].push(emitter);
  }
};

AddressModule.prototype.unsubscribeTransaction = function(emitter, addresses) {
  for(var i = 0; i < addresses.length; i++) {
    if(this.txSubscriptions[addresses[i]]) {
      var emitters = self.txSubscriptions[addresses[i]];
      var index = emitters.indexOf(emitter);
      if(index > -1) {
        emitters.splice(index, 1);
      }
    }
  }
};

AddressModule.prototype.unsubscribeBalance = function(emitter, addresses) {
  for(var i = 0; i < addresses.length; i++) {
    if(this.balanceSubscriptions[addresses[i]]) {
      var emitters = self.balanceSubscriptions[addresses[i]];
      var index = emitters.indexOf(emitter);
      if(index > -1) {
        emitters.splice(index, 1);
      }
    }
  }
};

AddressModule.prototype.getBalance = function(address, queryMempool, callback) {
  this.getUnspentOutputs(address, queryMempool, function(err, outputs) {
    if(err) {
      return callback(err);
    }

    var satoshis = outputs.map(function(output) {
      return output.satoshis;
    });

    var sum = satoshis.reduce(function(a, b) {
      return a + b;
    }, 0);

    return callback(null, sum);
  });
};

AddressModule.prototype.getOutputs = function(address, queryMempool, callback) {
  var self = this;

  var outputs = [];
  var key = [AddressModule.PREFIXES.OUTPUTS, address].join('-');

  var stream = this.db.store.createReadStream({
    start: key,
    end: key + '~'
  });

  stream.on('data', function(data) {

    var key = data.key.split('-');
    var value = data.value.split(':');

    var output = {
      address: key[1],
      txid: key[3],
      outputIndex: Number(key[4]),
      satoshis: Number(value[0]),
      script: value[1],
      blockHeight: Number(value[2])
    };

    outputs.push(output);

  });

  var error;

  stream.on('error', function(streamError) {
    if (streamError) {
      error = streamError;
    }
  });

  stream.on('close', function() {
    if (error) {
      return callback(error);
    }

    if(queryMempool) {
      outputs = outputs.concat(self.db.bitcoind.getMempoolOutputs(address));
    }

    callback(null, outputs);
  });

  return stream;

};

AddressModule.prototype.getUnspentOutputs = function(address, queryMempool, callback) {

  var self = this;

  this.getOutputs(address, queryMempool, function(err, outputs) {
    if (err) {
      return callback(err);
    } else if(!outputs.length) {
      return callback(new errors.NoOutputs('Address ' + address + ' has no outputs'), []);
    }

    var isUnspent = function(output, callback) {
      self.isUnspent(output, queryMempool, callback);
    };

    async.filter(outputs, isUnspent, function(results) {
      callback(null, results);
    });
  });
};

AddressModule.prototype.isUnspent = function(output, queryMempool, callback) {
  this.isSpent(output, queryMempool, function(spent) {
    callback(!spent);
  });
};

AddressModule.prototype.isSpent = function(output, queryMempool, callback) {
  var self = this;
  var txid = output.prevTxId ? output.prevTxId.toString('hex') : output.txid;

  setImmediate(function() {
    callback(self.db.bitcoind.isSpent(txid, output.outputIndex));
  });
};

module.exports = AddressModule;