'use strict';

var Encoding = require('./encoding');

var inherits = require('util').inherits;
var LRU = require('lru-cache');
var utils = require('../../../lib/utils');

/*

1. getAddressSummary
2. getAddressUnspentOutputs
3. bitcoind.height
4. getBlockHeader
5. getDetailedTransaction
6. getTransaction
7. sendTransaction
8. getInfo
9. bitcoind.tiphash
10. getBestBlockHash
11. isSynced
12. getAddressHistory
13. getBlock
14. getRawBlock
15. getBlockHashesByTimestamp
16. estimateFee
17. getBlockOverview
18. syncPercentage

*/
function TimestampService(options) {
  BaseService.call(this, options);
  this._db = this.node.services.db;
  this._tip = null;
}

inherits(TimestampService, BaseService);

TimestampService.dependencies = [ 'db', 'block' ];

TimestampService.prototype.getAPIMethods = function() {
  return [
    ['getBlockHashesByTimestamp', this, this.getBlockHashesByTimestamp, 2],
    ['syncPercentage', this, this.syncPercentage, 0]
  ];
};

TimestampService.prototype.syncPercentage = function(callback) {
  return callback(null, ((this._tip.height / this._block.getBestBlockHeight()) * 100).toFixed(2) + '%');
};

TimestampService.prototype.getBlockHashesByTimestamp = function(callback) {
};

TimestampService.prototype.start = function(callback) {
  var self = this;
  self._setListeners();

  self._db.getPrefix(self.name, function(err, prefix) {

    if(err) {
      return callback(err);
    }

    self._prefix = prefix;
    self._encoding = new Encoding(self._prefix);

    self._db.getServiceTip(self.name, function(err, tip) {

      if (err) {
        return callback(err);
      }

      self._tip = tip;
      self._startSubscriptions();
      callback();

    });
  });

};

TimestampService.prototype._startSubscriptions = function() {

  if (this._subscribed) {
    return;
  }

  this._subscribed = true;
  if (!this._bus) {
    this._bus = this.node.openBus({remoteAddress: 'localhost'});
  }

  this._bus.on('block/block', this._onBlock.bind(this));
  this._bus.subscribe('block/block');
};

BlockService.prototype._sync = function() {

  if (--this._p2pBlockCallsNeeded > 0) {

    log.info('Blocks download progress: ' + this._numCompleted + '/' +
      this._numNeeded + '  (' + (this._numCompleted/this._numNeeded*100).toFixed(2) + '%)');
    this._p2p.getBlocks({ startHash: this._latestBlockHash });
    return;

  }

};
TimestampService.prototype._setListeners = function() {

  var self = this;

  self._db.on('error', self._onDbError.bind(self));
  self.on('reorg', self._handleReorg.bind(self));

};

TimestampService.prototype._setTip = function(tip) {
  log.debug('Timestamp Service: Setting tip to height: ' + tip.height);
  log.debug('Timestamp Service: Setting tip to hash: ' + tip.hash);
  this._tip = tip;
  this._db.setServiceTip('block', this._tip);
};

TimestampService.prototype.stop = function(callback) {
  setImmediate(callback);
};

TimestampService.prototype._onBlock = function(block) {


  var prevHash = utils.reverseBufferToString(block.header.prevHash);

  var operations = [];

  operations = operations.concat([
    {
      type: action,
      key: self.encoding.encodeTimestampBlockKey(item.value),
      value: self.encoding.encodeTimestampBlockValue(item.key)
    },
    {
      type: action,
      key: self.encoding.encodeBlockTimestampKey(item.key),
      value: self.encoding.encodeBlockTimestampValue(item.value)
    }
  ]);

  callback(null, operations);

};

TimestampService.prototype.getTimestamp = function(hash, callback) {
  this._getValue(hash, callback);
};

TimestampService.prototype.getHash = function(timestamp, callback) {
  this._getValue(timestamp, callback);
};

TimestampService.prototype._getValue = function(key, callback) {

  var self = this;
  var keyBuf, fn;

  if (key.length === 64){
    keyBuf = self.encoding.encodeBlockTimestampKey(key);
    fn = self.encoding.decodeBlockTimestampValue;
  } else {
    keyBuf = self.encoding.encodeTimestampBlockKey(key);
    fn = self.encoding.decodeTimestampBlockValue;
  }

  self.db.get(keyBuf, function(err, value) {

    if (err) {
      return callback(err);
    }

    callback(null, fn(value));

  });
};

TimestampService.prototype._onReorg = function(commonAncestor, newBlockList) {
};

TimestampService.prototype.getBlockHashesByTimestamp = function(high, low, options, callback) {

  var self = this;
  if (_.isFunction(options)) {
    callback = options;
    options = {};
  }

};

module.exports = TimestampService;