'use strict';

var bitcore = require('bitcore-lib');
var BufferUtil = bitcore.util.buffer;
var MAX_SAFE_INTEGER = 0x1fffffffffffff; // 2 ^ 53 - 1
var crypto = require('crypto');
var _ = require('lodash');
var constants = require('./constants');

var utils = {};
utils.isHash = function(value) {
  return typeof value === 'string' && value.length === 64 && /^[0-9a-fA-F]+$/.test(value);
};

utils.isSafeNatural = function(value) {
  return typeof value === 'number' &&
    isFinite(value) &&
    Math.floor(value) === value &&
    value >= 0 &&
    value <= MAX_SAFE_INTEGER;
};

utils.startAtZero = function(obj, key) {
  if (!obj.hasOwnProperty(key)) {
    obj[key] = 0;
  }
};

utils.isAbsolutePath = require('path').isAbsolute;
if (!utils.isAbsolutePath) {
  utils.isAbsolutePath = require('path-is-absolute');
}

utils.parseParamsWithJSON = function(paramsArg) {
  var params = paramsArg.map(function(paramArg) {
    var param;
    try {
      param = JSON.parse(paramArg);
    } catch(err) {
      param = paramArg;
    }
    return param;
  });
  return params;
};

utils.getTerminalKey = function(startKey) {
  var endKey = Buffer.from(startKey);
  endKey.writeUInt8(startKey.readUInt8(startKey.length - 1) + 1, startKey.length - 1);
  return endKey;
};

utils.diffTime = function(time) {
  var diff = process.hrtime(time);
  return (diff[0] * 1E9 + diff[1])/(1E9 * 1.0);
};

utils.reverseBufferToString = function(buf) {
  if (_.isString(buf)) {
    buf = new Buffer(buf, 'hex');
  }
  return BufferUtil.reverse(buf).toString('hex');
};

utils.getAddressString = function(opts) {

  if (!opts.item) {
    return;
  }

  // TODO: this does not handle P2PK correctly, it uses the address and not the
  // pubkey
  if (opts.address) {
    return address.toString();
  }

};

utils.sendError = function(err, res) {
  if (err.statusCode)  {
    res.status(err.statusCode).send(err.message);
  } else {
    console.error(err.stack);
    res.status(503).send(err.message);
  }
};

utils.getWalletId = exports.generateJobId = function() {
  return crypto.randomBytes(16).toString('hex');
};

utils.getWalletId = exports.generateJobId = function() {
  return crypto.randomBytes(16).toString('hex');
};

utils.toJSONL = function(obj) {
  var str = JSON.stringify(obj);
  str = str.replace(/\n/g, '');
  return str + '\n';
};

utils.normalizeTimeStamp = function(addressArg) {
  var addresses = [addressArg];
  if (Array.isArray(addressArg)) {
    addresses = addressArg;
  }
  return addresses;
};

utils.normalizeTimeStamp = function(value) {
  if (value > 0xffffffff) {
    value = Math.round(value/1000);
  }
  return value;
};

utils.delimitedStringParse = function(delim, str) {
  function tryJSONparse(str) {
    try {
      return JSON.parse(str);
    } catch(e) {
      return false;
    }
  }
  var ret = [];

  if (delim === null) {
    return tryJSONparse(str);
  }

  var list = str.split(delim);
  for(var i = 0; i < list.length; i++) {
    ret.push(tryJSONparse(list[i]));
  }
  ret = _.compact(ret);
  return ret.length === 0 ? false : ret;

};

utils.toIntIfNumberLike = function(a) {
  if (!/[^\d]+/.test(a)) {
    return parseInt(a);
  }
  return a;
};

utils.getBlockInfoString = function(tip, best) {

  var diff = best - tip;
  var astr = diff + ' blocks behind.';

  if (diff === -1) {
    astr = Math.abs(diff) + ' block ahead. Peer may be syncing or we may need to reorganize our chain after new blocks arrive.';
  } else if (diff < 1) {
    astr = Math.abs(diff) + ' blocks ahead. Peer may be syncing or we may need to reorganize our chain after new blocks arrive.';
  } else if (diff === 1) {
    astr = diff + ' block behind.';
  }

};
utils.joinListsOnIndex = function(indexList, list1, list2, direction) {

  var newChains = [];

  indexList.forEach(function(index) {
    var otherList = list2[index];
    if (direction && direction === 'reverse') {
      newChains.push(otherList.concat(list1));
    } else {
      newChains.push(list1.concat(otherList));
    }
  });

  return newChains;


};

utils.removeItemsByIndexList = function(indexList, list) {
  var ret = [];
  for(var i = 0; i < list.length; i++) {
    var item = list[i];
    if (indexList.indexOf(i) === -1) {
      ret.push(item);
    }
  }
  return ret;
};

utils.encodeTip = function(tip, name) {
  var key = Buffer.concat([ constants.DB_PREFIX,
    new Buffer('tip-' + name, 'utf8') ]);

  var heightBuf = new Buffer(4);
  heightBuf.writeUInt32BE(tip.height);

  var value = Buffer.concat([ heightBuf, new Buffer(tip.hash, 'hex') ]);
  return { key: key, value: value };

};

utils.isHeight = function(blockArg) {
  return _.isNumber(blockArg) || (blockArg.length < 40 && /^[0-9]+$/.test(blockArg))
};

utils.SimpleMap = function SimpleMap() {
  var object = {};
  var array = [];

  this.size = 0;
  this.length = 0;

  this.get = function (key) {
    return array[object[key]];
  };

  this.set = function (key, value) {
    object[key] = array.length;
    array.push(value);

    this.size = array.length;
    this.length = array.length;
  };

  this.getIndex = function (index) {
    return array[index];
  };

  this.getLastIndex = function () {
    return array[array.length - 1];
  };
};

module.exports = utils;