'use strict';

var _ = require('lodash');
var constants = require('./constants');
var BN = require('bn.js');

var utils = {};

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

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

//main
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) {
  if (!startKey || !Buffer.isBuffer(startKey)) {
    return;
  }
  var bn = new BN(startKey);
  var endBN = bn.iaddn(1);
  return endBN.toBuffer();
};

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

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.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.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, pos) {
    object[key] = array.length;

    if (pos >= 0) {
      array[pos] = value;
    } else {
      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;