/*!
 * Sitemap
 * Copyright(c) 2011 Eugene Kalinin
 * MIT Licensed
 */

var _ = require('underscore');

/**
 * Exit with the given `str`.
 *
 * @param {String} str
 */
exports.abort = function (str) {
  console.error(str);
  process.exit(1);
}

/**
 * Escapes special characters in text.
 *
 * @param {String} text
 */
exports.htmlEscape = function (text) {
   return text.replace(/&/g,'&').
     replace(/</g,'&lt;').
     replace(/>/g,'&gt;').
     replace(/"/g,'&quot;').
     replace(/'/g,'&#039;');
}

/**
 *  Pads the left-side of a string with a specific
 *  set of characters.
 *
 *  @param {Object} n
 *  @param {Number} len
 *  @param {String} chr
 */
exports.lpad = function (n, len, chr) {
  var res = n.toString()
    , chr = chr || '0'
    , leading = (res.substr(0, 1) === '-') ? true : false;

  //If left side of string is a minus sign (negative number), we want to ignore that in the padding process
  if(leading){
    res = res.substr(1); //cut-off the leading '-'
  }

  while (res.length < len) {
    res = chr + res;
  }

  if(leading){ //If we initially cutoff the leading '-', we add it again here
    res = '-' + res;
  }

  return res;
}

/**
 *
 * @param {Array} arr
 */
exports.distinctArray = function (arr) {
    var hash = {}
      , res = []
      , arr_length = arr.length;
    while (arr_length-- ) {
        hash[arr[arr_length]] = true;
    }
    for (key in hash) {
        res.push(key);
    }
    return res;
}

exports.chunkArray = function(arr, chunkSize) {
  var lists = _.groupBy(arr, function(element, index) {
    return Math.floor(index/chunkSize);
  });
  lists = _.toArray(lists);
  return lists;
}

exports.getTimestamp = function() {
  return (new Date()).getTime();
}

exports.getTimestampFromDate = function(dt, bRealtime) {
  var timestamp =[ dt.getFullYear(), exports.lpad(dt.getMonth()+1, 2),
                    exports.lpad(dt.getDate(), 2) ].join('-');

  // Indicate that lastmod should include minutes and seconds (and timezone)
  if ( bRealtime && bRealtime === true ) {
      timestamp += 'T';
      timestamp += [ exports.lpad(dt.getHours(), 2),
                        exports.lpad(dt.getMinutes(), 2),
                        exports.lpad(dt.getSeconds(), 2)
                      ].join(':');
      timestamp += ( dt.getTimezoneOffset() >= 0 ? '+' : '');
      timestamp += [ exports.lpad(parseInt(dt.getTimezoneOffset()/60, 10 ), 2),
                        exports.lpad(dt.getTimezoneOffset() % 60, 2)
                      ].join ( ':' );
  }

  return timestamp;

}