/**
 * DateFormatter
 * 
 * @website http://clonedoppelganger.net/
 * @version 0.0.1
 * 
 * Example:
 *  var now = new Date();
 *  alert(DateFormatter.format(now, "Y/m/d H:i:s"));
 */
var DateFormatter = {

  /**
   * format
   * @param  {Date} target date object
   *         {String} pattern
   *  Y : A full numeric representation of a year, 4 digits
   *  y : A two digit representation of a year
   *  m : Numeric representation of a month, with leading zeros
   *  n : Numeric representation of a month, without leading zeros
   *  F : A full textual representation of a month, such as January or March
   *  M : A short textual representation of a month, three letters
   *  O : Japanese old month name
   *  d : Day of the month, 2 digits with leading zeros
   *  j : Day of the month without leading zeros
   *  w : Numeric representation of the day of the week
   *  l : A full textual representation of the day of the week
   *  D : A textual representation of a day, three letters
   *  N : ISO-8601 numeric representation of the day of the week
   *  J : A Japanese textual representation of the day of the week
   *  g : 12-hour format of an hour without leading zeros
   *  G : 24-hour format of an hour without leading zeros
   *  h : 12-hour format of an hour with leading zeros
   *  H : 24-hour format of an hour with leading zeros
   *  i : Minutes with leading zeros
   *  s : Seconds, with leading zeros
   *  a : Lowercase Ante meridiem and Post meridiem (am or pm)
   *  A : Uppercase Ante meridiem and Post meridiem ???AM or PM???
   *  S : English ordinal suffix for the day of the month, 2 characters
   *  z : The day of the year (starting from 0)
   *  t : Number of days in the given month
   *  L : Whether it's a leap year
   *  Escape character is #. Example: DateFormatter.format(new Date(), "#Y#m#d #i#s Ymd");
   * @return {String} formatted date
   */
  format: function(d, pattern) {
    if (typeof pattern != "string") return;
    var dYear = d.getFullYear();
    var dMonth = d.getMonth();
    var dDate = d.getDate();
    var dDay = d.getDay();
    var dHours = d.getHours();
    var dMinutes = d.getMinutes();
    var dSeconds = d.getSeconds();
    var res = "";
    for (var i = 0, len = pattern.length; i < len; i++) {
      var c = pattern.charAt(i);
      switch (c) {
        case "#": 
          if (i == len - 1) break;
          res += pattern.charAt(++i);
          break;
        case "Y": res += dYear; break;
        case "y": res += dYear.toString().substr(2, 2); break;
        case "m": res += this.preZero(dMonth + 1); break;
        case "n": res += dMonth + 1; break;
        case "d": res += this.preZero(dDate); break;
        case "j": res += dDate; break;
        case "w": res += dDay; break;
        case "N": res += this.isoDay(dDay); break
        case "l": res += this.weekFull_nl[dDay]; break;
        case "D": res += this.weekFull_nl[dDay].substr(0, 3); break;
        case "J": res += this.weekJp[dDay]; break;
        case "F": res += this.monthFull_nl[dMonth]; break;
        case "M": res += this.monthFull_nl[dMonth].substr(0, 3); break;
        case "O": res += this.monthOldJp[dMonth]; break;
        case "a": res += this.ampm(dHours); break;
        case "A": res += this.ampm(dHours).toUpperCase(); break;
        case "H": res += this.preZero(dHours); break;
        case "h": res += this.preZero(this.from24to12(dHours)); break;
        case "g": res += this.from24to12(dHours); break;
        case "G": res += dHours; break;
        case "i": res += this.preZero(dMinutes); break;
        case "s": res += this.preZero(dSeconds); break;
        case "t": res += this.lastDayOfMonth(d); break;
        case "L": res += this.isLeapYear(dYear); break;
        case "z": res += this.dateCount(dYear, dMonth, dDate); break;
        case "S": res += this.dateSuffix[dDate - 1]; break;
        default : res += c; break;
      }
    }
    return res;
  },

  weekFull_en: ["Sunday","Monday","Tuesday", "Wednesday","Thursday","Friday","Saturday"],

  weekFull_nl: ["zondag","maandag","dinsdag","woensdag","donderdag","vrijdag","zaterdag"],

  monthFull_en: ["January", "February", "March", "April", "May", "June",
    "July", "August", "September", "October", "November", "December"],

  monthFull_nl: ["januari", "februari", "maart", "april", "mei", "juni",
    "juli", "augustus", "september", "oktober", "november", "december"],

  dateSuffix_en: [
    "st", "nd", "rd", "th", "th", "th", "th", "th", "th", "th",
    "th", "th", "th", "th", "th", "th", "th", "th", "th", "th",
    "st", "nd", "rd", "th", "th", "th", "th", "th", "th", "th", "st"],

  preZero: function(value) {
    return (parseInt(value) < 10) ? "0" + value : value;
  },

  from24to12: function(hours) {
    return (hours > 12) ? hours - 12 : hours;
  },

  ampm: function(hours) {
    return (hours < 12) ? "am" : "pm";
  },

  isoDay: function(day) {
    return (day == 0) ? "7" : day;
  },

  startWeekDay : function(dateObj) {
    var tmp = new Date(dateObj.getFullYear(), dateObj.getMonth(), 1);
    return tmp.getDay();
  },

  lastDayOfMonth: function(dateObj) {
    var tmp = new Date(dateObj.getFullYear(), dateObj.getMonth() + 1, 1);
    tmp.setTime(tmp.getTime() - 1);
    return tmp.getDate();
  },

  isLeapYear: function(year) {
    var tmp = new Date(year, 0, 1);
    var sum = 0;
    for (var i = 0; i < 12; i++) {
      tmp.setMonth(i);
      sum += this.lastDayOfMonth(tmp);
    }
    return (sum == 365) ? "0" : "1";
  },

  dateCount: function(year, month, date) {
    var tmp = new Date(year, 0, 1);
    var sum = -1;
    for (var i = 0; i < month; i++) {
      tmp.setMonth(i);
      sum += this.lastDayOfMonth(tmp);
    }
    return sum + date;
  }
}