/*
 * Copyright (C) 2004 Baron Schwartz <baron at sequent dot org>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by the
 * Free Software Foundation, version 2.1.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 */

Date.parseFunctions = {count:0};
Date.parseRegexes = [];
Date.formatFunctions = {count:0};

Date.prototype.dateFormat = function(format) {
 if (Date.formatFunctions[format] == null) {
 Date.createNewFormat(format);
 }
 var func = Date.formatFunctions[format];
 return this[func]();
}

Date.createNewFormat = function(format) {
 var funcName = "format" + Date.formatFunctions.count++;
 Date.formatFunctions[format] = funcName;
 var code = "Date.prototype." + funcName + " = function(){return ";
 var special = false;
 var ch = '';
 for (var i = 0; i < format.length; ++i) {
 ch = format.charAt(i);
 if (!special && ch == "\\") {
 special = true;
 }
 else if (special) {
 special = false;
 code += "'" + String.escape(ch) + "' + ";
 }
 else {
 code += Date.getFormatCode(ch);
 }
 }
 eval(code.substring(0, code.length - 3) + ";}");
}

Date.getFormatCode = function(character) {
 switch (character) {
 case "d":
 return "String.leftPad(this.getDate(), 2, '0') + ";
 case "D":
 return "Date.dayNames[this.getDay()].substring(0, 3) + ";
 case "j":
 return "this.getDate() + ";
 case "l":
 return "Date.dayNames[this.getDay()] + ";
 case "S":
 return "this.getSuffix() + ";
 case "w":
 return "this.getDay() + ";
 case "z":
 return "this.getDayOfYear() + ";
 case "W":
 return "this.getWeekOfYear() + ";
 case "F":
 return "Date.monthNames[this.getMonth()] + ";
 case "m":
 return "String.leftPad(this.getMonth() + 1, 2, '0') + ";
 case "M":
 return "Date.monthNames[this.getMonth()].substring(0, 3) + ";
 case "n":
 return "(this.getMonth() + 1) + ";
 case "t":
 return "this.getDaysInMonth() + ";
 case "L":
 return "(this.isLeapYear() ? 1 : 0) + ";
 case "Y":
 return "this.getFullYear() + ";
 case "y":
 return "('' + this.getFullYear()).substring(2, 4) + ";
 case "a":
 return "(this.getHours() < 12 ? 'am' : 'pm') + ";
 case "A":
 return "(this.getHours() < 12 ? 'AM' : 'PM') + ";
 case "g":
 return "((this.getHours() %12) ? this.getHours() % 12 : 12) + ";
 case "G":
 return "this.getHours() + ";
 case "h":
 return "String.leftPad((this.getHours() %12) ? this.getHours() % 12 : 12, 2, '0') + ";
 case "H":
 return "String.leftPad(this.getHours(), 2, '0') + ";
 case "i":
 return "String.leftPad(this.getMinutes(), 2, '0') + ";
 case "s":
 return "String.leftPad(this.getSeconds(), 2, '0') + ";
 case "O":
 return "this.getGMTOffset() + ";
 case "T":
 return "this.getTimezone() + ";
 case "Z":
 return "(this.getTimezoneOffset() * -60) + ";
 default:
 return "'" + String.escape(character) + "' + ";
 }
}

Date.parseDate = function(input, format) {
 if (Date.parseFunctions[format] == null) {
 Date.createParser(format);
 }
 var func = Date.parseFunctions[format];
 return Date[func](input);
}

Date.createParser = function(format) {
 var funcName = "parse" + Date.parseFunctions.count++;
 var regexNum = Date.parseRegexes.length;
 var currentGroup = 1;
 Date.parseFunctions[format] = funcName;

 var code = "Date." + funcName + " = function(input){\n"
 + "var y = -1, m = -1, d = -1, h = -1, i = -1, s = -1;\n"
 + "var d = new Date();\n"
 + "y = d.getFullYear();\n"
 + "m = d.getMonth();\n"
 + "d = d.getDate();\n"
 + "var results = input.match(Date.parseRegexes[" + regexNum + "]);\n"
 + "if (results && results.length > 0) {"
 var regex = "";

 var special = false;
 var ch = '';
 for (var i = 0; i < format.length; ++i) {
 ch = format.charAt(i);
 if (!special && ch == "\\") {
 special = true;
 }
 else if (special) {
 special = false;
 regex += String.escape(ch);
 }
 else {
 obj = Date.formatCodeToRegex(ch, currentGroup);
 currentGroup += obj.g;
 regex += obj.s;
 if (obj.g && obj.c) {
 code += obj.c;
 }
 }
 }

 code += "if (y > 0 && m >= 0 && d > 0 && h >= 0 && i >= 0 && s >= 0)\n"
 + "{return new Date(y, m, d, h, i, s);}\n"
 + "else if (y > 0 && m >= 0 && d > 0 && h >= 0 && i >= 0)\n"
 + "{return new Date(y, m, d, h, i);}\n"
 + "else if (y > 0 && m >= 0 && d > 0 && h >= 0)\n"
 + "{return new Date(y, m, d, h);}\n"
 + "else if (y > 0 && m >= 0 && d > 0)\n"
 + "{return new Date(y, m, d);}\n"
 + "else if (y > 0 && m >= 0)\n"
 + "{return new Date(y, m);}\n"
 + "else if (y > 0)\n"
 + "{return new Date(y);}\n"
 + "}return null;}";

 Date.parseRegexes[regexNum] = new RegExp("^" + regex + "$");
 eval(code);
}

Date.formatCodeToRegex = function(character, currentGroup) {
 switch (character) {
 case "D":
 return {g:0,
 c:null,
 s:"(?:Sun|Mon|Tue|Wed|Thu|Fri|Sat)"};
 case "j":
 case "d":
 return {g:1,
 c:"d = parseInt(results[" + currentGroup + "], 10);\n",
 s:"(\\d{1,2})"};
 case "l":
 return {g:0,
 c:null,
 s:"(?:" + Date.dayNames.join("|") + ")"};
 case "S":
 return {g:0,
 c:null,
 s:"(?:st|nd|rd|th)"};
 case "w":
 return {g:0,
 c:null,
 s:"\\d"};
 case "z":
 return {g:0,
 c:null,
 s:"(?:\\d{1,3})"};
 case "W":
 return {g:0,
 c:null,
 s:"(?:\\d{2})"};
 case "F":
 return {g:1,
 c:"m = parseInt(Date.monthNumbers[results[" + currentGroup + "].substring(0, 3)], 10);\n",
 s:"(" + Date.monthNames.join("|") + ")"};
 case "M":
 return {g:1,
 c:"m = parseInt(Date.monthNumbers[results[" + currentGroup + "]], 10);\n",
 s:"(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)"};
 case "n":
 case "m":
 return {g:1,
 c:"m = parseInt(results[" + currentGroup + "], 10) - 1;\n",
 s:"(\\d{1,2})"};
 case "t":
 return {g:0,
 c:null,
 s:"\\d{1,2}"};
 case "L":
 return {g:0,
 c:null,
 s:"(?:1|0)"};
 case "Y":
 return {g:1,
 c:"y = parseInt(results[" + currentGroup + "], 10);\n",
 s:"(\\d{4})"};
 case "y":
 return {g:1,
 c:"var ty = parseInt(results[" + currentGroup + "], 10);\n"
 + "y = ty > Date.y2kYear ? 1900 + ty : 2000 + ty;\n",
 s:"(\\d{1,2})"};
 case "a":
 return {g:1,
 c:"if (results[" + currentGroup + "] == 'am') {\n"
 + "if (h == 12) { h = 0; }\n"
 + "} else { if (h < 12) { h += 12; }}",
 s:"(am|pm)"};
 case "A":
 return {g:1,
 c:"if (results[" + currentGroup + "] == 'AM') {\n"
 + "if (h == 12) { h = 0; }\n"
 + "} else { if (h < 12) { h += 12; }}",
 s:"(AM|PM)"};
 case "g":
 case "G":
 case "h":
 case "H":
 return {g:1,
 c:"h = parseInt(results[" + currentGroup + "], 10);\n",
 s:"(\\d{1,2})"};
 case "i":
 return {g:1,
 c:"i = parseInt(results[" + currentGroup + "], 10);\n",
 s:"(\\d{2})"};
 case "s":
 return {g:1,
 c:"s = parseInt(results[" + currentGroup + "], 10);\n",
 s:"(\\d{2})"};
 case "O":
 return {g:0,
 c:null,
 s:"[+-]\\d{4}"};
 case "T":
 return {g:0,
 c:null,
 s:"[A-Z]{3}"};
 case "Z":
 return {g:0,
 c:null,
 s:"[+-]\\d{1,5}"};
 default:
 return {g:0,
 c:null,
 s:String.escape(character)};
 }
}

Date.prototype.getTimezone = function() {
 return this.toString().replace(
 /^.*? ([A-Z]{3}) [0-9]{4}.*$/, "$1").replace(
 /^.*?\(([A-Z])[a-z]+ ([A-Z])[a-z]+ ([A-Z])[a-z]+\)$/, "$1$2$3");
}

Date.prototype.getGMTOffset = function() {
 return (this.getTimezoneOffset() > 0 ? "-" : "+")
 + String.leftPad(Math.floor(this.getTimezoneOffset() / 60), 2, "0")
 + String.leftPad(this.getTimezoneOffset() % 60, 2, "0");
}

Date.prototype.getDayOfYear = function() {
 var num = 0;
 Date.daysInMonth[1] = this.isLeapYear() ? 29 : 28;
 for (var i = 0; i < this.getMonth(); ++i) {
 num += Date.daysInMonth[i];
 }
 return num + this.getDate() - 1;
}

Date.prototype.getWeekOfYear = function() {
 // Skip to Thursday of this week
 var now = this.getDayOfYear() + (4 - this.getDay());
 // Find the first Thursday of the year
 var jan1 = new Date(this.getFullYear(), 0, 1);
 var then = (7 - jan1.getDay() + 4);
 document.write(then);
 return String.leftPad(((now - then) / 7) + 1, 2, "0");
}

Date.prototype.isLeapYear = function() {
 var year = this.getFullYear();
 return ((year & 3) == 0 && (year % 100 || (year % 400 == 0 && year)));
}

Date.prototype.getFirstDayOfMonth = function() {
 var day = (this.getDay() - (this.getDate() - 1)) % 7;
 return (day < 0) ? (day + 7) : day;
}

Date.prototype.getLastDayOfMonth = function() {
 var day = (this.getDay() + (Date.daysInMonth[this.getMonth()] - this.getDate())) % 7;
 return (day < 0) ? (day + 7) : day;
}

Date.prototype.getDaysInMonth = function() {
 Date.daysInMonth[1] = this.isLeapYear() ? 29 : 28;
 return Date.daysInMonth[this.getMonth()];
}

Date.prototype.getSuffix = function() {
 switch (this.getDate()) {
 case 1:
 case 21:
 case 31:
 return "st";
 case 2:
 case 22:
 return "nd";
 case 3:
 case 23:
 return "rd";
 default:
 return "th";
 }
}

String.escape = function(string) {
 return string.replace(/('|\\)/g, "\\$1");
}

String.leftPad = function (val, size, ch) {
 var result = new String(val);
 if (ch == null) {
 ch = " ";
 }
 while (result.length < size) {
 result = ch + result;
 }
 return result;
}

Date.daysInMonth = [31,28,31,30,31,30,31,31,30,31,30,31];
Date.monthNames =
 ["January",
 "February",
 "March",
 "April",
 "May",
 "June",
 "July",
 "August",
 "September",
 "October",
 "November",
 "December"];
Date.dayNames =
 ["Sunday",
 "Monday",
 "Tuesday",
 "Wednesday",
 "Thursday",
 "Friday",
 "Saturday"];
Date.y2kYear = 50;
Date.monthNumbers = {
 Jan:0,
 Feb:1,
 Mar:2,
 Apr:3,
 May:4,
 Jun:5,
 Jul:6,
 Aug:7,
 Sep:8,
 Oct:9,
 Nov:10,
 Dec:11};
Date.patterns = {
 ISO8601LongPattern:"Y-m-d H:i:s",
 ISO8601ShortPattern:"Y-m-d",
 ShortDatePattern: "n/j/Y",
 LongDatePattern: "l, F d, Y",
 FullDateTimePattern: "l, F d, Y g:i:s A",
 MonthDayPattern: "F d",
 ShortTimePattern: "g:i A",
 LongTimePattern: "g:i:s A",
 SortableDateTimePattern: "Y-m-d\\TH:i:s",
 UniversalSortableDateTimePattern: "Y-m-d H:i:sO",
 YearMonthPattern: "F, Y"};