/*\
title: $:/core/modules/utils/utils.js
type: application/javascript
module-type: utils

Various static utility functions.

\*/
(function(){

/*jslint node: true, browser: true */
/*global $tw: false */
"use strict";

/*
Push entries onto an array, removing them first if they already exist in the array
	array: array to modify
	value: a single value to push or an array of values to push
*/
exports.pushTop = function(array,value) {
	var t,p;
	if($tw.utils.isArray(value)) {
		// Remove any array entries that are duplicated in the new values
		for(t=0; t<value.length; t++) {
			p = array.indexOf(value[t]);
			if(p !== -1) {
				array.splice(p,1);
			}
		}
		// Push the values on top of the main array
		array.push.apply(array,value);
	} else {
		p = array.indexOf(value);
		if(p !== -1) {
			array.splice(p,1);
		}
		array.push(value);
	}
};

/*
Remove entries from an array
	array: array to modify
	value: a single value to remove, or an array of values to remove
*/
exports.removeArrayEntries = function(array,value) {
	var t,p;
	if($tw.utils.isArray(value)) {
		for(t=0; t<value.length; t++) {
			p = array.indexOf(value[t]);
			if(p !== -1) {
				array.splice(p,1);
			}
		}
	} else {
		p = array.indexOf(value);
		if(p !== -1) {
			array.splice(p,1);
		}
	}
};

exports.deepCopy = function(object) {
	var result,t;
	if($tw.utils.isArray(object)) {
		// Copy arrays
		result = object.slice(0);
	} else if(typeof object === "object") {
		result = {};
		for(t in object) {
			if(object[t] !== undefined) {
				result[t] = $tw.utils.deepCopy(object[t]);
			}
		}
	} else {
		result = object;
	}
	return result;
};

exports.extendDeepCopy = function(object,extendedProperties) {
	var result = $tw.utils.deepCopy(object),t;
	for(t in extendedProperties) {
		if(extendedProperties[t] !== undefined) {
			result[t] = $tw.utils.deepCopy(extendedProperties[t]);
		}
	}
	return result;
};

exports.formatDateString = function (date,template) {
	var t = template.replace(/0hh12/g,$tw.utils.pad($tw.utils.getHours12(date)));
	t = t.replace(/hh12/g,$tw.utils.getHours12(date));
	t = t.replace(/0hh/g,$tw.utils.pad(date.getHours()));
	t = t.replace(/hh/g,date.getHours());
	t = t.replace(/mmm/g,$tw.config.dateFormats.shortMonths[date.getMonth()]);
	t = t.replace(/0mm/g,$tw.utils.pad(date.getMinutes()));
	t = t.replace(/mm/g,date.getMinutes());
	t = t.replace(/0ss/g,$tw.utils.pad(date.getSeconds()));
	t = t.replace(/ss/g,date.getSeconds());
	t = t.replace(/[ap]m/g,$tw.utils.getAmPm(date).toLowerCase());
	t = t.replace(/[AP]M/g,$tw.utils.getAmPm(date).toUpperCase());
	t = t.replace(/wYYYY/g,$tw.utils.getYearForWeekNo(date));
	t = t.replace(/wYY/g,$tw.utils.pad($tw.utils.getYearForWeekNo(date)-2000));
	t = t.replace(/YYYY/g,date.getFullYear());
	t = t.replace(/YY/g,$tw.utils.pad(date.getFullYear()-2000));
	t = t.replace(/MMM/g,$tw.config.dateFormats.months[date.getMonth()]);
	t = t.replace(/0MM/g,$tw.utils.pad(date.getMonth()+1));
	t = t.replace(/MM/g,date.getMonth()+1);
	t = t.replace(/0WW/g,$tw.utils.pad($tw.utils.getWeek(date)));
	t = t.replace(/WW/g,$tw.utils.getWeek(date));
	t = t.replace(/DDD/g,$tw.config.dateFormats.days[date.getDay()]);
	t = t.replace(/ddd/g,$tw.config.dateFormats.shortDays[date.getDay()]);
	t = t.replace(/0DD/g,$tw.utils.pad(date.getDate()));
	t = t.replace(/DDth/g,date.getDate()+$tw.utils.getDaySuffix(date));
	t = t.replace(/DD/g,date.getDate());
	var tz = date.getTimezoneOffset();
	var atz = Math.abs(tz);
	t = t.replace(/TZD/g,(tz < 0 ? '+' : '-') + $tw.utils.pad(Math.floor(atz / 60)) + ':' + $tw.utils.pad(atz % 60));
	t = t.replace(/\\/g,"");
	return t;
};

exports.getAmPm = function(date) {
	return date.getHours() >= 12 ? $tw.config.dateFormats.pm : $tw.config.dateFormats.am;
};

exports.getDaySuffix = function(date) {
	return $tw.config.dateFormats.daySuffixes[date.getDate()-1];
};

exports.getWeek = function(date) {
	var dt = new Date(date.getTime());
	var d = dt.getDay();
	if(d === 0) d=7;// JavaScript Sun=0, ISO Sun=7
	dt.setTime(dt.getTime()+(4-d)*86400000);// shift day to Thurs of same week to calculate weekNo
	var n = Math.floor((dt.getTime()-new Date(dt.getFullYear(),0,1)+3600000)/86400000);
	return Math.floor(n/7)+1;
};

exports.getYearForWeekNo = function(date) {
	var dt = new Date(date.getTime());
	var d = dt.getDay();
	if(d === 0) d=7;// JavaScript Sun=0, ISO Sun=7
	dt.setTime(dt.getTime()+(4-d)*86400000);// shift day to Thurs of same week
	return dt.getFullYear();
};

exports.getHours12 = function(date) {
	var h = date.getHours();
	return h > 12 ? h-12 : ( h > 0 ? h : 12 );
};

// Convert & to "&amp;", < to "&lt;", > to "&gt;" and " to "&quot;"
exports.htmlEncode = function(s)
{
	if(s) {
		return s.toString().replace(/&/mg,"&amp;").replace(/</mg,"&lt;").replace(/>/mg,"&gt;").replace(/\"/mg,"&quot;");
	} else {
		return "";
	}
};

// Converts all HTML entities to their character equivalents
exports.entityDecode = function(s) {
	var e = s.substr(1,s.length-2); // Strip the & and the ;
	if(e.charAt(0) === "#") {
		if(e.charAt(1) === "x" || e.charAt(1) === "X") {
			return String.fromCharCode(parseInt(e.substr(2),16));	
		} else {
			return String.fromCharCode(parseInt(e.substr(1),10));
		}
	} else {
		var c = $tw.config.htmlEntities[e];
		if(c) {
			return String.fromCharCode(c);
		} else {
			return s; // Couldn't convert it as an entity, just return it raw
		}
	}
};

exports.unescapeLineBreaks = function(s) {
	return s.replace(/\\n/mg,"\n").replace(/\\b/mg," ").replace(/\\s/mg,"\\").replace(/\r/mg,"");
};

/*
 * Returns an escape sequence for given character. Uses \x for characters <=
 * 0xFF to save space, \u for the rest.
 *
 * The code needs to be in sync with th code template in the compilation
 * function for "action" nodes.
 */
// Copied from peg.js, thanks to David Majda
exports.escape = function(ch) {
	var charCode = ch.charCodeAt(0);
	if (charCode <= 0xFF) {
		return '\\x' + $tw.utils.pad(charCode.toString(16).toUpperCase());
	} else {
		return '\\u' + $tw.utils.pad(charCode.toString(16).toUpperCase(),4);
	}
};

// Turns a string into a legal JavaScript string
// Copied from peg.js, thanks to David Majda
exports.stringify = function(s) {
	/*
	* ECMA-262, 5th ed., 7.8.4: All characters may appear literally in a string
	* literal except for the closing quote character, backslash, carriage return,
	* line separator, paragraph separator, and line feed. Any character may
	* appear in the form of an escape sequence.
	*
	* For portability, we also escape escape all non-ASCII characters.
	*/
	return s
		.replace(/\\/g, '\\\\')            // backslash
		.replace(/"/g, '\\"')              // double quote character
		.replace(/'/g, "\\'")              // single quote character
		.replace(/\r/g, '\\r')             // carriage return
		.replace(/\n/g, '\\n')             // line feed
		.replace(/[\x80-\uFFFF]/g, exports.escape); // non-ASCII characters
};

/*
Escape the RegExp special characters with a preceding backslash
*/
exports.escapeRegExp = function(s) {
    return s.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&')
};

exports.nextTick = function(fn) {
/*global window: false */
	if(typeof window !== "undefined") {
		// Apparently it would be faster to use postMessage - http://dbaron.org/log/20100309-faster-timeouts
		window.setTimeout(fn,4);
	} else {
		process.nextTick(fn);
	}
};

/*
Convert a hyphenated CSS property name into a camel case one
*/
exports.unHyphenateCss = function(propName) {
	if($tw.browser.unHyphenateCss) {
		return propName.replace(/-([a-z])/gi, function(match0,match1) {
			return match1.toUpperCase();
		});
	} else {
		return propName;
	}
};

/*
Extract the version number from the meta tag or from the boot file
*/

if($tw.browser) {

// Browser version
exports.extractVersionInfo = function() {
	var metatags = document.getElementsByTagName("meta");
	for(var t=0; t<metatags.length; t++) {
		var m = metatags[t];
		if(m.name === "tiddlywiki-version") {
			return m.content;
		}
	}
	return null;
};

} else {

// Server version
exports.extractVersionInfo = function() {
	return $tw.packageInfo.version;
};

}

})();