/**
 * @fileOverview
 * @name JsPlate
 * @author Michael Mathews micmath@gmail.com
 * @url $HeadURL: http://jsdoc-toolkit.googlecode.com/svn/branches/version1.x/app/JsPlate.js $
 * @revision $Id: JsPlate.js 389 2007-12-26 17:26:27Z micmath $
 * @license <a href="http://en.wikipedia.org/wiki/MIT_License">X11/MIT License</a>
 *          (See the accompanying README file for full details.)

 */

 /**
  * @class A lightweight template engine for JavaScript.
  * @constructor
  * @author Michael Mathews <a href="mailto:micmath@gmail.com">micmath@gmail.com</a>
  * @param {string} template
  */
JsPlate = function(templateFile) {
	if (templateFile) this.template = IO.readFile(templateFile);
	
	this.templateFile = templateFile;
	this.code = "";
	this.parse();
}



/** Converts a template into evalable code. */
JsPlate.prototype.parse = function() {
	this.template = this.template.replace(/\{#[\s\S]+?#\}/gi, "");
	this.code = "var output=``"+this.template;

	this.code = this.code.replace(
		/<for +each="(.+?)" +in="(.+?)" *>/gi, 
		function (match, eachName, inName) {
			return "``;\rvar $"+eachName+"_keys = keys("+inName+");\rfor(var $"+eachName+"_i = 0; $"+eachName+"_i < $"+eachName+"_keys.length; $"+eachName+"_i++) {\rvar $"+eachName+"_last = ($"+eachName+"_i == $"+eachName+"_keys.length-1);\rvar $"+eachName+"_key = $"+eachName+"_keys[$"+eachName+"_i];\rvar "+eachName+" = "+inName+"[$"+eachName+"_key];\routput+=``";
		}
	);	
	this.code = this.code.replace(/<if test="(.+?)">/g, "``;\rif ($1) { output+=``");
	this.code = this.code.replace(/<\/(if|for)>/g, "``;\r};\routput+=``");
	this.code = this.code.replace(
		/\{\+\s*([\s\S]+?)\s*\+\}/gi,
		function (match, code) {
			code = code.replace(/"/g, "``"); // prevent qoute-escaping of inline code
			code = code.replace(/(\r?\n)/g, " ");
			return "``+"+code+"+``";
		}
	);
	this.code = this.code.replace(
		/\{!\s*([\s\S]+?)\s*!\}/gi,
		function (match, code) {
			code = code.replace(/"/g, "``"); // prevent qoute-escaping of inline code
			code = code.replace(/(\n)/g, " ");
			return "``; "+code+";\routput+=``";
		}
	);
	this.code = this.code+"``;";

	this.code = this.code.replace(/(\r?\n)/g, "\\n");
	this.code = this.code.replace(/"/g, "\\\"");
	this.code = this.code.replace(/``/g, "\"");
}

/**
 * @private
 */
JsPlate.prototype.toCode = function() {
	return this.code;
}

/**
 * @private
 * @static
 * @memberOf JsPlate
 */
JsPlate.keys = function(obj) {
	var keys = [];
	// TODO: Confirm that arrays are not treated as objects
	if (obj.constructor.toString().indexOf("Array") > -1) {
		for (var i = 0; i < obj.length; i++) {
			keys.push(i);
		}
	}
	else {
		for (var i in obj) {
			keys.push(i);
		}
	}
	return keys;
};

/**
 * @private
 * @static
 * @memberOf JsPlate
 */
JsPlate.values = function(obj) {
	var values = [];
	// TODO: Confirm that arrays are not treated as objects
	if (obj.constructor.toString().indexOf("Array") > -1) {
		for (var i = 0; i < obj.length; i++) {
			values.push(obj[i]);
		}
	}
	else {
		for (var i in obj) {
			values.push(obj[i]);
		}
	}
	return values;
};

/**
 * Return the output. This must be called after parse()
 * @param {object} data What shall represent the "data" in your template.
 * @return {string}
 */
JsPlate.prototype.process = function(data) {
	var keys = JsPlate.keys;
	var values = JsPlate.values;
	
	try {
		eval(this.code);
	}
	catch (e) {
		print(">> There was an error evaluating the compiled code from template: "+this.templateFile);
		print("   The error was on line "+e.lineNumber+" "+e.name+": "+e.message);
		var lines = this.code.split("\r");
		if (e.lineNumber-2 >= 0) print("line "+(e.lineNumber-1)+": "+lines[e.lineNumber-2]);
		print("line "+e.lineNumber+": "+lines[e.lineNumber-1]);
		print("");
	}
	return output;
	//print(this.code);
}