/**
 * Ajax Pages v0.5
 *
 * This software is licensed under the MIT License.
 *
 * The MIT License
 *
 * Copyright (c) 2005 Gustavo Ribeiro Amigo
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
 * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
/**  
 * Class responsable for processing Ajax Pages.
 * @constructor
 * @author Gustavo Amigo
 */
var AjaxPages = function() {
};

AjaxPages.cache = {};

/**
 * Loads an Ajax Pages template from a file
 * @param url The file to be loaded
 * @returns The template loaded
 */
AjaxPages.prototype.load = function(url) {
	var req;
	
	if (AjaxPages.cache[url]) {
		this.template = AjaxPages.cache[url];
		return AjaxPages.cache[url];
	} else {
		// branch for native XMLHttpRequest object
		if (window.XMLHttpRequest) {
			req = new XMLHttpRequest();
			req.open("GET", url, false);
			req.send(null);
			// branch for IE/Windows ActiveX version
		} else if (window.ActiveXObject) {
			req = new ActiveXObject("Microsoft.XMLHTTP");
			if (req) {
				req.open("GET", url, true);
				req.send();
			}
		}
		
		this.template = req.responseText;
		AjaxPages.cache[url] = this.template;
		return req.responseText;
	}
}

/** 
 * Parses the template
 * @param value (Optional) The template code
 * @returns The javascript code generated from the parsing
 */
AjaxPages.prototype.parse = function(value) {
	if (value == undefined) {
		value = this.template;
	}
	var out = "";
	var lineNumber = 1;
	try {
	
		var betweenPerc = false;
		
		out = "function(context) { \n";
		
		out += "var __ajp = new AjaxPages();\n";
		out += "var __include;\n";
		
		out += "try {\n"
		
		out += "   if ( context == undefined ) { \n";
		out += "       context = '';\n";
		out += "   }\n";
		
		out += "var out= unescape('";
		
		var line = "";
		
		for (i = 0; i < value.length; i++) {
			var nextTwo = "";
			if (i <= value.length - 2) {
				nextTwo = value.charAt(i) + value.charAt(i + 1);
			}
			
			var nextThree = "";
			if (i <= value.length - 3) {
				nextThree = value.charAt(i) + value.charAt(i + 1) + value.charAt(i + 2);
			}
			
			if (nextTwo == "<%" && nextThree != "<%=" && nextThree != "<%@") {
			
				out += "');\n";
				betweenPerc = true;
				i += 1;
				
			} else if (nextTwo == "<%" && nextThree == "<%=" && nextThree != "<%@") {
			
				out += escape(line) + "');\n";
				line = "";
				out += "    out+= ";
				
				betweenPerc = true;
				i += 2;
			} else if (nextTwo == "<%" && nextThree != "<%=" && nextThree == "<%@") {
			
				i += 3;
				var directive = "";
				
				while (nextTwo != "%>") {
					directive += value.charAt(i);
					i++;
					if (i <= value.length - 2) {
						nextTwo = value.charAt(i) + value.charAt(i + 1);
					}
					
				}
				
				out += escape(line) + "');\n";
				line = "";
				
				
				out += this._processDirective(directive);
				out += "    out+= unescape('";
				i++;
			} else if (nextTwo == "%>") {
				out += ";\n" + "    out+= unescape('";
				// TODO Throw error if it is off, wrong sintax
				betweenPerc = false;
				i += 1;
			} else if (value.charAt(i) == String.fromCharCode(10)) {
				if (!betweenPerc) {
					out += escape(line) + "\\n');\n" + "    out+= unescape('";
					line = "";
					lineNumber++;
				}
				
			} else if (value.charAt(i) == String.fromCharCode(13)) {
			} else {
				if (betweenPerc) {
					out += value.charAt(i);
				} else {
					line += value.charAt(i);
				}
			}
		}
		
		out += escape(line) + "');\n";
		
		out += "} catch (e) {"
		out += "return '" + "An exception occurred while excuting template. Error type: ' + e.name" +
		"+ '. Error message: ' + e.message;";
		out += "}"
		out += "    return out;\n";
		out += "}\n";
	} 
	catch (e) {
	
		out = "function(context) { \n";
		out += "return '" + "An exception occurred while parsing on line " + lineNumber + ". Error type: " + e.name +
		". Error message: " +
		e.message +
		"';";
		out += "}"
	}
	
	return out;
}





/** 
 * Private method. Should not be used externally.
 * @private
 */
AjaxPages.prototype._processDirective = function(directive) {
	var i = 0;
	
	var tolkenIndex = 0;
	var tolken = new Array();
	
	//Skip first spaces;    
	while (directive.charAt(i) == ' ') {
		i++;
	}
	
	tolken[tolkenIndex] = "";
	while (directive.charAt(i) != ' ' && i <= directive.length) {
		tolken[tolkenIndex] += directive.charAt(i);
		i++;
	}
	
	tolkenIndex++;
	
	//Skip first spaces;    
	while (directive.charAt(i) == ' ') {
		i++;
	}
	
	tolken[tolkenIndex] = "";
	while (directive.charAt(i) != ' ' && directive.charAt(i) != '=' && i <= directive.length) {
		tolken[tolkenIndex] += directive.charAt(i);
		i++;
	}
	
	tolkenIndex++;
	
	//Skip first spaces;    
	while (directive.charAt(i) == ' ') {
		i++;
	}
	
	if (directive.charAt(i) != '=') 
		throw new AjaxPagesException("Sintax error", "Tolken = expected attribute");
	i++
	
	//Skip first spaces;    
	while (directive.charAt(i) == ' ') {
		i++;
	}
	
	tolken[tolkenIndex] = "";
	while (directive.charAt(i) != ' ' && i <= directive.length) {
		tolken[tolkenIndex] += directive.charAt(i);
		i++;
	}
	tolkenIndex++;
	
	//Skip first spaces;    
	while (directive.charAt(i) == ' ' && i <= directive.length) {
		i++;
	}
	
	tolken[tolkenIndex] = "";
	while (directive.charAt(i) != ' ' && directive.charAt(i) != '=' && i <= directive.length && i <= directive.length) {
		tolken[tolkenIndex] += directive.charAt(i);
		i++;
	}
	
	tolkenIndex++;
	
	if (directive.charAt(i) != '=' && i <= directive.length) 
		throw new AjaxPagesException("Sintax error", "Tolken = expected after attribute");
	i++
	
	tolken[tolkenIndex] = "";
	while (directive.charAt(i) != ' ' && i <= directive.length && i <= directive.length) {
		tolken[tolkenIndex] += directive.charAt(i);
		i++;
	}
	
	var file = "";
	var context = "";
	
	if (tolken[0] != "include") 
		throw new AjaxPagesException("Sintax error", "Directive " + tolken[0] + " unknown.");
	
	if (tolken[1] != "file") 
		throw new AjaxPagesException("Sintax error", "Attribute file expected after include.");
	else 
		file = tolken[2];
	
	
	if (tolken[3] != "context" && tolken[3] != "") 
		throw new AjaxPagesException("Sintax error", "Attribute context expected after file.");
	else if (tolken[3] == "context") 
		context = tolken[4]
	else 
		context = "context";
	
	var path = "(context.filePath ? context.filePath : \"\") + ";
	
	var out = "    __ajp.load(" + path + file + ");\n";
	out += "    __include = __ajp.getProcessor();\n";
	out += "    out+= __include(" + context + ");\n";
	
	return out;
	
}

/** 
 * Processes the template
 * @param value (Optional) The template code.
 * @returns The output from processing the template
 */
AjaxPages.prototype.process = function(value) {
	eval("var processor =" + this.parse(value));
	return processor();
}

/** 
 * Get the function that processes the template
 * @param value (Optional) The template code
 * @returns The function that process the template
 */
AjaxPages.prototype.getProcessor = function(value) {
	eval("var processor =" + this.parse(value));
	return processor;
}

/** 
 * Exception throwed by AjaxPages
 */
AjaxPagesException = function(name, message) {
	this.name = name;
	this.message = message;
}