/**
* jQuery AOP - jQuery plugin to add features of aspect-oriented programming (AOP) to jQuery.
* http://jquery-aop.googlecode.com/
*
* Licensed under the MIT license:
* http://www.opensource.org/licenses/mit-license.php
*
* Version: 1.1
*/

(function() {

	var _after	= 1;
	var _before	= 2;
	var _around	= 3;
	var _intro  = 4;
	var _regexEnabled = true;

	/**
	 * Private weaving function.
	 */
	var weaveOne = function(source, method, advice) {

		var old = source[method];

		var aspect;
		if (advice.type == _after)
			aspect = function() {
				var returnValue = old.apply(this, arguments);
				return advice.value.apply(this, [returnValue, method]);
			};
		else if (advice.type == _before)
			aspect = function() {
				advice.value.apply(this, [arguments, method]);
				return old.apply(this, arguments);
			};
		else if (advice.type == _intro)
			aspect = function() {
				return advice.value.apply(this, arguments);
			};
		else if (advice.type == _around) {
			aspect = function() {
				var invocation = { object: this, args: Array.prototype.slice.call(arguments) };
				return advice.value.apply(invocation.object, [{ arguments: invocation.args, method: method, proceed : 
					function() {
						return old.apply(invocation.object, invocation.args);
					}
				}] );
			};
		}

		aspect.unweave = function() { 
			source[method] = old;
			pointcut = source = aspect = old = null;
		};

		source[method] = aspect;

		return aspect;

	};


	/**
	 * Private weaver and pointcut parser.
	 */
	var weave = function(pointcut, advice)
	{

		var source = (typeof(pointcut.target.prototype) != 'undefined') ? pointcut.target.prototype : pointcut.target;
		var advices = [];

		// If it's not an introduction and no method was found, try with regex...
		if (advice.type != _intro && typeof(source[pointcut.method]) == 'undefined')
		{

			for (var method in source)
			{
				if (source[method] != null && source[method] instanceof Function && method.match(pointcut.method))
				{
					advices[advices.length] = weaveOne(source, method, advice);
				}
			}

			if (advices.length == 0)
				throw 'No method: ' + pointcut.method;

		} 
		else
		{
			// Return as an array of one element
			advices[0] = weaveOne(source, pointcut.method, advice);
		}

		return _regexEnabled ? advices : advices[0];

	};

	jQuery.aop = 
	{
		/**
		 * Creates an advice after the defined point-cut. The advice will be executed after the point-cut method 
		 * has completed execution successfully, and will receive one parameter with the result of the execution.
		 * This function returns an array of weaved aspects (Function).
		 *
		 * @example jQuery.aop.after( {target: window, method: 'MyGlobalMethod'}, function(result) { alert('Returned: ' + result); } );
		 * @result Array<Function>
		 *
		 * @example jQuery.aop.after( {target: String, method: 'indexOf'}, function(index) { alert('Result found at: ' + index + ' on:' + this); } );
		 * @result Array<Function>
		 *
		 * @name after
		 * @param Map pointcut Definition of the point-cut to apply the advice. A point-cut is the definition of the object/s and method/s to be weaved.
		 * @option Object target Target object to be weaved. 
		 * @option String method Name of the function to be weaved. Regex are supported, but not on built-in objects.
		 * @param Function advice Function containing the code that will get called after the execution of the point-cut. It receives one parameter
		 *                        with the result of the point-cut's execution.
		 *
		 * @type Array<Function>
		 * @cat Plugins/General
		 */
		after : function(pointcut, advice)
		{
			return weave( pointcut, { type: _after, value: advice } );
		},

		/**
		 * Creates an advice before the defined point-cut. The advice will be executed before the point-cut method 
		 * but cannot modify the behavior of the method, or prevent its execution.
		 * This function returns an array of weaved aspects (Function).
		 *
		 * @example jQuery.aop.before( {target: window, method: 'MyGlobalMethod'}, function() { alert('About to execute MyGlobalMethod'); } );
		 * @result Array<Function>
		 *
		 * @example jQuery.aop.before( {target: String, method: 'indexOf'}, function(index) { alert('About to execute String.indexOf on: ' + this); } );
		 * @result Array<Function>
		 *
		 * @name before
		 * @param Map pointcut Definition of the point-cut to apply the advice. A point-cut is the definition of the object/s and method/s to be weaved.
		 * @option Object target Target object to be weaved. 
		 * @option String method Name of the function to be weaved. Regex are supported, but not on built-in objects.
		 * @param Function advice Function containing the code that will get called before the execution of the point-cut.
		 *
		 * @type Array<Function>
		 * @cat Plugins/General
		 */
		before : function(pointcut, advice)
		{
			return weave( pointcut, { type: _before, value: advice } );
		},


		/**
		 * Creates an advice 'around' the defined point-cut. This type of advice can control the point-cut method execution by calling
		 * the functions '.proceed()' on the 'invocation' object, and also, can modify the arguments collection before sending them to the function call.
		 * This function returns an array of weaved aspects (Function).
		 *
		 * @example jQuery.aop.around( {target: window, method: 'MyGlobalMethod'}, function(invocation) {
		 *                alert('# of Arguments: ' + invocation.arguments.length); 
		 *                return invocation.proceed(); 
		 *          } );
		 * @result Array<Function>
		 *
		 * @example jQuery.aop.around( {target: String, method: 'indexOf'}, function(invocation) { 
		 *                alert('Searching: ' + invocation.arguments[0] + ' on: ' + this); 
		 *                return invocation.proceed(); 
		 *          } );
		 * @result Array<Function>
		 *
		 * @example jQuery.aop.around( {target: window, method: /Get(\d+)/}, function(invocation) {
		 *                alert('Executing ' + invocation.method); 
		 *                return invocation.proceed(); 
		 *          } );
		 * @desc Matches all global methods starting with 'Get' and followed by a number.
		 * @result Array<Function>
		 *
		 *
		 * @name around
		 * @param Map pointcut Definition of the point-cut to apply the advice. A point-cut is the definition of the object/s and method/s to be weaved.
		 * @option Object target Target object to be weaved. 
		 * @option String method Name of the function to be weaved. Regex are supported, but not on built-in objects.
		 * @param Function advice Function containing the code that will get called around the execution of the point-cut. This advice will be called with one
		 *                        argument containing one function '.proceed()', the collection of arguments '.arguments', and the matched method name '.method'.
		 *
		 * @type Array<Function>
		 * @cat Plugins/General
		 */
		around : function(pointcut, advice)
		{
			return weave( pointcut, { type: _around, value: advice } );
		},

		/**
		 * Creates an introduction on the defined point-cut. This type of advice replaces any existing methods with the same
		 * name. To restore them, just unweave it.
		 * This function returns an array with only one weaved aspect (Function).
		 *
		 * @example jQuery.aop.introduction( {target: window, method: 'MyGlobalMethod'}, function(result) { alert('Returned: ' + result); } );
		 * @result Array<Function>
		 *
		 * @example jQuery.aop.introduction( {target: String, method: 'log'}, function() { alert('Console: ' + this); } );
		 * @result Array<Function>
		 *
		 * @name introduction
		 * @param Map pointcut Definition of the point-cut to apply the advice. A point-cut is the definition of the object/s and method/s to be weaved.
		 * @option Object target Target object to be weaved. 
		 * @option String method Name of the function to be weaved.
		 * @param Function advice Function containing the code that will be executed on the point-cut. 
		 *
		 * @type Array<Function>
		 * @cat Plugins/General
		 */
		introduction : function(pointcut, advice)
		{
			return weave( pointcut, { type: _intro, value: advice } );
		},
		
		/**
		 * Configures global options.
		 *
		 * @name setup
		 * @param Map settings Configuration options.
		 * @option Boolean regexMatch Enables/disables regex matching of method names.
		 *
		 * @example jQuery.aop.setup( { regexMatch: false } );
		 * @desc Disable regex matching.
		 *
		 * @type Void
		 * @cat Plugins/General
		 */
		setup: function(settings)
		{
			_regexEnabled = settings.regexMatch;
		}
	};

})();