/*
Copyright (c) 2008, Yahoo! Inc. All rights reserved.
Code licensed under the BSD License:
http://developer.yahoo.net/yui/license.txt
version: 2.6.0
*/
YAHOO.namespace("tool");

/**
 * The YUI JavaScript profiler.
 * @module profiler
 * @namespace YAHOO.tool
 * @requires yahoo
 */

/**
 * Profiles functions in JavaScript.
 * @namespace YAHOO.tool
 * @class Profiler
 * @static
 */
YAHOO.tool.Profiler = {

    //-------------------------------------------------------------------------
    // Private Properties
    //-------------------------------------------------------------------------

    /**
     * Container object on which to put the original unprofiled methods.
     * @type Object
     * @private
     * @static
     * @property _container
     */
    _container : new Object(),

    /**
     * Call information for functions.
     * @type Object
     * @private
     * @static
     * @property _report
     */
    _report : new Object(),
    
    //-------------------------------------------------------------------------
    // Private Methods
    //-------------------------------------------------------------------------
    
    /**
     * Called when a method ends execution. Marks the start and end time of the 
     * method so it can calculate how long the function took to execute. Also 
     * updates min/max/avg calculations for the function.
     * @param {String} name The name of the function to mark as stopped.
     * @param {int} duration The number of milliseconds it took the function to
     *      execute.
     * @return {Void}
     * @private
     * @static
     */
    _saveData : function (name /*:String*/, duration /*:int*/){
        
        //get the function data
        var functionData /*:Object*/ = this._report[name];
    
        //increment the calls
        functionData.calls++;
        functionData.points.push(duration);

        //if it's already been called at least once, do more complex calculations
        if (functionData.calls > 1) {
            functionData.avg = ((functionData.avg*(functionData.calls-1))+duration)/functionData.calls;
            functionData.min = Math.min(functionData.min, duration);
            functionData.max = Math.max(functionData.max, duration);
        } else {
            functionData.avg = duration;
            functionData.min = duration;
            functionData.max = duration;
        }                             
    
    },

    //-------------------------------------------------------------------------
    // Reporting Methods
    //-------------------------------------------------------------------------    
    
    /**
     * Returns the average amount of time (in milliseconds) that the function
     * with the given name takes to execute.
     * @param {String} name The name of the function whose data should be returned.
     *      If an object type method, it should be 'constructor.prototype.methodName';
     *      a normal object method would just be 'object.methodName'.
     * @return {float} The average time it takes the function to execute.
     * @static
     */
    getAverage : function (name /*:String*/) /*:float*/ {
        return this._report[name].avg;
    },

    /**
     * Returns the number of times that the given function has been called.
     * @param {String} name The name of the function whose data should be returned.
     * @return {int} The number of times the function was called.
     * @static
     */
    getCallCount : function (name /*:String*/) /*:int*/ {
        return this._report[name].calls;    
    },
    
    /**
     * Returns the maximum amount of time (in milliseconds) that the function
     * with the given name takes to execute.
     * @param {String} name The name of the function whose data should be returned.
     *      If an object type method, it should be 'constructor.prototype.methodName';
     *      a normal object method would just be 'object.methodName'.
     * @return {float} The maximum time it takes the function to execute.
     */
    getMax : function (name /*:String*/) /*:int*/ {
        return this._report[name].max;
    },
    
    /**
     * Returns the minimum amount of time (in milliseconds) that the function
     * with the given name takes to execute.
     * @param {String} name The name of the function whose data should be returned.
     *      If an object type method, it should be 'constructor.prototype.methodName';
     *      a normal object method would just be 'object.methodName'.
     * @return {float} The minimum time it takes the function to execute.
     */
    getMin : function (name /*:String*/) /*:int*/ {
        return this._report[name].min;
    },

    /**
     * Returns an object containing profiling data for a single function.
     * The object has an entry for min, max, avg, calls, and points).
     * @return {Object} An object containing profile data for a given function.
     * @static
     */
    getFunctionReport : function (name /*:String*/) /*:Object*/ {
        return this._report[name];
    },

    /**
     * Returns an object containing profiling data for all of the functions 
     * that were profiled. The object has an entry for each function and 
     * returns all information (min, max, average, calls, etc.) for each
     * function.
     * @return {Object} An object containing all profile data.
     * @static
     */
    getFullReport : function (filter /*:Function*/) /*:Object*/ {
        filter = filter || function(){return true;};
    
        if (YAHOO.lang.isFunction(filter)) {
            var report = {};
            
            for (var name in this._report){
                if (filter(this._report[name])){
                    report[name] = this._report[name];    
                }
            }
            
            return report;
        }
    },

    //-------------------------------------------------------------------------
    // Profiling Methods
    //-------------------------------------------------------------------------   
    
    /**
     * Sets up a constructor for profiling, including all properties and methods on the prototype.
     * @param {string} name The fully-qualified name of the function including namespace information.
     * @param {Object} owner (Optional) The object that owns the function (namespace or containing object).
     * @return {Void}
     * @static
     */
    registerConstructor : function (name /*:String*/, owner /*:Object*/) /*:Void*/ {    
        this.registerFunction(name, owner, true);
    },

    /**
     * Sets up a function for profiling. It essentially overwrites the function with one
     * that has instrumentation data. This method also creates an entry for the function
     * in the profile report. The original function is stored on the _container object.
     * @param {String} name The full name of the function including namespacing. This
     *      is the name of the function that is stored in the report.
     * @param {Object} owner (Optional) The object that owns the function. If the function
     *      isn't global then this argument is required. This could be the namespace that
     *      the function belongs to, such as YAHOO.util.Dom, or the object on which it's
     *      a method.
     * @return {Void}
     * @method registerFunction
     */     
    registerFunction : function(name /*:String*/, owner /*:Object*/, registerPrototype /*:Boolean*/) /*:Void*/{
    
        //figure out the function name without namespacing
        var funcName /*:String*/ = (name.indexOf(".") > -1 ? name.substring(name.lastIndexOf(".")+1) : name);
        if (!YAHOO.lang.isObject(owner)){
            owner = eval(name.substring(0, name.lastIndexOf(".")));
        }
        
        //get the method and prototype
        var method /*:Function*/ = owner[funcName];
        var prototype /*:Object*/ = method.prototype;
        
        //see if the method has already been registered
        if (YAHOO.lang.isFunction(method) && !method.__yuiProfiled){
            
            //create a new slot for the original method
            this._container[name] = method;
            
            //replace the function with the profiling one
            owner[funcName] = function () {

                var start = new Date();     
                var retval = method.apply(this, arguments);
                var stop = new Date();
                
                YAHOO.tool.Profiler._saveData(name, stop-start);
                
                return retval;                
            
            };
            
            //copy the function properties over
            YAHOO.lang.augmentObject(owner[funcName], method);
            owner[funcName].__yuiProfiled = true;
            owner[funcName].prototype = prototype;
            this._container[name].__yuiOwner = owner;
            this._container[name].__yuiFuncName = funcName;        
        
            //register prototype if necessary
            if (registerPrototype) {            
                this.registerObject(name + ".prototype", prototype);          
            }
            
            //store function information
            this._report[name] = {
                calls: 0,
                max: 0,
                min: 0,
                avg: 0,
                points: []
            };        
        }
            
        return method;
    
    },
        
    
    /**
     * Sets up an object for profiling. It takes the object and looks for functions.
     * When a function is found, registerMethod() is called on it. If set to recrusive
     * mode, it will also setup objects found inside of this object for profiling, 
     * using the same methodology.
     * @param {String} name The name of the object to profile (shows up in report).
     * @param {Object} owner (Optional) The object represented by the name.
     * @param {Boolean} recurse (Optional) Determines if subobject methods are also profiled.
     * @return {Void}
     * @static
     */
    registerObject : function (name /*:String*/, object /*:Object*/, recurse /*:Boolean*/) /*:Void*/{
    
        //get the object
        object = (YAHOO.lang.isObject(object) ? object : eval(name));
    
        //save the object
        this._container[name] = object;
    
        for (var prop in object) {
            if (typeof object[prop] == "function"){
                if (prop != "constructor" && prop != "superclass"){ //don't do constructor or superclass, it's recursive
                    this.registerFunction(name + "." + prop, object);
                }
            } else if (typeof object[prop] == "object" && recurse){
                this.registerObject(name + "." + prop, object[prop], recurse);
            }
        }
    
    },    
    
    /**
     * Removes a constructor function from profiling. Reverses the registerConstructor() method.
     * @param {String} name The full name of the function including namespacing. This
     *      is the name of the function that is stored in the report.
     * @return {Void}
     * @method unregisterFunction
     */     
    unregisterConstructor : function(name /*:String*/) /*:Void*/{
            
        //see if the method has been registered
        if (YAHOO.lang.isFunction(this._container[name])){
        
            //get original data
            //var owner /*:Object*/ = this._container[name].__yuiOwner;
            //var funcName /*:String*/ = this._container[name].__yuiFuncName;
            //delete this._container[name].__yuiOwner;
            //delete this._container[name].__yuiFuncName;
            
            //replace instrumented function
            //owner[funcName] = this._container[name];
            //delete this._container[name];
            this.unregisterFunction(name, true);
       
        }

    
    },
    
    /**
     * Removes function from profiling. Reverses the registerFunction() method.
     * @param {String} name The full name of the function including namespacing. This
     *      is the name of the function that is stored in the report.
     * @return {Void}
     * @method unregisterFunction
     */     
    unregisterFunction : function(name /*:String*/, unregisterPrototype /*:Boolean*/) /*:Void*/{
            
        //see if the method has been registered
        if (YAHOO.lang.isFunction(this._container[name])){
        
            //check to see if you should unregister the prototype
            if (unregisterPrototype){
                this.unregisterObject(name + ".prototype", this._container[name].prototype);
            }
                
            //get original data
            var owner /*:Object*/ = this._container[name].__yuiOwner;
            var funcName /*:String*/ = this._container[name].__yuiFuncName;
            delete this._container[name].__yuiOwner;
            delete this._container[name].__yuiFuncName;
            
            //replace instrumented function
            owner[funcName] = this._container[name];
            
            //delete supporting information
            delete this._container[name];
            delete this._report[name];
       
        }
            
    
    },
    
    /**
     * Unregisters an object for profiling. It takes the object and looks for functions.
     * When a function is found, unregisterMethod() is called on it. If set to recrusive
     * mode, it will also unregister objects found inside of this object, 
     * using the same methodology.
     * @param {String} name The name of the object to unregister.
     * @param {Boolean} recurse (Optional) Determines if subobject methods should also be
     *      unregistered.
     * @return {Void}
     * @static
     */
    unregisterObject : function (name /*:String*/, recurse /*:Boolean*/) /*:Void*/{
    
        //get the object
        if (YAHOO.lang.isObject(this._container[name])){            
            var object = this._container[name];    
        
            for (var prop in object) {
                if (typeof object[prop] == "function"){
                    this.unregisterFunction(name + "." + prop);
                } else if (typeof object[prop] == "object" && recurse){
                    this.unregisterObject(name + "." + prop, recurse);
                }
            }
            
            delete this._container[name];
        }
    
    }
         

};
YAHOO.register("profiler", YAHOO.tool.Profiler, {version: "2.6.0", build: "1321"});
