var Events = new EventsManager();

function EventsManager()
{
    var registry    = null;
    var last_lable  = 0;
}



/**
 * Initiate the registry and add unload event to window
 */
EventsManager.prototype.init = function()
{
    if(this.registry != null)
        return;

    this.registry = new Array();
    this.add(window, 'unload', this.unloadEvents);
}





/**
 * Add an event listener to an object
 *
 * @param object    obj         The object to attach to
 * @param string    eventType   The type of event to attach to
 * @param string    lable       <i>(Opt)</i> Provide a virtual lable so removing listeners is easier
 *
 * @return The virtual lable used to register this event (so you may remove it later with ease), or false on failure
 */
EventsManager.prototype.add = function(obj, eventType, func, lable)
{
    this.init();

    if(typeof obj != 'object' || typeof func != 'function')
        return false;

    if(!lable)
        lable = 'EVENT_LABLE_' + (this.last_lable++);

    var success = true;
    var add_reg = false;
    var closure = null;


    //------------------------------
    // Add listeners
    //------------------------------
    // Moz
    if(obj.addEventListener)
        obj.addEventListener(eventType, func, false);

    // IE
    else if(obj.attachEvent)
    {
        closure = function() { func.call(obj); };
        success = obj.attachEvent('on' + eventType, closure);
    }

    // Attempt at others
    else
    {
        if(obj['on' + eventType])
        {
            var oldListener = obj['on' + eventType];
            closure = function() { func.call(obj); oldListener.call(obj); }
        }

        obj['on' + eventType] = closure;
    }


    //------------------------------
    // Add to reg
    //------------------------------
    if(success)
    {
        if(typeof closure == 'function')
            func = closure;

        this.registry[lable] = {obj: obj, eventType: eventType, func: func};
        return lable;
    }

    else
        return false;
}




/**
 * Remove an event listener with the lable it was added to the registry with
 *
 * @param string    lable       The label the event was added to the registry with
 * @param bool      forceDel    <i>(Opt)</i> If the browser doesn't support listener functions, we tried
 *                              to solve it by explicitly setting the event listener. In this case, we
 *                              cannot  choose to remove a single listener, we have to remove all of them. Defaults to true.
 *
 * @return True on success, false on failure
 */
EventsManager.prototype.remove = function(lable, forceDel)
{
    if(!this.registry[lable])
        return false;

    reg = this.registry[lable];


    //------------------------------
    // Remove listeners
    //------------------------------
    // Moz
    if(reg.obj.removeEventListener)
    {
        reg.obj.removeEventListener(reg.eventType, reg.func, false);
        done = true;
    }

    // IE
    else if(reg.obj.detatchEvent)
        done = reg.obj.detatchEvent('on' + reg.eventType, reg.func);

    // Attempt at others
    else
    {
        if(forceDel)
        {
            reg.obj['on' + reg.eventType] = null;
            done = true;
        }

        else
            done = false;
    }


    //------------------------------
    // Remove from reg
    //------------------------------
    if(done)
        this.registry[lable] = null;

    return done;
}





/**
 * Unload all events defined in the registry
 */
EventsManager.prototype.unloadEvents = function()
{
    for(var lable in Events.registry)
    {
        if(Events.registry[lable] == null)
            continue;

        Events.remove.call(Events, lable, true);
    }

    Events.registry = null;
}