// Effect.Tooltip
// Nick Stakenburg
// requires - prototype     : http://www.prototypejs.org
//          - scriptaculous : http://script.aculo.us

Effect.Tooltip = Class.create();
Object.extend(Object.extend(Effect.Tooltip.prototype, Effect.Base.prototype), {
    initialize: function(element, content) {
        this.element = $(element);
        if (!this.element) throw(Effect._elementDoesNotExistError);
        var options = Object.extend({
            content: content,
            title: false,
            className: 'tooltip',
            offset: {'x':16, 'y':16}
        }, arguments[2] || {});
        this.start(options);
    },
    setup: function() {
        // add observers
        this.element.observe('mousemove', this.showTip.bind(this));
        this.element.observe('mouseout', this.hideTip.bind(this));
    },
    buildTip: function() {
        // create a wrapper
        this.wrapper = document.createElement('div');
        this.wrapper.className = this.options.className;
        Element.setStyle(this.wrapper, {
            position: 'absolute',
            display: 'none'
        });
        // add the title
        if (this.options.title) {
            var title = document.createElement('div');
            title.className = 'title';
            Element.update(title, this.options.title);
            this.wrapper.appendChild(title);
        }
        // create the actual tooltip
        this.tip = document.createElement('div');
        this.tip.className = 'content';
        Element.update(this.tip, this.options.content);
        this.wrapper.appendChild(this.tip);


        var body = document.body;
        for(var i=0; i < body.childNodes.length; i++ ){
            var child = body.childNodes[i];
            if(child.nodeType===1){
                child.insertBefore(this.wrapper, child.childNodes[0]);
                i = body.childNodes.length;
            }
        }



        // add wrapper to the body
//        document.body.appendChild(this.wrapper);
//        var body = document.body;
//        var fc = document.body.childNodes[0];
//        fc.insertBefore(this.wrapper, fc.childNodes[0]);
//        var fc = document.body.firstChild.nextSibling;
//        fc.insertBefore(this.wrapper, fc.childNodes[0]);
//        document.getElementsByTagName('body')[0].appendChild(this.wrapper);
//        new Insertion.Top('body', this.wrapper.nodeValue);
    },
    showTip: function(event) {
        if (!this.wrapper) this.buildTip();
        this.positionTip(event);
        this.wrapper.show();
    },
    hideTip: function() {
        if(this.wrapper){
            this.wrapper.hide();
        }
    },
    positionTip: function(event) {
        var offsets = {'x': this.options.offset['x'],'y': this.options.offset['y']};
        var mouse = {'x': Event.pointerX(event), 'y': Event.pointerY(event)};
        var page = {'x':this.viewportSize()['x'], 'y':this.viewportSize()['y']};
        var tip = {'x': mouse['x'] + this.options.offset['x'] + this.wrapper.getWidth(),
            'y' : mouse['y'] + this.options.offset['y'] + this.wrapper.getHeight()};

        // inverse x or y to keep tooltip within viewport
        if (tip['x'] > page['x']) {
            offsets['x'] = 0 - (this.wrapper.getWidth() + this.options.offset['x']);
        }
        if (tip['y'] > page['y']) {
            offsets['y'] = 0 - (this.wrapper.getHeight() + this.options.offset['y']);
        }

        this.wrapper.setStyle({
            left: mouse['x'] + offsets['x'] + 'px',
            top: mouse['y'] + offsets['y'] + 'px'
        });
    },
    viewportSize : function() {
        var x = self.innerWidth || (document.documentElement.clientWidth || document.body.clientWidth);
        var y = self.innerHeight || (document.documentElement.clientHeight || document.body.clientHeight);
        return {'x': x, 'y': y};
    }
});