Modal = Class.create();

Modal.prototype = {
    initialize: function() {
        var objBody = $$('body')[0];

	objBody.appendChild(Builder.node('div',{id:'modalOverlay'}));

        $('modalOverlay').hide();
        var th = this;
        (function(){
            var ids =
                'modalOverlay';
            $w(ids).each(function(id){ th[id] = $(id); });
        }).defer();
    },

    //
    //  start()
    //  Display overlay and lightbox. If image is part of a set, add siblings to imageArray.
    //
    start: function() {

        $$('select', 'object', 'embed').each(function(node){ node.style.visibility = 'hidden' });

        // stretch overlay to fill page and fade in
        var arrayPageSize = this.getPageSize();
        $('modalOverlay').setStyle({ width: arrayPageSize[0] + 'px', height: arrayPageSize[1] + 'px' });

        new Effect.Appear($('modalOverlay'), { duration: 1, from: 0.0, to: 0.1 });

        // calculate top and left offset for the lightbox
        /*
        var arrayPageScroll = document.viewport.getScrollOffsets();
        var lightboxTop = arrayPageScroll[1] + (document.viewport.getHeight() / 10);
        var lightboxLeft = arrayPageScroll[0];
        this.lightbox.setStyle({ top: lightboxTop + 'px', left: lightboxLeft + 'px' }).show();
        */
    },

    //
    //  end()
    //
    end: function() {
        new Effect.Fade(this.modalOverlay, { duration: 1 });
        $$('select', 'object', 'embed').each(function(node){ node.style.visibility = 'visible' });
    },

    //
    //  getPageSize()
    //
    getPageSize: function() {
	     var xScroll, yScroll;

		if (window.innerHeight && window.scrollMaxY) {
			xScroll = window.innerWidth + window.scrollMaxX;
			yScroll = window.innerHeight + window.scrollMaxY;
		} else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
			xScroll = document.body.scrollWidth;
			yScroll = document.body.scrollHeight;
		} else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
			xScroll = document.body.offsetWidth;
			yScroll = document.body.offsetHeight;
		}

		var windowWidth, windowHeight;

		if (self.innerHeight) {	// all except Explorer
			if(document.documentElement.clientWidth){
				windowWidth = document.documentElement.clientWidth;
			} else {
				windowWidth = self.innerWidth;
			}
			windowHeight = self.innerHeight;
		} else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
			windowWidth = document.documentElement.clientWidth;
			windowHeight = document.documentElement.clientHeight;
		} else if (document.body) { // other Explorers
			windowWidth = document.body.clientWidth;
			windowHeight = document.body.clientHeight;
		}

		// for small pages with total height less then height of the viewport
		if(yScroll < windowHeight){
			pageHeight = windowHeight;
		} else {
			pageHeight = yScroll;
		}

		// for small pages with total width less then width of the viewport
		if(xScroll < windowWidth){
			pageWidth = xScroll;
		} else {
			pageWidth = windowWidth;
		}

		return [pageWidth,pageHeight];
	}
}