var BEBOP = YAHOO.namespace("bebop");

    BEBOP.Infobox = function(listElem, cycle, delay) {
        delay = delay || 1000;
        this.init(listElem, cycle, delay);
    }

    BEBOP.Infobox.prototype = {

        init: function(listElem, cycle, delay) {
            this.cycle = cycle;
            this.delay = delay;
            this.current = 0;
            var listElem = document.getElementById(listElem);
            var items = listElem.getElementsByTagName('li');
            var anims = new Array(2*items.length);
            var Anim = YAHOO.util.Anim;
            var setStyle = YAHOO.util.Dom.setStyle;
            var easing = YAHOO.util.Easing.easeOutStrong;
            var callbacks = this.getCallbacks();
            var item;
            for (i=0; i<items.length; i++) {
                item = items[i];
                animin = new Anim(item, { opacity: { to: 1 } }, 1.0, easing);
                animout = new Anim(item, { opacity: { from: 1, to: 0 } }, 1.0, easing);
                animin.onStart.subscribe(callbacks.start);
                animin.onComplete.subscribe(callbacks.next);
                animout.onStart.subscribe(callbacks.start);
                animout.onComplete.subscribe(callbacks.next);
                anims[2*i] = animin;
                anims[2*i+1] = animout;
                setStyle( item , 'list-item-type', 'none');
                if (i>0) {
                    setStyle( item , 'opacity', 0);
                    setStyle( item, 'display', 'none');
                }
            }
            this.anims = anims;
        },

        getCallbacks : function() {
            var instance = this;
            return {
                start: function() {
                    YAHOO.util.Dom.setStyle(this.getEl(), 'display', 'block');
                },
                next: function() {
                    var nextindex = instance.current + 1;
                    var anims = instance.anims;
                    if (instance.cycle) {
                        if (nextindex == anims.length) {
                            nextindex = 0;
                        }
                    }
                    else {
                        if (nextindex == anims.length-1) {
                            //don't fade the last message
                            return;
                        }
                    }
                    var elem = this.getEl();
                    var anim = anims[nextindex];
                    if ( nextindex % 2 == 0 ) {
                        instance.show(elem, anim);
                    }
                    else {
                        setTimeout(function() {instance.show(elem, anim);}, instance.delay);
                    }
                    instance.current = nextindex;
                }
            }
        },

        run: function() {
            if (this.anims.length > 0) {
                this.anims[0].animate();
            }
        },

        show: function(prev, anim) {
            YAHOO.util.Dom.setStyle(prev, 'display', 'none');
            anim.animate();
        }
    }