(function(){

    var tags;

    var defaults = {

        height: 400,

        width: 400,

        radius: 120,

        speed: 2,

        slower: 0.99,

        timer: 5,

        fontMultiplier: 15,

        tagCSSOver: {

            border: 'solid 1px blue',

            color: 'blue'

        },

        tagCSSOut: {

            border: '',

            color: ''

        }

    }

    var forCalcs = {

        halfHeight: null,

        halfWidth: null,

        hwratio: null,

        dtr: null,

        diametr: null,

        speedX: null,

        speedY: null,

        tLength: null

    }

    var curState = {

        mouseOver: null,

        lastFy: null,

        lastFx: null,

        sy: null,

        cy: null,

        sx: null,

        cx: null,

        mouseX: null,

        mouseY: null

    }

    var options = {};

    jQuery.fn.tagSphere = function(opt){

        options = jQuery.extend(defaults, opt);

        initContainer(this);

        initTags(this);

        initCalcs();

        deployTags();

        setInterval(updateTags, options.timer);

        return this;

    };

    

    function initCalcs(){

        forCalcs.halfHeight = options.height / 2;

        forCalcs.halfWidth = options.width / 2;

        forCalcs.speedX = options.speed / forCalcs.halfWidth;

        forCalcs.speedY = options.speed / forCalcs.halfHeight;

        forCalcs.dtr = Math.PI / 180;

        forCalcs.diametr = options.radius * 2;

        forCalcs.hwratio = options.height / options.width;

        forCalcs.whratio = options.width / options.height;

        forCalcs.tLength = tags.length - 1;

        curState.mouseOver = false;

        curState.lastFx = options.speed;

        curState.lastFy = options.speed;

    }

    

    function initContainer(tagCont){

        tagCont.height(options.height);

        tagCont.width(options.width);

        tagCont.css({

            'overflow': 'hidden',

            'position': 'relative'

        });

        tagCont.mousemove(function(e){

            curState.mouseX = e.pageX - this.offsetLeft;

            curState.mouseY = e.pageY - this.offsetTop;

        });

        tagCont.hover(function(){

            curState.mouseOver = true;

        }, function(){

            curState.mouseOver = false;

        });

    }

    

    function initTags(tagCont){

        tags = tagCont.children('ul').children();

        tags.css({

            'position': 'absolute',

            'list-style-type': 'none',

            'list-style-position': 'outside',

            'list-style-image': 'none'

        });

        for (var i = 0; i < tags.length; i++) {

            var jTag = jQuery(tags[i]);

            tags[i] = jTag;

            jTag.hover(function(){

                jQuery(this).css(options.tagCSSOver);

            }, function(){

                jQuery(this).css(options.tagCSSOut);

            })

        }

    }

    

    function deployTags(){

        var phi = 0;

        var theta = 0;

        var max = forCalcs.tLength + 1;

        var i = 0;

        while (i++ < max) {

            phi = Math.acos(-1 + (2 * i - 1) / max);

            theta = Math.sqrt(max * Math.PI) * phi;

            tags[i - 1].cx = options.radius * Math.cos(theta) * Math.sin(phi);

            tags[i - 1].cy = options.radius * Math.sin(theta) * Math.sin(phi);

            tags[i - 1].cz = options.radius * Math.cos(phi);

            tags[i - 1].h = jQuery(tags[i - 1]).height() / 4;

            tags[i - 1].w = jQuery(tags[i - 1]).width() / 4;

        }

    }

    

    function calcRotation(fy, fx){

        curState.sy = Math.sin(fy * forCalcs.dtr);

        curState.cy = Math.cos(fy * forCalcs.dtr);

        curState.sx = Math.sin(fx * forCalcs.dtr);

        curState.cx = Math.cos(fx * forCalcs.dtr);

    }

    

    function updateTags(){

        var fy;

        var fx;

		// Pour inverser le comportement, arret si over, rotation si out ...

		if (curState.mouseOver) {
		 	fy = curState.lastFy * options.slower;
		 	
 			fx = curState.lastFx * options.slower;
 			
			}  
			
		else {
 			
 			fy = options.speed - forCalcs.speedY * curState.mouseY;
 			
 			fx = forCalcs.speedX * curState.mouseX - options.speed;
			}    
			    
		curState.lastFy = fy;

        curState.lastFx = fx;

        if (Math.abs(fy) > 0.01 || Math.abs(fx) > 0.01) {

            calcRotation(fy, fx);

            j = -1;

            while (j++ < forCalcs.tLength) {

                rx1 = tags[j].cx;

                ry1 = tags[j].cy * curState.cy + tags[j].cz * -curState.sy;

                rz1 = tags[j].cy * curState.sy + tags[j].cz * curState.cy;

                tags[j].cx = rx1 * curState.cx + rz1 * curState.sx;

                tags[j].cy = tags[j].cy * curState.cy + tags[j].cz * -curState.sy;

                tags[j].cz = rx1 * -curState.sx + rz1 * curState.cx;

                var per = forCalcs.diametr / (forCalcs.diametr + tags[j].cz);

                tags[j].x = tags[j].cx * per;

                tags[j].y = tags[j].cy * per;

                tags[j].alpha = per / 2;

                tags[j].css({

                    'left': forCalcs.whratio * (tags[j].x - tags[j].w * per) + forCalcs.halfWidth,

                    'top': forCalcs.hwratio * (tags[j].y - tags[j].h * per) + forCalcs.halfHeight,

                    'opacity': tags[j].alpha,

                    'font-size': options.fontMultiplier * tags[j].alpha + 'px',

                    'z-index': Math.round(-tags[j].cz)

                });

            }

        }

    }

})()