/**
 * Copyright (C) 2010-2011 Graham Breach
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
/**
 * jQuery.tagcanvas 1.8
 * For more information, please contact <graham@goat1000.com>
 */
(function($) {
    var i, j, abs = Math.abs, sin = Math.sin, cos = Math.cos, hexlookup3 = {}, hexlookup2 = {}, hexlookup1 = {
        "0":"0,",   
        "1":"17,",  
        "2":"34,",  
        "3":"51,",  
        "4":"68,",  
        "5":"85,",
        "6":"102,", 
        "7":"119,", 
        "8":"136,", 
        "9":"153,", 
        a:"170,",   
        A:"170,",
        b:"187,",   
        B:"187,",   
        c:"204,",   
        C:"204,",   
        d:"221,",   
        D:"221,",
        e:"238,",   
        E:"238,",   
        f:"255,",   
        F:"255,"	
    };
    for(i = 0; i < 256; ++i) {
        j = i.toString(16);
        if(i < 16)
            j = '0' + j;
        hexlookup2[j] = hexlookup2[j.toUpperCase()] = i.toString() + ',';
    }
    function PointsOnSphere(n) {
        var i, y, r, phi, pts = [], inc = Math.PI * (3-Math.sqrt(5)), off = 2/n;
        for(i = 0; i < n; ++i) {
            y = i * off - 1 + (off / 2);
            r = Math.sqrt(1 - y*y);
            phi = i * inc;
            pts.push([cos(phi)*r, y, sin(phi)*r]);
        }
        return pts;
    }
    function SetAlpha(c,a) {
        var d = c, p1, p2, ae = (a*1).toPrecision(3) + ')';
        if(c[0] === '#') {
            if(!hexlookup3[c])
                if(c.length === 4)
                    hexlookup3[c] = 'rgba(' + hexlookup1[c[1]] + hexlookup1[c[2]] + hexlookup1[c[3]];
                else
                    hexlookup3[c] = 'rgba(' + hexlookup2[c.substr(1,2)] + hexlookup2[c.substr(3,2)] + hexlookup2[c.substr(5,2)];
            d = hexlookup3[c] + ae;
        } else if(c.substr(0,4) === 'rgb(' || c.substr(0,4) === 'hsl(') {
            d = (c.replace('(','a(').replace(')', ',' + ae));
        } else if(c.substr(0,5) === 'rgba(' || c.substr(0,5) === 'hsla(') {
            p1 = c.lastIndexOf(',') + 1, p2 = c.indexOf(')');
            a *= parseFloat(c.substring(p1,p2));
            d = c.substr(0,p1) + a.toPrecision(3) + ')';
        } else {
            d = c; // give up!
        }
        return d;
    }
    function NewCanvas(w,h) {
        // if using excanvas, give up now
        if(window.G_vmlCanvasManager)
            return null;
        var c = document.createElement('canvas');
        c.width = w;
        c.height = h;
        return c;
    }
    function ShadowAlphaBroken() {
        var cv = NewCanvas(3,3), c, i;
        if(!cv)
            return false;
        c = cv.getContext('2d');
        c.strokeStyle = '#000';
        c.shadowColor = '#fff';
        c.shadowBlur = '3';
        c.globalAlpha = 0.0;
        c.strokeRect(2,2,2,2);
        c.globalAlpha = 1.0;
        i = c.getImageData(2,2,1,1);
        cv = null;
        return (i.data[0] > 0);
    }
    function FindGradientColour(t,p) {
        var l = 1024, g = t.weightGradient, cv, c, i, gd, d;
        if(t.gCanvas) {
            c = t.gCanvas.getContext('2d');
        } else {
            t.gCanvas = cv = NewCanvas(l,1);
            if(!cv)
                return null;
            c = cv.getContext('2d');
            gd = c.createLinearGradient(0,0,l,0);
            for(i in g)
                gd.addColorStop(1-i, g[i]);
            c.fillStyle = gd;
            c.fillRect(0,0,l,1);
        }
        d = c.getImageData(~~((l-1)*p),0,1,1).data;
        return 'rgba(' + d[0] + ',' + d[1] + ',' + d[2] + ',' + (d[3]/255) + ')';
    }
    function TextSet(c,f,l,s,sc,sb,so) {
        var xo = (sb || 0) + (so && so[0] < 0 ? abs(so[0]) : 0),
        yo = (sb || 0) + (so && so[1] < 0 ? abs(so[1]) : 0);
        c.font = f;
        c.textBaseline = 'top';
        c.fillStyle = l;
        sc && (c.shadowColor = sc);
        sb && (c.shadowBlur = sb);
        so && (c.shadowOffsetX = so[0], c.shadowOffsetY = so[1]);
        c.fillText(s, xo, yo);
    }
    function TextToCanvas(s,f,ht,w,h,l,sc,sb,so) {
        var cw = w + abs(so[0]) + sb + sb, ch = h + abs(so[1]) + sb + sb, cv, c;
        cv = NewCanvas(cw,ch);
        if(!cv)
            return null;
        c = cv.getContext('2d');
        TextSet(c,f,l,s,sc,sb,so);
        return cv;
    }
    function AddShadowToImage(i,sc,sb,so) {
        var cw = i.width + abs(so[0]) + sb + sb, ch = i.height + abs(so[1]) + sb + sb, cv, c,
        xo = (sb || 0) + (so && so[0] < 0 ? abs(so[0]) : 0),
        yo = (sb || 0) + (so && so[1] < 0 ? abs(so[1]) : 0);
        cv = NewCanvas(cw,ch);
        if(!cv)
            return null;
        c = cv.getContext('2d');
        sc && (c.shadowColor = sc);
        sb && (c.shadowBlur = sb);
        so && (c.shadowOffsetX = so[0], c.shadowOffsetY = so[1]);
        c.drawImage(i, xo, yo);
        return cv;
    }
    function FindTextBoundingBox(s,f,ht) {
        var w = parseInt(s.length * ht), h = parseInt(ht * 2), cv = NewCanvas(w,h), c, idata, w1, h1, x, y, i, ex;
        if(!cv)
            return null;
        c = cv.getContext('2d');
        c.fillStyle = '#000';
        c.fillRect(0,0,w,h);
        TextSet(c,ht + 'px ' + f,'#fff',s)

        idata = c.getImageData(0,0,w,h);
        w1 = idata.width;
        h1 = idata.height;
        ex = {
            min: {
                x: w1, 
                y: h1
            },
            max: {
                x: -1, 
                y: -1
            }
        };
        for(y = 0; y < h1; ++y) {
            for(x = 0; x < w1; ++x) {
                i = (y * w1 + x) * 4;
                if(idata.data[i+1] > 0) {
                    if(x < ex.min.x) ex.min.x = x;
                    if(x > ex.max.x) ex.max.x = x;
                    if(y < ex.min.y) ex.min.y = y;
                    if(y > ex.max.y) ex.max.y = y;
                }
            }
        }
        // device pixels might not be css pixels
        if(w1 != w) {
            ex.min.x *= (w / w1);
            ex.max.x *= (w / w1);
        }
        if(h1 != h) {
            ex.min.y *= (w / h1);
            ex.max.y *= (w / h1);
        }

        cv = null;
        return ex;
    }
    function FixFont(f) {
        return "'" + f.replace(/(\'|\")/g,'').replace(/\s*,\s*/g, "', '") + "'";
    }
    function AddImage(i,t,tl) {
        if(i.complete) {
            t.w = i.width;
            t.h = i.height;
            tl.push(t);
        } else {
            jQuery(i).bind('load',function() {
                t.w = this.width;
                t.h = this.height;
                tl.push(t);
            });
        }
    }
    function FindWeight(t,a) {
        var w = 1, p;
        if(t.weightFrom) {
            w = 1 * (a.getAttribute(t.weightFrom) || t.textHeight);
        } else if(document.defaultView && document.defaultView.getComputedStyle) {
            p = document.defaultView.getComputedStyle(a,null).getPropertyValue('font-size');
            w = p.replace('px','') * 1;
        } else {
            t.weight = false;
        }
        return w;
    }
    function MouseMove(e) {
        var i, tc, dd = document.documentElement;
        for(i in TagCanvas.tc) {
            tc = TagCanvas.tc[i]
            if(e.pageX) {
                tc.mx = e.pageX - tc.cx;
                tc.my = e.pageY - tc.cy;
            } else {
                tc.mx = e.clientX + (dd.scrollLeft || document.body.scrollLeft) - tc.cx;
                tc.my = e.clientY + (dd.scrollTop || document.body.scrollTop)	- tc.cy;
            }
        }
    }
    function MouseClick(e) {
        var t = TagCanvas, cb = document.addEventListener ? 0 : 1,
        tg = e.target && e.target.id != undefined ? e.target.id : e.srcElement.parentNode.id;
        if(tg && e.button == cb && t.tc[tg]) {
            MouseMove(e);
            t.tc[tg].Clicked(e);
        }
    }
    function DrawCanvas() {
        var t = TagCanvas.tc, i;
        for(i in t)
            t[i].Draw();
    }
    function RotX(p1,t) {
        var s = sin(t), c = cos(t); 
        return {
            x:p1.x, 
            y:(p1.y * c) + (p1.z * s), 
            z:(p1.y * -s) + (p1.z * c)
            };
    }
    function RotY(p1,t) {
        var s = sin(t), c = cos(t); 
        return {
            x:(p1.x * c) + (p1.z * -s), 
            y:p1.y, 
            z:(p1.x * s) + (p1.z * c)
            };
    }
    function Project(tc,p1,w,h,fov,asp) {
        var yn, xn, zn, m = tc.z1 / (tc.z1 + tc.z2 + p1.z);
        yn = p1.y * m;
        xn = p1.x * m;
        zn = tc.z2 + p1.z;
        return {
            x:xn, 
            y:yn, 
            z:zn
        };
    }
    function Outline(tc) {
        this.ts = new Date().valueOf();
        this.tc = tc;
        this.x = this.y = this.w = this.h = this.sc = 1;
        this.z = 0;
    }
    Outline.prototype.Update = function(x,y,w,h,sc,p) {
        var o = this.tc.outlineOffset;
        this.x = sc * (x - o);
        this.y = sc * (y - o);
        this.w = sc * (w + o * 2);
        this.h = sc * (h + o * 2);
        this.sc = sc;
        this.z = p.z;
    };
    Outline.prototype.Draw = function(c) {
        var diff = new Date().valueOf() - this.ts, t = this.tc;
        c.setTransform(1,0,0,1,0,0);
        c.strokeStyle = t.outlineColour;
        c.lineWidth = t.outlineThickness;
        c.shadowBlur = c.shadowOffsetX = c.shadowOffsetY = 0;
        if(t.pulsateTo < 1.0)
            c.globalAlpha = t.pulsateTo + ((1.0 - t.pulsateTo) * 
                (0.5 + (cos(2 * Math.PI * diff / (1000 * t.pulsateTime)) / 2.0)));
        else
            c.globalAlpha = 1.0;
        c.strokeRect(this.x, this.y, this.w, this.h);
    };
    Outline.prototype.Active = function(c,x,y) {
        return (x >= this.x && y >= this.y &&
            x <= this.x + this.w && y <= this.y + this.h);
    };
    function Tag(tc,name,a,v,w,h) {
        var c = tc.ctxt, i;
        this.tc = tc;
        this.image = name.src ? name : null;
        this.name = name.src ? '' : name;
        this.a = a;
        this.p3d = {
            x: v[0] * tc.radius * 1.1, 
            y: v[1] * tc.radius * 1.1, 
            z: v[2] * tc.radius * 1.1
            };
        this.x = this.y = 0;
        this.w = w;
        this.h = h;
        this.colour = tc.textColour;
        this.weight = this.sc = this.alpha = 1;
        this.weighted = !tc.weight;
        this.outline = new Outline(tc);
        if(this.image) {
            if(tc.txtOpt && (tc.shadowBlur || tc.shadowOffset[0] || tc.shadowOffset[1])) {
                i = AddShadowToImage(this.image,tc.shadow,tc.shadowBlur,tc.shadowOffset);
                if(i) {
                    this.image = i;
                    this.w = i.width;
                    this.h = i.height;
                }
            }
        } else {
            this.textHeight = tc.textHeight;
            this.extents = FindTextBoundingBox(this.name, tc.textFont, this.textHeight);
            this.Measure(c,tc);
        }
        this.SetShadowColour = tc.shadowAlpha ? this.SetShadowColourAlpha : this.SetShadowColourFixed;
        this.Draw = this.image ? this.DrawImage : this.DrawText;
    }
    Tag.prototype.Measure = function(c,t) {
        this.h = this.extents ? this.extents.max.y + this.extents.min.y : this.textHeight;
        c.font = this.font = this.textHeight + 'px ' + t.textFont;
        this.w1 = c.measureText(this.name).width;
        if(t.txtOpt) {
            this.image = TextToCanvas(this.name, this.font, this.textHeight, this.w1, this.h, this.colour,
                t.shadow, t.shadowBlur, t.shadowOffset);
            if(this.image)
                this.Draw = this.DrawImage;
            else
                t.txtOpt = false;
        }
    };
    Tag.prototype.SetWeight = function(w) {
        this.weight = w;
        this.Weight(this.tc.ctxt, this.tc);
        this.Measure(this.tc.ctxt, this.tc);
    };
    Tag.prototype.Weight = function(c,t) {
        var w = this.weight, m = t.weightMode;
        this.weighted = true;
        if(m === 'colour' || m === 'both')
            this.colour = FindGradientColour(t, (w - t.min_weight) / (t.max_weight-t.min_weight));
        if(m == 'size' || m == 'both')
            this.textHeight = w * t.weightSize;
        this.extents = FindTextBoundingBox(this.name, t.textFont, this.textHeight);
    };
    Tag.prototype.SetShadowColourFixed = function(c,s,a) {
        c.shadowColor = s;
    };
    Tag.prototype.SetShadowColourAlpha = function(c,s,a) {
        c.shadowColor = SetAlpha(s, a);
    };
    Tag.prototype.DrawText = function(c,xoff,yoff) {
        var t = this.tc, x = this.x, y = this.y, w, h, s = this.sc, o = this.outline;

        c.globalAlpha = this.alpha;
        c.setTransform(s,0,0,s,0,0);
        c.fillStyle = this.colour;
        this.SetShadowColour(c,t.shadow,this.alpha);
        c.font = this.font;
        w = this.w1 * s;
        h = this.h * s;
        x += 1 + (xoff / s) - (w / 2.0);
        y += 1 + (yoff / s) - (h / 2.0);

        c.fillText(this.name, x, y);
        o.Update(x, y, this.w1, this.h, s, this.p3d);
        return o.Active(c, t.mx, t.my) ? o : null;
    };
    Tag.prototype.DrawImage = function(c,xoff,yoff) {
        var t = this.tc, x = this.x, y = this.y, w, h, s = this.sc, o = this.outline, i = this.image;
        c.globalAlpha = this.alpha;
        c.setTransform(s,0,0,s,0,0);
        c.fillStyle = this.colour;
        t.shadow && this.SetShadowColour(c,t.shadow,this.alpha);
        w = i.width;
        h = i.height;
        x += (xoff / s) - (w / 2.0);
        y += (yoff / s) - (h / 2.0);

        c.drawImage(i, x, y, w, h);
        o.Update(x, y, w, h, s, this.p3d);
        return o.Active(c, t.mx, t.my) ? o : null;
    };
    Tag.prototype.Calc = function(yaw,pitch) {
        var pp = RotY(this.p3d,yaw), t = this.tc, mb = t.minBrightness, r = t.radius;
        this.p3d = RotX(pp,pitch);
        pp = Project(t, this.p3d, this.w, this.h, Math.PI / 4, 20);
        this.x = pp.x;
        this.y = pp.y;
        this.sc = (t.z1 + t.z2 - pp.z) / t.z2;
        this.alpha = Math.max(mb,Math.min(1.0,mb + 1 - ((pp.z - t.z2 + r) / (2 * r))));
    };
    Tag.prototype.Clicked = function(e) {
        var a = this.a, t = a.target, h = a.href, evt;
        if(t != '' && t != '_self') {
            if(self.frames[t])
                self.frames[t] = h;
            else if(top.frames[t])
                top.frames[t] = h;
            else
                window.open(h, t);
            return;
        }
        if(a.fireEvent) {
            if(!a.fireEvent('onclick'))
                return;
        } else {
            evt = document.createEvent('MouseEvents');
            evt.initMouseEvent('click', true, true, window,
                0, 0, 0, 0, 0, false, false, false, false, 0, null);
            if(!a.dispatchEvent(evt))
                return;
        }
        document.location = h;
    };
    function TagCanvas() { 
        var i, opts = {
            mx : -1, 
            my : -1,
            cx : 0, 
            cy : 0,
            z1 : 20000, 
            z2 : 20000, 
            z0 : 0.0002,
            freezeActive : false,
            pulsateTo : 1.0,
            pulsateTime : 3,
            reverse : false,
            depth : 0.5,
            maxSpeed : 0.05,
            minSpeed : 0.0,
            decel : 0.95,
            interval : 20,
            initial : null,
            hideTags: true,
            minBrightness : 0.1,
            outlineColour : '#ffff99',
            outlineThickness : 2,
            outlineOffset : 5,
            textColour : '#ff99ff',
            textHeight : 15,
            textFont : 'Helvetica, Arial, sans-serif',
            shadow: '#000',
            shadowBlur: 0,
            shadowOffset: [0,0],
            zoom: 1.0,
            weight: false,
            weightMode: 'size',
            weightFrom: null,
            weightSize: 1.0,
            weightGradient: {
                0:'#f00', 
                0.33:'#ff0', 
                0.66:'#0f0', 
                1:'#00f'
            },
            txtOpt: true,
            frontSelect: false
        };
        for(i in opts)
            this[i] = opts[i];
        this.max_weight = 0;
        this.min_weight = 200;
    }
    TagCanvas.prototype.Draw = function() {
        var cv = this.canvas, max_sc = 0, x1, y1, c = this.ctxt, a, i, l = this.taglist.length;
        c.setTransform(1,0,0,1,0,0);
        x1 = cv.width / 2;
        y1 = cv.height / 2;
        this.active = null;
        for(i = 0; i < l; ++i)
            this.taglist[i].Calc(this.yaw, this.pitch);
        this.taglist = this.taglist.sort(function(a,b) {
            return a.sc-b.sc;
        });
        c.textBaseline = 'top';

        if(!this.txtOpt && (this.shadowBlur || this.shadowOffset[0] || this.shadowOffset[1])) {
            c.shadowBlur = this.shadowBlur;
            c.shadowOffsetX = this.shadowOffset[0];
            c.shadowOffsetY = this.shadowOffset[1];
        }
        c.clearRect(0,0,cv.width,cv.height);
        for(i = 0; i < l; ++i) {
            a = this.taglist[i].Draw(c, x1, y1);
            if(a && a.sc > max_sc && (!this.frontSelect || a.z <= 0)) {
                this.active = a;
                this.active.index = i;
                max_sc = a.sc;
            }
        }
        if(this.freezeActive && this.active)
            this.yaw = this.pitch = 0;
        else
            this.Animate(cv.width, cv.height);
        if(this.active)
            this.active.Draw(c);
    };
    TagCanvas.prototype.Animate = function(w,h) {
        var tc = this, x = tc.mx, y = tc.my, s, ay, ap, r;
        if(x >= 0 && y >= 0 && x < w && y < h)
        {
            s = tc.maxSpeed, r = tc.reverse ? -1 : 1;
            this.yaw = r * ((s * 2.0 * x / w) - s);
            this.pitch = r * -((s * 2.0 * y / h) - s);
            this.initial = null;
        }
        else if(!tc.initial)
        {
            s = tc.minSpeed, ay = abs(this.yaw), ap = abs(this.pitch);
            if(ay > s)
                this.yaw = ay > tc.z0 ? tc.yaw * tc.decel : 0.0;
            if(ap > s)
                this.pitch = ap > tc.z0 ? tc.pitch * tc.decel : 0.0;
        }
    };
    TagCanvas.prototype.Clicked = function(e) {
        var a = this.active, t = this.taglist;
        try {
            if(a && t[a.index]) 
                t[a.index].Clicked(e);
        } catch(ex) {
        }
    };

    TagCanvas.tc = {};

    jQuery.fn.tagcanvas = function(options,lctr) {
        var links, ctr = lctr ? jQuery('#'+lctr) : this;
        if(document.all && !lctr) return false; // IE must have external list
        links = ctr.find('a');
        if(typeof(window.G_vmlCanvasManager) != 'undefined')
            this.each(function() {
                $(this)[0] = window.G_vmlCanvasManager.initElement($(this)[0]);
            });

        if(!links.length || !this[0].getContext || !this[0].getContext('2d').fillText)
            return false;

        this.each(function() {
            var i, vl, im, ii, tag, jqt, o = $(this).offset(), w, weights = [];

            // if using internal links, get only the links for this canvas
            if(!lctr)
                links = $(this).find('a');
			
            jqt = new TagCanvas;
            for(i in options)
                jqt[i] = options[i];

            jqt.z1 = (19800 / (Math.exp(jqt.depth) * (1-1/Math.E))) +
            20000 - 19800 / (1-(1/Math.E));
            jqt.z2 = jqt.z1 * (1/jqt.zoom);

            jqt.radius = (this.height > this.width ? this.width : this.height)
            * 0.33 * (jqt.z2 + jqt.z1) / (jqt.z1);
            jqt.yaw = jqt.initial ? jqt.initial[0] * jqt.maxSpeed : 0;
            jqt.pitch = jqt.initial ? jqt.initial[1] * jqt.maxSpeed : 0;
            jqt.cx = o.left;
            jqt.cy = o.top;
            jqt.canvas = $(this)[0];
            jqt.ctxt = jqt.canvas.getContext('2d');
            jqt.textFont = FixFont(jqt.textFont);
            // let the browser translate "red" into "#ff0000"
            jqt.ctxt.shadowColor = jqt.shadow;
            jqt.shadow = jqt.ctxt.shadowColor;
            jqt.shadowAlpha = (jqt.shadowBlur || jqt.shadowOffset[0] || jqt.shadowOffset[1]) && ShadowAlphaBroken();
            jqt.taglist = [];

            vl = PointsOnSphere(links.length);
            for(i = 0; i < links.length; ++i) {
                im = links[i].getElementsByTagName('img');
                if(im.length) {
                    ii = new Image;
                    ii.src = im[0].src;
                    tag = new Tag(jqt,ii, links[i], vl[i], 1, 1);
                    AddImage(ii,tag,jqt.taglist);
                } else {
                    jqt.taglist.push(new Tag(jqt,links[i].innerText || links[i].textContent, links[i],
                        vl[i], 2, jqt.textHeight + 2));
                }
                if(jqt.weight) {
                    w = FindWeight(jqt,links[i]);
                    if(w > jqt.max_weight) jqt.max_weight = w;
                    if(w < jqt.min_weight) jqt.min_weight = w;
                    weights.push(w);
                }
            }
            if(jqt.weight = (jqt.max_weight > jqt.min_weight)) {
                for(i = 0; i < jqt.taglist.length; ++i) {
                    jqt.taglist[i].SetWeight(weights[i]);
                }
            }

            TagCanvas.tc[$(this)[0].id] = jqt;
            if(!TagCanvas.started) {
                jQuery(document).bind('mousemove', MouseMove);
                jQuery(document).bind('mouseout', MouseMove);
                jQuery(document).bind('mouseup', MouseClick);
                TagCanvas.started = setInterval(DrawCanvas, jqt.interval);
            }
            if(lctr && jqt.hideTags)
                ctr.hide();
        });
        return true;
    };
})(jQuery);