// A few configuration settings
var CROSSHAIRS_LOCATION = '/images/color-search/crosshairs.png';
var HUE_SLIDER_LOCATION = '/images/color-search/h.png';
var HUE_SLIDER_ARROWS_LOCATION = '/images/color-search/position.png';
var SAT_VAL_SQUARE_LOCATION = '/images/color-search/sv.png';

// Here are some boring utility functions. The real code comes later.

function hexToRgb(hexString, defaultColor) {

    if (hexString.charAt(0) == '#') {
        hexString = hexString.substring(1);
    }
    
    var r;
    var g;
    var b;
    if (hexString.length == 3) {
        r = hexString.substr(0, 1);
        r += r;
        g = hexString.substr(1, 1);
        g += g;
        b = hexString.substr(2, 1);
        b += b;
    } else if (hexString.length == 6) {
        r = hexString.substr(0, 2);
        g = hexString.substr(2, 2);
        b = hexString.substr(4, 2);
    } else {
        return defaultColor;
    }
    
    r = parseInt(r, 16);
    g = parseInt(g, 16);
    b = parseInt(b, 16);
    if (isNaN(r) || isNaN(g) || isNaN(b)) {
        return defaultColor;
    } else {
        return {r: r / 255, g: g / 255, b: b / 255};
    }
}

function rgbToHex(color, includeHash) {
    var r = Math.round(color.r * 255);
    var g = Math.round(color.g * 255);
    var b = Math.round(color.b * 255);
    
    r = r.toString(16);
    if (r.length == 1) r = '0' + r;
    g = g.toString(16);
    if (g.length == 1) g = '0' + g;
    b = b.toString(16);
    if (b.length == 1) b = '0' + b;

    return ((includeHash ? '#' : '') + r + g + b);
}

var arVersion = navigator.appVersion.split("MSIE");
var version = parseFloat(arVersion[1]);

function fixPNG(myImage)
{
    if ((version >= 5.5) && (version < 7) && (document.body.filters)) 
    {
        var node = document.createElement('span');
        node.id = myImage.id;
        node.className = myImage.className;
        node.title = myImage.title;
        node.style.cssText = myImage.style.cssText;
        node.style.setAttribute('filter', "progid:DXImageTransform.Microsoft.AlphaImageLoader"
                                        + "(src=\'" + myImage.src + "\', sizingMethod='scale')");
        node.style.fontSize = '0';
        node.style.width = myImage.width.toString() + 'px';
        node.style.height = myImage.height.toString() + 'px';
        node.style.display = 'inline-block';
        return node;
    }
    else
    {
        return myImage.cloneNode(false);
    }
}

function trackDrag(node, handler)
{
    function fixCoords(x, y)
    {
        var nodePageCoords = pageCoords(node);
        x = (x - nodePageCoords.x) + document.documentElement.scrollLeft;
        y = (y - nodePageCoords.y) + document.documentElement.scrollTop;
        if (x < 0) x = 0;
        if (y < 0) y = 0;
        if (x > node.offsetWidth - 1) x = node.offsetWidth - 1;
        if (y > node.offsetHeight - 1) y = node.offsetHeight - 1;
        return {x: x, y: y};
    }
    function mouseDown(ev)
    {
        var coords = fixCoords(ev.clientX, ev.clientY);
        var lastX = coords.x;
        var lastY = coords.y;
        handler(coords.x, coords.y);

        function moveHandler(ev)
        {
            var coords = fixCoords(ev.clientX, ev.clientY);
            if (coords.x != lastX || coords.y != lastY)
            {
                lastX = coords.x;
                lastY = coords.y;
                handler(coords.x, coords.y);
            }
        }
        function upHandler(ev)
        {
            myRemoveEventListener(document, 'mouseup', upHandler);
            myRemoveEventListener(document, 'mousemove', moveHandler);
            myAddEventListener(node, 'mousedown', mouseDown);
        }
        myAddEventListener(document, 'mouseup', upHandler);
        myAddEventListener(document, 'mousemove', moveHandler);
        myRemoveEventListener(node, 'mousedown', mouseDown);
        if (ev.preventDefault) ev.preventDefault();
    }
    myAddEventListener(node, 'mousedown', mouseDown);
    node.onmousedown = function(e) { return false; };
    node.onselectstart = function(e) { return false; };
    node.ondragstart = function(e) { return false; };
}

var eventListeners = [];

function findEventListener(node, event, handler)
{
    var i;
    for (i in eventListeners)
    {
        if (eventListeners[i].node == node && eventListeners[i].event == event
         && eventListeners[i].handler == handler)
        {
            return i;
        }
    }
    return null;
}
function myAddEventListener(node, event, handler)
{
    if (findEventListener(node, event, handler) != null)
    {
        return;
    }

    if (!node.addEventListener)
    {
        node.attachEvent('on' + event, handler);
    }
    else
    {
        node.addEventListener(event, handler, false);
    }

    eventListeners.push({node: node, event: event, handler: handler});
}

function removeEventListenerIndex(index)
{
    var eventListener = eventListeners[index];
    delete eventListeners[index];
    
    if (!eventListener.node.removeEventListener)
    {
        eventListener.node.detachEvent('on' + eventListener.event,
                                       eventListener.handler);
    }
    else
    {
        eventListener.node.removeEventListener(eventListener.event,
                                               eventListener.handler, false);
    }
}

function myRemoveEventListener(node, event, handler)
{
    removeEventListenerIndex(findEventListener(node, event, handler));
}

function cleanupEventListeners()
{
    var i;
    for (i = eventListeners.length; i > 0; i--)
    {
        if (eventListeners[i] != undefined)
        {
            removeEventListenerIndex(i);
        }
    }
}
myAddEventListener(window, 'unload', cleanupEventListeners);

// This copyright statement applies to the following two functions,
// which are taken from MochiKit.
//
// Copyright 2005 Bob Ippolito <bob@redivi.com>
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject
// to the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
// BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
// ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

function hsvToRgb(hue, saturation, value)
{
    var red;
    var green;
    var blue;
    if (value == 0.0)
    {
        red = 0;
        green = 0;
        blue = 0;
    }
    else
    {
        var i = Math.floor(hue * 6);
        var f = (hue * 6) - i;
        var p = value * (1 - saturation);
        var q = value * (1 - (saturation * f));
        var t = value * (1 - (saturation * (1 - f)));
        switch (i)
        {
            case 1: red = q; green = value; blue = p; break;
            case 2: red = p; green = value; blue = t; break;
            case 3: red = p; green = q; blue = value; break;
            case 4: red = t; green = p; blue = value; break;
            case 5: red = value; green = p; blue = q; break;
            case 6: // fall through
            case 0: red = value; green = t; blue = p; break;
        }
    }
    return {r: red, g: green, b: blue};
}

function rgbToHsv(red, green, blue)
{
    var max = Math.max(Math.max(red, green), blue);
    var min = Math.min(Math.min(red, green), blue);
    var hue;
    var saturation;
    var value = max;
    if (min == max)
    {
        hue = 0;
        saturation = 0;
    }
    else
    {
        var delta = (max - min);
        saturation = delta / max;
        if (red == max)
        {
            hue = (green - blue) / delta;
        }
        else if (green == max)
        {
            hue = 2 + ((blue - red) / delta);
        }
        else
        {
            hue = 4 + ((red - green) / delta);
        }
        hue /= 6;
        if (hue < 0)
        {
            hue += 1;
        }
        if (hue > 1)
        {
            hue -= 1;
        }
    }
    return {
        h: hue,
        s: saturation,
        v: value
    };
}

function pageCoords(node)
{
    var x = node.offsetLeft;
    var y = node.offsetTop;
    var parent = node.offsetParent;
    while (parent != null)
    {
        x += parent.offsetLeft;
        y += parent.offsetTop;
        parent = parent.offsetParent;
    }
    return {x: x, y: y};
}

// The real code begins here.
var csSize = 128;
var csSize1 = csSize - 1;
var csWidth = 35;
var csPadding = 15;
var csCHSize = 10;
var csHASize = 5;

var huePositionImg = new Image(csWidth, csHASize*2 + 1);
//var huePositionImg = document.createElement('img');
//huePositionImg.width = csWidth;
//huePositionImg.height = csHASize*2 + 1;
huePositionImg.galleryImg = false;
huePositionImg.src = HUE_SLIDER_ARROWS_LOCATION;
huePositionImg.style.position = 'absolute';

var hueSelectorImg = new Image(csWidth, csSize);
//var hueSelectorImg = document.createElement('img');
//hueSelectorImg.width = csWidth;
//hueSelectorImg.height = csSize;
hueSelectorImg.galleryImg = false;
hueSelectorImg.src = HUE_SLIDER_LOCATION;
hueSelectorImg.style.display = 'block';

var satValImg = new Image(csSize, csSize);
//var satValImg = document.createElement('img');
//satValImg.width = csSize;
//satValImg.height = csSize;
satValImg.galleryImg = false;
satValImg.src = SAT_VAL_SQUARE_LOCATION;
satValImg.style.display = 'block';

var crossHairsImg = new Image(csCHSize*2 + 1, csCHSize*2 + 1);
//var crossHairsImg = document.createElement('img');
//crossHairsImg.width = csCHSize*2 + 1;
//crossHairsImg.height = csCHSize*2 + 1;
crossHairsImg.galleryImg = false;
crossHairsImg.src = CROSSHAIRS_LOCATION;
crossHairsImg.style.position = 'absolute';

function makeColorSelector(rgbObserver)
{
    var rgb, hsv
    
    function colorChanged()
    {
        var hex = rgbToHex(rgb, true);
        var hueRgb = hsvToRgb(hsv.h, 1, 1);
        var hueHex = rgbToHex(hueRgb, true);
        if (rgbObserver) rgbObserver(rgb);
        satValDiv.style.background = hueHex;
        crossHairs.style.left = ((hsv.v*csSize1)-csCHSize).toString() + 'px';
        crossHairs.style.top = (((1-hsv.s)*csSize1)-csCHSize).toString() + 'px';
        huePos.style.top = ((hsv.h*csSize1)-csHASize).toString() + 'px';
    }
    function rgbChanged()
    {
        hsv = rgbToHsv(rgb.r, rgb.g, rgb.b);
        colorChanged();
    }
    function hsvChanged()
    {
        rgb = hsvToRgb(hsv.h, hsv.s, hsv.v);
        colorChanged();
    }
    
    var colorSelectorDiv = document.createElement('div');
    colorSelectorDiv.style.cssText = "padding: "+csPadding+"px; position: relative; height: "+csSize+"px; width: "+(csSize1+csPadding+csWidth)+"px";
    
    var satValDiv = document.createElement('div');
    satValDiv.style.cssText = "position: relative; width: "+csSize+"px; height: "+csSize+"px";
    var newSatValImg = fixPNG(satValImg);
    satValDiv.appendChild(newSatValImg);
    var crossHairs = crossHairsImg.cloneNode(false);
    satValDiv.appendChild(crossHairs);
    function satValDragged(x, y)
    {
        hsv.s = 1-(y/csSize1);
        hsv.v = (x/csSize1);
        hsvChanged();
    }
    trackDrag(satValDiv, satValDragged)
    colorSelectorDiv.appendChild(satValDiv);

    var hueDiv = document.createElement('div');
    hueDiv.style.position = 'absolute';
    hueDiv.style.left = (csSize + 2*csPadding) + 'px';
    hueDiv.style.top = csPadding + 'px';
    hueDiv.style.width = csWidth+'px';
    hueDiv.style.height = csSize + 'px';
    var huePos = fixPNG(huePositionImg);
    hueDiv.appendChild(hueSelectorImg.cloneNode(false));
    hueDiv.appendChild(huePos);
    function hueDragged(x, y)
    {
        hsv.h = y/csSize1;
        hsvChanged();
    }
    trackDrag(hueDiv, hueDragged);
    colorSelectorDiv.appendChild(hueDiv);
    
    return {
    	element: colorSelectorDiv,
    	
	    setValue: function(value) {
	        var newrgb = hexToRgb(value);
	        if (newrgb) {
		        rgb = newrgb;
    		    rgbChanged();
    		}
	    },
	    
		getValue: function(includeHash) {
			return rgb ?  rgbToHex(rgb, includeHash) : null;
		},
	    
    	setRGB: function(newrgb) {
        	rgb = newrgb;
        	rgbChanged();
	    },

    	getRGB: function() {
        	return rgb;
	    }
	}
    return ret;
}




//myAddEventListener(window, 'load', init());