/**
 * @fileOverview Graphics utility functions and constants
 * @name SimileAjax.Graphics
 */

SimileAjax.Graphics = new Object();

/**
 * A boolean value indicating whether PNG translucency is supported on the
 * user's browser or not.
 *
 * @type Boolean
 */
SimileAjax.Graphics.pngIsTranslucent = (!SimileAjax.Platform.browser.isIE) || (SimileAjax.Platform.browser.majorVersion > 6);
if (!SimileAjax.Graphics.pngIsTranslucent) {
    SimileAjax.includeCssFile(document, SimileAjax.urlPrefix + "styles/graphics-ie6.css");
}

/*==================================================
 *  Opacity, translucency
 *==================================================
 */
SimileAjax.Graphics._createTranslucentImage1 = function(url, verticalAlign) {
    var elmt = document.createElement("img");
    elmt.setAttribute("src", url);
    if (verticalAlign != null) {
        elmt.style.verticalAlign = verticalAlign;
    }
    return elmt;
};
SimileAjax.Graphics._createTranslucentImage2 = function(url, verticalAlign) {
    var elmt = document.createElement("img");
    elmt.style.width = "1px";  // just so that IE will calculate the size property
    elmt.style.height = "1px";
    elmt.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" + url +"', sizingMethod='image')";
    elmt.style.verticalAlign = (verticalAlign != null) ? verticalAlign : "middle";
    return elmt;
};

/**
 * Creates a DOM element for an <code>img</code> tag using the URL given. This
 * is a convenience method that automatically includes the necessary CSS to
 * allow for translucency, even on IE.
 * 
 * @function
 * @param {String} url the URL to the image
 * @param {String} verticalAlign the CSS value for the image's vertical-align
 * @return {Element} a DOM element containing the <code>img</code> tag
 */
SimileAjax.Graphics.createTranslucentImage = SimileAjax.Graphics.pngIsTranslucent ?
    SimileAjax.Graphics._createTranslucentImage1 :
    SimileAjax.Graphics._createTranslucentImage2;

SimileAjax.Graphics._createTranslucentImageHTML1 = function(url, verticalAlign) {
    return "<img src=\"" + url + "\"" +
        (verticalAlign != null ? " style=\"vertical-align: " + verticalAlign + ";\"" : "") +
        " />";
};
SimileAjax.Graphics._createTranslucentImageHTML2 = function(url, verticalAlign) {
    var style = 
        "width: 1px; height: 1px; " +
        "filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" + url +"', sizingMethod='image');" +
        (verticalAlign != null ? " vertical-align: " + verticalAlign + ";" : "");
        
    return "<img src='" + url + "' style=\"" + style + "\" />";
};

/**
 * Creates an HTML string for an <code>img</code> tag using the URL given.
 * This is a convenience method that automatically includes the necessary CSS
 * to allow for translucency, even on IE.
 * 
 * @function
 * @param {String} url the URL to the image
 * @param {String} verticalAlign the CSS value for the image's vertical-align
 * @return {String} a string containing the <code>img</code> tag
 */
SimileAjax.Graphics.createTranslucentImageHTML = SimileAjax.Graphics.pngIsTranslucent ?
    SimileAjax.Graphics._createTranslucentImageHTML1 :
    SimileAjax.Graphics._createTranslucentImageHTML2;

/**
 * Sets the opacity on the given DOM element.
 *
 * @param {Element} elmt the DOM element to set the opacity on
 * @param {Number} opacity an integer from 0 to 100 specifying the opacity
 */
SimileAjax.Graphics.setOpacity = function(elmt, opacity) {
    if (SimileAjax.Platform.browser.isIE) {
        elmt.style.filter = "progid:DXImageTransform.Microsoft.Alpha(Style=0,Opacity=" + opacity + ")";
    } else {
        var o = (opacity / 100).toString();
        elmt.style.opacity = o;
        elmt.style.MozOpacity = o;
    }
};

/*==================================================
 *  Bubble
 *==================================================
 */

SimileAjax.Graphics.bubbleConfig = {
    containerCSSClass:              "simileAjax-bubble-container",
    innerContainerCSSClass:         "simileAjax-bubble-innerContainer",
    contentContainerCSSClass:       "simileAjax-bubble-contentContainer",
    
    borderGraphicSize:              50,
    borderGraphicCSSClassPrefix:    "simileAjax-bubble-border-",
    
    arrowGraphicTargetOffset:       33,  // from tip of arrow to the side of the graphic that touches the content of the bubble
    arrowGraphicLength:             100, // dimension of arrow graphic along the direction that the arrow points
    arrowGraphicWidth:              49,  // dimension of arrow graphic perpendicular to the direction that the arrow points
    arrowGraphicCSSClassPrefix:     "simileAjax-bubble-arrow-",
    
    closeGraphicCSSClass:           "simileAjax-bubble-close",
    
    extraPadding:                   20
};

/**
 * Creates a nice, rounded bubble popup with the given content in a div,
 * page coordinates and a suggested width. The bubble will point to the 
 * location on the page as described by pageX and pageY.  All measurements 
 * should be given in pixels.
 *
 * @param {Element} the content div
 * @param {Number} pageX the x coordinate of the point to point to
 * @param {Number} pageY the y coordinate of the point to point to
 * @param {Number} contentWidth a suggested width of the content
 * @param {String} orientation a string ("top", "bottom", "left", or "right")
 *   that describes the orientation of the arrow on the bubble
 * @param {Number} maxHeight. Add a scrollbar div if bubble would be too tall.
 *   Default of 0 or null means no maximum
 */
SimileAjax.Graphics.createBubbleForContentAndPoint = function(
       div, pageX, pageY, contentWidth, orientation, maxHeight) {
    if (typeof contentWidth != "number") {
        contentWidth = 300;
    }
    if (typeof maxHeight != "number") {
        maxHeight = 0;
    }

    div.style.position = "absolute";
    div.style.left = "-5000px";
    div.style.top = "0px";
    div.style.width = contentWidth + "px";
    document.body.appendChild(div);
    
    window.setTimeout(function() {
        var width = div.scrollWidth + 10;
        var height = div.scrollHeight + 10;
        var scrollDivW = 0; // width of the possible inner container when we want vertical scrolling
        if (maxHeight > 0 && height > maxHeight) {
          height = maxHeight;
          scrollDivW = width - 25;
        }  
       
        var bubble = SimileAjax.Graphics.createBubbleForPoint(pageX, pageY, width, height, orientation);
        
        document.body.removeChild(div);
        div.style.position = "static";
        div.style.left = "";
        div.style.top = "";
        
        // create a scroll div if needed
        if (scrollDivW > 0) {
          var scrollDiv = document.createElement("div");
          div.style.width = "";
          scrollDiv.style.width = scrollDivW + "px";
          scrollDiv.appendChild(div);
          bubble.content.appendChild(scrollDiv);
        } else {
          div.style.width = width + "px";
          bubble.content.appendChild(div);
        }
    }, 200);
};

/**
 * Creates a nice, rounded bubble popup with the given page coordinates and
 * content dimensions.  The bubble will point to the location on the page
 * as described by pageX and pageY.  All measurements should be given in
 * pixels.
 *
 * @param {Number} pageX the x coordinate of the point to point to
 * @param {Number} pageY the y coordinate of the point to point to
 * @param {Number} contentWidth the width of the content box in the bubble
 * @param {Number} contentHeight the height of the content box in the bubble
 * @param {String} orientation a string ("top", "bottom", "left", or "right")
 *   that describes the orientation of the arrow on the bubble
 * @return {Element} a DOM element for the newly created bubble
 */
SimileAjax.Graphics.createBubbleForPoint = function(pageX, pageY, contentWidth, contentHeight, orientation) {
    contentWidth = parseInt(contentWidth, 10); // harden against bad input bugs
    contentHeight = parseInt(contentHeight, 10); // getting numbers-as-strings
    
    var bubbleConfig = SimileAjax.Graphics.bubbleConfig;
    var pngTransparencyClassSuffix = 
        SimileAjax.Graphics.pngIsTranslucent ? "pngTranslucent" : "pngNotTranslucent";
    
    var bubbleWidth = contentWidth + 2 * bubbleConfig.borderGraphicSize;
    var bubbleHeight = contentHeight + 2 * bubbleConfig.borderGraphicSize;
    
    var generatePngSensitiveClass = function(className) {
        return className + " " + className + "-" + pngTransparencyClassSuffix;
    };
    
    /*
     *  Render container divs
     */
    var div = document.createElement("div");
    div.className = generatePngSensitiveClass(bubbleConfig.containerCSSClass);
    div.style.width = contentWidth + "px";
    div.style.height = contentHeight + "px";
    
    var divInnerContainer = document.createElement("div");
    divInnerContainer.className = generatePngSensitiveClass(bubbleConfig.innerContainerCSSClass);
    div.appendChild(divInnerContainer);
    
    /*
     *  Create layer for bubble
     */
    var close = function() { 
        if (!bubble._closed) {
            document.body.removeChild(bubble._div);
            bubble._doc = null;
            bubble._div = null;
            bubble._content = null;
            bubble._closed = true;
        }
    }
    var bubble = { _closed: false };
    var layer = SimileAjax.WindowManager.pushLayer(close, true, div);
    bubble._div = div;
    bubble.close = function() { SimileAjax.WindowManager.popLayer(layer); }
    
    /*
     *  Render border graphics
     */
    var createBorder = function(classNameSuffix) {
        var divBorderGraphic = document.createElement("div");
        divBorderGraphic.className = generatePngSensitiveClass(bubbleConfig.borderGraphicCSSClassPrefix + classNameSuffix);
        divInnerContainer.appendChild(divBorderGraphic);
    };
    createBorder("top-left");
    createBorder("top-right");
    createBorder("bottom-left");
    createBorder("bottom-right");
    createBorder("left");
    createBorder("right");
    createBorder("top");
    createBorder("bottom");
    
    /*
     *  Render content
     */
    var divContentContainer = document.createElement("div");
    divContentContainer.className = generatePngSensitiveClass(bubbleConfig.contentContainerCSSClass);
    divInnerContainer.appendChild(divContentContainer);
    bubble.content = divContentContainer;
    
    /*
     *  Render close button
     */
    var divClose = document.createElement("div");
    divClose.className = generatePngSensitiveClass(bubbleConfig.closeGraphicCSSClass);
    divInnerContainer.appendChild(divClose);
    SimileAjax.WindowManager.registerEventWithObject(divClose, "click", bubble, "close");
    
    (function() {
        var dims = SimileAjax.Graphics.getWindowDimensions();
        var docWidth = dims.w;
        var docHeight = dims.h;
        
        var halfArrowGraphicWidth = Math.ceil(bubbleConfig.arrowGraphicWidth / 2);
        
        var createArrow = function(classNameSuffix) {
            var divArrowGraphic = document.createElement("div");
            divArrowGraphic.className = generatePngSensitiveClass(bubbleConfig.arrowGraphicCSSClassPrefix + "point-" + classNameSuffix);
            divInnerContainer.appendChild(divArrowGraphic);
            return divArrowGraphic;
        };
        
        if (pageX - halfArrowGraphicWidth - bubbleConfig.borderGraphicSize - bubbleConfig.extraPadding > 0 &&
            pageX + halfArrowGraphicWidth + bubbleConfig.borderGraphicSize + bubbleConfig.extraPadding < docWidth) {
            
            /*
             *  Bubble can be positioned above or below the target point.
             */
            
            var left = pageX - Math.round(contentWidth / 2);
            left = pageX < (docWidth / 2) ?
                Math.max(left, bubbleConfig.extraPadding + bubbleConfig.borderGraphicSize) : 
                Math.min(left, docWidth - bubbleConfig.extraPadding - bubbleConfig.borderGraphicSize - contentWidth);
                
            if ((orientation && orientation == "top") || 
                (!orientation && 
                    (pageY 
                        - bubbleConfig.arrowGraphicTargetOffset 
                        - contentHeight 
                        - bubbleConfig.borderGraphicSize 
                        - bubbleConfig.extraPadding > 0))) {
                
                /*
                 *  Position bubble above the target point.
                 */
                
                var divArrow = createArrow("down");
                divArrow.style.left = (pageX - halfArrowGraphicWidth - left) + "px";
                
                div.style.left = left + "px";
                div.style.top = (pageY - bubbleConfig.arrowGraphicTargetOffset - contentHeight) + "px";
                
                return;
            } else if ((orientation && orientation == "bottom") || 
                (!orientation && 
                    (pageY 
                        + bubbleConfig.arrowGraphicTargetOffset 
                        + contentHeight 
                        + bubbleConfig.borderGraphicSize 
                        + bubbleConfig.extraPadding < docHeight))) {
                        
                /*
                 *  Position bubble below the target point.
                 */
                
                var divArrow = createArrow("up");
                divArrow.style.left = (pageX - halfArrowGraphicWidth - left) + "px";
                
                div.style.left = left + "px";
                div.style.top = (pageY + bubbleConfig.arrowGraphicTargetOffset) + "px";
                
                return;
            }
        }
        
        var top = pageY - Math.round(contentHeight / 2);
        top = pageY < (docHeight / 2) ?
            Math.max(top, bubbleConfig.extraPadding + bubbleConfig.borderGraphicSize) : 
            Math.min(top, docHeight - bubbleConfig.extraPadding - bubbleConfig.borderGraphicSize - contentHeight);
            
        if ((orientation && orientation == "left") || 
            (!orientation && 
                (pageX 
                    - bubbleConfig.arrowGraphicTargetOffset 
                    - contentWidth
                    - bubbleConfig.borderGraphicSize 
                    - bubbleConfig.extraPadding > 0))) {
            
            /*
             *  Position bubble left of the target point.
             */
            
            var divArrow = createArrow("right");
            divArrow.style.top = (pageY - halfArrowGraphicWidth - top) + "px";
            
            div.style.top = top + "px";
            div.style.left = (pageX - bubbleConfig.arrowGraphicTargetOffset - contentWidth) + "px";
        } else {
            
            /*
             *  Position bubble right of the target point, as the last resort.
             */
            
            var divArrow = createArrow("left");
            divArrow.style.top = (pageY - halfArrowGraphicWidth - top) + "px";
            
            div.style.top = top + "px";
            div.style.left = (pageX + bubbleConfig.arrowGraphicTargetOffset) + "px";
        }
    })();
    
    document.body.appendChild(div);
    
    return bubble;
};

SimileAjax.Graphics.getWindowDimensions = function() {
    if (typeof window.innerHeight == 'number') {
        return { w:window.innerWidth, h:window.innerHeight }; // Non-IE
    } else if (document.documentElement && document.documentElement.clientHeight) {
        return { // IE6+, in "standards compliant mode"
            w:document.documentElement.clientWidth,
            h:document.documentElement.clientHeight
        };
    } else if (document.body && document.body.clientHeight) {
        return { // IE 4 compatible
            w:document.body.clientWidth,
            h:document.body.clientHeight
        };
    }
};


/**
 * Creates a floating, rounded message bubble in the center of the window for
 * displaying modal information, e.g. "Loading..."
 *
 * @param {Document} doc the root document for the page to render on
 * @param {Object} an object with two properties, contentDiv and containerDiv,
 *   consisting of the newly created DOM elements
 */
SimileAjax.Graphics.createMessageBubble = function(doc) {
    var containerDiv = doc.createElement("div");
    if (SimileAjax.Graphics.pngIsTranslucent) {
        var topDiv = doc.createElement("div");
        topDiv.style.height = "33px";
        topDiv.style.background = "url(" + SimileAjax.urlPrefix + "images/message-top-left.png) top left no-repeat";
        topDiv.style.paddingLeft = "44px";
        containerDiv.appendChild(topDiv);
        
        var topRightDiv = doc.createElement("div");
        topRightDiv.style.height = "33px";
        topRightDiv.style.background = "url(" + SimileAjax.urlPrefix + "images/message-top-right.png) top right no-repeat";
        topDiv.appendChild(topRightDiv);
        
        var middleDiv = doc.createElement("div");
        middleDiv.style.background = "url(" + SimileAjax.urlPrefix + "images/message-left.png) top left repeat-y";
        middleDiv.style.paddingLeft = "44px";
        containerDiv.appendChild(middleDiv);
        
        var middleRightDiv = doc.createElement("div");
        middleRightDiv.style.background = "url(" + SimileAjax.urlPrefix + "images/message-right.png) top right repeat-y";
        middleRightDiv.style.paddingRight = "44px";
        middleDiv.appendChild(middleRightDiv);
        
        var contentDiv = doc.createElement("div");
        middleRightDiv.appendChild(contentDiv);
        
        var bottomDiv = doc.createElement("div");
        bottomDiv.style.height = "55px";
        bottomDiv.style.background = "url(" + SimileAjax.urlPrefix + "images/message-bottom-left.png) bottom left no-repeat";
        bottomDiv.style.paddingLeft = "44px";
        containerDiv.appendChild(bottomDiv);
        
        var bottomRightDiv = doc.createElement("div");
        bottomRightDiv.style.height = "55px";
        bottomRightDiv.style.background = "url(" + SimileAjax.urlPrefix + "images/message-bottom-right.png) bottom right no-repeat";
        bottomDiv.appendChild(bottomRightDiv);
    } else {
        containerDiv.style.border = "2px solid #7777AA";
        containerDiv.style.padding = "20px";
        containerDiv.style.background = "white";
        SimileAjax.Graphics.setOpacity(containerDiv, 90);
        
        var contentDiv = doc.createElement("div");
        containerDiv.appendChild(contentDiv);
    }
    
    return {
        containerDiv:   containerDiv,
        contentDiv:     contentDiv
    };
};

/*==================================================
 *  Animation
 *==================================================
 */

/**
 * Creates an animation for a function, and an interval of values.  The word
 * "animation" here is used in the sense of repeatedly calling a function with
 * a current value from within an interval, and a delta value.
 *
 * @param {Function} f a function to be called every 50 milliseconds throughout
 *   the animation duration, of the form f(current, delta), where current is
 *   the current value within the range and delta is the current change.
 * @param {Number} from a starting value
 * @param {Number} to an ending value
 * @param {Number} duration the duration of the animation in milliseconds
 * @param {Function} [cont] an optional function that is called at the end of
 *   the animation, i.e. a continuation.
 * @return {SimileAjax.Graphics._Animation} a new animation object
 */
SimileAjax.Graphics.createAnimation = function(f, from, to, duration, cont) {
    return new SimileAjax.Graphics._Animation(f, from, to, duration, cont);
};

SimileAjax.Graphics._Animation = function(f, from, to, duration, cont) {
    this.f = f;
    this.cont = (typeof cont == "function") ? cont : function() {};
    
    this.from = from;
    this.to = to;
    this.current = from;
    
    this.duration = duration;
    this.start = new Date().getTime();
    this.timePassed = 0;
};

/**
 * Runs this animation.
 */
SimileAjax.Graphics._Animation.prototype.run = function() {
    var a = this;
    window.setTimeout(function() { a.step(); }, 50);
};

/**
 * Increments this animation by one step, and then continues the animation with
 * <code>run()</code>.
 */
SimileAjax.Graphics._Animation.prototype.step = function() {
    this.timePassed += 50;
    
    var timePassedFraction = this.timePassed / this.duration;
    var parameterFraction = -Math.cos(timePassedFraction * Math.PI) / 2 + 0.5;
    var current = parameterFraction * (this.to - this.from) + this.from;
    
    try {
        this.f(current, current - this.current);
    } catch (e) {
    }
    this.current = current;
    
    if (this.timePassed < this.duration) {
        this.run();
    } else {
        this.f(this.to, 0);
        this["cont"]();
    }
};

/*==================================================
 *  CopyPasteButton
 *
 *  Adapted from http://spaces.live.com/editorial/rayozzie/demo/liveclip/liveclipsample/techPreview.html.
 *==================================================
 */

/**
 * Creates a button and textarea for displaying structured data and copying it
 * to the clipboard.  The data is dynamically generated by the given 
 * createDataFunction parameter.
 *
 * @param {String} image an image URL to use as the background for the 
 *   generated box
 * @param {Number} width the width in pixels of the generated box
 * @param {Number} height the height in pixels of the generated box
 * @param {Function} createDataFunction a function that is called with no
 *   arguments to generate the structured data
 * @return a new DOM element
 */
SimileAjax.Graphics.createStructuredDataCopyButton = function(image, width, height, createDataFunction) {
    var div = document.createElement("div");
    div.style.position = "relative";
    div.style.display = "inline";
    div.style.width = width + "px";
    div.style.height = height + "px";
    div.style.overflow = "hidden";
    div.style.margin = "2px";
    
    if (SimileAjax.Graphics.pngIsTranslucent) {
        div.style.background = "url(" + image + ") no-repeat";
    } else {
        div.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" + image +"', sizingMethod='image')";
    }
    
    var style;
    if (SimileAjax.Platform.browser.isIE) {
        style = "filter:alpha(opacity=0)";
    } else {
        style = "opacity: 0";
    }
    div.innerHTML = "<textarea rows='1' autocomplete='off' value='none' style='" + style + "' />";
    
    var textarea = div.firstChild;
    textarea.style.width = width + "px";
    textarea.style.height = height + "px";
    textarea.onmousedown = function(evt) {
        evt = (evt) ? evt : ((event) ? event : null);
        if (evt.button == 2) {
            textarea.value = createDataFunction();
            textarea.select();
        }
    };
    
    return div;
};

/*==================================================
 *  getWidthHeight
 *==================================================
 */
SimileAjax.Graphics.getWidthHeight = function(el) {
    // RETURNS hash {width:  w, height: h} in pixels
    
    var w, h;
    // offsetWidth rounds on FF, so doesn't work for us.
    // See https://bugzilla.mozilla.org/show_bug.cgi?id=458617
    if (el.getBoundingClientRect == null) {
    	// use offsetWidth
      w = el.offsetWidth;
      h = el.offsetHeight;
    } else {
    	// use getBoundingClientRect
      var rect = el.getBoundingClientRect();
      w = Math.ceil(rect.right - rect.left);
    	h = Math.ceil(rect.bottom - rect.top);
    }
    return {
        width:  w,
        height: h
    };
};
 

/*==================================================
 *  FontRenderingContext
 *==================================================
 */
SimileAjax.Graphics.getFontRenderingContext = function(elmt, width) {
    return new SimileAjax.Graphics._FontRenderingContext(elmt, width);
};

SimileAjax.Graphics._FontRenderingContext = function(elmt, width) {
    this._elmt = elmt;
    this._elmt.style.visibility = "hidden";
    if (typeof width == "string") {
        this._elmt.style.width = width;
    } else if (typeof width == "number") {
        this._elmt.style.width = width + "px";
    }
};

SimileAjax.Graphics._FontRenderingContext.prototype.dispose = function() {
    this._elmt = null;
};

SimileAjax.Graphics._FontRenderingContext.prototype.update = function() {
    this._elmt.innerHTML = "A";
    this._lineHeight = this._elmt.offsetHeight;
};

SimileAjax.Graphics._FontRenderingContext.prototype.computeSize = function(text, className) {
    // className arg is optional
    var el = this._elmt;
    el.innerHTML = text;
    el.className = className === undefined ? '' : className;
    var wh = SimileAjax.Graphics.getWidthHeight(el);
    el.className = ''; // reset for the next guy
    
    return wh;
};

SimileAjax.Graphics._FontRenderingContext.prototype.getLineHeight = function() {
    return this._lineHeight;
};

