/*
 Flot plugin for rendering pie charts. The plugin assumes the data is 
 coming is as a single data value for each series, and each of those 
 values is a positive value or zero (negative numbers don't make 
 any sense and will cause strange effects). The data values do 
 NOT need to be passed in as percentage values because it 
 internally calculates the total and percentages.

 * Created by Brian Medendorp, June 2009
 * Updated November 2009 with contributions from: btburnett3, Anthony Aragues and Xavi Ivars

 * Changes:
 2009-10-22: lineJoin set to round
 2009-10-23: IE full circle fix, donut
 2009-11-11: Added basic hover from btburnett3 - does not work in IE, and center is off in Chrome and Opera
 2009-11-17: Added IE hover capability submitted by Anthony Aragues
 2009-11-18: Added bug fix submitted by Xavi Ivars (issues with arrays when other JS libraries are included as well)


 Available options are:
 series: {
 pie: {
 show: true/false
 radius: 0-1 for percentage of fullsize, or a specified pixel length, or 'auto'
 innerRadius: 0-1 for percentage of fullsize or a specified pixel length, for creating a donut effect
 startAngle: 0-2 factor of PI used for starting angle (in radians) i.e 3/2 starts at the top, 0 and 2 have the same result
 tilt: 0-1 for percentage to tilt the pie, where 1 is no tilt, and 0 is completely flat (nothing will show)
 offset: {
 top: integer value to move the pie up or down
 left: integer value to move the pie left or right, or 'auto'
 },
 stroke: {
 color: any hexidecimal color value (other formats may or may not work, so best to stick with something like '#FFF')
 width: integer pixel width of the stroke
 },
 label: {
 show: true/false, or 'auto'
 formatter:  a user-defined function that modifies the text/style of the label text
 radius: 0-1 for percentage of fullsize, or a specified pixel length
 background: {
 color: any hexidecimal color value (other formats may or may not work, so best to stick with something like '#000')
 opacity: 0-1
 },
 threshold: 0-1 for the percentage value at which to hide labels (if they're too small)
 },
 combine: {
 threshold: 0-1 for the percentage value at which to combine slices (if they're too small)
 color: any hexidecimal color value (other formats may or may not work, so best to stick with something like '#CCC'), if null, the plugin will automatically use the color of the first slice to be combined
 label: any text value of what the combined slice should be labeled
 }
 highlight: {
 opacity: 0-1
 }
 }
 }

 More detail and specific examples can be found in the included HTML file.

 */

(function ($) {
    function init(plot) // this is the "body" of the plugin
    {
        var canvas = null;
        var target = null;
        var maxRadius = null;
        var centerLeft = null;
        var centerTop = null;
        var total = 0;
        var redraw = true;
        var redrawAttempts = 10;
        var shrink = 0.95;
        var legendWidth = 0;
        var processed = false;
        var raw = false;

        // interactive variables	
        var highlights = [];

        // add hook to determine if pie plugin in enabled, and then perform necessary operations
        plot.hooks.processOptions.push(checkPieEnabled);
        plot.hooks.bindEvents.push(bindEvents);

        // check to see if the pie plugin is enabled
        function checkPieEnabled(plot, options) {
            if (options.series.pie.show) {
                //disable grid
                options.grid.show = false;

                // set labels.show
                if (options.series.pie.label.show == 'auto')
                    if (options.legend.show)
                        options.series.pie.label.show = false;
                    else
                        options.series.pie.label.show = true;

                // set radius
                if (options.series.pie.radius == 'auto')
                    if (options.series.pie.label.show)
                        options.series.pie.radius = 3 / 4;
                    else
                        options.series.pie.radius = 1;

                // ensure sane tilt
                if (options.series.pie.tilt > 1)
                    options.series.pie.tilt = 1;
                if (options.series.pie.tilt < 0)
                    options.series.pie.tilt = 0;

                // add processData hook to do transformations on the data
                plot.hooks.processDatapoints.push(processDatapoints);
                plot.hooks.drawOverlay.push(drawOverlay);

                // add draw hook
                plot.hooks.draw.push(draw);
            }
        }

        // bind hoverable events
        function bindEvents(plot, eventHolder) {
            var options = plot.getOptions();

            if (options.series.pie.show && options.grid.hoverable)
                eventHolder.unbind('mousemove').mousemove(onMouseMove);

            if (options.series.pie.show && options.grid.clickable)
                eventHolder.unbind('click').click(onClick);
        }


        // debugging function that prints out an object
        function alertObject(obj) {
            var msg = '';

            function traverse(obj, depth) {
                if (!depth)
                    depth = 0;
                for (var i = 0; i < obj.length; ++i) {
                    for (var j = 0; j < depth; j++)
                        msg += '\t';

                    if (typeof obj[i] == "object") {	// its an object
                        msg += '' + i + ':\n';
                        traverse(obj[i], depth + 1);
                    }
                    else {	// its a value
                        msg += '' + i + ': ' + obj[i] + '\n';
                    }
                }
            }

            traverse(obj);
            alert(msg);
        }

        function calcTotal(data) {
            for (var i = 0; i < data.length; ++i) {
                var item = parseFloat(data[i].data[0][1]);
                if (item)
                    total += item;
            }
        }

        function processDatapoints(plot, series, data, datapoints) {
            if (!processed) {
                processed = true;

                canvas = plot.getCanvas();
                target = $(canvas).parent();
                options = plot.getOptions();

                plot.setData(combine(plot.getData()));
            }
        }

        function setupPie() {
            legendWidth = target.children().filter('.legend').children().width();

            // calculate maximum radius and center point
            maxRadius = Math.min(canvas.width, (canvas.height / options.series.pie.tilt)) / 2;
            centerTop = (canvas.height / 2) + options.series.pie.offset.top;
            centerLeft = (canvas.width / 2);

            if (options.series.pie.offset.left == 'auto')
                if (options.legend.position.match('w'))
                    centerLeft += legendWidth / 2;
                else
                    centerLeft -= legendWidth / 2;
            else
                centerLeft += options.series.pie.offset.left;

            if (centerLeft < maxRadius)
                centerLeft = maxRadius;
            else if (centerLeft > canvas.width - maxRadius)
                centerLeft = canvas.width - maxRadius;
        }

        function fixData(data) {
            for (var i = 0; i < data.length; ++i) {
                if (typeof(data[i].data) == 'number')
                    data[i].data = [[1, data[i].data]];
                else if (typeof(data[i].data) == 'undefined' || typeof(data[i].data[0]) == 'undefined') {
                    if (typeof(data[i].data) != 'undefined' && typeof(data[i].data.label) != 'undefined')
                        data[i].label = data[i].data.label; // fix weirdness coming from flot
                    data[i].data = [[1, 0]];

                }
            }
            return data;
        }

        function combine(data) {
            data = fixData(data);
            calcTotal(data);
            var combined = 0;
            var numCombined = 0;
            var color = options.series.pie.combine.color;

            var newdata = [];
            for (var i = 0; i < data.length; ++i) {
                // make sure its a number
                data[i].data[0][1] = parseFloat(data[i].data[0][1]);
                if (!data[i].data[0][1])
                    data[i].data[0][1] = 0;

                if (data[i].data[0][1] / total <= options.series.pie.combine.threshold) {
                    combined += data[i].data[0][1];
                    numCombined++;
                    if (!color)
                        color = data[i].color;
                }
                else {
                    newdata.push({
                        data: [[1, data[i].data[0][1]]],
                        color: data[i].color,
                        label: data[i].label,
                        angle: (data[i].data[0][1] * (Math.PI * 2)) / total,
                        percent: (data[i].data[0][1] / total * 100)
                    });
                }
            }
            if (numCombined > 0)
                newdata.push({
                    data: [[1, combined]],
                    color: color,
                    label: options.series.pie.combine.label,
                    angle: (combined * (Math.PI * 2)) / total,
                    percent: (combined / total * 100)
                });
            return newdata;
        }

        function draw(plot, newCtx) {
            if (!target) return; // if no series were passed
            ctx = newCtx;

            setupPie();
            var slices = plot.getData();

            var attempts = 0;
            while (redraw && attempts < redrawAttempts) {
                redraw = false;
                if (attempts > 0)
                    maxRadius *= shrink;
                attempts += 1;
                clear();
                if (options.series.pie.tilt <= 0.8)
                    drawShadow();
                drawPie();
            }
            if (attempts >= redrawAttempts) {
                clear();
                target.prepend('<div class="error">Could not draw pie with labels contained inside canvas</div>');
            }

            if (plot.setSeries && plot.insertLegend) {
                plot.setSeries(slices);
                plot.insertLegend();
            }

            // we're actually done at this point, just defining internal functions at this point

            function clear() {
                ctx.clearRect(0, 0, canvas.width, canvas.height);
                target.children().filter('.pieLabel, .pieLabelBackground').remove();
            }

            function drawShadow() {
                var shadowLeft = 5;
                var shadowTop = 15;
                var edge = 10;
                var alpha = 0.02;

                // set radius
                if (options.series.pie.radius > 1)
                    var radius = options.series.pie.radius;
                else
                    var radius = maxRadius * options.series.pie.radius;

                if (radius >= (canvas.width / 2) - shadowLeft || radius * options.series.pie.tilt >= (canvas.height / 2) - shadowTop || radius <= edge)
                    return;	// shadow would be outside canvas, so don't draw it

                ctx.save();
                ctx.translate(shadowLeft, shadowTop);
                ctx.globalAlpha = alpha;
                ctx.fillStyle = '#000';

                // center and rotate to starting position
                ctx.translate(centerLeft, centerTop);
                ctx.scale(1, options.series.pie.tilt);

                //radius -= edge;
                for (var i = 1; i <= edge; i++) {
                    ctx.beginPath();
                    ctx.arc(0, 0, radius, 0, Math.PI * 2, false);
                    ctx.fill();
                    radius -= i;
                }

                ctx.restore();
            }

            function drawPie() {
                startAngle = Math.PI * options.series.pie.startAngle;

                // set radius
                if (options.series.pie.radius > 1)
                    var radius = options.series.pie.radius;
                else
                    var radius = maxRadius * options.series.pie.radius;

                // center and rotate to starting position
                ctx.save();
                ctx.translate(centerLeft, centerTop);
                ctx.scale(1, options.series.pie.tilt);
                //ctx.rotate(startAngle); // start at top; -- This doesn't work properly in Opera

                // draw slices
                ctx.save();
                var currentAngle = startAngle;
                for (var i = 0; i < slices.length; ++i) {
                    slices[i].startAngle = currentAngle;
                    drawSlice(slices[i].angle, slices[i].color, true);
                }
                ctx.restore();

                // draw slice outlines
                ctx.save();
                ctx.lineWidth = options.series.pie.stroke.width;
                currentAngle = startAngle;
                for (var i = 0; i < slices.length; ++i)
                    drawSlice(slices[i].angle, options.series.pie.stroke.color, false);
                ctx.restore();

                // draw donut hole
                drawDonutHole(ctx);

                // draw labels
                if (options.series.pie.label.show)
                    drawLabels();

                // restore to original state
                ctx.restore();

                function drawSlice(angle, color, fill) {
                    if (angle <= 0)
                        return;

                    if (fill)
                        ctx.fillStyle = color;
                    else {
                        ctx.strokeStyle = color;
                        ctx.lineJoin = 'round';
                    }

                    ctx.beginPath();
                    if (Math.abs(angle - Math.PI * 2) > 0.000000001)
                        ctx.moveTo(0, 0); // Center of the pie
                    else if ($.browser.msie)
                        angle -= 0.0001;
                    //ctx.arc(0,0,radius,0,angle,false); // This doesn't work properly in Opera
                    ctx.arc(0, 0, radius, currentAngle, currentAngle + angle, false);
                    ctx.closePath();
                    //ctx.rotate(angle); // This doesn't work properly in Opera
                    currentAngle += angle;

                    if (fill)
                        ctx.fill();
                    else
                        ctx.stroke();
                }

                function drawLabels() {
                    var currentAngle = startAngle;

                    // set radius
                    if (options.series.pie.label.radius > 1)
                        var radius = options.series.pie.label.radius;
                    else
                        var radius = maxRadius * options.series.pie.label.radius;

                    for (var i = 0; i < slices.length; ++i) {
                        if (slices[i].percent >= options.series.pie.label.threshold * 100)
                            drawLabel(slices[i], currentAngle, i);
                        currentAngle += slices[i].angle;
                    }

                    function drawLabel(slice, startAngle, index) {
                        if (slice.data[0][1] == 0)
                            return;

                        // format label text
                        var lf = options.legend.labelFormatter, text, plf = options.series.pie.label.formatter;
                        if (lf)
                            text = lf(slice.label, slice);
                        else
                            text = slice.label;
                        if (plf)
                            text = plf(text, slice);

                        var halfAngle = ((startAngle + slice.angle) + startAngle) / 2;
                        var x = centerLeft + Math.round(Math.cos(halfAngle) * radius);
                        var y = centerTop + Math.round(Math.sin(halfAngle) * radius) * options.series.pie.tilt;

                        var html = '<span class="pieLabel" id="pieLabel' + index + '" style="position:absolute;top:' + y + 'px;left:' + x + 'px;">' + text + "</span>";
                        target.append(html);
                        var label = target.children('#pieLabel' + index);
                        var labelTop = (y - label.height() / 2);
                        var labelLeft = (x - label.width() / 2);
                        label.css('top', labelTop);
                        label.css('left', labelLeft);

                        // check to make sure that the label is not outside the canvas
                        if (0 - labelTop > 0 || 0 - labelLeft > 0 || canvas.height - (labelTop + label.height()) < 0 || canvas.width - (labelLeft + label.width()) < 0)
                            redraw = true;

                        if (options.series.pie.label.background.opacity != 0) {
                            // put in the transparent background separately to avoid blended labels and label boxes
                            var c = options.series.pie.label.background.color;
                            if (c == null) {
                                c = slice.color;
                            }
                            var pos = 'top:' + labelTop + 'px;left:' + labelLeft + 'px;';
                            $('<div class="pieLabelBackground" style="position:absolute;width:' + label.width() + 'px;height:' + label.height() + 'px;' + pos + 'background-color:' + c + ';"> </div>').insertBefore(label).css('opacity', options.series.pie.label.background.opacity);
                        }
                    } // end individual label function
                } // end drawLabels function
            } // end drawPie function
        } // end draw function

        // Placed here because it needs to be accessed from multiple locations 
        function drawDonutHole(layer) {
            // draw donut hole
            if (options.series.pie.innerRadius > 0) {
                // subtract the center
                layer.save();
                innerRadius = options.series.pie.innerRadius > 1 ? options.series.pie.innerRadius : maxRadius * options.series.pie.innerRadius;
                layer.globalCompositeOperation = 'destination-out'; // this does not work with excanvas, but it will fall back to using the stroke color
                layer.beginPath();
                layer.fillStyle = options.series.pie.stroke.color;
                layer.arc(0, 0, innerRadius, 0, Math.PI * 2, false);
                layer.fill();
                layer.closePath();
                layer.restore();

                // add inner stroke
                layer.save();
                layer.beginPath();
                layer.strokeStyle = options.series.pie.stroke.color;
                layer.arc(0, 0, innerRadius, 0, Math.PI * 2, false);
                layer.stroke();
                layer.closePath();
                layer.restore();
                // TODO: add extra shadow inside hole (with a mask) if the pie is tilted.
            }
        }

        //-- Additional Interactive related functions --

        function isPointInPoly(poly, pt) {
            for (var c = false, i = -1, l = poly.length, j = l - 1; ++i < l; j = i)
                ((poly[i][1] <= pt[1] && pt[1] < poly[j][1]) || (poly[j][1] <= pt[1] && pt[1] < poly[i][1]))
                && (pt[0] < (poly[j][0] - poly[i][0]) * (pt[1] - poly[i][1]) / (poly[j][1] - poly[i][1]) + poly[i][0])
                && (c = !c);
            return c;
        }

        function findNearbySlice(mouseX, mouseY) {
            var slices = plot.getData(),
                options = plot.getOptions(),
                radius = options.series.pie.radius > 1 ? options.series.pie.radius : maxRadius * options.series.pie.radius;

            for (var i = 0; i < slices.length; ++i) {
                var s = slices[i];

                if (s.pie.show) {
                    ctx.save();
                    ctx.beginPath();
                    ctx.moveTo(0, 0); // Center of the pie
                    //ctx.scale(1, options.series.pie.tilt);	// this actually seems to break everything when here.
                    ctx.arc(0, 0, radius, s.startAngle, s.startAngle + s.angle, false);
                    ctx.closePath();
                    x = mouseX - centerLeft;
                    y = mouseY - centerTop;
                    if (ctx.isPointInPath) {
                        if (ctx.isPointInPath(mouseX - centerLeft, mouseY - centerTop)) {
                            //alert('found slice!');
                            ctx.restore();
                            return {datapoint: [s.percent, s.data], dataIndex: 0, series: s, seriesIndex: i};
                        }
                    }
                    else {
                        // excanvas for IE doesn;t support isPointInPath, this is a workaround. 
                        p1X = (radius * Math.cos(s.startAngle));
                        p1Y = (radius * Math.sin(s.startAngle));
                        p2X = (radius * Math.cos(s.startAngle + (s.angle / 4)));
                        p2Y = (radius * Math.sin(s.startAngle + (s.angle / 4)));
                        p3X = (radius * Math.cos(s.startAngle + (s.angle / 2)));
                        p3Y = (radius * Math.sin(s.startAngle + (s.angle / 2)));
                        p4X = (radius * Math.cos(s.startAngle + (s.angle / 1.5)));
                        p4Y = (radius * Math.sin(s.startAngle + (s.angle / 1.5)));
                        p5X = (radius * Math.cos(s.startAngle + s.angle));
                        p5Y = (radius * Math.sin(s.startAngle + s.angle));
                        arrPoly = [[0, 0], [p1X, p1Y], [p2X, p2Y], [p3X, p3Y], [p4X, p4Y], [p5X, p5Y]];
                        arrPoint = [x, y];
                        // TODO: perhaps do some mathmatical trickery here with the Y-coordinate to compensate for pie tilt?
                        if (isPointInPoly(arrPoly, arrPoint)) {
                            ctx.restore();
                            return {datapoint: [s.percent, s.data], dataIndex: 0, series: s, seriesIndex: i};
                        }
                    }
                    ctx.restore();
                }
            }

            return null;
        }

        function onMouseMove(e) {
            triggerClickHoverEvent('plothover', e);
        }

        function onClick(e) {
            triggerClickHoverEvent('plotclick', e);
        }

        // trigger click or hover event (they send the same parameters so we share their code)
        function triggerClickHoverEvent(eventname, e) {
            var offset = plot.offset(),
                canvasX = parseInt(e.pageX - offset.left),
                canvasY = parseInt(e.pageY - offset.top),
                item = findNearbySlice(canvasX, canvasY);

            if (options.grid.autoHighlight) {
                // clear auto-highlights
                for (var i = 0; i < highlights.length; ++i) {
                    var h = highlights[i];
                    if (h.auto == eventname && !(item && h.series == item.series))
                        unhighlight(h.series);
                }
            }

            // highlight the slice
            if (item)
                highlight(item.series, eventname);

            // trigger any hover bind events
            var pos = {pageX: e.pageX, pageY: e.pageY};
            target.trigger(eventname, [pos, item]);
        }

        function highlight(s, auto) {
            if (typeof s == "number")
                s = series[s];

            var i = indexOfHighlight(s);
            if (i == -1) {
                highlights.push({series: s, auto: auto});
                plot.triggerRedrawOverlay();
            }
            else if (!auto)
                highlights[i].auto = false;
        }

        function unhighlight(s) {
            if (s == null) {
                highlights = [];
                plot.triggerRedrawOverlay();
            }

            if (typeof s == "number")
                s = series[s];

            var i = indexOfHighlight(s);
            if (i != -1) {
                highlights.splice(i, 1);
                plot.triggerRedrawOverlay();
            }
        }

        function indexOfHighlight(s) {
            for (var i = 0; i < highlights.length; ++i) {
                var h = highlights[i];
                if (h.series == s)
                    return i;
            }
            return -1;
        }

        function drawOverlay(plot, octx) {
            //alert(options.series.pie.radius);
            var options = plot.getOptions();
            //alert(options.series.pie.radius);

            var radius = options.series.pie.radius > 1 ? options.series.pie.radius : maxRadius * options.series.pie.radius;

            octx.save();
            octx.translate(centerLeft, centerTop);
            octx.scale(1, options.series.pie.tilt);

            for (i = 0; i < highlights.length; ++i)
                drawHighlight(highlights[i].series);

            drawDonutHole(octx);

            octx.restore();

            function drawHighlight(series) {
                if (series.angle < 0) return;

                //octx.fillStyle = parseColor(options.series.pie.highlight.color).scale(null, null, null, options.series.pie.highlight.opacity).toString();
                octx.fillStyle = "rgba(255, 255, 255, " + options.series.pie.highlight.opacity + ")"; // this is temporary until we have access to parseColor

                octx.beginPath();
                if (Math.abs(series.angle - Math.PI * 2) > 0.000000001)
                    octx.moveTo(0, 0); // Center of the pie
                octx.arc(0, 0, radius, series.startAngle, series.startAngle + series.angle, false);
                octx.closePath();
                octx.fill();
            }

        }

    } // end init (plugin body)

    // define pie specific options and their default values
    var options = {
        series: {
            pie: {
                show: false,
                radius: 'auto',	// actual radius of the visible pie (based on full calculated radius if <=1, or hard pixel value)
                innerRadius: 0, /* for donut */
                startAngle: 3 / 2,
                tilt: 1,
                offset: {
                    top: 0,
                    left: 'auto'
                },
                stroke: {
                    color: '#FFF',
                    width: 1
                },
                label: {
                    show: 'auto',
                    formatter: function (label, slice) {
                        return '<div style="font-size:x-small;text-align:center;padding:2px;color:' + slice.color + ';">' + label + '<br/>' + Math.round(slice.percent) + '%</div>';
                    },	// formatter function
                    radius: 1,	// radius at which to place the labels (based on full calculated radius if <=1, or hard pixel value)
                    background: {
                        color: null,
                        opacity: 0
                    },
                    threshold: 0	// percentage at which to hide the label (i.e. the slice is too narrow)
                },
                combine: {
                    threshold: -1,	// percentage at which to combine little slices into one larger slice
                    color: null,	// color to give the new slice (auto-generated if null)
                    label: 'Other'	// label to give the new slice
                },
                highlight: {
                    //color: '#FFF',		// will add this functionality once parseColor is available
                    opacity: 0.5
                }
            }
        }
    };

    $.plot.plugins.push({
        init: init,
        options: options,
        name: "pie",
        version: "1.0"
    });
})(jQuery);