/**
 * @class Ext.chart.Mask
 *
 * Defines a mask for a chart's series.
 * The 'chart' member must be set prior to rendering.
 *
 * A Mask can be used to select a certain region in a chart.
 * When enabled, the `select` event will be triggered when a
 * region is selected by the mask, allowing the user to perform
 * other tasks like zooming on that region, etc.
 *
 * In order to use the mask one has to set the Chart `mask` option to
 * `true`, `vertical` or `horizontal`. Then a possible configuration for the
 * listener could be:
 *
        items: {
            xtype: 'chart',
            animate: true,
            store: store1,
            mask: 'horizontal',
            listeners: {
                select: {
                    fn: function(me, selection) {
                        me.setZoom(selection);
                        me.mask.hide();
                    }
                }
            },

 * In this example we zoom the chart to that particular region. You can also get
 * a handle to a mask instance from the chart object. The `chart.mask` element is a
 * `Ext.Panel`.
 * 
 */
Ext.define('Ext.chart.Mask', {
    /**
     * Creates new Mask.
     * @param {Object} config (optional) Config object.
     */
    constructor: function(config) {
        var me = this;

        me.addEvents('select');

        if (config) {
            Ext.apply(me, config);
        }
        if (me.mask) {
            me.on('afterrender', function() {
                //create a mask layer component
                var comp = Ext.create('Ext.chart.MaskLayer', {
                    renderTo: me.el
                });
                comp.el.on({
                    'mousemove': function(e) {
                        me.onMouseMove(e);
                    },
                    'mouseup': function(e) {
                        me.resized(e);
                    }
                });
                //create a resize handler for the component
                var resizeHandler = Ext.create('Ext.resizer.Resizer', {
                    el: comp.el,
                    handles: 'all',
                    pinned: true
                });
                resizeHandler.on({
                    'resize': function(e) {
                        me.resized(e);    
                    }    
                });
                comp.initDraggable();
                me.maskType = me.mask;
                me.mask = comp;
                me.maskSprite = me.surface.add({
                    type: 'path',
                    path: ['M', 0, 0],
                    zIndex: 1001,
                    opacity: 0.7,
                    hidden: true,
                    stroke: '#444'
                });
            }, me, { single: true });
        }
    },
    
    resized: function(e) {
        var me = this,
            bbox = me.bbox || me.chartBBox,
            x = bbox.x,
            y = bbox.y,
            width = bbox.width,
            height = bbox.height,
            box = me.mask.getBox(true),
            max = Math.max,
            min = Math.min,
            staticX = box.x - x,
            staticY = box.y - y;
        
        staticX = max(staticX, x);
        staticY = max(staticY, y);
        staticX = min(staticX, width);
        staticY = min(staticY, height);
        box.x = staticX;
        box.y = staticY;
        me.fireEvent('select', me, box);
    },

    onMouseUp: function(e) {
        var me = this,
            bbox = me.bbox || me.chartBBox,
            sel = me.maskSelection;
        me.maskMouseDown = false;
        me.mouseDown = false;
        if (me.mouseMoved) {
            me.onMouseMove(e);
            me.mouseMoved = false;
            me.fireEvent('select', me, {
                x: sel.x - bbox.x,
                y: sel.y - bbox.y,
                width: sel.width,
                height: sel.height
            });
        }
    },

    onMouseDown: function(e) {
        var me = this;
        me.mouseDown = true;
        me.mouseMoved = false;
        me.maskMouseDown = {
            x: e.getPageX() - me.el.getX(),
            y: e.getPageY() - me.el.getY()
        };
    },

    onMouseMove: function(e) {
        var me = this,
            mask = me.maskType,
            bbox = me.bbox || me.chartBBox,
            x = bbox.x,
            y = bbox.y,
            math = Math,
            floor = math.floor,
            abs = math.abs,
            min = math.min,
            max = math.max,
            height = floor(y + bbox.height),
            width = floor(x + bbox.width),
            posX = e.getPageX(),
            posY = e.getPageY(),
            staticX = posX - me.el.getX(),
            staticY = posY - me.el.getY(),
            maskMouseDown = me.maskMouseDown,
            path;
        
        me.mouseMoved = me.mouseDown;
        staticX = max(staticX, x);
        staticY = max(staticY, y);
        staticX = min(staticX, width);
        staticY = min(staticY, height);
        if (maskMouseDown && me.mouseDown) {
            if (mask == 'horizontal') {
                staticY = y;
                maskMouseDown.y = height;
                posY = me.el.getY() + bbox.height + me.insetPadding;
            }
            else if (mask == 'vertical') {
                staticX = x;
                maskMouseDown.x = width;
            }
            width = maskMouseDown.x - staticX;
            height = maskMouseDown.y - staticY;
            path = ['M', staticX, staticY, 'l', width, 0, 0, height, -width, 0, 'z'];
            me.maskSelection = {
                x: width > 0 ? staticX : staticX + width,
                y: height > 0 ? staticY : staticY + height,
                width: abs(width),
                height: abs(height)
            };
            me.mask.updateBox({
                x: posX - abs(width),
                y: posY - abs(height),
                width: abs(width),
                height: abs(height)
            });
            me.mask.show();
            me.maskSprite.setAttributes({
                hidden: true    
            }, true);
        }
        else {
            if (mask == 'horizontal') {
                path = ['M', staticX, y, 'L', staticX, height];
            }
            else if (mask == 'vertical') {
                path = ['M', x, staticY, 'L', width, staticY];
            }
            else {
                path = ['M', staticX, y, 'L', staticX, height, 'M', x, staticY, 'L', width, staticY];
            }
            me.maskSprite.setAttributes({
                path: path,
                fill: me.maskMouseDown ? me.maskSprite.stroke : false,
                'stroke-width': mask === true ? 1 : 3,
                hidden: false
            }, true);
        }
    },

    onMouseLeave: function(e) {
        var me = this;
        me.mouseMoved = false;
        me.mouseDown = false;
        me.maskMouseDown = false;
        me.mask.hide();
        me.maskSprite.hide(true);
    }
});