/**
 * Module for using patterns or images as point fills.
 *
 * (c) 2010-2018 Highsoft AS
 * Author: Torstein Hønsi, Øystein Moseng
 *
 * License: www.highcharts.com/license
 */
'use strict';
import H from '../parts/Globals.js';
import '../parts/Utilities.js';

var wrap = H.wrap,
    each = H.each,
    merge = H.merge;


/**
 * Utility function to compute a hash value from an object. Modified Java
 * String.hashCode implementation in JS. Use the preSeed parameter to add an
 * additional seeding step.
 *
 * @param {Object} obj The javascript object to compute the hash from.
 * @param {Bool} [preSeed=false] Add an optional preSeed stage.
 *
 * @return {String} The computed hash.
 */
function hashFromObject(obj, preSeed) {
    var str = JSON.stringify(obj),
        strLen = str.length || 0,
        hash = 0,
        i = 0,
        char,
        seedStep;

    if (preSeed) {
        seedStep = Math.max(Math.floor(strLen / 500), 1);
        for (var a = 0; a < strLen; a += seedStep) {
            hash += str.charCodeAt(a);
        }
        hash = hash & hash;
    }

    for (; i < strLen; ++i) {
        char = str.charCodeAt(i);
        hash = ((hash << 5) - hash) + char;
        hash = hash & hash;
    }

    return hash.toString(16).replace('-', '1');
}


/**
 * Set dimensions on pattern from point. This function will set internal
 * pattern._width/_height properties if width and height are not both already
 * set. We only do this on image patterns. The _width/_height properties are
 * set to the size of the bounding box of the point, optionally taking aspect
 * ratio into account. If only one of width or height are supplied as options,
 * the undefined option is calculated as above.
 *
 * @param {Object} pattern The pattern to set dimensions on.
 */
H.Point.prototype.calculatePatternDimensions = function (pattern) {
    if (pattern.width && pattern.height) {
        return;
    }

    var bBox = this.graphic && (
            this.graphic.getBBox &&
            this.graphic.getBBox(true) ||
            this.graphic.element &&
            this.graphic.element.getBBox()
        ) || {},
        shapeArgs = this.shapeArgs;

    // Prefer using shapeArgs, as it is animation agnostic
    if (shapeArgs) {
        bBox.width = shapeArgs.width || bBox.width;
        bBox.height = shapeArgs.height || bBox.height;
        bBox.x = shapeArgs.x || bBox.x;
        bBox.y = shapeArgs.y || bBox.y;
    }

    // For images we stretch to bounding box
    if (pattern.image) {
        // If we do not have a bounding box at this point, simply add a defer
        // key and pick this up in the fillSetter handler, where the bounding
        // box should exist.
        if (!bBox.width || !bBox.height) {
            pattern._width = 'defer';
            pattern._height = 'defer';
            return;
        }

        // Handle aspect ratio filling
        if (pattern.aspectRatio) {
            bBox.aspectRatio = bBox.width / bBox.height;
            if (pattern.aspectRatio > bBox.aspectRatio) {
                // Height of bBox will determine width
                bBox.aspectWidth = bBox.height * pattern.aspectRatio;
            } else {
                // Width of bBox will determine height
                bBox.aspectHeight = bBox.width / pattern.aspectRatio;
            }
        }

        // We set the width/height on internal properties to differentiate
        // between the options set by a user and by this function.
        pattern._width = pattern.width ||
            Math.ceil(bBox.aspectWidth || bBox.width);
        pattern._height = pattern.height ||
            Math.ceil(bBox.aspectHeight || bBox.height);
    }

    // Set x/y accordingly, centering if using aspect ratio, otherwise adjusting
    // so bounding box corner is 0,0 of pattern.
    if (!pattern.width) {
        pattern._x = pattern.x || 0;
        pattern._x += bBox.x - Math.round(
            bBox.aspectWidth ?
                Math.abs(bBox.aspectWidth - bBox.width) / 2 :
                0
            );
    }
    if (!pattern.height) {
        pattern._y = pattern.y || 0;
        pattern._y += bBox.y - Math.round(
            bBox.aspectHeight ?
                Math.abs(bBox.aspectHeight - bBox.height) / 2 :
                0
            );
    }
};


/**
 * @typedef {Object} PatternOptions
 * @property {Object} pattern Holds a pattern definition.
 * @property {String} pattern.image URL to an image to use as the pattern.
 * @property {Number} pattern.width Width of the pattern. For images this is
 *  automatically set to the width of the element bounding box if not supplied.
 *  For non-image patterns the default is 32px. Note that automatic resizing of
 *  image patterns to fill a bounding box dynamically is only supported for
 *  patterns with an automatically calculated ID.
 * @property {Number} pattern.height Analogous to pattern.width.
 * @property {Number} pattern.aspectRatio For automatically calculated width and
 *  height on images, it is possible to set an aspect ratio. The image will be
 *  zoomed to fill the bounding box, maintaining the aspect ratio defined.
 * @property {Number} pattern.x Horizontal offset of the pattern. Defaults to 0.
 * @property {Number} pattern.y Vertical offset of the pattern. Defaults to 0.
 * @property {Object|String} pattern.path Either an SVG path as string, or an
 *  object. As an object, supply the path string in the `path.d` property. Other
 *  supported properties are standard SVG attributes like `path.stroke` and
 *  `path.fill`. If a path is supplied for the pattern, the `image` property is
 *  ignored.
 * @property {String} pattern.color Pattern color, used as default path stroke.
 * @property {Number} pattern.opacity Opacity of the pattern as a float value
 *     from 0 to 1.
 * @property {String} pattern.id ID to assign to the pattern. This is
 *    automatically computed if not added, and identical patterns are reused. To
 *    refer to an existing pattern for a Highcharts color, use
 *    `color: "url(#pattern-id)"`.
 * @property {Object|Boolean} animation Animation options for the image pattern
 *  loading.
 *
 * @example
 * // Pattern used as a color option
 * color: {
 *     pattern: {
 *            path: {
 *                 d: 'M 3 3 L 8 3 L 8 8 Z',
 *                fill: '#102045'
 *            },
 *            width: 12,
 *            height: 12,
 *            color: '#907000',
 *            opacity: 0.5
 *     }
 * }
 *
 * @sample highcharts/series/pattern-fill-area/
 *         Define a custom path pattern
 * @sample highcharts/series/pattern-fill-pie/
 *         Default patterns and a custom image pattern
 * @sample maps/demo/pattern-fill-map/
 *         Custom images on map
 */
/**
 * Add a pattern to the renderer.
 *
 * @private
 * @param {PatternOptions} options The pattern options.
 *
 * @return {Object} The added pattern. Undefined if the pattern already exists.
 */
H.SVGRenderer.prototype.addPattern = function (options, animation) {
    var pattern,
        animate = H.pick(animation, true),
        path,
        defaultSize = 32,
        width = options.width || options._width || defaultSize,
        height = options.height || options._height || defaultSize,
        color = options.color || '#343434',
        id = options.id,
        ren = this,
        rect = function (fill) {
            ren.rect(0, 0, width, height)
                .attr({
                    fill: fill
                })
                .add(pattern);
        };

    if (!id) {
        this.idCounter = this.idCounter || 0;
        id = 'highcharts-pattern-' + this.idCounter;
        ++this.idCounter;
    }

    // Do nothing if ID already exists
    this.defIds = this.defIds || [];
    if (H.inArray(id, this.defIds) > -1) {
        return;
    }

    // Store ID in list to avoid duplicates
    this.defIds.push(id);

    // Create pattern element
    pattern = this.createElement('pattern').attr({
        id: id,
        patternUnits: 'userSpaceOnUse',
        width: width,
        height: height,
        x: options._x || options.x || 0,
        y: options._y || options.y || 0
    }).add(this.defs);

    // Set id on the SVGRenderer object
    pattern.id = id;

    // Use an SVG path for the pattern
    if (options.path) {
        path = options.path;

        // The background
        if (path.fill) {
            rect(path.fill);
        }

        // The pattern
        this.createElement('path').attr({
            'd': path.d || path,
            'stroke': path.stroke || color,
            'stroke-width': path.strokeWidth || 2
        }).add(pattern);
        pattern.color = color;

    // Image pattern
    } else if (options.image) {
        if (animate) {
            this.image(
                options.image, 0, 0, width, height, function () {
                    // Onload
                    this.animate({ opacity: 1 }, animate);
                    H.removeEvent(this.element, 'load');
                }
            ).attr({ opacity: 0 }).add(pattern);
        } else {
            this.image(options.image, 0, 0, width, height).add(pattern);
        }
    }

    if (options.opacity !== undefined) {
        each(pattern.element.childNodes, function (child) {
            child.setAttribute('opacity', options.opacity);
        });
    }

    // Store for future reference
    this.patternElements = this.patternElements || {};
    this.patternElements[id] = pattern;

    return pattern;
};


/**
 * Make sure we have a series color
 */
wrap(H.Series.prototype, 'getColor', function (proceed) {
    var oldColor = this.options.color;
    // Temporarely remove color options to get defaults
    if (oldColor && oldColor.pattern && !oldColor.pattern.color) {
        delete this.options.color;
        // Get default
        proceed.apply(this, Array.prototype.slice.call(arguments, 1));
        // Replace with old, but add default color
        oldColor.pattern.color = this.color;
        this.color = this.options.color = oldColor;
    } else {
        // We have a color, no need to do anything special
        proceed.apply(this, Array.prototype.slice.call(arguments, 1));
    }
});


/**
 * Calculate pattern dimensions on points that have their own pattern.
 */
wrap(H.Series.prototype, 'render', function (proceed) {
    var isResizing = this.chart.isResizing;
    if (this.isDirtyData || isResizing || !this.chart.hasRendered) {
        each(this.points || [], function (point) {
            var colorOptions = point.options && point.options.color;
            if (colorOptions && colorOptions.pattern) {
                // For most points we want to recalculate the dimensions on
                // render, where we have the shape args and bbox. But if we
                // are resizing and don't have the shape args, defer it, since
                // the bounding box is still not resized.
                if (
                    isResizing &&
                    !(
                        point.shapeArgs &&
                        point.shapeArgs.width &&
                        point.shapeArgs.height
                    )
                ) {
                    colorOptions.pattern._width = 'defer';
                    colorOptions.pattern._height = 'defer';
                } else {
                    point.calculatePatternDimensions(colorOptions.pattern);
                }
            }
        });
    }
    return proceed.apply(this, Array.prototype.slice.call(arguments, 1));
});


/**
 * Merge series color options to points
 */
wrap(H.Point.prototype, 'applyOptions', function (proceed) {
    var point = proceed.apply(this, Array.prototype.slice.call(arguments, 1)),
        colorOptions = point.options.color;

    // Only do this if we have defined a specific color on this point. Otherwise
    // we will end up trying to re-add the series color for each point.
    if (colorOptions && colorOptions.pattern) {
        // Move path definition to object, allows for merge with series path
        // definition
        if (typeof colorOptions.pattern.path === 'string') {
            colorOptions.pattern.path = {
                d: colorOptions.pattern.path
            };
        }
        // Merge with series options
        point.color = point.options.color = merge(
            point.series.options.color, colorOptions
        );
    }
    return point;
});


/**
 * Add functionality to SVG renderer to handle patterns as complex colors
 */
H.addEvent(H.SVGRenderer, 'complexColor', function (args) {
    var color = args.args[0],
        prop = args.args[1],
        element = args.args[2],
        pattern = color.pattern,
        value = '#343434',
        forceHashId;

    // Skip and call default if there is no pattern
    if (!pattern) {
        return true;
    }

    // We have a pattern.
    if (
        pattern.image ||
        typeof pattern.path === 'string' ||
        pattern.path && pattern.path.d
    ) {
        // Real pattern. Add it and set the color value to be a reference.

        // Force Hash-based IDs for legend items, as they are drawn before
        // point render, meaning they are drawn before autocalculated image
        // width/heights. We don't want them to highjack the width/height for
        // this ID if it is defined by users.
        forceHashId = element.parentNode &&
            element.parentNode.getAttribute('class');
        forceHashId = forceHashId &&
            forceHashId.indexOf('highcharts-legend') > -1;

        // If we don't have a width/height yet, handle it. Try faking a point
        // and running the algorithm again.
        if (pattern._width === 'defer' || pattern._height === 'defer') {
            H.Point.prototype.calculatePatternDimensions.call(
                { graphic: { element: element } }, pattern
            );
        }

        // If we don't have an explicit ID, compute a hash from the
        // definition and use that as the ID. This ensures that points with
        // the same pattern definition reuse existing pattern elements by
        // default. We combine two hashes, the second with an additional
        // preSeed algorithm, to minimize collision probability.
        if (forceHashId || !pattern.id) {
            // Make a copy so we don't accidentally edit options when setting ID
            pattern = merge({}, pattern);
            pattern.id = 'highcharts-pattern-' + hashFromObject(pattern) +
                hashFromObject(pattern, true);
        }

        // Add it. This function does nothing if an element with this ID
        // already exists.
        this.addPattern(pattern, !this.forExport && H.animObject(H.pick(
            pattern.animation,
            this.globalAnimation,
            { duration: 100 }
        )));

        value = 'url(' + this.url + '#' + pattern.id + ')';

    } else {
        // Not a full pattern definition, just add color
        value = pattern.color || value;
    }

    // Set the fill/stroke prop on the element
    element.setAttribute(prop, value);

    // Allow the color to be concatenated into tooltips formatters etc.
    color.toString = function () {
        return value;
    };

    // Skip default handler
    return false;
});


/**
 * When animation is used, we have to recalculate pattern dimensions after
 * resize, as the bounding boxes are not available until then.
 */
H.addEvent(H.Chart, 'endResize', function () {
    if (
        H.grep(this.renderer.defIds || [], function (id) {
            return id && id.indexOf && id.indexOf('highcharts-pattern-') === 0;
        }).length
    ) {
        // We have non-default patterns to fix. Find them by looping through
        // all points.
        each(this.series, function (series) {
            each(series.points, function (point) {
                var colorOptions = point.options && point.options.color;
                if (colorOptions && colorOptions.pattern) {
                    colorOptions.pattern._width = 'defer';
                    colorOptions.pattern._height = 'defer';
                }
            });
        });
        // Redraw without animation
        this.redraw(false);
    }
});


/**
 * Add a garbage collector to delete old patterns with autogenerated hashes that
 * are no longer being referenced.
 */
H.addEvent(H.Chart, 'redraw', function () {
    var usedIds = [],
        renderer = this.renderer,
        // Get the autocomputed patterns - these are the ones we might delete
        patterns = H.grep(renderer.defIds || [], function (pattern) {
            return pattern.indexOf &&
                pattern.indexOf('highcharts-pattern-') === 0;
        });

    if (patterns.length) {
        // Look through the DOM for usage of the patterns. This can be points,
        // series, tooltips etc.
        each(this.renderTo.querySelectorAll(
            '[color^="url(#"], [fill^="url(#"], [stroke^="url(#"]'
        ), function (node) {
            var id = node.getAttribute('fill') ||
                    node.getAttribute('color') ||
                    node.getAttribute('stroke');
            if (id) {
                usedIds.push(id
                    .substring(id.indexOf('url(#') + 5)
                    .replace(')', '')
                );
            }
        });

        // Loop through the patterns that exist and see if they are used
        each(patterns, function (id) {
            if (H.inArray(id, usedIds) === -1) {
                // Remove id from used id list
                H.erase(renderer.defIds, id);
                // Remove pattern element
                if (renderer.patternElements[id]) {
                    renderer.patternElements[id].destroy();
                    delete renderer.patternElements[id];
                }
            }
        });
    }
});


/**
 * Add the predefined patterns
 */
H.Chart.prototype.callbacks.push(function (chart) {
    var colors = H.getOptions().colors;
    each([
        'M 0 0 L 10 10 M 9 -1 L 11 1 M -1 9 L 1 11',
        'M 0 10 L 10 0 M -1 1 L 1 -1 M 9 11 L 11 9',
        'M 3 0 L 3 10 M 8 0 L 8 10',
        'M 0 3 L 10 3 M 0 8 L 10 8',
        'M 0 3 L 5 3 L 5 0 M 5 10 L 5 7 L 10 7',
        'M 3 3 L 8 3 L 8 8 L 3 8 Z',
        'M 5 5 m -4 0 a 4 4 0 1 1 8 0 a 4 4 0 1 1 -8 0',
        'M 10 3 L 5 3 L 5 0 M 5 10 L 5 7 L 0 7',
        'M 2 5 L 5 2 L 8 5 L 5 8 Z',
        'M 0 0 L 5 10 L 10 0'
    ], function (pattern, i) {
        chart.renderer.addPattern({
            id: 'highcharts-default-pattern-' + i,
            path: pattern,
            color: colors[i],
            width: 10,
            height: 10
        });
    });
});
