/*
 * charts for WeChat small app v1.0
 *
 * https://github.com/xiaolin3303/wx-charts
 * 2016-11-28
 *
 * Designed and built with all the love of Web
 */

'use strict';

var config = {
    yAxisWidth: 15,
    yAxisSplit: 5,
    xAxisHeight: 15,
    xAxisLineHeight: 15,
    legendHeight: 15,
    yAxisTitleWidth: 15,
    padding: 12,
    columePadding: 3,
    fontSize: 10,
    dataPointShape: ['diamond', 'circle', 'triangle', 'rect'],
    colors: ['#7cb5ec', '#f7a35c', '#434348', '#90ed7d', '#f15c80', '#8085e9'],
    pieChartLinePadding: 25,
    pieChartTextPadding: 15,
    xAxisTextPadding: 3,
    titleColor: '#333333',
    titleFontSize: 20,
    subtitleColor: '#999999',
    subtitleFontSize: 15,
    toolTipPadding: 3,
    toolTipBackground: '#000000',
    toolTipOpacity: 0.7,
    toolTipLineHeight: 14,
    radarGridCount: 3,
    radarLabelTextMargin: 15
};

// Object.assign polyfill
// https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Object/assign
function assign(target, varArgs) {
    if (target == null) {
        // TypeError if undefined or null
        throw new TypeError('Cannot convert undefined or null to object');
    }

    var to = Object(target);

    for (var index = 1; index < arguments.length; index++) {
        var nextSource = arguments[index];

        if (nextSource != null) {
            // Skip over if undefined or null
            for (var nextKey in nextSource) {
                // Avoid bugs when hasOwnProperty is shadowed
                if (Object.prototype.hasOwnProperty.call(nextSource, nextKey)) {
                    to[nextKey] = nextSource[nextKey];
                }
            }
        }
    }
    return to;
}

var util = {
    toFixed: function toFixed(num, limit) {
        limit = limit || 2;
        if (this.isFloat(num)) {
            num = num.toFixed(limit);
        }
        return num;
    },
    isFloat: function isFloat(num) {
        return num % 1 !== 0;
    },
    approximatelyEqual: function approximatelyEqual(num1, num2) {
        return Math.abs(num1 - num2) < 1e-10;
    },
    isSameSign: function isSameSign(num1, num2) {
        return Math.abs(num1) === num1 && Math.abs(num2) === num2 || Math.abs(num1) !== num1 && Math.abs(num2) !== num2;
    },
    isSameXCoordinateArea: function isSameXCoordinateArea(p1, p2) {
        return this.isSameSign(p1.x, p2.x);
    },
    isCollision: function isCollision(obj1, obj2) {
        obj1.end = {};
        obj1.end.x = obj1.start.x + obj1.width;
        obj1.end.y = obj1.start.y - obj1.height;
        obj2.end = {};
        obj2.end.x = obj2.start.x + obj2.width;
        obj2.end.y = obj2.start.y - obj2.height;
        var flag = obj2.start.x > obj1.end.x || obj2.end.x < obj1.start.x || obj2.end.y > obj1.start.y || obj2.start.y < obj1.end.y;

        return !flag;
    }
};

function findRange(num, type, limit) {
    if (isNaN(num)) {
        throw new Error('[wxCharts] unvalid series data!');
    }
    limit = limit || 10;
    type = type ? type : 'upper';
    var multiple = 1;
    while (limit < 1) {
        limit *= 10;
        multiple *= 10;
    }
    if (type === 'upper') {
        num = Math.ceil(num * multiple);
    } else {
        num = Math.floor(num * multiple);
    }
    while (num % limit !== 0) {
        if (type === 'upper') {
            num++;
        } else {
            num--;
        }
    }

    return num / multiple;
}

function calValidDistance(distance, chartData, config, opts) {

    var dataChartAreaWidth = opts.width - config.padding - chartData.xAxisPoints[0];
    var dataChartWidth = chartData.eachSpacing * opts.categories.length;
    var validDistance = distance;
    if (distance >= 0) {
        validDistance = 0;
    } else if (Math.abs(distance) >= dataChartWidth - dataChartAreaWidth) {
        validDistance = dataChartAreaWidth - dataChartWidth;
    }
    return validDistance;
}

function calRotateTranslate(x, y, h) {
    var xv = x;
    var yv = h - y;

    var transX = xv + (h - yv - xv) / Math.sqrt(2);
    transX *= -1;

    var transY = (h - yv) * (Math.sqrt(2) - 1) - (h - yv - xv) / Math.sqrt(2);

    return {
        transX: transX,
        transY: transY
    };
}

function createCurveControlPoints(points, i) {

    function isNotMiddlePoint(points, i) {
        if (points[i - 1] && points[i + 1]) {
            return points[i].y >= Math.max(points[i - 1].y, points[i + 1].y) || points[i].y <= Math.min(points[i - 1].y, points[i + 1].y);
        } else {
            return false;
        }
    }

    var a = 0.2;
    var b = 0.2;
    var pAx = null;
    var pAy = null;
    var pBx = null;
    var pBy = null;
    if (i < 1) {
        pAx = points[0].x + (points[1].x - points[0].x) * a;
        pAy = points[0].y + (points[1].y - points[0].y) * a;
    } else {
        pAx = points[i].x + (points[i + 1].x - points[i - 1].x) * a;
        pAy = points[i].y + (points[i + 1].y - points[i - 1].y) * a;
    }

    if (i > points.length - 3) {
        var last = points.length - 1;
        pBx = points[last].x - (points[last].x - points[last - 1].x) * b;
        pBy = points[last].y - (points[last].y - points[last - 1].y) * b;
    } else {
        pBx = points[i + 1].x - (points[i + 2].x - points[i].x) * b;
        pBy = points[i + 1].y - (points[i + 2].y - points[i].y) * b;
    }

    // fix issue https://github.com/xiaolin3303/wx-charts/issues/79
    if (isNotMiddlePoint(points, i + 1)) {
        pBy = points[i + 1].y;
    }
    if (isNotMiddlePoint(points, i)) {
        pAy = points[i].y;
    }

    return {
        ctrA: { x: pAx, y: pAy },
        ctrB: { x: pBx, y: pBy }
    };
}

function fillSeriesColor(series, config) {
    var index = 0;
    return series.map(function (item) {
        if (!item.color) {
            item.color = config.colors[index];
            index = (index + 1) % config.colors.length;
        }
        return item;
    });
}

function getDataRange(minData, maxData) {
    var limit = 0;
    var range = maxData - minData;
    if (range >= 10000) {
        limit = 1000;
    } else if (range >= 1000) {
        limit = 100;
    } else if (range >= 100) {
        limit = 10;
    } else if (range >= 10) {
        limit = 5;
    } else if (range >= 1) {
        limit = 1;
    } else if (range >= 0.1) {
        limit = 0.1;
    } else {
        limit = 0.01;
    }
    return {
        minRange: findRange(minData, 'lower', limit),
        maxRange: findRange(maxData, 'upper', limit)
    };
}

function measureText(text) {
    var fontSize = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 10;

    // wx canvas 未实现measureText方法, 此处自行实现
    text = String(text);
    var text = text.split('');
    var width = 0;
    text.forEach(function (item) {
        if (/[a-zA-Z]/.test(item)) {
            width += 7;
        } else if (/[0-9]/.test(item)) {
            width += 5.5;
        } else if (/\./.test(item)) {
            width += 2.7;
        } else if (/-/.test(item)) {
            width += 3.25;
        } else if (/[\u4e00-\u9fa5]/.test(item)) {
            width += 10;
        } else if (/\(|\)/.test(item)) {
            width += 3.73;
        } else if (/\s/.test(item)) {
            width += 2.5;
        } else if (/%/.test(item)) {
            width += 8;
        } else {
            width += 10;
        }
    });
    return width * fontSize / 10;
}

function dataCombine(series) {
    return series.reduce(function (a, b) {
        return (a.data ? a.data : a).concat(b.data);
    }, []);
}

function getSeriesDataItem(series, index) {
    var data = [];
    series.forEach(function (item) {
        if (item.data[index] !== null && typeof item.data[index] !== 'undefinded') {
            var seriesItem = {};
            seriesItem.color = item.color;
            seriesItem.name = item.name;
            seriesItem.data = item.format ? item.format(item.data[index]) : item.data[index];
            data.push(seriesItem);
        }
    });

    return data;
}

function getToolTipData(seriesData, calPoints, index, categories) {
    var option = arguments.length > 4 && arguments[4] !== undefined ? arguments[4] : {};

    var textList = seriesData.map(function (item) {
        return {
            text: option.format ? option.format(item, categories[index]) : item.name + ': ' + item.data,
            color: item.color
        };
    });
    var validCalPoints = [];
    var offset = {
        x: 0,
        y: 0
    };
    calPoints.forEach(function (points) {
        if (typeof points[index] !== 'undefinded' && points[index] !== null) {
            validCalPoints.push(points[index]);
        }
    });
    validCalPoints.forEach(function (item) {
        offset.x = Math.round(item.x);
        offset.y += item.y;
    });

    offset.y /= validCalPoints.length;
    return { textList: textList, offset: offset };
}

function findCurrentIndex(currentPoints, xAxisPoints, opts, config) {
    var offset = arguments.length > 4 && arguments[4] !== undefined ? arguments[4] : 0;

    var currentIndex = -1;
    if (isInExactChartArea(currentPoints, opts, config)) {
        xAxisPoints.forEach(function (item, index) {
            if (currentPoints.x + offset > item) {
                currentIndex = index;
            }
        });
    }
    return currentIndex;
}

function isInExactChartArea(currentPoints, opts, config) {
    return currentPoints.x < opts.width - config.padding && currentPoints.x > config.padding + config.yAxisWidth + config.yAxisTitleWidth && currentPoints.y > config.padding && currentPoints.y < opts.height - config.legendHeight - config.xAxisHeight - config.padding;
}

function splitPoints(points) {
    var newPoints = [];
    var items = [];
    points.forEach(function (item, index) {
        if (item !== null) {
            items.push(item);
        } else {
            if (items.length) {
                newPoints.push(items);
            }
            items = [];
        }
    });
    if (items.length) {
        newPoints.push(items);
    }

    return newPoints;
}

function calLegendData(series, opts, config) {
    if (opts.legend === false) {
        return {
            legendList: [],
            legendHeight: 0
        };
    }
    var padding = 5;
    var marginTop = 8;
    var shapeWidth = 15;
    var legendList = [];
    var widthCount = 0;
    var currentRow = [];
    series.forEach(function (item) {
        var itemWidth = 3 * padding + shapeWidth + measureText(item.name || 'undefinded');
        if (widthCount + itemWidth > opts.width) {
            legendList.push(currentRow);
            widthCount = itemWidth;
            currentRow = [item];
        } else {
            widthCount += itemWidth;
            currentRow.push(item);
        }
    });
    if (currentRow.length) {
        legendList.push(currentRow);
    }

    return {
        legendList: legendList,
        legendHeight: legendList.length * (config.fontSize + marginTop) + padding
    }
}

function calCategoriesData(categories, opts, config) {
    var result = {
        angle: 0,
        xAxisHeight: config.xAxisHeight
    };

    var _getXAxisPoints = getXAxisPoints(categories, opts, config),
        eachSpacing = _getXAxisPoints.eachSpacing;

    // get max length of categories text


    var categoriesTextLenth = categories.map(function (item) {
        return measureText(item);
    });

    var maxTextLength = Math.max.apply(this, categoriesTextLenth);

    if (maxTextLength + 2 * config.xAxisTextPadding > eachSpacing) {
        result.angle = 45 * Math.PI / 180;
        result.xAxisHeight = 2 * config.xAxisTextPadding + maxTextLength * Math.sin(result.angle);
    }

    return result;
}

function getXAxisPoints(categories, opts, config) {
    var yAxisTotalWidth = config.yAxisWidth + config.yAxisTitleWidth
    var spacingValid = opts.width - 2 * config.padding - yAxisTotalWidth
    var dataCount = opts.enableScroll ? Math.min(5, categories.length) : categories.length
    var eachSpacing = spacingValid / dataCount

    var xAxisPoints = []
    var startX = config.padding + yAxisTotalWidth
    var endX = opts.width - config.padding
    categories.forEach(function (item, index) {
        xAxisPoints.push(startX + index * eachSpacing)
    });
    if (opts.enableScroll === true) {
        xAxisPoints.push(startX + categories.length * eachSpacing)
    } else {
        xAxisPoints.push(endX)
    }
    return { xAxisPoints: xAxisPoints, startX: startX, endX: endX, eachSpacing: eachSpacing };
}

function getDataPoints(data, minRange, maxRange, xAxisPoints, eachSpacing, opts, config) {
    var process = arguments.length > 7 && arguments[7] !== undefined ? arguments[7] : 1
    var points = []
    var validHeight = opts.height - 2 * config.padding - config.xAxisHeight - config.legendHeight
    data.forEach(function (item, index) {
        if (item === null) {
            points.push(null)
        } else {
            var point = {}
            point.x = xAxisPoints[index] + Math.round(eachSpacing / 2);
            var height = validHeight * (item - minRange) / (maxRange - minRange)
            height *= process
            point.y = opts.height - config.xAxisHeight - config.legendHeight - Math.round(height) - config.padding
            points.push(point)
        }
    })
    return points
}

function getYAxisTextList(series, opts, config) {
    var data = dataCombine(series);
    // remove null from data
    data = data.filter(function (item) {
        return item !== null;
    });
    var minData = Math.min.apply(this, data)
    var maxData = Math.max.apply(this, data)
    if (typeof opts.yAxis.min === 'number') {
        minData = Math.min(opts.yAxis.min, minData);
    }
    if (typeof opts.yAxis.max === 'number') {
        maxData = Math.max(opts.yAxis.max, maxData);
    }

    // fix issue https://github.com/xiaolin3303/wx-charts/issues/9
    if (minData === maxData) {
        var rangeSpan = maxData || 1;
        minData -= rangeSpan;
        maxData += rangeSpan;
    }

    var dataRange = getDataRange(minData, maxData);
    var minRange = dataRange.minRange;
    var maxRange = dataRange.maxRange;

    var range = [];
    var eachRange = (maxRange - minRange) / config.yAxisSplit;

    for (var i = 0; i <= config.yAxisSplit; i++) {
        range.push(minRange + eachRange * i);
    }
    return range.reverse();
}

function calYAxisData(series, opts, config) {

    var ranges = getYAxisTextList(series, opts, config);
    var yAxisWidth = config.yAxisWidth;
    var rangesFormat = ranges.map(function (item) {
        item = util.toFixed(item, 2);
        item = opts.yAxis.format ? opts.yAxis.format(Number(item)) : item;
        yAxisWidth = Math.max(yAxisWidth, measureText(item) + 5);
        return item;
    });
    if (opts.yAxis.disabled === true) {
        yAxisWidth = 0;
    }

    return { rangesFormat: rangesFormat, ranges: ranges, yAxisWidth: yAxisWidth };
}

function drawPointShape(points, color, shape, context) {
    context.beginPath();
    context.setStrokeStyle("#ffffff");
    context.setLineWidth(1);
    context.setFillStyle(color);
    
    if (shape === 'diamond') {
        points.forEach(function (item, index) {
            if (item !== null) {
                context.moveTo(item.x, item.y - 4.5);
                context.lineTo(item.x - 4.5, item.y);
                context.lineTo(item.x, item.y + 4.5);
                context.lineTo(item.x + 4.5, item.y);
                context.lineTo(item.x, item.y - 4.5);
            }
        });
    } else if (shape === 'circle') {
        points.forEach(function (item, index) {
            if (item !== null) {
                context.moveTo(item.x + 3.5, item.y);
                context.arc(item.x, item.y, 4, 0, 2 * Math.PI, false);
            }
        });
    } else if (shape === 'rect') {
        points.forEach(function (item, index) {
            if (item !== null) {
                context.moveTo(item.x - 3.5, item.y - 3.5);
                context.rect(item.x - 3.5, item.y - 3.5, 7, 7);
            }
        });
    } else if (shape === 'triangle') {
        points.forEach(function (item, index) {
            if (item !== null) {
                context.moveTo(item.x, item.y - 4.5);
                context.lineTo(item.x - 4.5, item.y + 4.5);
                context.lineTo(item.x + 4.5, item.y + 4.5);
                context.lineTo(item.x, item.y - 4.5);
            }
        });
    }
    context.closePath();
    context.fill();
    context.stroke();
}
 
function drawPointText(points, series, config, context) {
    // 绘制数据文案
    var data = series.data;

    context.beginPath();
    context.setFontSize(config.fontSize);
    context.setFillStyle('#666666');
    points.forEach(function (item, index) {
        if (item !== null && item.dataLabel) {
            var formatVal = series.format ? series.format(data[index]) : data[index];
            context.fillText(formatVal, item.x - measureText(formatVal) / 2, item.y - 2);
        }
    });
    context.closePath();
    context.stroke();
}

function drawToolTipSplitLine(offsetX, opts, config, context) {
    var startY = config.padding;
    var endY = opts.height - config.padding - config.xAxisHeight - config.legendHeight;
    context.beginPath();
    context.setStrokeStyle('#cccccc');
    context.setLineWidth(1);
    context.moveTo(offsetX, startY);
    context.lineTo(offsetX, endY);
    context.stroke();
    context.closePath();
}

function drawToolTip(textList, offset, opts, config, context) {
    var legendWidth = 4;
    var legendMarginRight = 5;
    var arrowWidth = 8;
    var isOverRightBorder = false;
    offset = assign({
        x: 0,
        y: 0
    }, offset);
    offset.y -= 8;
    var textWidth = textList.map(function (item) {
        return measureText(item.text);
    });

    var toolTipWidth = legendWidth + legendMarginRight + 4 * config.toolTipPadding + Math.max.apply(null, textWidth);
    var toolTipHeight = 2 * config.toolTipPadding + textList.length * config.toolTipLineHeight;

    // if beyond the right border
    if (offset.x - Math.abs(opts._scrollDistance_) + arrowWidth + toolTipWidth > opts.width) {
        isOverRightBorder = true;
    }

    // draw background rect
    context.beginPath();
    context.setFillStyle(opts.tooltip.option.background || config.toolTipBackground);
    context.setGlobalAlpha(config.toolTipOpacity);
    if (isOverRightBorder) {
        context.moveTo(offset.x, offset.y + 10);
        context.lineTo(offset.x - arrowWidth, offset.y + 10 - 5);
        context.lineTo(offset.x - arrowWidth, offset.y + 10 + 5);
        context.moveTo(offset.x, offset.y + 10);
        context.fillRect(offset.x - toolTipWidth - arrowWidth, offset.y, toolTipWidth, toolTipHeight);
    } else {
        context.moveTo(offset.x, offset.y + 10);
        context.lineTo(offset.x + arrowWidth, offset.y + 10 - 5);
        context.lineTo(offset.x + arrowWidth, offset.y + 10 + 5);
        context.moveTo(offset.x, offset.y + 10);
        context.fillRect(offset.x + arrowWidth, offset.y, toolTipWidth, toolTipHeight);
    }

    context.closePath();
    context.fill();
    context.setGlobalAlpha(1);

    // draw legend
    textList.forEach(function (item, index) {
        context.beginPath();
        context.setFillStyle(item.color);
        var startX = offset.x + arrowWidth + 2 * config.toolTipPadding;
        var startY = offset.y + (config.toolTipLineHeight - config.fontSize) / 2 + config.toolTipLineHeight * index + config.toolTipPadding;
        if (isOverRightBorder) {
            startX = offset.x - toolTipWidth - arrowWidth + 2 * config.toolTipPadding;
        }
        context.fillRect(startX, startY, legendWidth, config.fontSize);
        context.closePath();
    });
    // draw text list
    context.beginPath();
    context.setFontSize(config.fontSize);
    context.setFillStyle('#ffffff');
    textList.forEach(function (item, index) {
        var startX = offset.x + arrowWidth + 2 * config.toolTipPadding + legendWidth + legendMarginRight;
        if (isOverRightBorder) {
            startX = offset.x - toolTipWidth - arrowWidth + 2 * config.toolTipPadding + +legendWidth + legendMarginRight;
        }
        var startY = offset.y + (config.toolTipLineHeight - config.fontSize) / 2 + config.toolTipLineHeight * index + config.toolTipPadding;
        context.fillText(item.text, startX, startY + config.fontSize);
    });
    context.stroke();
    context.closePath();
}

function drawYAxisTitle(title, opts, config, context) {
    var startX = config.xAxisHeight + (opts.height - config.xAxisHeight - measureText(title)) / 2;
    context.save();
    context.beginPath();
    context.setFontSize(config.fontSize);
    context.setFillStyle(opts.yAxis.titleFontColor || '#333333');
    context.translate(0, opts.height);
    context.rotate(-90 * Math.PI / 180);
    context.fillText(title, startX, config.padding + 0.5 * config.fontSize);
    context.stroke();
    context.closePath();
    context.restore();
}

function drawLineDataPoints(series, opts, config, context) {
    var process = arguments.length > 4 && arguments[4] !== undefined ? arguments[4] : 1;

    var _calYAxisData3 = calYAxisData(series, opts, config),
        ranges = _calYAxisData3.ranges;

    var _getXAxisPoints3 = getXAxisPoints(opts.categories, opts, config),
        xAxisPoints = _getXAxisPoints3.xAxisPoints,
        eachSpacing = _getXAxisPoints3.eachSpacing;

    var minRange = ranges.pop();
    var maxRange = ranges.shift();
    var calPoints = [];

    context.save();
    if (opts._scrollDistance_ && opts._scrollDistance_ !== 0 && opts.enableScroll === true) {
        context.translate(opts._scrollDistance_, 0);
    }

    if (opts.tooltip && opts.tooltip.textList && opts.tooltip.textList.length && process === 1) {
        drawToolTipSplitLine(opts.tooltip.offset.x, opts, config, context);
    }

    series.forEach(function (eachSeries, seriesIndex) {
        var data = eachSeries.data;
        var points = getDataPoints(data, minRange, maxRange, xAxisPoints, eachSpacing, opts, config, process);
        calPoints.push(points);
        var splitPointList = splitPoints(points);

        splitPointList.forEach(function (points, index) {
            context.beginPath();
            context.setStrokeStyle(eachSeries.color);
            context.setLineWidth(2);
            if (points.length === 1) {
                context.moveTo(points[0].x, points[0].y);
                context.arc(points[0].x, points[0].y, 1, 0, 2 * Math.PI);
            } else {
                context.moveTo(points[0].x, points[0].y);
                if (opts.extra.lineStyle === 'curve') {
                    points.forEach(function (item, index) {
                        if (index > 0) {
                            var ctrlPoint = createCurveControlPoints(points, index - 1);
                            context.bezierCurveTo(ctrlPoint.ctrA.x, ctrlPoint.ctrA.y, ctrlPoint.ctrB.x, ctrlPoint.ctrB.y, item.x, item.y);
                        }
                    });
                } else {
                    points.forEach(function (item, index) {
                        if (index > 0) {
                            context.lineTo(item.x, item.y);
                        }
                    });
                }
                context.moveTo(points[0].x, points[0].y);
            }
            context.closePath();
            context.stroke();
        });

        if (opts.dataPointShape !== false) {
            drawPointShape(points, eachSeries.color, opts.dataPointShape, context);
        }
    });
    if (opts.dataLabel !== false && process === 1) {
        series.forEach(function (eachSeries, seriesIndex) {
            var data = eachSeries.data;
            var points = getDataPoints(data, minRange, maxRange, xAxisPoints, eachSpacing, opts, config, process);
            drawPointText(points, eachSeries, config, context);
        });
    }

    context.restore();

    return {
        xAxisPoints: xAxisPoints,
        calPoints: calPoints,
        eachSpacing: eachSpacing
    };
}

function drawToolTipBridge(opts, config, context, process) {
    context.save();
    if (opts._scrollDistance_ && opts._scrollDistance_ !== 0 && opts.enableScroll === true) {
        context.translate(opts._scrollDistance_, 0);
    }
    if (opts.tooltip && opts.tooltip.textList && opts.tooltip.textList.length && process === 1) {
        drawToolTip(opts.tooltip.textList, opts.tooltip.offset, opts, config, context);
    }
    context.restore();
}

function drawXAxis(categories, opts, config, context) {
    var _getXAxisPoints4 = getXAxisPoints(categories, opts, config),
        xAxisPoints = _getXAxisPoints4.xAxisPoints,
        startX = _getXAxisPoints4.startX,
        endX = _getXAxisPoints4.endX,
        eachSpacing = _getXAxisPoints4.eachSpacing;

    var startY = opts.height - config.padding - config.xAxisHeight - config.legendHeight;
    var endY = startY + config.xAxisLineHeight;

    context.save();
    if (opts._scrollDistance_ && opts._scrollDistance_ !== 0) {
        context.translate(opts._scrollDistance_, 0);
    }

    context.beginPath();
    context.setStrokeStyle(opts.xAxis.gridColor || "#f3f3f3");
    if (opts.xAxis.disableGrid !== true) {
        if (opts.xAxis.type === 'calibration') {
            xAxisPoints.forEach(function (item, index) {
                if (index > 0) {
                    context.moveTo(item - eachSpacing / 2, startY);
                    context.lineTo(item - eachSpacing / 2, startY + 4);
                }
            });
        } else {
            xAxisPoints.forEach(function (item, index) {
                context.moveTo(item, startY);
                context.lineTo(item, endY);
            });
        }
    }
    context.closePath();
    context.stroke();

    // 对X轴列表做抽稀处理
    var validWidth = opts.width - 2 * config.padding - config.yAxisWidth - config.yAxisTitleWidth;
    var maxXAxisListLength = Math.min(categories.length, Math.ceil(validWidth / config.fontSize / 1.5));
    var ratio = Math.ceil(categories.length / maxXAxisListLength);

    categories = categories.map(function (item, index) {
        return index % ratio !== 0 ? '' : item;
    });

    if (config._xAxisTextAngle_ === 0) {
        context.beginPath();
        context.setFontSize(config.fontSize);
        context.setFillStyle(opts.xAxis.fontColor || '#666666');
        categories.forEach(function (item, index) {
            var offset = eachSpacing / 2 - measureText(item) / 2;
            context.fillText(item, xAxisPoints[index] + offset, startY + config.fontSize + 5);
        });
        context.closePath();
        context.stroke();
    } else {
        categories.forEach(function (item, index) {
            context.save();
            context.beginPath();
            context.setFontSize(config.fontSize);
            context.setFillStyle(opts.xAxis.fontColor || '#666666');
            var textWidth = measureText(item);
            var offset = eachSpacing / 2 - textWidth;

            var _calRotateTranslate = calRotateTranslate(xAxisPoints[index] + eachSpacing / 2, startY + config.fontSize / 2 + 5, opts.height),
                transX = _calRotateTranslate.transX,
                transY = _calRotateTranslate.transY;

            context.rotate(-1 * config._xAxisTextAngle_);
            context.translate(transX, transY);
            context.fillText(item, xAxisPoints[index] + offset, startY + config.fontSize + 5);
            context.closePath();
            context.stroke();
            context.restore();
        });
    }

    context.restore();
}

function drawYAxisGrid(opts, config, context) {
    var spacingValid = opts.height - 2 * config.padding - config.xAxisHeight - config.legendHeight;
    var eachSpacing = Math.floor(spacingValid / config.yAxisSplit);
    var yAxisTotalWidth = config.yAxisWidth + config.yAxisTitleWidth;
    var startX = config.padding + yAxisTotalWidth;
    var endX = opts.width - config.padding;

    var points = [];
    for (var i = 0; i < config.yAxisSplit; i++) {
        points.push(config.padding + eachSpacing * i);
    }
    points.push(config.padding + eachSpacing * config.yAxisSplit + 2);

    context.beginPath();
    context.setStrokeStyle(opts.yAxis.gridColor || "#999999");
    context.setLineWidth(0.2);
    points.forEach(function (item, index) {
        context.moveTo(startX, item);
        context.lineTo(endX, item);
    });
    context.closePath();
    context.stroke();
}

function drawYAxis(series, opts, config, context) {
    if (opts.yAxis.disabled === true) {
        return;
    }

    var _calYAxisData4 = calYAxisData(series, opts, config),
        rangesFormat = _calYAxisData4.rangesFormat;

    var yAxisTotalWidth = config.yAxisWidth + config.yAxisTitleWidth;

    var spacingValid = opts.height - 2 * config.padding - config.xAxisHeight - config.legendHeight;
    var eachSpacing = Math.floor(spacingValid / config.yAxisSplit);
    var startX = config.padding + yAxisTotalWidth;
    var endX = opts.width - config.padding;
    var endY = opts.height - config.padding - config.xAxisHeight - config.legendHeight;

    // set YAxis background
    context.setFillStyle(opts.background || '#ffffff');
    if (opts._scrollDistance_ < 0) {
        context.fillRect(0, 0, startX, endY + config.xAxisHeight + 5);
    }
    context.fillRect(endX, 0, opts.width, endY + config.xAxisHeight + 5);

    var points = [];
    for (var i = 0; i <= config.yAxisSplit; i++) {
        points.push(config.padding + eachSpacing * i);
    }

    context.stroke();
    context.beginPath();
    context.setFontSize(config.fontSize);
    context.setFillStyle(opts.yAxis.fontColor || '#666666');
    rangesFormat.forEach(function (item, index) {
        var pos = points[index] ? points[index] : endY;
        context.fillText(item, config.padding + config.yAxisTitleWidth, pos + config.fontSize / 2);
    });
    context.closePath();
    context.stroke();

    if (opts.yAxis.title) {
        drawYAxisTitle(opts.yAxis.title, opts, config, context);
    }
}

function drawLegend(series, opts, config, context) {
    if (!opts.legend) {
        return;
    }
    // each legend shape width 15px
    // the spacing between shape and text in each legend is the `padding`
    // each legend spacing is the `padding`
    // legend margin top `config.padding`

    var _calLegendData = calLegendData(series, opts, config),
        legendList = _calLegendData.legendList;

    var padding = 5;
    var marginTop = 8;
    var shapeWidth = 15;
    legendList.forEach(function (itemList, listIndex) {
        var width = 0;
        itemList.forEach(function (item) {
            item.name = item.name || 'undefined'
            width += 3 * padding + measureText(item.name) + shapeWidth
        })
        var startX = (opts.width - width) / 2 + padding;
        var startY = opts.height - config.padding - config.legendHeight + listIndex * (config.fontSize + marginTop) + padding + marginTop;

        context.setFontSize(config.fontSize);
        itemList.forEach(function (item) {
            switch (opts.type) {
                case 'line':
                    context.beginPath();
                    context.setLineWidth(1);
                    context.setStrokeStyle(item.color);
                    context.moveTo(startX , startY + 6);
                    context.lineTo(startX + 12, startY + 6);
                    context.stroke();
                    context.closePath();
                    // context.beginPath();
                    // context.setLineWidth(1);
                    // context.setStrokeStyle('#ffffff');
                    // context.setFillStyle(item.color);
                    // context.moveTo(startX, startY + 5);
                    // context.arc(startX, startY + 6, 5, 0, 2 * Math.PI);
                    // context.fill();
                    // context.stroke();
                    // context.closePath();
                    break;
                default:
                    context.beginPath();
                    context.setFillStyle(item.color);
                    context.moveTo(startX, startY);
                    context.rect(startX, startY, 15, 10);
                    context.closePath();
                    context.fill();
            }
            startX += padding + shapeWidth;
            context.beginPath();
            context.setFillStyle(opts.extra.legendTextColor || '#333333');
            context.fillText(item.name, startX - 6, startY + 9);
            context.closePath();
            context.stroke();
            startX += measureText(item.name) + 2 * padding;
        });
    })
}

function drawCanvas(opts, context) {
    context.draw();
}

var Timing = {
    easeIn: function easeIn(pos) {
        return Math.pow(pos, 3);
    },

    easeOut: function easeOut(pos) {
        return Math.pow(pos - 1, 3) + 1;
    },

    easeInOut: function easeInOut(pos) {
        if ((pos /= 0.5) < 1) {
            return 0.5 * Math.pow(pos, 3);
        } else {
            return 0.5 * (Math.pow(pos - 2, 3) + 2);
        }
    },

    linear: function linear(pos) {
        return pos;
    }
};

function Animation(opts) {
    this.isStop = false;
    opts.duration = typeof opts.duration === 'undefined' ? 1000 : opts.duration;
    opts.timing = opts.timing || 'linear';

    var delay = 17;

    var createAnimationFrame = function createAnimationFrame() {
        if (typeof requestAnimationFrame !== 'undefined') {
            return requestAnimationFrame;
        } else if (typeof setTimeout !== 'undefined') {
            return function (step, delay) {
                setTimeout(function () {
                    var timeStamp = +new Date();
                    step(timeStamp);
                }, delay);
            };
        } else {
            return function (step) {
                step(null);
            };
        }
    };
    var animationFrame = createAnimationFrame();
    var startTimeStamp = null;
    var _step = function step(timestamp) {
        if (timestamp === null || this.isStop === true) {
            opts.onProcess && opts.onProcess(1);
            opts.onAnimationFinish && opts.onAnimationFinish();
            return;
        }
        if (startTimeStamp === null) {
            startTimeStamp = timestamp;
        }
        if (timestamp - startTimeStamp < opts.duration) {
            var process = (timestamp - startTimeStamp) / opts.duration;
            var timingFunction = Timing[opts.timing];
            process = timingFunction(process);
            opts.onProcess && opts.onProcess(process);
            animationFrame(_step, delay);
        } else {
            opts.onProcess && opts.onProcess(1);
            opts.onAnimationFinish && opts.onAnimationFinish();
        }
    };
    _step = _step.bind(this);

    animationFrame(_step, delay);
}

// stop animation immediately
// and tigger onAnimationFinish
Animation.prototype.stop = function () {
    this.isStop = true;
};

function drawCharts(type, opts, config, context) {
    var _this = this;

    var series = opts.series;
    var categories = opts.categories;
    series = fillSeriesColor(series, config);

    var _calLegendData = calLegendData(series, opts, config),
        legendHeight = _calLegendData.legendHeight;

    config.legendHeight = legendHeight;

    var _calYAxisData = calYAxisData(series, opts, config),
        yAxisWidth = _calYAxisData.yAxisWidth;

    config.yAxisWidth = yAxisWidth;
    if (categories && categories.length) {
        var _calCategoriesData = calCategoriesData(categories, opts, config),
            xAxisHeight = _calCategoriesData.xAxisHeight,
            angle = _calCategoriesData.angle;

        config.xAxisHeight = xAxisHeight;
        config._xAxisTextAngle_ = angle;
    }

    var duration = opts.animation ? 1000 : 0;
    this.animationInstance && this.animationInstance.stop();
    switch (type) {
        case 'line':
            this.animationInstance = new Animation({
                timing: 'easeIn',
                duration: duration,
                onProcess: function onProcess(process) {
                    drawYAxisGrid(opts, config, context);

                    var _drawLineDataPoints = drawLineDataPoints(series, opts, config, context, process),
                        xAxisPoints = _drawLineDataPoints.xAxisPoints,
                        calPoints = _drawLineDataPoints.calPoints,
                        eachSpacing = _drawLineDataPoints.eachSpacing;

                    _this.chartData.xAxisPoints = xAxisPoints;
                    _this.chartData.calPoints = calPoints;
                    _this.chartData.eachSpacing = eachSpacing;
                    drawXAxis(categories, opts, config, context);
                    drawLegend(opts.series, opts, config, context);
                    drawYAxis(series, opts, config, context);
                    drawToolTipBridge(opts, config, context, process);
                    drawCanvas(opts, context);
                },
                onAnimationFinish: function onAnimationFinish() {
                    _this.event.trigger('renderComplete');
                }
            });
            break;
    }
}

// simple event implement

function Event() {
	this.events = {};
}

Event.prototype.addEventListener = function (type, listener) {
	this.events[type] = this.events[type] || [];
	this.events[type].push(listener);
};

Event.prototype.trigger = function () {
	for (var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++) {
		args[_key] = arguments[_key];
	}

	var type = args[0];
	var params = args.slice(1);
	if (!!this.events[type]) {
		this.events[type].forEach(function (listener) {
			try {
				listener.apply(null, params);
			} catch (e) {
				console.error(e);
			}
		});
	}
};

var Charts = function Charts(opts, _component) {
    opts.title = opts.title || {};
    opts.subtitle = opts.subtitle || {};
    opts.yAxis = opts.yAxis || {};
    opts.xAxis = opts.xAxis || {};
    opts.extra = opts.extra || {};
    opts.legend = opts.legend === false ? false : true;
    opts.animation = opts.animation === false ? false : true;
    var config$$1 = assign({}, config);
    config$$1.yAxisTitleWidth = opts.yAxis.disabled !== true && opts.yAxis.title ? config$$1.yAxisTitleWidth : 0;
    config$$1.pieChartLinePadding = opts.dataLabel === false ? 0 : config$$1.pieChartLinePadding;
    config$$1.pieChartTextPadding = opts.dataLabel === false ? 0 : config$$1.pieChartTextPadding;

    this.opts = opts;
    this.config = config$$1;
    this.context = _component? wx.createCanvasContext(opts.canvasId, _component) : wx.createCanvasContext(opts.canvasId);
    // store calcuated chart data
    // such as chart point coordinate
    this.chartData = {};
    this.event = new Event();
    this.scrollOption = {
        currentOffset: 0,
        startTouchX: 0,
        distance: 0
    };
    drawCharts.call(this, opts.type, opts, config$$1, this.context);
}

Charts.prototype.updateData = function () {
    var data = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};

    this.opts.series = data.series || this.opts.series;
    this.opts.categories = data.categories || this.opts.categories;

    this.opts.title = assign({}, this.opts.title, data.title || {});
    this.opts.subtitle = assign({}, this.opts.subtitle, data.subtitle || {});

    drawCharts.call(this, this.opts.type, this.opts, this.config, this.context);
};

Charts.prototype.stopAnimation = function () {
    this.animationInstance && this.animationInstance.stop();
};

Charts.prototype.addEventListener = function (type, listener) {
    this.event.addEventListener(type, listener);
};

Charts.prototype.getCurrentDataIndex = function (e) {
    var touches = e.touches && e.touches.length ? e.touches : e.changedTouches;
    if (touches && touches.length) {
        var _touches$ = touches[0],
            x = _touches$.x,
            y = _touches$.y;
        return findCurrentIndex({ x: x, y: y }, this.chartData.xAxisPoints, this.opts, this.config, Math.abs(this.scrollOption.currentOffset));
    }
    return -1;
};

Charts.prototype.showToolTip = function (e) {
    var option = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};

    if (this.opts.type === 'line' || this.opts.type === 'area') {
        var index = this.getCurrentDataIndex(e);
        var currentOffset = this.scrollOption.currentOffset;

        var opts = assign({}, this.opts, {
            _scrollDistance_: currentOffset,
            animation: false
        });
        if (index > -1) {
            var seriesData = getSeriesDataItem(this.opts.series, index);
            if (seriesData.length === 0) {
                drawCharts.call(this, opts.type, opts, this.config, this.context);
            } else {
                var _getToolTipData = getToolTipData(seriesData, this.chartData.calPoints, index, this.opts.categories, option),
                    textList = _getToolTipData.textList,
                    offset = _getToolTipData.offset;

                opts.tooltip = {
                    textList: textList,
                    offset: offset,
                    option: option
                };
                drawCharts.call(this, opts.type, opts, this.config, this.context);
            }
        } else {
            drawCharts.call(this, opts.type, opts, this.config, this.context);
        }
    }
};

Charts.prototype.scrollStart = function (e) {
    if (e.touches[0] && this.opts.enableScroll === true) {
        this.scrollOption.startTouchX = e.touches[0].x;
    }
};

Charts.prototype.scroll = function (e) {
    // TODO throtting...
    if (e.touches[0] && this.opts.enableScroll === true) {
        var _distance = e.touches[0].x - this.scrollOption.startTouchX;
        var currentOffset = this.scrollOption.currentOffset;

        var validDistance = calValidDistance(currentOffset + _distance, this.chartData, this.config, this.opts);

        this.scrollOption.distance = _distance = validDistance - currentOffset;
        var opts = assign({}, this.opts, {
            _scrollDistance_: currentOffset + _distance,
            animation: false
        });

        drawCharts.call(this, opts.type, opts, this.config, this.context);
    }
};

Charts.prototype.scrollEnd = function (e) {
    if (this.opts.enableScroll === true) {
        var _scrollOption = this.scrollOption,
            currentOffset = _scrollOption.currentOffset,
            distance = _scrollOption.distance;

        this.scrollOption.currentOffset = currentOffset + distance;
        this.scrollOption.distance = 0;
    }
};

module.exports = Charts;