/*
 * 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: ['#6F39FF', '#FF76A5', '#EF344D', '#FFBB23', '#2092FF'],
  pieChartLinePadding: 25,
  pieChartTextPadding: 15,
  xAxisTextPadding: 3,
  titleColor: '#333333',
  titleFontSize: 20,
  subtitleColor: '#999999',
  subtitleFontSize: 15,
  toolTipPadding: 3,
  toolTipBackground: '#000000',
  toolTipOpacity: 0.7,
  toolTipLineHeight: 14,
};

// 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 isInAngleRange(angle, startAngle, endAngle) {
  function adjust(angle) {
    while (angle < 0) {
      angle += 2 * Math.PI;
    }
    while (angle > 2 * Math.PI) {
      angle -= 2 * Math.PI;
    }

    return angle;
  }

  angle = adjust(angle);
  startAngle = adjust(startAngle);
  endAngle = adjust(endAngle);
  if (startAngle > endAngle) {
    endAngle += 2 * Math.PI;
    if (angle < startAngle) {
      angle += 2 * Math.PI;
    }
  }

  return angle >= startAngle && angle <= endAngle;
}

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 convertCoordinateOrigin(x, y, center) {
  return {
    x: center.x + x,
    y: center.y - y
  };
}

function avoidCollision(obj, target) {
  if (target) {
    // is collision test
    while (util.isCollision(obj, target)) {
      if (obj.start.x > 0) {
        obj.start.y--;
      } else if (obj.start.x < 0) {
        obj.start.y++;
      } else {
        if (obj.start.y > 0) {
          obj.start.y++;
        } else {
          obj.start.y--;
        }
      }
    }
  }
  return obj;
}

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 getMaxTextListLength(list) {
  var lengthList = list.map(function(item) {
    return measureText(item);
  });
  return Math.max.apply(null, lengthList);
}

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 findPieChartCurrentIndex(currentPoints, pieData) {
  var currentIndex = -1;
  if (isInExactPieChartArea(currentPoints, pieData.center, pieData.radius)) {
    var angle = Math.atan2(pieData.center.y - currentPoints.y, currentPoints.x - pieData.center.x);
    angle = -angle;
    for (var i = 0, len = pieData.series.length; i < len; i++) {
      var item = pieData.series[i];
      if (isInAngleRange(angle, item._start_, item._start_ + item._proportion_ * 2 * Math.PI)) {
        currentIndex = i;
        break;
      }
    }
  }

  return currentIndex;
}

function isInExactPieChartArea(currentPoints, center, radius) {
  return Math.pow(currentPoints.x - center.x, 2) + Math.pow(currentPoints.y - center.y, 2) <= Math.pow(radius, 2);
}

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 getPieDataPoints(series) {
  var process = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 1;

  var count = 0;
  var _start_ = 0;
  series.forEach(function(item) {
    item.data = item.data === null ? 0 : item.data;
    count += item.data;
  });
  series.forEach(function(item) {
    item.data = item.data === null ? 0 : item.data;
    item._proportion_ = item.data / count * process;
  });
  series.forEach(function(item) {
    item._start_ = _start_;
    _start_ += 2 * item._proportion_ * Math.PI;
  });

  return series;
}

function getPieTextMaxLength(series) {
  series = getPieDataPoints(series);
  var maxLength = 0;
  series.forEach(function(item) {
    var text = item.format ? item.format(+item._proportion_.toFixed(2)) : util.toFixed(item._proportion_ * 100) + '%';
    maxLength = Math.max(maxLength, measureText(text));
  });

  return maxLength;
}

function fixColumeData(points, eachSpacing, columnLen, index, config, opts) {
  return points.map(function(item) {
    if (item === null) {
      return null;
    }
    item.width = (eachSpacing - 2 * config.columePadding) / columnLen;

    if (opts.extra.column && opts.extra.column.width && +opts.extra.column.width > 0) {
      // customer column width
      item.width = Math.min(item.width, +opts.extra.column.width);
    } else {
      // default width should less tran 25px
      // don't ask me why, I don't know
      item.width = Math.min(item.width, 25);
    }
    item.x += (index + 0.5 - columnLen / 2) * item.width;

    return item;
  });
}

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) {
      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 drawPieText(series, opts, config, context, radius, center) {
  var lineRadius = radius + config.pieChartLinePadding;
  var textObjectCollection = [];
  var lastTextObject = null;

  var seriesConvert = series.map(function(item) {
    var arc = 2 * Math.PI - (item._start_ + 2 * Math.PI * item._proportion_ / 2);
    // var text = item.format ? item.format(+item._proportion_.toFixed(2)) : util.toFixed(item._proportion_ * 100) + '%';
    var text = item.data.toFixed(2) + '元';
    var color = item.color;
    return {
      arc: arc,
      text: text ,
      color: color
    };
  });
  seriesConvert.forEach(function(item) {
    // line end
    var orginX1 = Math.cos(item.arc) * lineRadius;
    var orginY1 = Math.sin(item.arc) * lineRadius;

    // line start
    var orginX2 = Math.cos(item.arc) * radius;
    var orginY2 = Math.sin(item.arc) * radius;

    // text start
    var orginX3 = orginX1 >= 0 ? orginX1 + config.pieChartTextPadding : orginX1 - config.pieChartTextPadding;
    var orginY3 = orginY1;

    var textWidth = measureText(item.text);
    var startY = orginY3;

    if (lastTextObject && util.isSameXCoordinateArea(lastTextObject.start, {
        x: orginX3
      })) {
      if (orginX3 > 0) {
        startY = Math.min(orginY3, lastTextObject.start.y);
      } else if (orginX1 < 0) {
        startY = Math.max(orginY3, lastTextObject.start.y);
      } else {
        if (orginY3 > 0) {
          startY = Math.max(orginY3, lastTextObject.start.y);
        } else {
          startY = Math.min(orginY3, lastTextObject.start.y);
        }
      }
    }

    if (orginX3 < 0) {
      orginX3 -= textWidth;
    }

    var textObject = {
      lineStart: {
        x: orginX2,
        y: orginY2
      },
      lineEnd: {
        x: orginX1,
        y: orginY1
      },
      start: {
        x: orginX3,
        y: startY
      },
      width: textWidth,
      height: config.fontSize,
      text: item.text,
      color: item.color
    };

    lastTextObject = avoidCollision(textObject, lastTextObject);
    textObjectCollection.push(lastTextObject);
  });

  textObjectCollection.forEach(function(item) {
    var lineStartPoistion = convertCoordinateOrigin(item.lineStart.x, item.lineStart.y, center);
    var lineEndPoistion = convertCoordinateOrigin(item.lineEnd.x, item.lineEnd.y, center);
    var textPosition = convertCoordinateOrigin(item.start.x, item.start.y, center);
    context.setLineWidth(1);
    context.setFontSize(config.fontSize);
    context.beginPath();
    context.setStrokeStyle(item.color);
    context.setFillStyle(item.color);
    context.moveTo(lineStartPoistion.x, lineStartPoistion.y);
    var curveStartX = item.start.x < 0 ? textPosition.x + item.width : textPosition.x;
    var textStartX = item.start.x < 0 ? textPosition.x - 5 : textPosition.x + 5;
    context.quadraticCurveTo(lineEndPoistion.x, lineEndPoistion.y, curveStartX, textPosition.y);
    context.moveTo(lineStartPoistion.x, lineStartPoistion.y);
    context.stroke();
    context.closePath();
    context.beginPath();
    context.moveTo(textPosition.x + item.width, textPosition.y);
    context.arc(curveStartX, textPosition.y, 2, 0, 2 * Math.PI);
    context.closePath();
    context.fill();
    context.beginPath();
    context.setFillStyle('#666666');
    context.fillText(item.text, textStartX, textPosition.y + 3);
    context.closePath();
    context.stroke();

    context.closePath();
  });
}

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 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 || "#cccccc");

  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 || "#cccccc");
  context.setLineWidth(1);
  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 - 2, startY + 5);
          context.lineTo(startX + 17, startY + 5);
          context.stroke();
          context.closePath();
          context.beginPath();
          context.setLineWidth(1);
          context.setStrokeStyle('#ffffff');
          context.setFillStyle(item.color);
          context.moveTo(startX + 7.5, startY + 5);
          context.arc(startX + 7.5, startY + 5, 4, 0, 2 * Math.PI);
          context.fill();
          context.stroke();
          context.closePath();
          break;
        case 'pie':
        case 'ring':
          context.beginPath();
          context.setFillStyle(item.color);
          context.moveTo(startX + 7.5, startY + 5);
          context.arc(startX + 7.5, startY + 5, 8, 0, 2 * Math.PI);
          context.closePath();
          context.fill();
          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, startY + 9);
      context.closePath();
      context.stroke();
      startX += measureText(item.name) + 2 * padding;
    });
  });
}

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

  var pieOption = opts.extra.pie || {};
  series = getPieDataPoints(series, process);
  var centerPosition = {
    x: opts.width / 2,
    y: (opts.height - config.legendHeight) / 2
  };
  var radius = Math.min(centerPosition.x - config.pieChartLinePadding - config.pieChartTextPadding - config._pieTextMaxLength_, centerPosition.y - config.pieChartLinePadding - config.pieChartTextPadding);
  if (opts.dataLabel) {
    radius -= 10;
  } else {
    radius -= 2 * config.padding;
  }
  series = series.map(function(eachSeries) {
    eachSeries._start_ += (pieOption.offsetAngle || 0) * Math.PI / 180;
    return eachSeries;
  });
  series.forEach(function(eachSeries) {
    context.beginPath();
    context.setLineWidth(2);
    context.setStrokeStyle('#ffffff');
    context.setFillStyle(eachSeries.color);
    context.moveTo(centerPosition.x, centerPosition.y);
    context.arc(centerPosition.x, centerPosition.y, radius, eachSeries._start_, eachSeries._start_ + 2 * eachSeries._proportion_ * Math.PI);
    context.closePath();
    context.fill();
    if (opts.disablePieStroke !== true) {
      context.stroke();
    }
  });

  if (opts.type === 'ring') {
    var innerPieWidth = radius * 0.6;
    if (typeof opts.extra.ringWidth === 'number' && opts.extra.ringWidth > 0) {
      innerPieWidth = Math.max(0, radius - opts.extra.ringWidth);
    }
    context.beginPath();
    context.setFillStyle(opts.background || '#ffffff');
    context.moveTo(centerPosition.x, centerPosition.y);
    context.arc(centerPosition.x, centerPosition.y, innerPieWidth, 0, 2 * Math.PI);
    context.closePath();
    context.fill();
  }

  if (opts.dataLabel !== false && process === 1) {
    // fix https://github.com/xiaolin3303/wx-charts/issues/132
    var valid = false;
    for (var i = 0, len = series.length; i < len; i++) {
      if (series[i].data > 0) {
        valid = true;
        break;
      }
    }

    if (valid) {
      drawPieText(series, opts, config, context, radius, centerPosition);
    }
  }

  if (process === 1 && opts.type === 'ring') {
    drawRingTitle(opts, config, context);
  }

  return {
    center: centerPosition,
    radius: radius,
    series: series
  };
}

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;
  }
  if (type === 'pie' || type === 'ring') {
    config._pieTextMaxLength_ = opts.dataLabel === false ? 0 : getPieTextMaxLength(series);
  }

  var duration = opts.animation ? 1000 : 0;
  this.animationInstance && this.animationInstance.stop();
  switch (type) {
    case 'ring':
    case 'pie':
      this.animationInstance = new Animation({
        timing: 'easeInOut',
        duration: duration,
        onProcess: function onProcess(process) {
          _this.chartData.pieData = drawPieDataPoints(series, opts, config, context, process);
          drawLegend(opts.series, opts, config, context);
          drawCanvas(opts, context);
        },
        onAnimationFinish: function onAnimationFinish() {
          _this.event.trigger('renderComplete');
        }
      });
      break;
    case 'radar':
      // this.animationInstance = new Animation({
      //     timing: 'easeInOut',
      //     duration: duration,
      //     onProcess: function onProcess(process) {
      //         _this.chartData.radarData = drawRadarDataPoints(series, opts, config, context, process);
      //         drawLegend(opts.series, opts, config, context);
      //         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) {
  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 = 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;

    if (this.opts.type === 'pie' || this.opts.type === 'ring') {
      return findPieChartCurrentIndex({
        x: x,
        y: y
      }, this.chartData.pieData);
    } else if (this.opts.type === 'radar') {
      return findRadarChartCurrentIndex({
        x: x,
        y: y
      }, this.chartData.radarData, this.opts.categories.length);
    } else {
      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;