// 统计图表统一清爽简洁风格（echarts 4 兼容）
// 供 statistics/*.vue 复用，保证视觉一致

const toRgba = (hex, alpha) => {
  const n = parseInt(hex.slice(1), 16);
  const r = (n >> 16) & 255;
  const g = (n >> 8) & 255;
  const b = n & 255;
  return `rgba(${r}, ${g}, ${b}, ${alpha})`;
};

export const COLORS = {
  blue: '#5B8FF9',
  green: '#5AD8A6',
  amber: '#F6BD16',
  coral: '#E8684A',
  sky: '#6DC8EC',
  purple: '#9270CA',
  orange: '#FF9D4D',
  teal: '#269A99'
};

export const PALETTE = Object.values(COLORS);

const tipBase = {
  backgroundColor: '#ffffff',
  borderColor: '#e8eaf0',
  borderWidth: 1,
  padding: [10, 14],
  textStyle: { color: '#333', fontSize: 13 },
  extraCssText: 'box-shadow:0 6px 18px rgba(31,45,61,.1);border-radius:10px;'
};

// 坐标轴类 tooltip（柱状/折线）
export function axisTooltip() {
  return { trigger: 'axis', ...tipBase, axisPointer: { lineStyle: { color: '#c9d2e0' } } };
}

// 图形类 tooltip（饼图）
export function itemTooltip() {
  return { trigger: 'item', ...tipBase, formatter: '{b}：{c} ({d}%)' };
}

export function grid() {
  return { left: 8, right: 16, top: 44, bottom: 8, containLabel: true };
}

// 类目轴
export function xAxis(data) {
  return {
    type: 'category',
    data,
    axisLine: { show: false },
    axisTick: { show: false },
    axisLabel: { color: '#8a919f', fontSize: 12 }
  };
}

// 数值轴
export function yAxis(name) {
  return {
    type: 'value',
    name,
    nameTextStyle: { color: '#b0b6c3', fontSize: 12 },
    axisLabel: { color: '#8a919f', fontSize: 12 },
    splitLine: { lineStyle: { type: 'dashed', color: '#f0f1f5' } }
  };
}

export function legend(data) {
  return {
    data,
    icon: 'roundRect',
    itemWidth: 10,
    itemHeight: 10,
    itemGap: 18,
    textStyle: { color: '#8a919f', fontSize: 12 }
  };
}

// 柱状系列
export function barSeries(name, data, color, opts = {}) {
  return {
    name,
    type: 'bar',
    data,
    barMaxWidth: opts.maxWidth || 20,
    itemStyle: { color, borderRadius: opts.radius || [4, 4, 0, 0] },
    stack: opts.stack,
    yAxisIndex: opts.yAxisIndex
  };
}

// 折线系列
export function lineSeries(name, data, color, opts = {}) {
  const s = {
    name,
    type: 'line',
    data,
    smooth: true,
    symbol: 'circle',
    symbolSize: opts.symbolSize || 6,
    lineStyle: { width: 3, color },
    itemStyle: { color },
    yAxisIndex: opts.yAxisIndex
  };
  if (opts.area) {
    s.areaStyle = {
      color: {
        type: 'linear',
        x: 0,
        y: 0,
        x2: 0,
        y2: 1,
        colorStops: [
          { offset: 0, color: toRgba(color, 0.24) },
          { offset: 1, color: toRgba(color, 0) }
        ]
      }
    };
  }
  return s;
}

// 环形图系列
export function donutSeries(name, data) {
  return {
    name,
    type: 'pie',
    radius: ['52%', '72%'],
    center: ['50%', '50%'],
    avoidLabelOverlap: false,
    itemStyle: { borderColor: '#fff', borderWidth: 2 },
    label: { show: false },
    labelLine: { show: false },
    data,
    color: PALETTE
  };
}