/**
 * 功能诊断热力图按指标含义配色，不用同一条色带。
 * 异常率、次数、角度：数值越大越需要关注。
 * 功率曲线符合度：数值越高越好，颜色按「偏离满分」加深。
 */

const SCALES = {
  anomaly: { cap: 100 },
  conformity: { cap: 100, invert: true },
  degree: { cap: 15 },
  count: { cap: 40 },
};

/** 报告和浅色页面用浅底色带；科技蓝页面用深底色带，贴近大屏底色 */
const PALETTES = {
  light: {
    anomaly: { low: "#dbeafe", high: "#1d4ed8" },
    conformity: { low: "#dcfce7", high: "#15803d" },
    degree: { low: "#ffedd5", high: "#c2410c" },
    count: { low: "#ede9fe", high: "#6d28d9" },
  },
  dark: {
    anomaly: { low: "#16324a", high: "#22d3ee" },
    conformity: { low: "#14382c", high: "#34d399" },
    degree: { low: "#3a2a16", high: "#f59e0b" },
    count: { low: "#2a2244", high: "#c4b5fd" },
  },
};

function familyOf(metric, tone = "light") {
  const scale = SCALES[metric] || SCALES.anomaly;
  const palette = PALETTES[tone] || PALETTES.light;
  const colors = palette[metric] || palette.anomaly;
  return { ...scale, ...colors };
}

function parseHex(hex) {
  const text = String(hex || "").replace("#", "");
  return [0, 2, 4].map((index) => parseInt(text.slice(index, index + 2), 16));
}

function mixHex(from, to, amount) {
  const start = parseHex(from);
  const end = parseHex(to);
  const t = Math.max(0, Math.min(1, amount));
  const mixed = start.map((channel, index) =>
    Math.round(channel + (end[index] - channel) * t),
  );
  return `#${mixed.map((channel) => channel.toString(16).padStart(2, "0")).join("")}`;
}

function relativeLuminance(hex) {
  const [r, g, b] = parseHex(hex).map((channel) => {
    const value = channel / 255;
    return value <= 0.03928 ? value / 12.92 : ((value + 0.055) / 1.055) ** 2.4;
  });
  return 0.2126 * r + 0.7152 * g + 0.0722 * b;
}

/** 行标签或字段类型 → 配色家族 */
export function resolveHeatmapMetric(meta = {}) {
  const label = String(meta.label || "");
  const mapKey = String(meta.mapKey || "");
  const kind = String(meta.valueKind || "");
  if (
    kind === "degree" ||
    /静态偏航误差|最小桨距角/.test(label) ||
    /yawerror|minpitch/i.test(mapKey)
  ) {
    return "degree";
  }
  if (
    kind === "count" ||
    /偏航次数/.test(label) ||
    /yawcount/i.test(mapKey)
  ) {
    return "count";
  }
  if (
    /风功率曲线情况|功率曲线符合|符合度/.test(label) ||
    /powercurve/i.test(mapKey)
  ) {
    return "conformity";
  }
  return "anomaly";
}

export function heatmapFamilyColors(metric, tone = "light") {
  const family = familyOf(metric, tone);
  return [family.low, family.high];
}

/** 映射到 0~1。符合度按偏离满分计算，其余按绝对值相对上限计算 */
export function heatmapSeverity(value, metric) {
  const family = familyOf(metric);
  const num = Number(value);
  const magnitude = Number.isFinite(num) ? Math.abs(num) : 0;
  const capped = Math.min(magnitude, family.cap) / family.cap;
  return family.invert ? 1 - capped : capped;
}

export function heatmapLabelColor(value, metric, tone = "light") {
  const [low, high] = heatmapFamilyColors(metric, tone);
  const color = mixHex(low, high, heatmapSeverity(value, metric));
  const lightText = tone === "dark" ? "#d8efff" : "#ffffff";
  const darkText = tone === "dark" ? "#071018" : "#0f172a";
  return relativeLuminance(color) < (tone === "dark" ? 0.42 : 0.45)
    ? lightText
    : darkText;
}

/** 每个指标单独一条 visualMap，热力图才能按不同色带上色 */
export function heatmapMetricVisualMap(metric, seriesIndex, tone = "light") {
  return {
    type: "continuous",
    show: false,
    min: 0,
    max: 1,
    dimension: 2,
    seriesIndex,
    inRange: { color: heatmapFamilyColors(metric, tone) },
  };
}