export function clamp(value, minimum, maximum) {
  return Math.min(maximum, Math.max(minimum, Number(value)));
}

export function normalizeHex(value) {
  const match = /^#?([0-9a-f]{6})$/i.exec(String(value).trim());
  return match ? `#${match[1].toUpperCase()}` : null;
}

export function rgbToHex({ r, g, b }) {
  return `#${[r, g, b]
    .map((channel) => Math.round(clamp(channel, 0, 255)).toString(16).padStart(2, "0"))
    .join("")}`.toUpperCase();
}

export function hexToRgb(value) {
  const hex = normalizeHex(value);
  if (!hex) throw new TypeError("颜色必须是 #RRGGBB");
  return {
    r: Number.parseInt(hex.slice(1, 3), 16),
    g: Number.parseInt(hex.slice(3, 5), 16),
    b: Number.parseInt(hex.slice(5, 7), 16),
  };
}

export function rgbToHsv({ r, g, b }) {
  const red = clamp(r, 0, 255) / 255;
  const green = clamp(g, 0, 255) / 255;
  const blue = clamp(b, 0, 255) / 255;
  const maximum = Math.max(red, green, blue);
  const minimum = Math.min(red, green, blue);
  const delta = maximum - minimum;
  let hue = 0;
  if (delta !== 0) {
    if (maximum === red) hue = 60 * (((green - blue) / delta) % 6);
    else if (maximum === green) hue = 60 * ((blue - red) / delta + 2);
    else hue = 60 * ((red - green) / delta + 4);
  }
  if (hue < 0) hue += 360;
  return {
    h: Math.round(hue),
    s: Math.round(maximum === 0 ? 0 : (delta / maximum) * 100),
    v: Math.round(maximum * 100),
  };
}

export function hsvToRgb({ h, s, v }) {
  const hue = ((Number(h) % 360) + 360) % 360;
  const saturation = clamp(s, 0, 100) / 100;
  const value = clamp(v, 0, 100) / 100;
  const chroma = value * saturation;
  const segment = hue / 60;
  const secondary = chroma * (1 - Math.abs((segment % 2) - 1));
  let channels = [0, 0, 0];
  if (segment < 1) channels = [chroma, secondary, 0];
  else if (segment < 2) channels = [secondary, chroma, 0];
  else if (segment < 3) channels = [0, chroma, secondary];
  else if (segment < 4) channels = [0, secondary, chroma];
  else if (segment < 5) channels = [secondary, 0, chroma];
  else channels = [chroma, 0, secondary];
  const match = value - chroma;
  return {
    r: Math.round((channels[0] + match) * 255),
    g: Math.round((channels[1] + match) * 255),
    b: Math.round((channels[2] + match) * 255),
  };
}

export function updateRecentColors(colors, value, limit = 10) {
  const normalized = normalizeHex(value);
  if (!normalized) return Array.isArray(colors) ? colors.slice(0, limit) : [];
  const existing = Array.isArray(colors)
    ? colors.map(normalizeHex).filter(Boolean).filter((color) => color !== normalized)
    : [];
  return [normalized, ...existing].slice(0, limit);
}