/**
 * 主题色工具：根据取色器选中的主色，计算 hover/light 并写入 :root CSS 变量
 * 用于导航栏、侧边菜单、按钮等公共颜色统一切换
 */

const STORAGE_KEY = 'app-theme-color';
const THEME_MODE_KEY = 'app-theme-mode';

/** 旧默认色：切到新主色时自动迁移，避免 localStorage 卡住旧主题 */
const LEGACY_THEME_COLORS = new Set([
  '#132c44',
  '#132C44',
  '#2d8c8c',
  '#2D8C8C',
  '#007979',
  '#1d7281',
  '#1D7281',
  '#1e7fa0',
  '#1E7FA0',
]);

export const DEFAULT_THEME_COLOR = '#054f74';
export type ThemeMode = 'light' | 'dark';

export function getStoredThemeColor(): string | null {
  try {
    const stored = localStorage.getItem(STORAGE_KEY);
    if (!stored) return null;
    if (LEGACY_THEME_COLORS.has(stored)) {
      localStorage.setItem(STORAGE_KEY, DEFAULT_THEME_COLOR);
      return DEFAULT_THEME_COLOR;
    }
    return stored;
  } catch {
    return null;
  }
}

export function setStoredThemeColor(hex: string): void {
  try {
    localStorage.setItem(STORAGE_KEY, hex);
  } catch {
    // ignore
  }
}

export function getStoredThemeMode(): ThemeMode | null {
  try {
    const stored = localStorage.getItem(THEME_MODE_KEY);
    if (stored === 'light' || stored === 'dark') return stored;
    return null;
  } catch {
    return null;
  }
}

export function setStoredThemeMode(mode: ThemeMode): void {
  try {
    localStorage.setItem(THEME_MODE_KEY, mode);
  } catch {
    // ignore
  }
}

/** 将 hex 转为 r,g,b (0-255) */
function hexToRgb(hex: string): { r: number; g: number; b: number } | null {
  const m = hex.replace(/^#/, '').match(/^([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i);
  if (!m) return null;
  return {
    r: parseInt(m[1], 16),
    g: parseInt(m[2], 16),
    b: parseInt(m[3], 16),
  };
}

/** 将 r,g,b 转为 #rrggbb */
function rgbToHex(r: number, g: number, b: number): string {
  return (
    '#' +
    [r, g, b]
      .map((x) => Math.round(Math.max(0, Math.min(255, x))).toString(16).padStart(2, '0'))
      .join('')
  );
}

/** 在 hex 颜色基础上按比例变暗（用于 hover） */
function darkenHex(hex: string, ratio: number): string {
  const rgb = hexToRgb(hex);
  if (!rgb) return hex;
  return rgbToHex(rgb.r * (1 - ratio), rgb.g * (1 - ratio), rgb.b * (1 - ratio));
}

/** 生成浅色背景（用于 menu hover 等） */
function lightenHex(hex: string, mixWhite = 0.92): string {
  const rgb = hexToRgb(hex);
  if (!rgb) return hex;
  const r = Math.round(rgb.r * (1 - mixWhite) + 255 * mixWhite);
  const g = Math.round(rgb.g * (1 - mixWhite) + 255 * mixWhite);
  const b = Math.round(rgb.b * (1 - mixWhite) + 255 * mixWhite);
  return rgbToHex(r, g, b);
}

/**
 * 将主题色应用到页面：设置 :root 上的 CSS 变量
 * @param primaryHex 主色，如 #1d7281
 */
export function applyThemeColor(primaryHex: string): void {
  const hex = primaryHex.startsWith('#') ? primaryHex : `#${primaryHex}`;
  const root = document.documentElement;
  const rgb = hexToRgb(hex);
  const isDark = document.body.getAttribute('arco-theme') === 'dark';

  const primary = hex;
  const primaryHover = darkenHex(hex, 0.05);
  const primaryLight = lightenHex(hex, 0.92);

  root.style.setProperty('--app-primary-color', primary);
  root.style.setProperty('--app-primary-color-hover', primaryHover);
  root.style.setProperty('--app-primary-color-light', primaryLight);
  root.style.setProperty('--color-primary-light-1', primaryLight);

  // 顶栏：日间用主色；夜间用深色壳（由 applyThemeMode / 下方分支写入）
  if (isDark) {
    applyNavbarDarkTokens();
  } else {
    root.style.setProperty('--app-navbar-bg', primary);
    root.style.setProperty('--app-navbar-item-active-bg', lightenHex(hex, 0.16));
    root.style.setProperty('--app-sidebar-bg', primary);
  }

  // 同步 Arco Design primary 色阶，保证按钮/链接等组件跟主题一致
  if (rgb) {
    const rgbStr = `${rgb.r}, ${rgb.g}, ${rgb.b}`;
    const hover = hexToRgb(primaryHover);
    const light = hexToRgb(lightenHex(hex, 0.15));
    root.style.setProperty('--primary-6', rgbStr);
    root.style.setProperty('--primary-7', hover ? `${hover.r}, ${hover.g}, ${hover.b}` : rgbStr);
    root.style.setProperty('--primary-5', light ? `${light.r}, ${light.g}, ${light.b}` : rgbStr);
    root.style.setProperty('--arcoblue-6', rgbStr);
  }
}

/** 夜间顶栏 / 侧栏表面色（与内容区一致的深色壳，选中胶囊带主色） */
function applyNavbarDarkTokens(): void {
  const root = document.documentElement;
  root.style.setProperty('--app-navbar-bg', 'var(--color-bg-2)');
  root.style.setProperty(
    '--app-navbar-item-active-bg',
    'color-mix(in srgb, var(--app-primary-color) 34%, var(--color-bg-3))',
  );
  root.style.setProperty('--app-sidebar-bg', 'var(--color-bg-2)');
}

/** 将日间/夜间模式应用到 DOM */
export function applyThemeMode(mode: ThemeMode): void {
  const root = document.documentElement;
  if (mode === 'dark') {
    document.body.setAttribute('arco-theme', 'dark');
    root.setAttribute('data-theme', 'dark');
    // 同步写到 :root，避免仅依赖 body 变量时列表壳仍读到 global.less 的浅色默认值
    root.style.setProperty('--app-page-bg', 'var(--color-bg-1)');
    root.style.setProperty('--app-card-bg', 'var(--color-bg-2)');
    root.style.setProperty('--app-card-border', 'var(--color-border-2)');
    root.style.setProperty('--app-elevated-bg', 'var(--color-bg-3)');
    applyNavbarDarkTokens();
  } else {
    document.body.removeAttribute('arco-theme');
    root.setAttribute('data-theme', 'light');
    root.style.removeProperty('--app-page-bg');
    root.style.removeProperty('--app-card-bg');
    root.style.removeProperty('--app-card-border');
    root.style.removeProperty('--app-elevated-bg');
    // 恢复日间主色顶栏
    const primary =
      getComputedStyle(root).getPropertyValue('--app-primary-color').trim() ||
      DEFAULT_THEME_COLOR;
    root.style.setProperty('--app-navbar-bg', primary);
    root.style.setProperty('--app-navbar-item-active-bg', lightenHex(primary, 0.16));
    root.style.setProperty('--app-sidebar-bg', primary);
  }
}