import type { InstalledTheme } from './plugin-types';

/**
 * Resolve which logo to show.
 *
 * Precedence:
 *   1. An admin-configured global logo (Branding tab / APP_LOGO_*_URL /
 *      LOGIN_LOGO_*_URL) - set `hasGlobalOverride` when the caller's config
 *      source for that field is 'admin' or 'env', not 'default'. This is
 *      what makes the Branding tab's existing logo fields actually take
 *      effect for customers who want their own mark regardless of theme.
 *   2. The active theme's own brand logo (logoLightUrl/logoDarkUrl) - so
 *      switching theme still switches the whole brand (VNClagoon wordmark
 *      vs SRC mark) for anyone who HASN'T set an explicit override.
 *   3. The fallback value itself (theme has no logo and nothing was
 *      configured).
 *
 * Returns a raw path; the caller applies withBasePath().
 */
export function resolveThemeLogo(
  themes: InstalledTheme[],
  activeThemeId: string | null,
  isDark: boolean,
  fallbackLight: string,
  fallbackDark: string,
  hasGlobalOverride = false,
): string {
  const fallback = isDark ? (fallbackDark || fallbackLight) : (fallbackLight || fallbackDark);
  if (hasGlobalOverride && fallback) return fallback;

  const theme = activeThemeId ? themes.find((t) => t.id === activeThemeId) : undefined;
  if (theme) {
    const themed = isDark
      ? (theme.logoDarkUrl ?? theme.logoLightUrl)
      : (theme.logoLightUrl ?? theme.logoDarkUrl);
    if (themed) return themed;
  }
  return fallback;
}