/**
 * Root layout — site header with portfolio-style navigation.
 * Shows all subpages + standalone albums as nav links.
 * Injects theme CSS custom properties from gallery.yaml config.
 */

import type { Metadata } from 'next';
import { cookies, headers } from 'next/headers';
import Link from 'next/link';
import './globals.css';
import { SubpageNav } from '@/components/SubpageNav';
import { ThemeToggle } from '@/components/ThemeToggle';
import { ScrollToTop } from '@/components/ScrollToTop';
import { Footer } from '@/components/Footer';
import { SetupScreen } from '@/components/SetupScreen';
import { getConfigOrNull, getGoogleFontsUrl, AppConfig } from '@/lib/config';
import { isAdminPath } from '@/lib/admin/paths';
import { isInstallPath } from '@/lib/install';
import { isSiteLocked, isSiteUnlocked } from '@/lib/auth';
// DevToolbarLoader is a Client Component (ssr: false is only allowed there)
import { DevToolbarLoader } from '@/components/DevToolbarLoader';
import AssetProtection from '@/components/AssetProtection';
import AnalyticsTracker from '@/components/AnalyticsTracker';
import { I18nProvider } from '@/components/I18nProvider';
import { resolveLocale, getDictionary } from '@/lib/i18n';

export async function generateMetadata(): Promise<Metadata> {
  const config = getConfigOrNull();
  if (!config) {
    // Nothing to describe, and nothing that should be indexed while broken.
    return {
      title: 'Setup Required',
      robots: { index: false, follow: false },
      icons: { icon: '/api/favicon' },
    };
  }

  const siteTitle = config.seo.title;
  const siteDescription = config.seo.description;
  // A site behind a password has nothing to offer a crawler, and the SEO
  // toggles are about a *public* site — so the lock overrides them rather
  // than depending on the operator also remembering to set noIndex.
  const locked = isSiteLocked();
  const robots = {
    index: !locked && !config.seo.noIndex,
    follow: !locked && !config.seo.noFollow,
  };

  return {
    // Without this, Next resolves Open Graph and canonical URLs against
    // localhost. Absent when nobody configured a site URL, which leaves the
    // previous behaviour rather than inventing a host.
    ...(config.siteUrl ? { metadataBase: new URL(config.siteUrl) } : {}),
    title: {
      default: siteTitle,
      template: config.seo.titleTemplate,
    },
    description: siteDescription,
    robots,
    icons: {
      icon: '/api/favicon',
      apple: '/apple-touch-icon.png',
    },
    openGraph: {
      title: siteTitle,
      description: siteDescription,
      type: 'website',
      images: [`/api/og?title=${encodeURIComponent(siteTitle)}`],
    },
    twitter: {
      card: 'summary_large_image',
      title: siteTitle,
      description: siteDescription,
      images: [`/api/og?title=${encodeURIComponent(siteTitle)}`],
    },
  };
}

export default async function RootLayout({ children }: { children: React.ReactNode }) {
  const config = getConfigOrNull();
  const pathname = (await headers()).get('x-pathname');

  // gallery.yaml exists but cannot be derived — an empty gallery, a nameless
  // subpage, a subpage with no albums. The admin page builder can write all
  // three, and this layout is what /admin renders inside, so throwing here
  // would take down the only tool that can undo the save. Render the minimum
  // that keeps /admin usable and show everyone else the setup screen.
  if (!config) {
    return (
      <html lang="en" suppressHydrationWarning>
        <body>{isAdminPath(pathname) || isInstallPath(pathname) ? children : <SetupScreen />}</body>
      </html>
    );
  }

  const { theme } = config;
  const fontsUrl = getGoogleFontsUrl(theme);

  const themeVars: Record<string, string> = {
    '--accent': theme.accent,
    '--accent-dim': `${theme.accent}1f`,
    '--font-serif': `'${theme.fonts.heading}', Georgia, 'Times New Roman', serif`,
    '--font-sans': `'${theme.fonts.body}', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif`,
    '--font-caption': `'${theme.fonts.caption}', Georgia, serif`,
    '--radius-sm': `${theme.radius}px`,
    '--radius-md': `${Math.round(theme.radius * 1.5)}px`,
    '--radius-lg': `${theme.radius * 2}px`,
  };

  // /admin and /install stay reachable during setup — /admin is the tool that
  // completes an existing setup, /install is the wizard that performs the first
  // one, so the setup screen must not lock either of them out (#326).
  if (
    (config as AppConfig & { needsSetup?: boolean }).needsSetup &&
    !isAdminPath(pathname) &&
    !isInstallPath(pathname)
  ) {
    return (
      <html lang="en" suppressHydrationWarning>
        <body>
          <SetupScreen />
        </body>
      </html>
    );
  }

  const isAdmin = isAdminPath(pathname);
  const locale = resolveLocale(config.lang);
  const t = getDictionary(locale);

  /*
   * Whether this render is the site-wide gate. The gate itself is a page
   * (`app/gate/page.tsx`) that `proxy.ts` rewrites to; all the layout does is
   * strip the chrome around it, because a header listing every subpage would
   * give away the shape of a site that is supposed to be shut.
   */
  const cookieStore = await cookies();
  const siteGated =
    !isAdmin && !isInstallPath(pathname) && !isSiteUnlocked((name) => cookieStore.get(name)?.value);

  return (
    <html
      lang={config.lang || 'en'}
      suppressHydrationWarning
      style={themeVars as React.CSSProperties}
      data-preset={theme.preset}
      data-grain={String(theme.grain)}
      data-header-dot={String(theme.headerDot)}
      data-photo-frame={theme.photoFrame}
      data-transitions={String(config.transitions)}
      /* The configured starting mode is rendered server-side so the first paint
         is already right; `auto` deliberately carries no data-theme and lets the
         inline script below decide from the OS. data-default-theme is what
         ThemeToggle reads for a visitor who has never chosen (#512). */
      {...(config.colorMode === 'auto' ? {} : { 'data-theme': config.colorMode })}
      data-default-theme={config.colorMode}
    >
      <head>
        <link rel="preconnect" href="https://fonts.googleapis.com" />
        <link rel="preconnect" href="https://fonts.gstatic.com" crossOrigin="anonymous" />
        <link rel="stylesheet" href={fontsUrl} />
      </head>
      <body>
        <I18nProvider locale={locale}>
          {siteGated || isAdmin ? (
            children
          ) : (
            <>
              <a href="#main-content" className="skip-link">
                {t.nav.skipToContent}
              </a>
              <header className="header">
                <nav className="header__nav">
                  {/* Brand wordmark — presets that show it pair it with the dot. */}
                  <span className="header__wordmark" aria-hidden="true">
                    {config.siteTitle}
                  </span>
                  <Link href="/" className="header__nav-link">
                    {t.nav.home}
                  </Link>
                  <SubpageNav />
                  {config.aboutEnabled && (
                    <Link href="/about" className="header__nav-link">
                      {t.nav.about}
                    </Link>
                  )}
                  {config.map && (
                    <Link href="/map" className="header__nav-link">
                      {t.nav.map}
                    </Link>
                  )}
                  <ThemeToggle />
                </nav>
              </header>
              <main id="main-content" tabIndex={-1} className="main">
                {children}
              </main>
              <Footer />
              {config.scrollToTop && <ScrollToTop />}
              <AssetProtection
                disableRightClick={config.protection?.disableRightClick}
                disableImageDrag={config.protection?.disableImageDrag}
              />
              <AnalyticsTracker />
              {process.env.NODE_ENV === 'development' && <DevToolbarLoader />}
            </>
          )}
        </I18nProvider>
      </body>
    </html>
  );
}