import Link from "next/link";
import { logoutAction } from "@/actions/auth";
import { requireUser } from "@/lib/auth/dal";
import { countCommentsByStatus } from "@/lib/services/comments";
import { getSettings } from "@/lib/services/settings";

const navLinkClasses =
  "rounded-md px-2.5 py-1.5 text-sm font-medium text-ink transition-colors hover:bg-background hover:text-ink-strong";

/**
 * Every route in this group is server-guarded: the layout redirects
 * anonymous visitors, each page calls requireAdmin() again (defense in
 * depth), and every mutating server action re-checks on its own.
 */
export default async function AdminLayout({ children }: { children: React.ReactNode }) {
  const user = await requireUser();
  const isAdmin = user.role === "admin";
  const canModerate = user.permissions.approveComments;
  const [settings, commentCounts] = await Promise.all([
    getSettings(),
    canModerate
      ? countCommentsByStatus(isAdmin ? undefined : { postAuthorId: user.id })
      : { pending: 0, approved: 0 },
  ]);

  return (
    <>
      <header className="border-b border-edge bg-surface">
        <div className="container-site flex flex-wrap items-center justify-between gap-x-6 gap-y-2 py-3">
          <div className="flex min-w-0 flex-wrap items-center gap-x-6 gap-y-2">
            <Link
              href="/admin"
              className="font-semibold text-ink-bright transition-colors hover:text-link"
            >
              {settings.siteTitle}
              <span className="font-normal text-ink-muted"> · Admin</span>
            </Link>
            <nav aria-label="Admin sections">
              {/* Authors only manage posts; everything else is the admin's. */}
              <ul className="flex items-center gap-1">
                {isAdmin && <li><Link href="/admin" className={navLinkClasses}>Dashboard</Link></li>}
                <li><Link href="/admin/posts" className={navLinkClasses}>Posts</Link></li>
                {isAdmin && (
                  <li><Link href="/admin/pages" className={navLinkClasses}>Pages</Link></li>
                )}
                {canModerate && (
                  <li>
                    <Link href="/admin/comments" className={navLinkClasses}>
                      Comments
                      {commentCounts.pending > 0 && (
                        <span className="ml-1.5 inline-flex min-w-5 items-center justify-center rounded-full bg-warning/20 px-1.5 py-0.5 text-xs font-semibold text-warning">
                          {commentCounts.pending}
                        </span>
                      )}
                    </Link>
                  </li>
                )}
                {isAdmin && (
                  <>
                    <li><Link href="/admin/users" className={navLinkClasses}>Users</Link></li>
                    <li><Link href="/admin/settings" className={navLinkClasses}>Settings</Link></li>
                  </>
                )}
              </ul>
            </nav>
          </div>
          <div className="flex items-center gap-3 text-sm">
            <Link href="/" className="text-ink-muted transition-colors hover:text-link">
              View site
            </Link>
            <span aria-hidden="true" className="text-edge-strong">|</span>
            <span className="text-ink-muted">
              Signed in as{" "}
              <Link
                href="/admin/account"
                className="text-ink-strong underline-offset-4 transition-colors hover:text-link hover:underline"
                title="Account settings"
              >
                {user.username}
              </Link>
            </span>
            <form action={logoutAction}>
              <button
                type="submit"
                className="rounded-md border border-edge px-3 py-1.5 font-medium text-ink transition-colors hover:border-edge-strong hover:text-ink-strong"
              >
                Log out
              </button>
            </form>
          </div>
        </div>
      </header>
      <main id="main" className="container-site flex-1 py-8">
        {children}
      </main>
    </>
  );
}