'use client';

import { useEffect, useRef, useState } from 'react';
import Link from 'next/link';
import { useTranslations } from 'next-intl';
import { TesseraLogo } from '@/components/brand/tessera-logo';
import { useSidebarStore } from '@/lib/stores/sidebar-store';
import { useAuthStore } from '@/lib/stores/auth-store';
import { fetchSessionState, logout } from '@/lib/auth-actions';
import { buildNextParam } from '@/lib/safe-next';
import { ThemeToggle } from '@/components/theme-toggle';
import { BugReportButton } from '@/components/bug-report/bug-report-button';
import { HEADER_CENTER_SLOT_ID } from '@/components/layout/header-slot';
import { usePathname } from 'next/navigation';

export function Header() {
  const t = useTranslations();
  const tHeader = useTranslations('header');
  const setMobileOpen = useSidebarStore((s) => s.setMobileOpen);
  const { user, setUser, avatarVersion } = useAuthStore();
  const [dropdownOpen, setDropdownOpen] = useState(false);
  const dropdownRef = useRef<HTMLDivElement>(null);
  const pathname = usePathname();

  const isAdmin = user?.role === 'ADMIN' || user?.role === 'SUPER_ADMIN';

  // Redirect-Sperre gegen doppelte Navigation (StrictMode-Doppeleffekt,
  // Effekt-Wiederholungen) — quick-260917-gyd.
  const redirectedRef = useRef(false);

  // Sitzungswaechter (quick-260917-gyd): Der Header ist der EINZIGE
  // Waechter, weil er auf jeder Portalseite genau einmal gerendert wird
  // (AppShell im (portal)-Layout); das (auth)-Layout hat keinen Header,
  // /login ist oeffentlich (middleware.ts publicRoutes) — Seitenleiste
  // und Widget-Aufrufe brauchen deshalb keinen eigenen Umbau, ein
  // Doppel-Redirect ist ausgeschlossen. `authenticated` fuellt den Store,
  // `unauthenticated` (tote Sitzung, Cookie bereits serverseitig
  // geloescht) leitet per Vollnavigation zur Anmeldeseite mit `next` auf
  // die aktuelle Seite, `unavailable` (API-Ausfall) bleibt still.
  useEffect(() => {
    if (user) {
      return;
    }
    fetchSessionState().then((state) => {
      if (state.status === 'authenticated') {
        const u = state.user;
        setUser({
          id: u.id,
          username: u.username,
          displayName: u.displayName,
          role: u.role,
          tenantId: u.tenantId,
          hasAvatar: u.hasAvatar,
          accentColor: u.accentColor,
        });
      } else if (state.status === 'unauthenticated') {
        if (redirectedRef.current) {
          return;
        }
        redirectedRef.current = true;
        const next = buildNextParam(
          window.location.pathname,
          window.location.search,
        );
        window.location.href = next
          ? `/login?next=${encodeURIComponent(next)}`
          : '/login';
      }
      // 'unavailable' (T-gyd-02): kein Redirect, bisheriges stilles
      // Verhalten -- ein API-Ausfall darf keine Abmelde-Schleife ausloesen.
    });
  }, [user, setUser]);

  // Close dropdown on outside click
  useEffect(() => {
    function handleClickOutside(event: MouseEvent) {
      if (
        dropdownRef.current &&
        !dropdownRef.current.contains(event.target as Node)
      ) {
        setDropdownOpen(false);
      }
    }
    if (dropdownOpen) {
      document.addEventListener('mousedown', handleClickOutside);
    }
    return () => document.removeEventListener('mousedown', handleClickOutside);
  }, [dropdownOpen]);

  const [avatarError, setAvatarError] = useState(false);

  const userInitial = user
    ? (user.displayName ?? user.username).charAt(0).toUpperCase()
    : '?';

  const roleLabel = user ? tHeader(`role.${user.role}`) : '';

  return (
    <header className="sticky top-0 z-50 flex h-[var(--header-height)] items-center border-b border-border bg-background px-4 shadow-sm">
      {/* Left: Logo + Mobile hamburger */}
      <div className="flex shrink-0 items-center gap-3">
        <button
          type="button"
          onClick={() => setMobileOpen(true)}
          className="inline-flex items-center justify-center rounded-md p-2 text-muted-foreground hover:bg-muted hover:text-foreground transition-colors md:hidden"
          aria-label={t('common.menu')}
        >
          <svg
            aria-hidden="true"
            xmlns="http://www.w3.org/2000/svg"
            width="20"
            height="20"
            viewBox="0 0 24 24"
            fill="none"
            stroke="currentColor"
            strokeWidth="2"
            strokeLinecap="round"
            strokeLinejoin="round"
          >
            <line x1="3" y1="6" x2="21" y2="6" />
            <line x1="3" y1="12" x2="21" y2="12" />
            <line x1="3" y1="18" x2="21" y2="18" />
          </svg>
        </button>
        <TesseraLogo
          variant="horizontal"
          size={28}
          // Gelb traegt nur auf dunklem Grund: gemessen 13,1:1 im dunklen
          // Erscheinungsbild gegen 1,26:1 im hellen (WCAG verlangt 3:1 fuer
          // grossen fetten Text). Im hellen Modus erbt der Schriftzug daher
          // die Vordergrundfarbe, im dunklen steht die Markenfarbe.
          wordmarkClassName="dark:text-primary"
        />
      </div>

      {/* Mitte: Einhaengepunkt fuer die Dashboard-Reiter (quick-260924-h7x).
          `DashboardTabs` rendert per Portal hierher; der Punkt muss deshalb
          im React-Baum der Kopfzeile LEER bleiben. Auf der Startseite
          entfaellt der Text „Startseite“, auf allen anderen Seiten bleibt
          er wie bisher. `min-w-0` laesst die Mitte schrumpfen, damit Logo
          und Aktionen rechts auch bei schmalem Fenster Platz behalten. */}
      <div className="flex min-w-0 flex-1 items-center justify-center px-2 text-center md:px-4">
        <div id={HEADER_CENTER_SLOT_ID} className="flex min-w-0 max-w-full justify-center" />
        {pathname !== '/' && (
          <span className="text-sm text-muted-foreground truncate">
            {tHeader('breadcrumb.home')}
          </span>
        )}
      </div>

      {/* Right: Actions */}
      <div className="flex shrink-0 items-center gap-2">
        <BugReportButton />
        <ThemeToggle />

        {/* User avatar dropdown */}
        <div className="relative" ref={dropdownRef}>
          <button
            type="button"
            onClick={() => setDropdownOpen(!dropdownOpen)}
            className="h-8 w-8 rounded-full overflow-hidden bg-primary flex items-center justify-center text-xs font-medium text-primary-foreground hover:opacity-90 transition-opacity"
            aria-label={tHeader('userMenu')}
          >
            {user?.hasAvatar && !avatarError ? (
              <img
                src={`/api-proxy/users/me/avatar?v=${avatarVersion}`}
                alt=""
                aria-hidden="true"
                className="h-8 w-8 rounded-full object-cover"
                onError={() => setAvatarError(true)}
              />
            ) : (
              <span>{userInitial}</span>
            )}
          </button>

          {/* Dropdown menu */}
          {dropdownOpen && (
            <div className="absolute right-0 top-full mt-2 w-56 rounded-md border border-border bg-card shadow-lg py-2 z-50">
              {/* User info */}
              <div className="px-4 py-2 border-b border-border">
                <p className="text-sm font-medium text-foreground truncate">
                  {user?.displayName ?? user?.username ?? '...'}
                </p>
                {user && (
                  <span
                    className={`inline-block mt-1 rounded-full px-2 py-0.5 text-xs font-medium ${
                      user.role === 'SUPER_ADMIN'
                        ? 'bg-red-100 text-red-700 dark:bg-red-900/30 dark:text-red-400'
                        : user.role === 'ADMIN'
                          ? 'bg-blue-100 text-blue-700 dark:bg-blue-900/30 dark:text-blue-400'
                          : 'bg-gray-100 text-gray-700 dark:bg-gray-800 dark:text-gray-400'
                    }`}
                  >
                    {roleLabel}
                  </span>
                )}
              </div>

              {/* Settings link */}
              <div className="px-2 py-1">
                <Link
                  href="/settings"
                  onClick={() => setDropdownOpen(false)}
                  className="flex w-full items-center gap-2 rounded-md px-2 py-1.5 text-sm text-foreground hover:bg-muted transition-colors"
                >
                  <svg
                    aria-hidden="true"
                    xmlns="http://www.w3.org/2000/svg"
                    width="16"
                    height="16"
                    viewBox="0 0 24 24"
                    fill="none"
                    stroke="currentColor"
                    strokeWidth="2"
                    strokeLinecap="round"
                    strokeLinejoin="round"
                  >
                    <circle cx="12" cy="12" r="3" />
                    <path d="M19.4 15a1.65 1.65 0 0 0 .33 1.82l.06.06a2 2 0 0 1 0 2.83 2 2 0 0 1-2.83 0l-.06-.06a1.65 1.65 0 0 0-1.82-.33 1.65 1.65 0 0 0-1 1.51V21a2 2 0 0 1-2 2 2 2 0 0 1-2-2v-.09A1.65 1.65 0 0 0 9 19.4a1.65 1.65 0 0 0-1.82.33l-.06.06a2 2 0 0 1-2.83 0 2 2 0 0 1 0-2.83l.06-.06A1.65 1.65 0 0 0 4.68 15a1.65 1.65 0 0 0-1.51-1H3a2 2 0 0 1-2-2 2 2 0 0 1 2-2h.09A1.65 1.65 0 0 0 4.6 9a1.65 1.65 0 0 0-.33-1.82l-.06-.06a2 2 0 0 1 0-2.83 2 2 0 0 1 2.83 0l.06.06A1.65 1.65 0 0 0 9 4.68a1.65 1.65 0 0 0 1-1.51V3a2 2 0 0 1 2-2 2 2 0 0 1 2 2v.09a1.65 1.65 0 0 0 1 1.51 1.65 1.65 0 0 0 1.82-.33l.06-.06a2 2 0 0 1 2.83 0 2 2 0 0 1 0 2.83l-.06.06A1.65 1.65 0 0 0 19.4 9a1.65 1.65 0 0 0 1.51 1H21a2 2 0 0 1 2 2 2 2 0 0 1-2 2h-.09a1.65 1.65 0 0 0-1.51 1z" />
                  </svg>
                  {tHeader('settings')}
                </Link>
              </div>

              {/* Administration link */}
              {isAdmin && (
                <div className="px-2 py-1">
                  <Link
                    href="/admin/users"
                    onClick={() => setDropdownOpen(false)}
                    className={`flex w-full items-center gap-2 rounded-md px-2 py-1.5 text-sm transition-colors ${
                      pathname.startsWith('/admin')
                        ? 'bg-muted text-foreground font-medium'
                        : 'text-foreground hover:bg-muted'
                    }`}
                  >
                    <svg aria-hidden="true" xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
                      <path d="M12 22s8-4 8-10V5l-8-3-8 3v7c0 6 8 10 8 10z" />
                    </svg>
                    {tHeader('admin.label')}
                  </Link>
                </div>
              )}

              {/* Logout button */}
              <div className="border-t border-border my-1" />
              <div className="px-2 py-1">
                <button
                  type="button"
                  onClick={() => {
                    setDropdownOpen(false);
                    logout();
                  }}
                  className="flex w-full items-center gap-2 rounded-md px-2 py-1.5 text-sm text-foreground hover:bg-muted transition-colors"
                >
                  <svg
                    aria-hidden="true"
                    xmlns="http://www.w3.org/2000/svg"
                    width="16"
                    height="16"
                    viewBox="0 0 24 24"
                    fill="none"
                    stroke="currentColor"
                    strokeWidth="2"
                    strokeLinecap="round"
                    strokeLinejoin="round"
                  >
                    <path d="M9 21H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h4" />
                    <polyline points="16 17 21 12 16 7" />
                    <line x1="21" y1="12" x2="9" y2="12" />
                  </svg>
                  {tHeader('logout')}
                </button>
              </div>
            </div>
          )}
        </div>
      </div>
    </header>
  );
}