import type { PondView } from '@dorfteich/shared';
import { useQuery } from '@tanstack/react-query';
import { Menu, Monitor, Moon, Search, Settings, Sun } from 'lucide-react';
import { useEffect, useRef, useState } from 'react';
import { useTranslation } from 'react-i18next';
import { Link, useNavigate } from 'react-router-dom';

import { useAuth } from '../auth/auth-context';
import { IconButton } from '../components/IconButton';
import { apiGet } from '../lib/api';
import { isTypingTarget } from '../lib/keyboard';
import { useDismissable } from '../lib/use-dismissable';
import { SearchPalette } from '../search/SearchPalette';
import { NotificationsBell } from '../notifications/NotificationsBell';
import { nextThemeMode, useThemeMode, type ThemeMode } from '../theme/theme';
import { usePageActionsSlot } from './page-actions';
import { PondSwitcher } from './PondSwitcher';
import { useCurrentPondRoute } from './use-pond-route';

import { singleKeyShortcutsDisabled } from '../lib/single-key-shortcuts';

/** Icon per CHOSEN mode (not per effective theme): the monitor tells the
 * user "following the OS" apart from an explicit light/dark pick. */
const THEME_MODE_ICONS: Record<ThemeMode, typeof Sun> = {
  light: Sun,
  dark: Moon,
  system: Monitor,
};

/** Three-way theme cycle (issue #182) — sits between the bell and the user
 * menu; also rendered for signed-out visitors (device-local preference). */
function ThemeToggle(): React.JSX.Element {
  const { t } = useTranslation();
  const [mode, setMode] = useThemeMode();
  const Icon = THEME_MODE_ICONS[mode];
  return (
    <IconButton
      className="topbar__theme"
      label={t('settings:appearance.cycle', { mode: t(`settings:appearance.${mode}`) })}
      onClick={() => setMode(nextThemeMode(mode))}
    >
      <Icon aria-hidden />
    </IconButton>
  );
}

interface TopBarProps {
  sidebarCollapsed: boolean;
  onToggleSidebar: () => void;
}

export function TopBar({ sidebarCollapsed, onToggleSidebar }: TopBarProps): React.JSX.Element {
  const { t } = useTranslation();
  const { user, logout } = useAuth();
  const navigate = useNavigate();
  const [menuOpen, setMenuOpen] = useState(false);
  const [searchOpen, setSearchOpen] = useState(false);
  const userMenuRef = useRef<HTMLDivElement>(null);
  useDismissable(userMenuRef, menuOpen, () => setMenuOpen(false));
  const { setElement: setPageActionsElement, setPresenceElement } = usePageActionsSlot();
  // Pond-settings shortcut next to the pond name (M10 follow-up): owners get
  // a gear icon while a pond route is active. Shares the sidebar's query key.
  const { pondSlug } = useCurrentPondRoute();
  const pond = useQuery({
    queryKey: ['pond', pondSlug],
    queryFn: () => apiGet<PondView>(`/ponds/${pondSlug}`),
    enabled: Boolean(user && pondSlug),
  });
  const isPondOwner = Boolean(user && pond.data && user.id === pond.data.ownerId);

  async function handleLogout(): Promise<void> {
    setMenuOpen(false);
    await logout();
    navigate('/login');
  }

  // Global "/" shortcut opens search (unless typing in a field) — issue #50.
  useEffect(() => {
    if (!user) return undefined;
    const onKeyDown = (event: KeyboardEvent): void => {
      if (
        event.key === '/' &&
        !isTypingTarget(event.target) &&
        !searchOpen &&
        !singleKeyShortcutsDisabled()
      ) {
        event.preventDefault();
        setSearchOpen(true);
      }
    };
    document.addEventListener('keydown', onKeyDown);
    return () => document.removeEventListener('keydown', onKeyDown);
  }, [user, searchOpen]);

  return (
    <header className="topbar">
      <button
        type="button"
        className="icon-button"
        onClick={onToggleSidebar}
        aria-expanded={!sidebarCollapsed}
        aria-label={sidebarCollapsed ? t('layout.sidebar.expand') : t('layout.sidebar.collapse')}
      >
        <Menu aria-hidden />
      </button>
      <Link to="/" className="topbar__brand">
        Dorfteich
      </Link>
      {user && <PondSwitcher />}
      {isPondOwner && pondSlug && (
        <Link
          to={`/p/${pondSlug}/settings`}
          className="icon-button topbar__pond-settings"
          aria-label={t('labels:link')}
          title={t('labels:link')}
        >
          <Settings aria-hidden />
        </Link>
      )}
      <span className="topbar__spacer" />
      {/* Page-scoped slots, rendered only for signed-in users: live presence
          (#102) and the page's icon actions (#101) portal in while a page
          route is active. */}
      {user && <div className="topbar__presence" ref={setPresenceElement} />}
      {user && <div className="topbar__page-actions" ref={setPageActionsElement} />}
      {user && (
        <button
          type="button"
          className="topbar__search"
          onClick={() => setSearchOpen(true)}
          aria-label={t('search:open')}
        >
          <Search aria-hidden />
          <span className="topbar__search-text">{t('search:open')}</span>
        </button>
      )}
      {searchOpen && user && <SearchPalette onClose={() => setSearchOpen(false)} />}
      {user && <NotificationsBell />}
      <ThemeToggle />
      {user ? (
        <div className="user-menu" ref={userMenuRef}>
          <button
            type="button"
            className="user-menu__trigger"
            aria-haspopup="menu"
            aria-expanded={menuOpen}
            onClick={() => setMenuOpen(!menuOpen)}
          >
            {user.displayName}
          </button>
          {menuOpen && (
            <div className="user-menu__list" role="menu">
              <Link role="menuitem" to="/settings" onClick={() => setMenuOpen(false)}>
                {t('auth:menu.settings')}
              </Link>
              {user.isSiteAdmin && (
                <Link role="menuitem" to="/admin" onClick={() => setMenuOpen(false)}>
                  {t('auth:menu.admin')}
                </Link>
              )}
              <button type="button" role="menuitem" onClick={() => void handleLogout()}>
                {t('auth:menu.logout')}
              </button>
            </div>
          )}
        </div>
      ) : (
        <nav className="topbar__nav">
          <Link to="/login">{t('auth:menu.login')}</Link>
          <Link to="/signup">{t('auth:menu.signup')}</Link>
        </nav>
      )}
    </header>
  );
}