import React, { useState, useEffect, useRef, useCallback, Suspense } from "react";
import { Link, Navigate, Route, Routes, useLocation, useNavigate } from "react-router-dom";
import Home from "./pages/Home";
import SearchResults from "./pages/SearchResults";
import TechniquePage from "./pages/TechniquePage";
import CreatorsBrowse from "./pages/CreatorsBrowse";
import CreatorDetail from "./pages/CreatorDetail";
import TopicsBrowse from "./pages/TopicsBrowse";
import SubTopicPage from "./pages/SubTopicPage";
import Login from "./pages/Login";
import Register from "./pages/Register";

// Lazy-loaded pages — admin, creator, and info routes split into separate chunks
const AdminReports = React.lazy(() => import("./pages/AdminReports"));
const AdminPipeline = React.lazy(() => import("./pages/AdminPipeline"));
const AdminTechniquePages = React.lazy(() => import("./pages/AdminTechniquePages"));
const About = React.lazy(() => import("./pages/About"));
const CreatorDashboard = React.lazy(() => import("./pages/CreatorDashboard"));
const CreatorSettings = React.lazy(() => import("./pages/CreatorSettings"));
const WatchPage = React.lazy(() => import("./pages/WatchPage"));
import AdminDropdown from "./components/AdminDropdown";
import AppFooter from "./components/AppFooter";
import SearchAutocomplete from "./components/SearchAutocomplete";
import ProtectedRoute from "./components/ProtectedRoute";
import { AuthProvider, useAuth } from "./context/AuthContext";

function LoadingFallback() {
  return (
    <div style={{ display: "flex", justifyContent: "center", alignItems: "center", minHeight: "40vh" }}>
      <p style={{ color: "var(--text-secondary, #94a3b8)", fontSize: "0.95rem" }}>Loading…</p>
    </div>
  );
}

function AuthNav() {
  const { isAuthenticated, user, logout } = useAuth();
  const navigate = useNavigate();

  if (isAuthenticated) {
    return (
      <>
        <Link to="/creator/dashboard" className="auth-nav__user">
          {user?.display_name ?? "Dashboard"}
        </Link>
        <button
          className="auth-nav__logout"
          onClick={() => { logout(); navigate("/"); }}
        >
          Logout
        </button>
      </>
    );
  }

  return <Link to="/login" className="auth-nav__login">Login</Link>;
}

function AppShell() {
  const location = useLocation();
  const navigate = useNavigate();
  const showNavSearch = location.pathname !== "/";
  const [menuOpen, setMenuOpen] = useState(false);
  const headerRef = useRef<HTMLElement>(null);

  // Close menu on route change
  useEffect(() => {
    setMenuOpen(false);
  }, [location.pathname]);

  // Close menu on Escape
  useEffect(() => {
    if (!menuOpen) return;
    const handleKey = (e: KeyboardEvent) => {
      if (e.key === "Escape") setMenuOpen(false);
    };
    document.addEventListener("keydown", handleKey);
    return () => document.removeEventListener("keydown", handleKey);
  }, [menuOpen]);

  // Close menu on outside click
  const handleOutsideClick = useCallback(
    (e: MouseEvent) => {
      if (
        menuOpen &&
        headerRef.current &&
        !headerRef.current.contains(e.target as Node)
      ) {
        setMenuOpen(false);
      }
    },
    [menuOpen],
  );

  useEffect(() => {
    if (!menuOpen) return;
    document.addEventListener("mousedown", handleOutsideClick);
    return () => document.removeEventListener("mousedown", handleOutsideClick);
  }, [menuOpen, handleOutsideClick]);

  return (
    <div className="app">
      <a href="#main-content" className="skip-link">Skip to content</a>
      <header className="app-header" ref={headerRef}>
        <Link to="/" className="app-header__brand">
          <span className="app-header__logo" aria-hidden="true">
            <svg viewBox="0 0 32 32" width="24" height="24" fill="none">
              <path d="M22 10.5a6.5 6.5 0 0 0-6.5-6.5C11.36 4 8 7.36 8 11.5c0 4.14 3.36 7.5 7.5 7.5" stroke="#22d3ee" strokeWidth="3" strokeLinecap="round"/>
              <circle cx="22" cy="22" r="3" fill="#22d3ee" opacity="0.5"/>
            </svg>
          </span>
          <span>Chrysopedia</span>
        </Link>
        {showNavSearch && (
          <SearchAutocomplete
            variant="nav"
            globalShortcut
            placeholder="Search… Ctrl+⇧F"
            onSearch={(q) => navigate(`/search?q=${encodeURIComponent(q)}`)}
          />
        )}
        <div className="app-header__right">
          <button
            className="hamburger-btn"
            onClick={() => setMenuOpen((v) => !v)}
            aria-label="Toggle navigation"
            aria-expanded={menuOpen}
          >
            <svg width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round">
              {menuOpen ? (
                <>
                  <line x1="6" y1="6" x2="18" y2="18" />
                  <line x1="6" y1="18" x2="18" y2="6" />
                </>
              ) : (
                <>
                  <line x1="3" y1="6" x2="21" y2="6" />
                  <line x1="3" y1="12" x2="21" y2="12" />
                  <line x1="3" y1="18" x2="21" y2="18" />
                </>
              )}
            </svg>
          </button>
          <nav className={`app-nav${menuOpen ? " app-nav--open" : ""}`}>
            <Link to="/">Home</Link>
            <Link to="/topics">Topics</Link>
            <Link to="/creators">Creators</Link>
            <AuthNav />
            <AdminDropdown />
            {/* Mobile-only: search bar inside menu when not shown in header */}
            {menuOpen && showNavSearch && (
              <div className="mobile-nav-search">
                <SearchAutocomplete
                  variant="nav"
                  placeholder="Search…"
                  onSearch={(q) => navigate(`/search?q=${encodeURIComponent(q)}`)}
                />
              </div>
            )}
          </nav>
        </div>
      </header>

      <main className="app-main" id="main-content">
        <Routes>
          {/* Public routes */}
          <Route path="/" element={<Home />} />
          <Route path="/search" element={<SearchResults />} />
          <Route path="/techniques/:slug" element={<TechniquePage />} />
          <Route path="/watch/:videoId" element={<Suspense fallback={<LoadingFallback />}><WatchPage /></Suspense>} />

          {/* Browse routes */}
          <Route path="/creators" element={<CreatorsBrowse />} />
          <Route path="/creators/:slug" element={<CreatorDetail />} />
          <Route path="/topics/:category/:subtopic" element={<SubTopicPage />} />
          <Route path="/topics" element={<TopicsBrowse />} />

          {/* Admin routes */}
          <Route path="/admin/reports" element={<Suspense fallback={<LoadingFallback />}><AdminReports /></Suspense>} />
          <Route path="/admin/pipeline" element={<Suspense fallback={<LoadingFallback />}><AdminPipeline /></Suspense>} />
          <Route path="/admin/techniques" element={<Suspense fallback={<LoadingFallback />}><AdminTechniquePages /></Suspense>} />

          {/* Info routes */}
          <Route path="/about" element={<Suspense fallback={<LoadingFallback />}><About /></Suspense>} />

          {/* Auth routes */}
          <Route path="/login" element={<Login />} />
          <Route path="/register" element={<Register />} />

          {/* Creator routes (protected) */}
          <Route path="/creator/dashboard" element={<ProtectedRoute><Suspense fallback={<LoadingFallback />}><CreatorDashboard /></Suspense></ProtectedRoute>} />
          <Route path="/creator/settings" element={<ProtectedRoute><Suspense fallback={<LoadingFallback />}><CreatorSettings /></Suspense></ProtectedRoute>} />

          {/* Fallback */}
          <Route path="*" element={<Navigate to="/" replace />} />
        </Routes>
      </main>

      <AppFooter />
    </div>
  );
}

export default function App() {
  return (
    <AuthProvider>
      <AppShell />
    </AuthProvider>
  );
}