import { useEffect, useState } from 'react';
import { Navigate, Route, Routes, useLocation, useNavigate } from 'react-router-dom';
import { checkAuth, logout, setUnauthorizedHandler } from './api/client';
import { clearAllStoredSessionIds } from './utils/sessionStorage';
import { loadBlockedWords } from './utils/wordFilter';
import { AuthView } from './components/AuthView';
import { ChatView } from './components/ChatView';
import { MindSpaceView } from './components/MindSpaceView';
import { ChatProvider } from './context/ChatProvider';
import { PREVIEW_USER } from './dev/mindspacePreviewData';
import { MindSpaceRoute } from './routes/MindSpaceRoute';
import { FeedbackRoutes } from './routes/FeedbackRoute';
import type { CapabilityMap, PortalUser } from './types';

function isMindSpacePreview() {
  return (
    import.meta.env.DEV &&
    new URLSearchParams(window.location.search).get('preview') === 'mindspace'
  );
}

function MindSpaceAuthGate({
  user,
  onLogout,
}: {
  user: PortalUser | null;
  onLogout: () => void;
}) {
  const location = useLocation();
  if (!user) {
    const params = new URLSearchParams();
    params.set('return_to', `${location.pathname}${location.search}`);
    const utmSource = new URLSearchParams(location.search).get('utm_source');
    if (utmSource) params.set('utm_source', utmSource);
    return <Navigate to={`/?${params.toString()}`} replace />;
  }
  return <MindSpaceRoute user={user} onLogout={onLogout} />;
}

function AuthenticatedApp({
  user,
  capabilities,
  grantedSkills,
  onUserUpdate,
  onLogout,
}: {
  user: PortalUser | null;
  capabilities?: CapabilityMap;
  grantedSkills?: string[];
  onUserUpdate: (user: PortalUser) => void;
  onLogout: () => void;
}) {
  const navigate = useNavigate();

  const handleLogout = () => {
    clearAllStoredSessionIds();
    void logout().finally(() => {
      onLogout();
      navigate('/', { replace: true });
    });
  };

  const chatElement = (
    <ChatView
      user={user}
      capabilities={capabilities}
      grantedSkills={grantedSkills}
      onUserUpdate={onUserUpdate}
      onOpenSpace={
        user
          ? (target) => {
              if (target?.pageId) {
                navigate(`/space/page/${target.pageId}`);
                return;
              }
              if (target?.categoryCode) {
                navigate(`/space?category=${target.categoryCode}`);
                return;
              }
              navigate('/space');
            }
          : undefined
      }
      onOpenPage={user ? (pageId) => navigate(`/space/page/${pageId}`) : undefined}
      onOpenAdmin={
        user?.role === 'admin'
          ? () => { window.location.href = import.meta.env.VITE_ADMIN_APP_URL ?? '/admin-app'; }
          : undefined
      }
      onOpenFeedback={() => navigate('/feedback')}
      onLogout={handleLogout}
    />
  );

  return (
    <ChatProvider
      user={user}
      capabilities={capabilities}
      grantedSkills={grantedSkills}
      onUserUpdate={onUserUpdate}
    >
      <Routes>
        <Route
          path="/space/*"
          element={<MindSpaceAuthGate user={user} onLogout={handleLogout} />}
        />
        <Route
          path="/feedback/*"
          element={<FeedbackRoutes user={user} onLogout={handleLogout} />}
        />
        <Route path="/" element={chatElement} />
        <Route path="*" element={<Navigate to="/" replace />} />
      </Routes>
    </ChatProvider>
  );
}

export function App() {
  const mindSpacePreview = isMindSpacePreview();
  const navigate = useNavigate();
  const [authed, setAuthed] = useState<boolean | null>(null);
  const [user, setUser] = useState<PortalUser | null>(null);
  const [capabilities, setCapabilities] = useState<CapabilityMap | undefined>();
  const [grantedSkills, setGrantedSkills] = useState<string[] | undefined>();
  const [legacyMode, setLegacyMode] = useState(false);
  const [authUnavailable, setAuthUnavailable] = useState<string | null>(null);

  useEffect(() => {
    if (mindSpacePreview) return;
    setUnauthorizedHandler(() => {
      setAuthed(false);
      setUser(null);
      if (window.location.pathname !== '/') {
        navigate('/', { replace: true });
      }
    });
    void checkAuth().then((status) => {
      if (status.mode === 'unavailable') {
        setAuthUnavailable(status.message ?? '用户认证服务暂时不可用，请稍后刷新');
        setAuthed(false);
        return;
      }
      setAuthUnavailable(null);
      setLegacyMode(status.mode === 'legacy');
      setAuthed(status.authenticated);
      setUser(status.user ?? null);
      setCapabilities(status.capabilities);
      setGrantedSkills(status.grantedSkills);
      if (status.authenticated) void loadBlockedWords();
    });
    return () => setUnauthorizedHandler(null);
  }, [mindSpacePreview, navigate]);

  if (mindSpacePreview) {
    return (
      <ChatProvider user={PREVIEW_USER}>
        <MindSpaceView
          previewMode
          user={PREVIEW_USER}
          onBack={() => {
            window.location.href = '/';
          }}
          onLogout={() => {
            window.location.href = '/';
          }}
        />
      </ChatProvider>
    );
  }

  if (authed === null) {
    return <div className="app-loading">正在验证登录状态…</div>;
  }

  if (authUnavailable) {
    return (
      <div className="app-loading">
        {authUnavailable}
        <button type="button" className="login-link" onClick={() => window.location.reload()}>
          重新加载
        </button>
      </div>
    );
  }

  if (!authed) {
    return (
      <AuthView
        legacyMode={legacyMode}
        onAuth={(nextUser, nextCapabilities, nextSkills) => {
          const params = new URLSearchParams(window.location.search);
          const returnTo = params.get('return_to') ?? null;
          if (returnTo) {
            try {
              const url = new URL(returnTo, window.location.origin);
              if (url.origin === window.location.origin) {
                window.location.href = url.toString();
                return;
              }
            } catch {
              // ignore invalid URLs
            }
          }
          setAuthed(true);
          setUser(nextUser ?? null);
          setCapabilities(nextCapabilities);
          setGrantedSkills(nextSkills);
        }}
      />
    );
  }

  return (
    <AuthenticatedApp
      user={user}
      capabilities={capabilities}
      grantedSkills={grantedSkills}
      onUserUpdate={setUser}
      onLogout={() => {
        clearAllStoredSessionIds();
        setAuthed(false);
        setUser(null);
      }}
    />
  );
}