import { useState } from 'react';
import { Home } from '@/features/home/Home';
import { JoinScreen, MissingAccess } from '@/features/scan/JoinScreen';
import { useChannels } from '@/store/channels';
import { useShares } from '@/store/shares';
import { useWorkspace } from '@/store/workspace';
import { ChannelScreen } from './ChannelScreen';
import { ShareScreen } from './ShareScreen';
import { channelPath, navigate, useRoute } from './navigation';
import { Splash } from './Splash';

const SEEN_KEY = 'wd.splash';

function splashSeen(): boolean {
  try {
    return sessionStorage.getItem(SEEN_KEY) === '1';
  } catch {
    return false;
  }
}

export function App() {
  const route = useRoute();
  const list = useChannels((s) => s.list);
  const channelsHydrated = useChannels((s) => s.hydrated);
  const pendingLink = useChannels((s) => s.pendingLink);
  const setPendingLink = useChannels((s) => s.setPendingLink);
  const sharesHydrated = useShares((s) => s.hydrated);
  const pendingShareLink = useShares((s) => s.pendingLink);
  const wsReady = useWorkspace((s) => s.ready);
  const [splash, setSplash] = useState(() => !splashSeen());

  const saved = route.name === 'channel' && list.some((c) => c.id === route.id);
  // 只有打开已保存的频道才需要等数据;首页与加入页没有加载过程
  const waitingOnSavedChannel = route.name === 'channel' && !pendingLink && !channelsHydrated;
  const waitingOnSavedShare = route.name === 'share' && pendingShareLink?.id !== route.id && !sharesHydrated;
  const ready = route.name === 'home' || (route.name === 'channel'
    ? pendingLink?.id === route.id || (channelsHydrated && (!saved || wsReady))
    : pendingShareLink?.id === route.id || sharesHydrated);

  function onSplashDone() {
    try {
      sessionStorage.setItem(SEEN_KEY, '1');
    } catch {
      /* 无存储时每次都播,不影响功能 */
    }
    setSplash(false);
  }

  let screen;
  if (route.name === 'home') screen = <Home />;
  else if (route.name === 'share' && waitingOnSavedShare) screen = null;
  else if (route.name === 'share') screen = <ShareScreen id={route.id} />;
  else if (route.name === 'channel' && waitingOnSavedChannel) screen = null;
  else if (saved) screen = <ChannelScreen id={route.id} />;
  else if (pendingLink?.id === route.id) {
    screen = (
      <JoinScreen
        link={pendingLink}
        onJoined={(c) => navigate(channelPath(c.id))}
        onCancel={() => {
          setPendingLink(null);
          navigate('/');
        }}
      />
    );
  } else screen = <MissingAccess onHome={() => navigate('/')} />;

  return (
    <>
      {screen}
      {splash ? <Splash ready={ready} onDone={onSplashDone} /> : null}
    </>
  );
}