<script lang="ts">
  import { onMount } from 'svelte';
  import { cubicOut } from 'svelte/easing';
  import { app, bootstrap } from './lib/app.svelte';
  import { router, type RouteName } from './lib/router.svelte';
  import { t } from './lib/i18n/index.svelte';
  import { initNativeShell } from './lib/native';
  import Toast from './components/Toast.svelte';
  import Splash from './components/Splash.svelte';
  import StaleInviteModal from './components/StaleInviteModal.svelte';
  import WelcomeRedeemModal from './components/WelcomeRedeemModal.svelte';
  import Coachmark from './components/Coachmark.svelte';
  import MaintenanceOverlay from './components/MaintenanceOverlay.svelte';
  import UpdateOverlay from './components/UpdateOverlay.svelte';
  import DebugPanel from './components/DebugPanel.svelte';
  import Login from './screens/Login.svelte';
  import Lobby from './screens/Lobby.svelte';
  import NewGame from './screens/NewGame.svelte';
  import SettingsHub from './screens/SettingsHub.svelte';
  import Stats from './screens/Stats.svelte';
  import Confirm from './screens/Confirm.svelte';
  import Game from './game/Game.svelte';
  import CommsHub from './game/CommsHub.svelte';
  import Feedback from './screens/Feedback.svelte';
  import Blocked from './screens/Blocked.svelte';
  import AccountDeleted from './screens/AccountDeleted.svelte';
  import BootError from './screens/BootError.svelte';
  import LaunchError from './screens/LaunchError.svelte';

  onMount(() => {
    // Tell the index.html boot guard that startup completed, so its reactive net does not raise the
    // unsupported-engine screen on a healthy boot — it only fires when an uncaught error occurred
    // AND this flag never sets (a bundle that failed to parse, or an unforeseen incompatibility).
    void bootstrap().then(() => {
      (window as unknown as { __booted?: boolean }).__booted = true;
    });
    // Native shell only: wire the Android hardware Back button. No-op — and pulls no
    // @capacitor/app — on web/Telegram/VK, where initNativeShell early-returns. At the
    // navigation root (lobby/login) Back exits the app; otherwise it steps history back.
    void initNativeShell(() => routeDepth(router.route.name) === 0);
  });

  // The lobby is the cold-start landing (an empty hash and Telegram launch params both parse
  // to it). The tile loading splash overlays it until its first load settles; a deep-link to
  // another screen is not covered.
  const routeIsLobby = $derived(router.route.name === 'lobby');

  // Screen transitions: the lobby is the navigation root. Entering a screen from the
  // lobby slides it in from the right (forward); returning to the lobby slides the
  // screen out to the right and reveals the lobby (back). Transitions are local, so
  // they do not play on the initial mount, and collapse to nothing under reduce-motion.
  // Slide direction by route depth: going deeper (lobby → game → chat/check) slides forward,
  // returning to a shallower screen slides back. A plain "lobby is back" rule slid the chat/check
  // back-to-the-game the wrong way. dir is read with the previous depth (the effect updates it
  // only after the transition has captured its sign).
  function routeDepth(name: RouteName): number {
    if (name === 'gameChat' || name === 'gameCheck' || name === 'feedback') return 2;
    if (name === 'lobby' || name === 'login') return 0;
    return 1;
  }
  const curDepth = $derived(routeDepth(router.route.name));
  let prevDepth = $state(routeDepth(router.route.name));
  const dir = $derived(curDepth < prevDepth ? 'back' : 'forward');
  $effect(() => {
    prevDepth = curDepth;
  });
  const enterSign = $derived(dir === 'forward' ? 1 : -1);
  const leaveSign = $derived(dir === 'forward' ? -1 : 1);
  const routeKey = $derived(router.route.name + (router.route.params.id ?? ''));
  const animMs = $derived(app.reduceMotion ? 0 : 260);

  // slideX slides a pane horizontally by a full width. sign>0 enters from / exits to
  // the right; sign<0 the left. Percentage keeps it viewport-relative without reading
  // innerWidth, and the .router clips the off-screen pane.
  function slideX(_node: Element, { duration, sign }: { duration: number; sign: number }) {
    return {
      duration,
      easing: cubicOut,
      css: (tt: number) => `transform: translateX(${(1 - tt) * sign * 100}%)`,
    };
  }
</script>

{#if !app.ready}
  <!-- On a cold lobby open the tile splash (below) covers bootstrap too; a deep-link to
       another screen keeps the plain text splash while bootstrap runs. -->
  {#if !routeIsLobby}
    <div class="splash">{t('common.loading')}</div>
  {/if}
{:else if app.launchError}
  <!-- A dedicated Mini App entry (/telegram/ or /vk/) opened without a valid launch: a compact,
       shareable diagnostic screen instead of bouncing to the marketing landing (Telegram) or
       silently proceeding as a guest (VK). Also the probe for the empty-initData failure on some
       Android Telegram clients. -->
  <LaunchError />
{:else if app.bootError}
  <!-- A Mini App launch that failed to authenticate (e.g. the backend was down mid-deploy):
       show the retry screen instead of falling back to the web login. -->
  <BootError />
{:else if app.accountDeleted}
  <AccountDeleted />
{:else if app.blocked}
  <Blocked />
{:else}
  <div class="router">
    {#key routeKey}
      <div class="pane" in:slideX={{ duration: animMs, sign: enterSign }} out:slideX={{ duration: animMs, sign: leaveSign }}>
        {#if router.route.name === 'login'}
          <Login />
        {:else if router.route.name === 'new'}
          <NewGame />
        {:else if router.route.name === 'game'}
          <Game id={router.route.params.id} />
        {:else if router.route.name === 'gameChat'}
          <CommsHub id={router.route.params.id} initialTab="chat" />
        {:else if router.route.name === 'gameCheck'}
          <CommsHub id={router.route.params.id} initialTab="dictionary" />
        {:else if router.route.name === 'profile'}
          <SettingsHub initialTab="profile" />
        {:else if router.route.name === 'settings'}
          <SettingsHub initialTab="settings" />
        {:else if router.route.name === 'about'}
          <SettingsHub initialTab="about" />
        {:else if router.route.name === 'friends'}
          <SettingsHub initialTab="friends" />
        {:else if router.route.name === 'wallet'}
          <SettingsHub initialTab="wallet" />
        {:else if router.route.name === 'feedback'}
          <Feedback />
        {:else if router.route.name === 'stats'}
          <Stats />
        {:else if router.route.name === 'confirm'}
          <Confirm token={router.route.params.token} />
        {:else}
          <Lobby />
        {/if}
      </div>
    {/key}
  </div>
{/if}

<Toast />
<StaleInviteModal />
<WelcomeRedeemModal />
<Coachmark />
<MaintenanceOverlay />
<UpdateOverlay />

{#if routeIsLobby && !app.splashDone && !app.blocked && !app.bootError && !app.launchError}
  <Splash />
{/if}

{#if app.debugOpen}
  <DebugPanel />
{/if}

<style>
  .splash {
    height: 100%;
    display: grid;
    place-items: center;
    color: var(--text-muted);
  }
  .router {
    position: relative;
    height: 100%;
    overflow: hidden;
  }
  .pane {
    position: absolute;
    inset: 0;
  }
</style>
