import { lazy, Suspense, useEffect, useMemo, useState, type ReactNode } from "react";
import { BASE_CLASS_IDS, classById } from "./app/characterCatalog";
import { useShellStore } from "./app/shellStore";
import { isShelvedShellPhase, SHELVED_MODES_ENABLED } from "./app/releaseFeatures";
import { preloadAbilityCatalogsForClasses } from "./game/abilityCatalog";
import { useAuthoritativeDualScreenSync, useForcedThorDisplays } from "./platform/useThorDualScreen";
import { LoginScreen } from "./ui/LoginScreen";
import { OnlineGroupCoordinator } from "./app/OnlineGroupCoordinator";
import { ShelvedModeRoute } from "@shelvedModeRoutes";
import { preloadTalentGameplayResources } from "./ui/talentGameplayResources";
import {
  getLoadedGameRuntime,
  loadGameRuntime,
  preloadSharedGameplayResources,
} from "./ui/gameplayResources";
import { useCompanionCooldownPolicyStore } from "./game/companionCooldownPolicyStore";
import { useCompanionSpecReadinessStore } from "./game/companionSpecReadinessStore";
import { usePartyBuffPolicyStore } from "./game/partyBuffPolicyStore";

const GameRuntime = lazy(loadGameRuntime);
const CharacterCreateScreen = lazy(() => import("./ui/CharacterCreateScreen").then((module) => ({ default: module.CharacterCreateScreen })));
const CharacterSelectScreen = lazy(() => import("./ui/CharacterSelectScreen").then((module) => ({ default: module.CharacterSelectScreen })));
const ClassHallScreen = lazy(() => import("./ui/ClassHallScreen").then((module) => ({ default: module.ClassHallScreen })));
const DungeonSelectScreen = lazy(() => import("./ui/DungeonSelectScreen").then((module) => ({ default: module.DungeonSelectScreen })));
const MainMenuScreen = lazy(() => import("./ui/MainMenuScreen").then((module) => ({ default: module.MainMenuScreen })));
const DungeonSimulationAdminScreen = lazy(() => import("./ui/DungeonSimulationAdminScreen").then((module) => ({ default: module.DungeonSimulationAdminScreen })));
function ShellTransition() {
  return <div className="world-transition"><span>HM</span><strong>Opening expedition</strong><small>Preparing the next screen...</small></div>;
}

function RuntimeCatalogGate({ children, preloadGameplay }: { readonly children: ReactNode; readonly preloadGameplay: boolean }) {
  const character = useShellStore((state) => (
    state.characters.find((candidate) => candidate.id === state.selectedCharacterId) ?? null
  ));
  const classIds = useMemo(() => {
    if (!character) return [];
    const definition = classById(character.classId);
    if (definition.mode === "conquest") return [...BASE_CLASS_IDS, character.classId];
    return [character.classId, ...(character.secondaryClassId ? [character.secondaryClassId] : [])];
  }, [character]);
  const talentClassId = character && !character.classId.startsWith("rom-")
    ? character.classId
    : null;
  const originalMediaEnabled = useShellStore((state) => state.combatPresentationSettings.originalMediaEnabled);
  const requestKey = classIds.length
    ? `${classIds.join(":")}|${preloadGameplay ? `game:${originalMediaEnabled}` : "shell"}`
    : "";
  const [loadedKey, setLoadedKey] = useState("");
  const [failedKey, setFailedKey] = useState("");

  useEffect(() => {
    if (!requestKey) return;
    let active = true;
    setFailedKey("");
    void Promise.all([
      preloadAbilityCatalogsForClasses(classIds),
      preloadGameplay && talentClassId ? preloadTalentGameplayResources(talentClassId) : Promise.resolve(),
      preloadGameplay ? preloadSharedGameplayResources(originalMediaEnabled) : Promise.resolve(),
    ]).then(() => {
      if (active) setLoadedKey(requestKey);
    }).catch(() => {
      if (active) setFailedKey(requestKey);
    });
    return () => { active = false; };
  }, [classIds, originalMediaEnabled, preloadGameplay, requestKey, talentClassId]);

  if (!requestKey || loadedKey === requestKey) return children;
  if (failedKey === requestKey) {
    return <div className="world-transition"><span>!</span><strong>Catalog unavailable</strong><small>Reload the app to retry loading combat data.</small></div>;
  }
  return <ShellTransition />;
}

export default function App() {
  useForcedThorDisplays();
  useAuthoritativeDualScreenSync();
  const phase = useShellStore((state) => state.phase);
  const session = useShellStore((state) => state.session);
  const PreloadedGameRuntime = getLoadedGameRuntime();
  const refreshCooldownPolicy = useCompanionCooldownPolicyStore((state) => state.refresh);
  const refreshSpecReadiness = useCompanionSpecReadinessStore((state) => state.refresh);
  const refreshPartyBuffPolicy = usePartyBuffPolicyStore((state) => state.refresh);

  useEffect(() => { void refreshCooldownPolicy(session); }, [refreshCooldownPolicy, session]);
  useEffect(() => { void refreshSpecReadiness(session); }, [refreshSpecReadiness, session]);
  useEffect(() => { void refreshPartyBuffPolicy(session); }, [refreshPartyBuffPolicy, session]);

  useEffect(() => {
    if (!SHELVED_MODES_ENABLED && isShelvedShellPhase(phase)) {
      useShellStore.getState().returnToMainMenu();
      useShellStore.getState().setNotice("That game mode is temporarily unavailable.");
    }
  }, [phase]);

  let screen = null;
  if (phase === "login") screen = <LoginScreen />;
  else if (phase === "characters") screen = <Suspense fallback={<ShellTransition />}><CharacterSelectScreen /></Suspense>;
  else if (phase === "create-character") screen = <Suspense fallback={<ShellTransition />}><CharacterCreateScreen /></Suspense>;
  else if (phase === "main-menu") screen = <Suspense fallback={<ShellTransition />}><MainMenuScreen /></Suspense>;
  else if (phase === "class-hall") screen = <Suspense fallback={<ShellTransition />}><ClassHallScreen /></Suspense>;
  else if (phase === "dungeons") screen = <Suspense fallback={<ShellTransition />}><DungeonSelectScreen /></Suspense>;
  else if (phase === "gm-admin") screen = <Suspense fallback={<ShellTransition />}><DungeonSimulationAdminScreen /></Suspense>;
  else if (isShelvedShellPhase(phase)) {
    screen = <Suspense fallback={<ShellTransition />}><ShelvedModeRoute phase={phase} session={session} /></Suspense>;
  }
  else if (phase === "game") screen = PreloadedGameRuntime
    ? <PreloadedGameRuntime />
    : <Suspense fallback={<ShellTransition />}><GameRuntime /></Suspense>;
  const requiresRuntimeCatalog = !["login", "characters", "create-character"].includes(phase);
  return <><OnlineGroupCoordinator />{requiresRuntimeCatalog
    ? <RuntimeCatalogGate preloadGameplay={phase === "game"}>{screen}</RuntimeCatalogGate>
    : screen}</>;
}