import { useEffect, useRef } from 'react';

import { RpgRuntimeShell } from './components/rpg-runtime-shell/RpgRuntimeShell';
import { useRpgRuntimeSession } from './hooks/rpg-session/useRpgRuntimeSession';
import type { HydratedSavedGameSnapshot } from './persistence/runtimeSnapshotTypes';
import type { CustomWorldProfile } from './types';

export type RpgRuntimeAppIntent =
  | {
      token: number;
      kind: 'custom-world';
      profile: CustomWorldProfile;
      mode?: 'play';
      disablePersistence?: boolean;
      exitToResult?: boolean;
    }
  | {
      token: number;
      kind: 'snapshot';
      snapshot: HydratedSavedGameSnapshot | null;
    };

export function RpgRuntimeApp({
  initialIntent,
  onExitRuntime,
}: {
  initialIntent: RpgRuntimeAppIntent | null;
  onExitRuntime?: () => void;
}) {
  const gameShellProps = useRpgRuntimeSession();
  const handledIntentTokenRef = useRef<number | null>(null);

  useEffect(() => {
    if (!initialIntent || handledIntentTokenRef.current === initialIntent.token) {
      return;
    }

    handledIntentTokenRef.current = initialIntent.token;
    if (initialIntent.kind === 'custom-world') {
      gameShellProps.entry.handleCustomWorldSelect(initialIntent.profile, {
        mode: initialIntent.mode ?? 'play',
        disablePersistence: initialIntent.disablePersistence,
      });
      return;
    }

    gameShellProps.entry.handleContinueGame(initialIntent.snapshot);
  }, [gameShellProps.entry, initialIntent]);

  return (
    <RpgRuntimeShell
      {...gameShellProps}
      onExitRuntimePreview={onExitRuntime}
      showRuntimePreviewExit={
        initialIntent?.kind === 'custom-world' &&
        initialIntent.exitToResult === true
      }
    />
  );
}

export default RpgRuntimeApp;