/// Active gameplay screen for the Flutter host.
library;

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:wolf_3d_dart/wolf_3d_data_types.dart';
import 'package:wolf_3d_dart/wolf_3d_engine.dart';
import 'package:wolf_3d_flutter/wolf_3d_input_flutter.dart';
import 'package:wolf_3d_renderer/wolf_3d_ascii_renderer.dart';
import 'package:wolf_3d_renderer/wolf_3d_flutter_renderer.dart';

/// Owns a [WolfEngine] instance and exposes renderer/input integrations to Flutter.
class GameScreen extends StatefulWidget {
  /// Fully parsed game data for the selected version.
  final WolfensteinData data;

  /// Difficulty applied when creating the engine session.
  final Difficulty difficulty;

  /// Episode index used as the starting world.
  final int startingEpisode;

  /// Shared audio backend reused across menu and gameplay screens.
  final EngineAudio audio;

  /// Flutter input adapter that translates widget events into engine input.
  final Wolf3dFlutterInput input;

  /// Creates a gameplay screen with the supplied game session configuration.
  const GameScreen({
    required this.data,
    required this.difficulty,
    required this.startingEpisode,
    required this.audio,
    required this.input,
    super.key,
  });

  @override
  State<GameScreen> createState() => _GameScreenState();
}

class _GameScreenState extends State<GameScreen> {
  late final WolfEngine _engine;
  bool _useAsciiMode = false;

  @override
  void initState() {
    super.initState();
    _engine = WolfEngine(
      data: widget.data,
      difficulty: widget.difficulty,
      startingEpisode: widget.startingEpisode,
      frameBuffer: FrameBuffer(320, 200),
      audio: widget.audio,
      input: widget.input,
      onGameWon: () => Navigator.of(context).pop(),
    );
    _engine.init();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Listener(
        onPointerDown: widget.input.onPointerDown,
        onPointerUp: widget.input.onPointerUp,
        onPointerMove: widget.input.onPointerMove,
        onPointerHover: widget.input.onPointerMove,
        child: Stack(
          children: [
            // Keep both renderers behind the same engine so mode switching does
            // not reset level state or audio playback.
            _useAsciiMode
                ? WolfAsciiRenderer(engine: _engine)
                : WolfFlutterRenderer(engine: _engine),

            if (!_engine.isInitialized)
              Container(
                color: Colors.black,
                child: const Center(
                  child: Column(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      CircularProgressIndicator(color: Colors.teal),
                      SizedBox(height: 20),
                      Text(
                        "GET PSYCHED!",
                        style: TextStyle(
                          color: Colors.teal,
                          fontFamily: 'monospace',
                        ),
                      ),
                    ],
                  ),
                ),
              ),

            // Tab toggles the renderer implementation for quick visual debugging.
            Focus(
              autofocus: true,
              onKeyEvent: (node, event) {
                if (event is KeyDownEvent &&
                    event.logicalKey == LogicalKeyboardKey.tab) {
                  setState(() => _useAsciiMode = !_useAsciiMode);
                  return KeyEventResult.handled;
                }
                return KeyEventResult.ignored;
              },
              child: const SizedBox.shrink(),
            ),

            // A second full-screen overlay keeps the presentation simple while
            // the engine is still warming up or decoding the first frame.
            if (!_engine.isInitialized)
              Container(
                color: Colors.black,
                child: const Center(
                  child: CircularProgressIndicator(color: Colors.teal),
                ),
              ),

            Positioned(
              top: 16,
              right: 16,
              child: Text(
                'TAB: Swap Renderer',
                style: TextStyle(color: Colors.white.withValues(alpha: 0.5)),
              ),
            ),
          ],
        ),
      ),
    );
  }
}