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

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:wolf_3d_dart/wolf_3d_engine.dart';
import 'package:wolf_3d_dart/wolf_3d_renderer.dart';
import 'package:wolf_3d_flutter/renderer/wolf_3d_ascii_renderer.dart';
import 'package:wolf_3d_flutter/renderer/wolf_3d_flutter_renderer.dart';
import 'package:wolf_3d_flutter/renderer/wolf_3d_glsl_renderer.dart';
import 'package:wolf_3d_flutter/wolf_3d_flutter.dart';

/// Launches a [WolfEngine] via [Wolf3d] and exposes renderer/input integrations.
class GameScreen extends StatefulWidget {
  /// Shared application facade owning the engine, audio, and input.
  final Wolf3d wolf3d;

  /// Optional host-level shortcut override.
  ///
  /// Return `true` when the event was consumed. Handlers may call
  /// [Wolf3dFlutterInput.suppressActionOnce] to keep actions from reaching the
  /// engine update loop.
  final HostShortcutHandler? hostShortcutHandler;

  /// Declarative host shortcut registry used when [hostShortcutHandler] is null.
  final HostShortcutRegistry hostShortcutRegistry;

  /// Optional host app-exit hook.
  ///
  /// Defaults to [SystemNavigator.pop] in production, but tests can inject a
  /// fake callback to assert quit behavior.
  final Future<void> Function()? appExitHandler;

  /// Skips engine bootstrap for lightweight widget tests.
  @visibleForTesting
  final bool skipEngineBootstrapForTest;

  /// Creates a gameplay screen driven by [wolf3d].
  const GameScreen({
    required this.wolf3d,
    this.hostShortcutHandler,
    this.hostShortcutRegistry = HostShortcutRegistry.defaults,
    this.appExitHandler,
    this.skipEngineBootstrapForTest = false,
    super.key,
  });

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

class _GameScreenState extends State<GameScreen> {
  WolfEngine? _engine;
  late final GameAppLifecycleManager _appLifecycleManager;
  late final GameDisplayManager _displayManager;
  late final GameScreenInputManager _inputManager;
  late final GamePersistenceManager _persistenceManager;

  /// Mirrors [WolfRendererSettings.mode] into the Flutter renderer enum.
  GameRendererMode _rendererMode = GameRendererMode.hardware;

  @override
  void initState() {
    super.initState();
    _appLifecycleManager = GameAppLifecycleManager(
      shutdownAudio: widget.wolf3d.shutdownAudio,
      appExitHandler: widget.appExitHandler,
    );
    _displayManager = GameDisplayManager();
    _persistenceManager = GamePersistenceManager();
    _inputManager = GameScreenInputManager(
      input: widget.wolf3d.input,
      hostShortcutHandler: widget.hostShortcutHandler,
      hostShortcutRegistry: widget.hostShortcutRegistry,
      onToggleFullscreen: _displayManager.toggleFullscreen,
    );

    if (widget.skipEngineBootstrapForTest) {
      return;
    }

    const Set<WolfRendererMode> supportedModes = <WolfRendererMode>{
      WolfRendererMode.hardware,
      WolfRendererMode.software,
      WolfRendererMode.ascii,
    };

    final engine = widget.wolf3d.launchEngine(
      rendererCapabilities: const WolfRendererCapabilities(
        supportedModes: supportedModes,
        supportsAsciiThemes: true,
        supportsHardwareEffects: true,
        supportsBloom: true,
        supportsFpsCounter: true,
      ),
      rendererSettings: const WolfRendererSettings(
        mode: WolfRendererMode.hardware,
      ),
      onRendererSettingsChanged: (settings) {
        unawaited(_persistenceManager.saveRendererSettings(settings));
        if (mounted) {
          setState(() {
            _rendererMode = gameRendererModeFromSettings(settings);
          });
        }
      },
      onGameWon: () {
        _engine?.difficulty = null;
        widget.wolf3d.clearActiveDifficulty();
        Navigator.of(context).pop();
      },
      onQuit: () {
        unawaited(_appLifecycleManager.quitApplication());
      },
      saveGamePersistence: _persistenceManager.saveGamePersistence,
    );

    _engine = engine;
    _rendererMode = gameRendererModeFromSettings(engine.rendererSettings);
    unawaited(_persistenceManager.restoreRendererSettings(engine));
  }

  @override
  void dispose() {
    unawaited(widget.wolf3d.shutdownAudio());
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final engine = _engine;
    if (engine == null) {
      return const Scaffold(body: SizedBox.shrink());
    }

    final WolfRendererSettings settings = engine.rendererSettings;
    final Widget renderer = switch (_rendererMode) {
      GameRendererMode.software => WolfFlutterRenderer(
        engine: engine,
        onKeyEvent: _handleRendererKeyEvent,
      ),
      GameRendererMode.ascii => WolfAsciiRenderer(
        engine: engine,
        theme: settings.asciiThemeId == WolfRendererSettings.asciiThemeQuadrant
            ? AsciiThemes.quadrant
            : AsciiThemes.blocks,
        onKeyEvent: _handleRendererKeyEvent,
      ),
      GameRendererMode.hardware => WolfGlslRenderer(
        engine: engine,
        effectsEnabled: settings.hardwareEffectsEnabled,
        bloomEnabled: settings.bloomEnabled,
        onKeyEvent: _handleRendererKeyEvent,
        onUnavailable: _handleGlslUnavailable,
      ),
    };

    return PopScope(
      canPop: engine.difficulty != null,
      onPopInvokedWithResult: (didPop, _) {
        if (!didPop && engine.difficulty == null) {
          widget.wolf3d.input.queueBackAction();
        }
      },
      child: Scaffold(
        floatingActionButton:
            widget.wolf3d.isDebugEnabled && engine.difficulty != null
            ? FloatingActionButton(
                onPressed: _openDebugTools,
                tooltip: 'Open Debug Tools',
                child: const Icon(Icons.bug_report),
              )
            : null,
        body: LayoutBuilder(
          builder: (context, constraints) {
            return Listener(
              onPointerDown: (event) {
                widget.wolf3d.input.onPointerDown(event);
              },
              onPointerUp: widget.wolf3d.input.onPointerUp,
              onPointerMove: widget.wolf3d.input.onPointerMove,
              onPointerHover: widget.wolf3d.input.onPointerMove,
              child: Stack(
                children: [
                  renderer,

                  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',
                              ),
                            ),
                          ],
                        ),
                      ),
                    ),

                  // 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),
                      ),
                    ),
                ],
              ),
            );
          },
        ),
      ),
    );
  }

  void _handleRendererKeyEvent(KeyEvent event) {
    _inputManager.handleRendererKeyEventForHost(
      event: event,
      engine: _engine,
      rendererMode: _rendererMode,
      onFpsToggled: (WolfEngine activeEngine) {
        setState(() => activeEngine.toggleFpsCounter());
      },
    );
  }

  void _handleGlslUnavailable() {
    handleGlslUnavailable(
      isMounted: mounted,
      rendererMode: _rendererMode,
      engine: _engine,
    );
  }

  void _openDebugTools() {
    Navigator.of(context).push(
      MaterialPageRoute(
        builder: (_) => DebugToolsScreen(wolf3d: widget.wolf3d),
      ),
    );
  }
}