import 'dart:io';

import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:gba_core/gba_core.dart';
import 'package:splashy_gba/main.dart';
import 'package:splashy_gba/src/emulator/game_pad.dart';
import 'package:splashy_gba/src/library/game_library.dart';
import 'package:splashy_gba/src/library/home_screen.dart';

/// A freely licensed test ROM (jsmolka/gba-tests, MIT), fetched by
/// `dart run tool/fetch_test_roms.dart` in packages/gba_core.
const String testRom = 'packages/gba_core/test/roms/jsmolka/arm.gba';

/// Lets real file IO and isolates progress, and the fake clock (snack bar
/// timers, animations) advance, until [finder] matches or 10 s pass.
Future<void> pumpUntil(WidgetTester tester, Finder finder) async {
  for (var i = 0; i < 100 && finder.evaluate().isEmpty; i++) {
    await tester.runAsync(
      () => Future<void>.delayed(const Duration(milliseconds: 50)),
    );
    await tester.pump(const Duration(milliseconds: 100));
  }
}

void main() {
  late Directory root;

  setUp(() => root = Directory.systemTemp.createTempSync('splashy_test'));
  tearDown(() => root.deleteSync(recursive: true));

  group('home screen', () {
    testWidgets('an empty library explains how to add a game', (tester) async {
      await tester.pumpWidget(SplashyGbaApp(library: GameLibrary(root)));
      await pumpUntil(tester, find.text('No games yet'));
      expect(find.text('No games yet'), findsOneWidget);
      expect(find.textContaining('No games or BIOS files'), findsOneWidget);
      expect(find.text('Add game'), findsOneWidget);
    });

    testWidgets('adding a ROM lists it; a non-ROM is refused', (tester) async {
      final notRom = File('${root.path}/notes.txt')..writeAsStringSync('hello');
      var next = (path: testRom, name: 'arm.gba');
      final library = GameLibrary(Directory('${root.path}/library'));
      await tester.pumpWidget(
        MaterialApp(
          home: HomeScreen(library: library, pickFile: () async => next),
        ),
      );
      await pumpUntil(tester, find.text('No games yet'));

      await tester.tap(find.text('Add game'));
      await pumpUntil(tester, find.text('GBA Tests'));
      expect(find.text('GBA Tests'), findsOneWidget);
      expect(find.textContaining('1337'), findsOneWidget);
      expect(File('${root.path}/library/roms/arm.gba').existsSync(), isTrue);

      next = (path: notRom.path, name: 'notes.txt');
      await tester.tap(find.text('Add game'));
      final refused = find.textContaining('too small to be a Game Boy');
      await pumpUntil(tester, refused);
      expect(refused, findsOneWidget);
    });
  });

  group('game pad layout', () {
    const portrait = Size(400, 800);
    final portraitScreen = Rect.fromLTWH(0, 48, 400, 400 / 1.5);

    test('each button presses its key', () {
      final layout = GamePadLayout.compute(portrait, portraitScreen);
      for (final button in layout.buttons) {
        expect(
          layout.keysAt(button.rect.center),
          button.key,
          reason: button.label,
        );
      }
    });

    test('the D-pad reads eight directions and has a dead zone', () {
      final layout = GamePadLayout.compute(portrait, portraitScreen);
      final center = layout.dpad.center;
      final r = layout.dpad.width / 2 * 0.8;
      expect(layout.keysAt(center), 0);
      expect(layout.keysAt(center + Offset(r, 0)), GbaKey.right);
      expect(layout.keysAt(center + Offset(0, -r)), GbaKey.up);
      expect(layout.keysAt(center + Offset(-r, 0)), GbaKey.left);
      expect(layout.keysAt(center + Offset(0, r)), GbaKey.down);
      expect(
        layout.keysAt(center + Offset(r, r) * 0.7),
        GbaKey.right | GbaKey.down,
      );
      expect(
        layout.keysAt(center + Offset(-r, -r) * 0.7),
        GbaKey.left | GbaKey.up,
      );
    });

    test('controls stay clear of the picture in both orientations', () {
      const landscape = Size(800, 400);
      final landscapeScreen = Rect.fromCenter(
        center: const Offset(400, 200),
        width: 448 / 1.0,
        height: 448 / 1.5,
      );
      for (final (size, screen) in [
        (portrait, portraitScreen),
        (landscape, landscapeScreen),
      ]) {
        final layout = GamePadLayout.compute(size, screen, topReserved: 48);
        // Nothing may sit under the close and pause buttons.
        final topBar = Rect.fromLTWH(0, 0, size.width, 48);
        if (size.width > size.height) {
          for (final button in layout.buttons) {
            expect(button.rect.overlaps(topBar), isFalse, reason: button.label);
          }
        }
        expect(layout.dpad.overlaps(screen), isFalse);
        for (final button in layout.buttons) {
          expect(
            button.rect.overlaps(screen),
            isFalse,
            reason: '${button.label} in $size',
          );
          expect(
            Offset.zero & size,
            predicate<Rect>((r) => r.contains(button.rect.center)),
          );
        }
      }
    });
  });
}