import 'package:flutter/services.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:halkyon_ui/halkyon_ui.dart';
import 'package:material_ui/material_ui.dart';

import '../support/test_app.dart';

/// Every Halkyon app's frame around its tabs: a rail with the app's icon
/// from medium windows on, a flush bar below with a fade above it, a tick on every choice.
void main() {
  /// A 1 × 1 PNG, the app's icon in these tests.
  final icon = MemoryImage(
    Uint8List.fromList(const [
      0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, 0x00, 0x00, 0x00, 0x0D, //
      0x49, 0x48, 0x44, 0x52, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01,
      0x08, 0x06, 0x00, 0x00, 0x00, 0x1F, 0x15, 0xC4, 0x89, 0x00, 0x00, 0x00,
      0x0B, 0x49, 0x44, 0x41, 0x54, 0x78, 0x9C, 0x63, 0x60, 0x00, 0x02, 0x00,
      0x00, 0x05, 0x00, 0x01, 0x7A, 0x5E, 0xAB, 0x3F, 0x00, 0x00, 0x00, 0x00,
      0x49, 0x45, 0x4E, 0x44, 0xAE, 0x42, 0x60, 0x82,
    ]),
  );

  /// The frame in a window [width] wide, on tab [selected]; the tabs chosen
  /// go into [chosen].
  Future<void> show(
    WidgetTester tester, {
    required double width,
    required List<int> chosen,
    int selected = 1,
  }) async {
    tester.view.physicalSize = Size(width, 800);
    tester.view.devicePixelRatio = 1;
    addTearDown(tester.view.reset);
    await tester.pumpWidget(
      testApp(
        NavigationFrame(
          appName: 'Halkyon Test',
          icon: icon,
          selectedIndex: selected,
          onSelected: chosen.add,
          destinations: const [
            (label: 'Home', icon: Icon(Icons.home), selectedIcon: null),
            (label: 'Maps', icon: Icon(Icons.map), selectedIcon: null),
            (label: 'Profile', icon: Icon(Icons.person), selectedIcon: null),
          ],
          child: const Scaffold(body: Text('The tab')),
        ),
      ),
    );
  }

  /// The ticks the platform was asked for while [act] ran.
  Future<List<Object?>> ticks(
    WidgetTester tester,
    Future<void> Function() act,
  ) async {
    final haptics = <Object?>[];
    tester.binding.defaultBinaryMessenger.setMockMethodCallHandler(
      SystemChannels.platform,
      (call) async {
        if (call.method == 'HapticFeedback.vibrate') {
          haptics.add(call.arguments);
        }
        return null;
      },
    );
    addTearDown(
      () => tester.binding.defaultBinaryMessenger.setMockMethodCallHandler(
        SystemChannels.platform,
        null,
      ),
    );
    await act();
    return haptics;
  }

  testWidgets('below medium windows, a bar stands at the foot', (
    tester,
  ) async {
    await show(tester, width: 400, chosen: []);

    expect(find.byType(FlushNavigationBar), findsOneWidget);
    expect(find.byType(NavigationRail), findsNothing);
    expect(find.text('The tab'), findsOneWidget);
  });

  testWidgets('below medium windows, the bar is flush with the foot: as wide '
      "as the window, 64 high above the system's bar, in the theme's colour", (
    tester,
  ) async {
    tester.view.padding = const FakeViewPadding(bottom: 24);
    tester.view.viewPadding = const FakeViewPadding(bottom: 24);
    await show(tester, width: 400, chosen: []);

    final bar = find.byType(NavigationBar);
    expect(
      tester.getRect(bar),
      const Rect.fromLTRB(0, 800 - 64 - 24, 400, 800),
    );
    expect(tester.widget<NavigationBar>(bar).backgroundColor, isNull);
    expect(tester.widget<NavigationBar>(bar).elevation, isNull);
  });

  testWidgets('right above the bar, a fade into the background of the screen '
      'in view, which taps pass through to the screen', (tester) async {
    tester.view.padding = const FakeViewPadding(bottom: 24);
    tester.view.viewPadding = const FakeViewPadding(bottom: 24);
    tester.view.physicalSize = const Size(400, 800);
    tester.view.devicePixelRatio = 1;
    addTearDown(tester.view.reset);
    var tapped = 0;
    const background = Color(0xFFFFE4C4);
    await tester.pumpWidget(
      testApp(
        NavigationFrame(
          appName: 'Halkyon Test',
          icon: icon,
          selectedIndex: 0,
          onSelected: (_) {},
          destinations: const [
            (label: 'Home', icon: Icon(Icons.home), selectedIcon: null),
            (label: 'Maps', icon: Icon(Icons.map), selectedIcon: null),
          ],
          child: TopGradient(
            background: background,
            child: GestureDetector(
              behavior: HitTestBehavior.opaque,
              onTap: () => tapped++,
              child: const SizedBox.expand(),
            ),
          ),
        ),
      ),
    );
    await tester.pumpAndSettle();

    final fade = find.byKey(FlushNavigationBar.fadeKey);
    final bar = tester.getRect(find.byType(NavigationBar));
    expect(
      tester.getRect(fade),
      Rect.fromLTRB(0, bar.top - FlushNavigationBar.fadeHeight, 400, bar.top),
    );
    final gradient =
        (tester.widget<DecoratedBox>(fade).decoration as BoxDecoration)
                .gradient!
            as LinearGradient;
    expect(gradient.colors, [background.withValues(alpha: 0), background]);

    await tester.tapAt(tester.getCenter(fade));
    expect(tapped, 1);
  });

  testWidgets('before a screen claims its background, the fade ends in the '
      "theme's surface, light and dark", (tester) async {
    tester.view.physicalSize = const Size(400, 800);
    tester.view.devicePixelRatio = 1;
    addTearDown(tester.view.reset);
    for (final brightness in Brightness.values) {
      await tester.pumpWidget(
        testApp(
          brightness: brightness,
          NavigationFrame(
            appName: 'Halkyon Test',
            icon: icon,
            selectedIndex: 0,
            onSelected: (_) {},
            destinations: const [
              (label: 'Home', icon: Icon(Icons.home), selectedIcon: null),
              (label: 'Maps', icon: Icon(Icons.map), selectedIcon: null),
            ],
            child: const Scaffold(body: Text('The tab')),
          ),
        ),
      );
      await tester.pumpAndSettle();

      final fade = find.byKey(FlushNavigationBar.fadeKey);
      final surface = Theme.of(tester.element(fade)).colorScheme.surface;
      final gradient =
          (tester.widget<DecoratedBox>(fade).decoration as BoxDecoration)
                  .gradient!
              as LinearGradient;
      expect(gradient.colors.last, surface, reason: '$brightness');
    }
  });

  testWidgets("a tab's content leaves room for the bar, its fade and the "
      "system's bar; its floating button rises above the fade, the Scaffold "
      "keeping it clear of the system's bar itself", (tester) async {
    tester.view.padding = const FakeViewPadding(bottom: 24);
    tester.view.viewPadding = const FakeViewPadding(bottom: 24);
    tester.view.physicalSize = const Size(400, 800);
    tester.view.devicePixelRatio = 1;
    addTearDown(tester.view.reset);
    late double cover;
    await tester.pumpWidget(
      testApp(
        NavigationFrame(
          appName: 'Halkyon Test',
          icon: icon,
          selectedIndex: 0,
          onSelected: (_) {},
          destinations: const [
            (label: 'Home', icon: Icon(Icons.home), selectedIcon: null),
            (label: 'Maps', icon: Icon(Icons.map), selectedIcon: null),
          ],
          child: Builder(
            builder: (context) => Scaffold(
              body: Builder(
                builder: (context) {
                  cover = FlushNavigationBar.coverOf(context);
                  return const SizedBox.expand(key: Key('tab'));
                },
              ),
              floatingActionButton: Padding(
                padding: EdgeInsets.only(
                  bottom: FlushNavigationBar.buttonLiftOf(context),
                ),
                child: FloatingActionButton(
                  onPressed: () {},
                  child: const Icon(Icons.add),
                ),
              ),
            ),
          ),
        ),
      ),
    );
    await tester.pumpAndSettle();

    expect(cover, FlushNavigationBar.fadeHeight + 64 + 24);
    expect(
      tester.getBottomLeft(find.byKey(const Key('tab'))).dy,
      800,
      reason: 'the content runs on beneath the fade and the bar',
    );
    expect(
      tester.getRect(find.byType(FloatingActionButton)).bottom,
      tester.getRect(find.byKey(FlushNavigationBar.fadeKey)).top - 16,
    );
  });

  testWidgets("outside the frame, content leaves room for the system's bar "
      'alone', (tester) async {
    tester.view.padding = const FakeViewPadding(bottom: 24);
    tester.view.viewPadding = const FakeViewPadding(bottom: 24);
    tester.view.physicalSize = const Size(400, 800);
    tester.view.devicePixelRatio = 1;
    addTearDown(tester.view.reset);
    late double cover;
    late double lift;
    await tester.pumpWidget(
      testApp(
        Scaffold(
          body: Builder(
            builder: (context) {
              cover = FlushNavigationBar.coverOf(context);
              lift = FlushNavigationBar.buttonLiftOf(context);
              return const SizedBox.expand();
            },
          ),
        ),
      ),
    );

    expect(cover, 24);
    expect(lift, 0);
  });

  testWidgets("from medium windows on, a rail with the app's icon on top, "
      'which leads to the first tab', (tester) async {
    final chosen = <int>[];
    await show(tester, width: 800, chosen: chosen);

    expect(find.byType(NavigationRail), findsOneWidget);
    expect(find.byType(NavigationBar), findsNothing);
    expect(find.bySemanticsLabel('Halkyon Test'), findsOneWidget);

    await tester.tap(find.byTooltip('Home'));
    await tester.pump();
    expect(chosen, [0]);
  });

  testWidgets('every choice on the bar ticks, lightly', (tester) async {
    final chosen = <int>[];
    await show(tester, width: 400, chosen: chosen);
    final haptics = await ticks(tester, () async {
      await tester.tap(find.text('Profile'));
      await tester.pump();
    });

    expect(haptics, ['HapticFeedbackType.selectionClick']);
    expect(chosen, [2]);
  });

  testWidgets('every choice on the rail ticks, lightly', (tester) async {
    final chosen = <int>[];
    await show(tester, width: 800, chosen: chosen);
    final haptics = await ticks(tester, () async {
      await tester.tap(find.text('Maps'));
      await tester.pump();
    });

    expect(haptics, ['HapticFeedbackType.selectionClick']);
    expect(chosen, [1]);
  });

  testWidgets('the window crossing from compact to medium and back swaps '
      'the bar for the rail', (tester) async {
    await show(tester, width: 400, chosen: []);
    for (final width in const [800.0, 400.0]) {
      tester.view.physicalSize = Size(width, 800);
      await tester.pumpAndSettle();
    }

    expect(find.byType(FlushNavigationBar), findsOneWidget);
    expect(find.text('The tab'), findsOneWidget);
  });

  testWidgets('the bar steps aside where a screen has a bar of its own, '
      "leaving the system's bar its room", (tester) async {
    tester.view.physicalSize = const Size(400, 800);
    tester.view.devicePixelRatio = 1;
    tester.view.padding = const FakeViewPadding(bottom: 24);
    tester.view.viewPadding = const FakeViewPadding(bottom: 24);
    addTearDown(tester.view.reset);
    await tester.pumpWidget(
      testApp(
        NavigationFrame(
          appName: 'Halkyon Test',
          icon: icon,
          selectedIndex: 0,
          onSelected: (_) {},
          hidesNavigationBar: true,
          destinations: const [
            (label: 'Home', icon: Icon(Icons.home), selectedIcon: null),
            (label: 'Maps', icon: Icon(Icons.map), selectedIcon: null),
          ],
          child: const Scaffold(body: Text('The tab')),
        ),
      ),
    );

    expect(find.byType(FlushNavigationBar), findsNothing);
    expect(tester.getBottomLeft(find.byType(Scaffold).last).dy, 800 - 24);
  });

  testWidgets('a status stands above the bar below medium windows, and at '
      "the foot of the screen's panel from there on", (tester) async {
    for (final width in const [400.0, 800.0]) {
      tester.view.physicalSize = Size(width, 800);
      tester.view.devicePixelRatio = 1;
      addTearDown(tester.view.reset);
      await tester.pumpWidget(
        testApp(
          NavigationFrame(
            appName: 'Halkyon Test',
            icon: icon,
            selectedIndex: 0,
            onSelected: (_) {},
            status: const Text('Recording'),
            destinations: const [
              (label: 'Home', icon: Icon(Icons.home), selectedIcon: null),
              (label: 'Maps', icon: Icon(Icons.map), selectedIcon: null),
            ],
            child: const Scaffold(body: Text('The tab')),
          ),
        ),
      );
      await tester.pumpAndSettle();

      final status = tester.getBottomLeft(find.text('Recording')).dy;
      final tab = tester.getTopLeft(find.text('The tab')).dy;
      expect(status, greaterThan(tab), reason: '$width');
      if (width < 600) {
        expect(
          status,
          lessThan(tester.getTopLeft(find.byType(NavigationBar)).dy),
        );
      }
    }
  });

  testWidgets("the keyboard leaves the frame's tab its size: the tab's own "
      'screen decides whether it makes way, as one with a field floating '
      "over it doesn't", (tester) async {
    tester.view.physicalSize = const Size(400, 800);
    tester.view.devicePixelRatio = 1;
    addTearDown(tester.view.reset);
    Widget frame({required bool screenResizes}) => testApp(
      NavigationFrame(
        appName: 'Halkyon Test',
        icon: icon,
        selectedIndex: 0,
        onSelected: (_) {},
        destinations: const [
          (label: 'Home', icon: Icon(Icons.home), selectedIcon: null),
          (label: 'Maps', icon: Icon(Icons.map), selectedIcon: null),
        ],
        child: Scaffold(
          resizeToAvoidBottomInset: screenResizes,
          body: const SizedBox.expand(key: Key('tab')),
        ),
      ),
    );
    await tester.pumpWidget(frame(screenResizes: false));
    final before = tester.getSize(find.byKey(const Key('tab')));

    tester.view.viewInsets = const FakeViewPadding(bottom: 300);
    addTearDown(tester.view.resetViewInsets);
    await tester.pump();
    expect(tester.getSize(find.byKey(const Key('tab'))), before);

    await tester.pumpWidget(frame(screenResizes: true));
    expect(
      tester.getSize(find.byKey(const Key('tab'))).height,
      lessThan(before.height),
      reason: 'a screen that resizes still makes way',
    );
  });
}