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

void main() {
  /// Opens a sheet titled "New studyset" with [body] and a Create button, in
  /// a window [width] wide, with a status bar [statusBar] high on top.
  Future<void> open(
    WidgetTester tester, {
    required double width,
    Widget body = const Text('Body'),
    double statusBar = 0,
    bool busy = false,
  }) async {
    tester.view.physicalSize = Size(width, 900);
    tester.view.devicePixelRatio = 1;
    tester.view.padding = FakeViewPadding(top: statusBar);
    tester.view.viewPadding = FakeViewPadding(top: statusBar);
    addTearDown(tester.view.reset);
    await tester.pumpWidget(
      MaterialApp(
        localizationsDelegates: HalkyonUiLocalizations.localizationsDelegates,
        supportedLocales: HalkyonUiLocalizations.supportedLocales,
        home: Scaffold(
          body: Builder(
            builder: (context) => TextButton(
              onPressed: () => showAdaptiveSheet<void>(
                context,
                swipeable: !busy,
                builder: (context) => SheetScaffold(
                  title: 'New studyset',
                  busy: busy,
                  body: body,
                  footer: FilledButton(
                    onPressed: () {},
                    child: const Text('Create'),
                  ),
                ),
              ),
              child: const Text('Open'),
            ),
          ),
        ),
      ),
    );
    await tester.tap(find.text('Open'));
    await tester.pumpAndSettle();
  }

  testWidgets('is a bottom sheet below expanded windows on a phone or a '
      'tablet', (tester) async {
    await open(tester, width: 839);

    expect(find.byType(BottomSheet), findsOneWidget);
    expect(find.byType(Dialog), findsNothing);
  });

  testWidgets('is a dialog from expanded windows on', (tester) async {
    await open(tester, width: 840);

    expect(find.byType(Dialog), findsOneWidget);
    expect(find.byType(BottomSheet), findsNothing);
  });

  testWidgets('sheetShowsAsDialog says which a sheet of its own will be: '
      'a dialog from expanded windows on, and on the desktop at every width', (
    tester,
  ) async {
    Future<bool> at(double width) async {
      tester.view.physicalSize = Size(width, 900);
      tester.view.devicePixelRatio = 1;
      late bool shows;
      await tester.pumpWidget(
        MaterialApp(
          home: Builder(
            builder: (context) {
              shows = sheetShowsAsDialog(context);
              return const SizedBox();
            },
          ),
        ),
      );
      return shows;
    }

    addTearDown(tester.view.reset);
    expect(await at(400), isFalse);
    expect(await at(840), isTrue);
    debugDefaultTargetPlatformOverride = TargetPlatform.linux;
    addTearDown(() => debugDefaultTargetPlatformOverride = null);
    expect(await at(400), isTrue);
    debugDefaultTargetPlatformOverride = null;
  });

  for (final platform in [
    TargetPlatform.linux,
    TargetPlatform.macOS,
    TargetPlatform.windows,
  ]) {
    testWidgets('is a dialog on the desktop however narrow the window '
        '(${platform.name})', (tester) async {
      debugDefaultTargetPlatformOverride = platform;
      addTearDown(() => debugDefaultTargetPlatformOverride = null);
      await open(tester, width: 400);

      expect(find.byType(Dialog), findsOneWidget);
      expect(find.byType(BottomSheet), findsNothing);
      debugDefaultTargetPlatformOverride = null;
    });
  }

  for (final width in [400.0, 1200.0]) {
    testWidgets('keeps its close button and footer in view above a long body '
        '(${width.round()} wide)', (tester) async {
      await open(
        tester,
        width: width,
        body: Column(
          children: [for (var i = 0; i < 80; i++) Text('Line $i')],
        ),
      );

      expect(find.byTooltip('Close').hitTestable(), findsOneWidget);
      expect(find.text('Create').hitTestable(), findsOneWidget);
    });
  }

  testWidgets('stays below the status bar with the keyboard open', (
    tester,
  ) async {
    await open(
      tester,
      width: 400,
      statusBar: 48,
      body: Column(
        children: [for (var i = 0; i < 80; i++) Text('Line $i')],
      ),
    );

    tester.view.viewInsets = const FakeViewPadding(bottom: 400);
    await tester.pumpAndSettle();

    expect(tester.getTopLeft(find.byType(BottomSheet)).dy, 48);
    expect(find.byTooltip('Close').hitTestable(), findsOneWidget);
    expect(find.text('Create').hitTestable(), findsOneWidget);
  });

  testWidgets('closes with its close button', (tester) async {
    await open(tester, width: 400);

    await tester.tap(find.byTooltip('Close'));
    await tester.pumpAndSettle();

    expect(find.text('New studyset'), findsNothing);
  });

  testWidgets('while busy, its close button is off and back keeps it open', (
    tester,
  ) async {
    await open(tester, width: 400, busy: true);

    expect(
      tester
          .widget<IconButton>(
            find.ancestor(
              of: find.byTooltip('Close'),
              matching: find.byType(IconButton),
            ),
          )
          .onPressed,
      isNull,
    );
    await tester.binding.handlePopRoute();
    await tester.pumpAndSettle();
    expect(find.text('New studyset'), findsOneWidget);
  });

  group('a body longer than the sheet', () {
    final tall = Column(
      children: [for (var i = 0; i < 40; i++) const Text('Line')],
    );
    Finder below() => find.byKey(SheetScaffold.moreBelowKey);
    Finder above() => find.byKey(SheetScaffold.moreAboveKey);

    testWidgets('shows a line above the buttons while more lies below, and '
        'one under the title while more lies above', (tester) async {
      // As a dialog: a modal bottom sheet takes a test's drag itself.
      await open(tester, width: 1000, body: tall);

      expect(below(), findsOneWidget);
      expect(above(), findsNothing);

      await tester.drag(
        find.byType(SingleChildScrollView),
        const Offset(0, -300),
      );
      await tester.pumpAndSettle();
      expect(below(), findsOneWidget);
      expect(above(), findsOneWidget);
      expect(
        tester
            .state<ScrollableState>(
              find.descendant(
                of: find.byType(SingleChildScrollView),
                matching: find.byType(Scrollable),
              ),
            )
            .position
            .pixels,
        greaterThan(0),
        reason: 'the line coming keeps where the body was scrolled to',
      );

      await tester.drag(
        find.byType(SingleChildScrollView),
        const Offset(0, -5000),
      );
      await tester.pumpAndSettle();
      expect(below(), findsNothing);
      expect(above(), findsOneWidget);
    });

    testWidgets('has a scrollbar, always shown on the desktop', (tester) async {
      debugDefaultTargetPlatformOverride = TargetPlatform.linux;
      addTearDown(() => debugDefaultTargetPlatformOverride = null);
      await open(tester, width: 1000, body: tall);

      final scrollbar = tester.widget<Scrollbar>(find.byType(Scrollbar));
      expect(scrollbar.thumbVisibility, isTrue);
      debugDefaultTargetPlatformOverride = null;
    });
  });

  testWidgets("a heading of its own takes the title's place, and the close "
      'button may give way to its action', (tester) async {
    tester.view.physicalSize = const Size(400, 900);
    tester.view.devicePixelRatio = 1;
    addTearDown(tester.view.reset);
    await tester.pumpWidget(
      MaterialApp(
        localizationsDelegates: HalkyonUiLocalizations.localizationsDelegates,
        supportedLocales: HalkyonUiLocalizations.supportedLocales,
        home: Scaffold(
          body: Builder(
            builder: (context) => TextButton(
              onPressed: () => showAdaptiveSheet<void>(
                context,
                builder: (context) => const SheetScaffold(
                  title: 'Task',
                  heading: Text('Inbox › Shopping'),
                  closeButton: false,
                  action: Text('More'),
                  body: Text('Body'),
                ),
              ),
              child: const Text('Open'),
            ),
          ),
        ),
      ),
    );
    await tester.tap(find.text('Open'));
    await tester.pumpAndSettle();

    expect(find.text('Inbox › Shopping'), findsOneWidget);
    expect(find.text('Task'), findsNothing);
    expect(find.byTooltip('Close'), findsNothing);
    expect(find.text('More'), findsOneWidget);
  });

  testWidgets('a body that fits shows no lines', (tester) async {
    await open(tester, width: 400);

    expect(find.byKey(SheetScaffold.moreBelowKey), findsNothing);
    expect(find.byKey(SheetScaffold.moreAboveKey), findsNothing);
  });

  testWidgets("the body keeps clear of the scroll view's edges, where it is "
      'cut and the scrollbar runs', (tester) async {
    for (final width in [400.0, 1000.0]) {
      await open(
        tester,
        width: width,
        body: const TextField(
          decoration: InputDecoration(border: OutlineInputBorder()),
        ),
      );

      final scrolling = tester.getRect(find.byType(SingleChildScrollView));
      final field = tester.getRect(find.byType(TextField));
      expect(field.left - scrolling.left, greaterThanOrEqualTo(16));
      expect(scrolling.right - field.right, greaterThanOrEqualTo(16));
      // The title and the button stay in line with the body.
      expect(tester.getTopLeft(find.text('New studyset')).dx, field.left);
      expect(tester.getTopRight(find.byType(FilledButton)).dx, field.right);
      await tester.tap(find.byTooltip('Close'));
      await tester.pumpAndSettle();
    }
  });
}