import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:muzzle_velocity/markdown_editing.dart';
import 'package:muzzle_velocity/markdown_view.dart';
import 'package:muzzle_velocity/note_editor.dart';
import 'package:muzzle_velocity/themes/day.dart';
import 'package:muzzle_velocity/themes/night.dart';
import 'package:shared_preferences/shared_preferences.dart';

Future<void> _press(WidgetTester tester, LogicalKeyboardKey key,
    {bool control = false, bool shift = false}) async {
  if (control) await tester.sendKeyDownEvent(LogicalKeyboardKey.controlLeft);
  if (shift) await tester.sendKeyDownEvent(LogicalKeyboardKey.shiftLeft);
  await tester.sendKeyEvent(key);
  if (shift) await tester.sendKeyUpEvent(LogicalKeyboardKey.shiftLeft);
  if (control) await tester.sendKeyUpEvent(LogicalKeyboardKey.controlLeft);
  await tester.pumpAndSettle();
}

void main() {
  late File note;

  setUp(() {
    SharedPreferences.setMockInitialValues({});
    note = File('${Directory.systemTemp.createTempSync('mv').path}/n.md')
      ..writeAsStringSync('one word\ntwo word\n');
  });

  Future<TextField> pumpEditor(WidgetTester tester,
      {Future<void> Function()? onQuit}) async {
    await tester.runAsync(() async {
      await tester.pumpWidget(MaterialApp(
        home: NoteEditorScreen(
          note: note,
          notesDirectoryPath: note.parent.path,
          searchTerms: const ['word'],
          onQuit: onQuit ?? () async {},
        ),
      ));
      // File reads complete outside the fake clock.
      await Future<void>.delayed(const Duration(milliseconds: 100));
    });
    await tester.pumpAndSettle();
    return tester.widget<TextField>(find.byType(TextField));
  }

  TextField field(WidgetTester tester) =>
      tester.widget<TextField>(find.byType(TextField));

  testWidgets('Ctrl+E toggles editing and Esc leaves it', (tester) async {
    expect((await pumpEditor(tester)).readOnly, isTrue);

    await _press(tester, LogicalKeyboardKey.keyE, control: true);
    expect(field(tester).readOnly, isFalse);

    await _press(tester, LogicalKeyboardKey.escape);
    expect(field(tester).readOnly, isTrue);
  });

  testWidgets('Ctrl+B and Ctrl+I wrap the selection in edit mode',
      (tester) async {
    await pumpEditor(tester);
    await _press(tester, LogicalKeyboardKey.keyE, control: true);

    final controller = field(tester).controller!;
    controller.selection = const TextSelection(baseOffset: 0, extentOffset: 3);
    await _press(tester, LogicalKeyboardKey.keyB, control: true);
    expect(controller.text, startsWith('**one** word'));

    await _press(tester, LogicalKeyboardKey.keyI, control: true);
    expect(controller.text, startsWith('***one*** word'));
  });

  testWidgets('F3 and Shift+F3 cycle search matches', (tester) async {
    await pumpEditor(tester);
    final controller = field(tester).controller! as MarkdownController;
    expect(controller.currentMatch, 0);

    await _press(tester, LogicalKeyboardKey.f3);
    expect(controller.currentMatch, 1);
    await _press(tester, LogicalKeyboardKey.f3);
    expect(controller.currentMatch, 0);
    await _press(tester, LogicalKeyboardKey.f3, shift: true);
    expect(controller.currentMatch, 1);
  });

  testWidgets('arrows scroll in read and preview mode, not in edit mode',
      (tester) async {
    note.writeAsStringSync(List.generate(200, (i) => 'line $i').join('\n'));
    await pumpEditor(tester);
    ScrollController sourceScroll() => field(tester).scrollController!;

    await _press(tester, LogicalKeyboardKey.arrowDown);
    expect(sourceScroll().offset, greaterThan(0));
    await _press(tester, LogicalKeyboardKey.arrowUp);
    expect(sourceScroll().offset, 0);

    await _press(tester, LogicalKeyboardKey.arrowDown);
    final readOffset = sourceScroll().offset;
    await _press(tester, LogicalKeyboardKey.keyE, control: true);
    expect(sourceScroll().offset, readOffset,
        reason: 'entering edit mode keeps the scroll position');
    await _press(tester, LogicalKeyboardKey.arrowDown);
    expect(sourceScroll().offset, readOffset,
        reason: 'arrows move the caret in edit mode');

    await _press(tester, LogicalKeyboardKey.keyP, control: true);
    final preview = tester
        .widget<SingleChildScrollView>(find.byType(SingleChildScrollView))
        .controller!;
    await _press(tester, LogicalKeyboardKey.arrowDown);
    expect(preview.offset, greaterThan(0));
  });

  testWidgets('Page Down and Page Up scroll by a screen in read mode',
      (tester) async {
    note.writeAsStringSync(List.generate(400, (i) => 'line $i').join('\n'));
    await pumpEditor(tester);
    final scroll = field(tester).scrollController!;

    await _press(tester, LogicalKeyboardKey.pageDown);
    final page = scroll.offset;
    expect(page, closeTo(scroll.position.viewportDimension * 0.9, 1));
    await _press(tester, LogicalKeyboardKey.pageUp);
    expect(scroll.offset, 0);
  });

  testWidgets('Ctrl+Q quits, asking first about unsaved changes',
      (tester) async {
    var quits = 0;
    await pumpEditor(tester, onQuit: () async => quits++);

    await _press(tester, LogicalKeyboardKey.keyQ, control: true);
    expect(quits, 1);

    field(tester).controller!.text = 'changed';
    await _press(tester, LogicalKeyboardKey.keyQ, control: true);
    expect(find.text('Save Changes?'), findsOneWidget);
    expect(quits, 1);

    await tester.tap(find.text('Discard'));
    await tester.pumpAndSettle();
    expect(quits, 2);
  });

  testWidgets('Ctrl+L goes back to the list', (tester) async {
    await tester.runAsync(() async {
      await tester.pumpWidget(MaterialApp(
        home: Builder(
          builder: (context) => TextButton(
            onPressed: () => Navigator.push(
              context,
              MaterialPageRoute(
                builder: (_) => NoteEditorScreen(
                    note: note, notesDirectoryPath: note.parent.path),
              ),
            ),
            child: const Text('list'),
          ),
        ),
      ));
      await tester.tap(find.text('list'));
      await tester.pump();
      await Future<void>.delayed(const Duration(milliseconds: 100));
    });
    await tester.pumpAndSettle();
    expect(find.byType(NoteEditorScreen), findsOneWidget);

    await _press(tester, LogicalKeyboardKey.keyL, control: true);
    expect(find.byType(NoteEditorScreen), findsNothing);
  });

  testWidgets('holding the D-pad center goes back to the list',
      (tester) async {
    await tester.runAsync(() async {
      await tester.pumpWidget(MaterialApp(
        home: Builder(
          builder: (context) => TextButton(
            onPressed: () => Navigator.push(
              context,
              MaterialPageRoute(
                builder: (_) => NoteEditorScreen(
                    note: note, notesDirectoryPath: note.parent.path),
              ),
            ),
            child: const Text('list'),
          ),
        ),
      ));
      await tester.tap(find.text('list'));
      await tester.pump();
      await Future<void>.delayed(const Duration(milliseconds: 100));
    });
    await tester.pumpAndSettle();

    await tester.sendKeyDownEvent(LogicalKeyboardKey.select);
    await tester.pump(const Duration(milliseconds: 200));
    await tester.sendKeyUpEvent(LogicalKeyboardKey.select);
    await tester.pumpAndSettle();
    expect(find.byType(NoteEditorScreen), findsOneWidget,
        reason: 'a short press stays in the note');

    await tester.sendKeyDownEvent(LogicalKeyboardKey.select);
    await tester.pump(const Duration(milliseconds: 600));
    await tester.sendKeyUpEvent(LogicalKeyboardKey.select);
    await tester.pumpAndSettle();
    expect(find.byType(NoteEditorScreen), findsNothing);
  });

  testWidgets('D-pad Right opens the menu and Left goes back to the list',
      (tester) async {
    await tester.runAsync(() async {
      await tester.pumpWidget(MaterialApp(
        home: Builder(
          builder: (context) => TextButton(
            onPressed: () => Navigator.push(
              context,
              MaterialPageRoute(
                builder: (_) => NoteEditorScreen(
                    note: note, notesDirectoryPath: note.parent.path),
              ),
            ),
            child: const Text('list'),
          ),
        ),
      ));
      await tester.tap(find.text('list'));
      await tester.pump();
      await Future<void>.delayed(const Duration(milliseconds: 100));
    });
    await tester.pumpAndSettle();

    await _press(tester, LogicalKeyboardKey.arrowRight);
    expect(find.text('Save'), findsOneWidget);
    // Share has focus first; Down moves to Save, which closes the menu.
    await _press(tester, LogicalKeyboardKey.arrowDown);
    await _press(tester, LogicalKeyboardKey.select);
    expect(find.text('Save'), findsNothing);

    await _press(tester, LogicalKeyboardKey.keyE, control: true);
    await _press(tester, LogicalKeyboardKey.arrowRight);
    expect(find.text('Save'), findsNothing,
        reason: 'arrows move the caret in edit mode');
    await _press(tester, LogicalKeyboardKey.arrowLeft);
    expect(find.byType(NoteEditorScreen), findsOneWidget);

    await _press(tester, LogicalKeyboardKey.keyE, control: true);
    await _press(tester, LogicalKeyboardKey.arrowLeft);
    expect(find.byType(NoteEditorScreen), findsNothing);
  });

  testWidgets('the D-pad moves past the font size slider in the menu',
      (tester) async {
    await pumpEditor(tester);
    await _press(tester, LogicalKeyboardKey.arrowRight);

    String focusedLabel() {
      final context = FocusManager.instance.primaryFocus!.context!;
      if (context.findAncestorWidgetOfExactType<Slider>() != null ||
          context.widget is Slider) {
        return 'slider';
      }
      final texts = find.descendant(
          of: find.byWidget(context.widget), matching: find.byType(Text));
      return tester.widgetList<Text>(texts).map((t) => t.data).join();
    }

    // Share, Save, Autosave, slider, Preview.
    for (var i = 0; i < 3; i++) {
      await _press(tester, LogicalKeyboardKey.arrowDown);
    }
    expect(focusedLabel(), 'slider');

    await _press(tester, LogicalKeyboardKey.arrowRight);
    expect(tester.widget<MarkdownView>(find.byType(MarkdownView)).fontSize, 18,
        reason: 'Right adjusts the slider');

    await _press(tester, LogicalKeyboardKey.arrowDown);
    expect(focusedLabel(), 'Preview Mode');
  });

  testWidgets('the open note follows theme switches', (tester) async {
    final mode = ValueNotifier(ThemeMode.light);
    await tester.runAsync(() async {
      await tester.pumpWidget(ValueListenableBuilder(
        valueListenable: mode,
        builder: (context, themeMode, _) => MaterialApp(
          theme: ThemeData(brightness: Brightness.light),
          darkTheme: ThemeData(brightness: Brightness.dark),
          themeMode: themeMode,
          home: NoteEditorScreen(note: note, notesDirectoryPath: null),
        ),
      ));
      await Future<void>.delayed(const Duration(milliseconds: 100));
    });
    await tester.pumpAndSettle();
    final controller = field(tester).controller! as MarkdownController;
    expect(controller.theme, same(dayTheme));

    mode.value = ThemeMode.dark;
    await tester.pumpAndSettle();
    expect(controller.theme, same(nightTheme));
  });

  testWidgets('Ctrl+= and Ctrl+- change the font size', (tester) async {
    await pumpEditor(tester);
    double size() => tester.widget<MarkdownView>(find.byType(MarkdownView)).fontSize;

    await _press(tester, LogicalKeyboardKey.equal, control: true);
    expect(size(), 18);
    await _press(tester, LogicalKeyboardKey.minus, control: true);
    await _press(tester, LogicalKeyboardKey.minus, control: true);
    expect(size(), 14);
    await _press(tester, LogicalKeyboardKey.digit0, control: true);
    expect(size(), 16);
  });
}