// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter/cupertino.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/services.dart';
import 'package:flutter_test/flutter_test.dart';

import '../widgets/process_text_utils.dart';

Offset textOffsetToPosition(RenderParagraph paragraph, int offset) {
  const Rect caret = Rect.fromLTWH(0.0, 0.0, 2.0, 20.0);
  final Offset localOffset = paragraph.getOffsetForCaret(TextPosition(offset: offset), caret);
  return paragraph.localToGlobal(localOffset);
}

void main() {
  testWidgets('SelectionArea uses correct selection controls', (WidgetTester tester) async {
    await tester.pumpWidget(const MaterialApp(
      home: SelectionArea(
        child: Text('abc'),
      ),
    ));
    final SelectableRegion region = tester.widget<SelectableRegion>(find.byType(SelectableRegion));

    switch (defaultTargetPlatform) {
      case TargetPlatform.android:
      case TargetPlatform.fuchsia:
        expect(region.selectionControls, materialTextSelectionHandleControls);
      case TargetPlatform.iOS:
        expect(region.selectionControls, cupertinoTextSelectionHandleControls);
      case TargetPlatform.linux:
      case TargetPlatform.windows:
        expect(region.selectionControls, desktopTextSelectionHandleControls);
      case TargetPlatform.macOS:
        expect(region.selectionControls, cupertinoDesktopTextSelectionHandleControls);
    }
  }, variant: TargetPlatformVariant.all());

  testWidgets('Does not crash when long pressing on padding after dragging', (WidgetTester tester) async {
    // Regression test for https://github.com/flutter/flutter/issues/123378
    await tester.pumpWidget(
      const MaterialApp(
        color: Color(0xFF2196F3),
        title: 'Demo',
        home: Scaffold(
          body: SelectionArea(
            child: Padding(
              padding: EdgeInsets.all(100.0),
              child: Text('Hello World'),
            ),
          ),
        ),
      ),
    );
    final TestGesture dragging = await tester.startGesture(const Offset(10, 10));
    addTearDown(dragging.removePointer);
    await tester.pump(const Duration(milliseconds: 500));
    await dragging.moveTo(const Offset(90, 90));
    await dragging.up();

    final TestGesture longpress = await tester.startGesture(const Offset(20,20));
    addTearDown(longpress.removePointer);
    await tester.pump(const Duration(milliseconds: 500));
    await longpress.up();

    expect(tester.takeException(), isNull);
  });

  // Regression test for https://github.com/flutter/flutter/issues/111370
  testWidgets('Handle is correctly transformed when the text is inside of a FittedBox ',(WidgetTester tester) async {
      final Key textKey = UniqueKey();
      await tester.pumpWidget(
        MaterialApp(
          color: const Color(0xFF2196F3),
          home: Scaffold(
            body: SelectionArea(
              child: SizedBox(
                height: 100,
                child: FittedBox(
                  fit: BoxFit.fill,
                  child: Text('test', key: textKey),
                ),
              ),
            ),
          ),
        ),
      );

      final TestGesture longpress = await tester.startGesture(tester.getCenter(find.byType(Text)));
      addTearDown(longpress.removePointer);
      await tester.pump(const Duration(milliseconds: 500));
      await longpress.up();

      // Text box is scaled by 5.
      final RenderBox textBox = tester.firstRenderObject(find.byKey(textKey));
      expect(textBox.size.height, 20.0);
      final Offset textPoint = textBox.localToGlobal(const Offset(0, 20));
      expect(textPoint, equals(const Offset(0, 100)));

      // Find handles and verify their sizes.
      expect(find.byType(Overlay), findsOneWidget);
      expect(find.descendant(of: find.byType(Overlay),matching: find.byType(CustomPaint),),findsNWidgets(2));
      final Iterable<RenderBox> handles = tester.renderObjectList(find.descendant(
        of: find.byType(Overlay),
        matching: find.byType(CustomPaint),
      ));

      // The handle height is determined by the formula:
      // textLineHeight + _kSelectionHandleRadius * 2 - _kSelectionHandleOverlap .
      // The text line height will be the value of the fontSize.
      // The constant _kSelectionHandleRadius has the value of 6.
      // The constant _kSelectionHandleOverlap has the value of 1.5.
      // The handle height before scaling is 20.0 + 6 * 2 - 1.5 = 30.5.

      final double handleHeightBeforeScaling = handles.first.size.height;
      expect(handleHeightBeforeScaling, 30.5);

      final Offset handleHeightAfterScaling = handles.first.localToGlobal(const Offset(0, 30.5)) - handles.first.localToGlobal(Offset.zero);

      // The handle height after scaling is  30.5 * 5 = 152.5
      expect(handleHeightAfterScaling, equals(const Offset(0.0, 152.5)));
    },
    skip: isBrowser, // [intended]
    variant: const TargetPlatformVariant(<TargetPlatform>{TargetPlatform.iOS}),
  );

  testWidgets('builds the default context menu by default', (WidgetTester tester) async {
    final FocusNode focusNode = FocusNode();
    addTearDown(focusNode.dispose);

    await tester.pumpWidget(
      MaterialApp(
        home: SelectionArea(
          focusNode: focusNode,
          child: const Text('How are you?'),
        ),
      ),
    );
    await tester.pumpAndSettle();

    expect(find.byType(AdaptiveTextSelectionToolbar), findsNothing);

    // Show the toolbar by longpressing.
    final RenderParagraph paragraph1 = tester.renderObject<RenderParagraph>(find.descendant(of: find.text('How are you?'), matching: find.byType(RichText)));
    final TestGesture gesture = await tester.startGesture(textOffsetToPosition(paragraph1, 6)); // at the 'r'
    addTearDown(gesture.removePointer);
    await tester.pump(const Duration(milliseconds: 500));
    // `are` is selected.
    expect(paragraph1.selections[0], const TextSelection(baseOffset: 4, extentOffset: 7));

    await gesture.up();
    await tester.pumpAndSettle();

    expect(find.byType(AdaptiveTextSelectionToolbar), findsOneWidget);
  },
    skip: kIsWeb, // [intended]
  );

  testWidgets('builds a custom context menu if provided', (WidgetTester tester) async {
    final GlobalKey key = GlobalKey();
    final FocusNode focusNode = FocusNode();
    addTearDown(focusNode.dispose);

    await tester.pumpWidget(
      MaterialApp(
        home: SelectionArea(
          focusNode: focusNode,
          contextMenuBuilder: (
            BuildContext context,
            SelectableRegionState selectableRegionState,
          ) {
            return Placeholder(key: key);
          },
          child: const Text('How are you?'),
        ),
      ),
    );
    await tester.pumpAndSettle();

    expect(find.byType(AdaptiveTextSelectionToolbar), findsNothing);
    expect(find.byKey(key), findsNothing);

    // Show the toolbar by longpressing.
    final RenderParagraph paragraph1 = tester.renderObject<RenderParagraph>(find.descendant(of: find.text('How are you?'), matching: find.byType(RichText)));
    final TestGesture gesture = await tester.startGesture(textOffsetToPosition(paragraph1, 6)); // at the 'r'
    addTearDown(gesture.removePointer);
    await tester.pump(const Duration(milliseconds: 500));
    // `are` is selected.
    expect(paragraph1.selections[0], const TextSelection(baseOffset: 4, extentOffset: 7));

    await gesture.up();
    await tester.pumpAndSettle();

    expect(find.byType(AdaptiveTextSelectionToolbar), findsNothing);
    expect(find.byKey(key), findsOneWidget);
  },
    skip: kIsWeb, // [intended]
  );

  testWidgets('Text processing actions are added to the toolbar', (WidgetTester tester) async {
    final MockProcessTextHandler mockProcessTextHandler = MockProcessTextHandler();
    TestWidgetsFlutterBinding.ensureInitialized().defaultBinaryMessenger
        .setMockMethodCallHandler(SystemChannels.processText, mockProcessTextHandler.handleMethodCall);
    addTearDown(() => tester.binding.defaultBinaryMessenger.setMockMethodCallHandler(SystemChannels.processText, null));

    final FocusNode focusNode = FocusNode();
    addTearDown(focusNode.dispose);

    await tester.pumpWidget(
      MaterialApp(
        home: SelectionArea(
          focusNode: focusNode,
          child: const Text('How are you?'),
        ),
      ),
    );
    await tester.pumpAndSettle();

    expect(find.byType(AdaptiveTextSelectionToolbar), findsNothing);

    final RenderParagraph paragraph = tester.renderObject<RenderParagraph>(
      find.descendant(
        of: find.text('How are you?'),
        matching: find.byType(RichText),
      ),
    );
    final TestGesture gesture = await tester.startGesture(textOffsetToPosition(paragraph, 6)); // at the 'r'
    addTearDown(gesture.removePointer);
    await tester.pump(const Duration(milliseconds: 500));
    // `are` is selected.
    expect(paragraph.selections[0], const TextSelection(baseOffset: 4, extentOffset: 7));

    await gesture.up();
    await tester.pumpAndSettle();

    // The toolbar is visible.
    expect(find.byType(AdaptiveTextSelectionToolbar), findsOneWidget);

    // The text processing actions are visible on Android only.
    final bool areTextActionsSupported = defaultTargetPlatform == TargetPlatform.android;
    expect(find.text(fakeAction1Label), areTextActionsSupported ? findsOneWidget : findsNothing);
    expect(find.text(fakeAction2Label), areTextActionsSupported ? findsOneWidget : findsNothing);
  },
    variant: TargetPlatformVariant.all(),
    skip: kIsWeb, // [intended]
  );

  testWidgets('onSelectionChange is called when the selection changes', (WidgetTester tester) async {
    SelectedContent? content;

    await tester.pumpWidget(MaterialApp(
      home: SelectionArea(
        child: const Text('How are you'),
        onSelectionChanged: (SelectedContent? selectedContent) => content = selectedContent,
      ),
    ));
    final RenderParagraph paragraph = tester.renderObject<RenderParagraph>(find.descendant(of: find.text('How are you'), matching: find.byType(RichText)));
    final TestGesture gesture = await tester.startGesture(textOffsetToPosition(paragraph, 4), kind: PointerDeviceKind.mouse);
    expect(content, isNull);
    addTearDown(gesture.removePointer);
    await tester.pump();

    await gesture.moveTo(textOffsetToPosition(paragraph, 7));
    await gesture.up();
    await tester.pump();
    expect(content, isNotNull);
    expect(content!.plainText, 'are');

    // Backwards selection.
    await gesture.down(textOffsetToPosition(paragraph, 3));
    await tester.pump();
    await gesture.up();
    await tester.pumpAndSettle(kDoubleTapTimeout);
    expect(content, isNotNull);
    expect(content!.plainText, '');

    await gesture.down(textOffsetToPosition(paragraph, 3));
    await tester.pump();
    await gesture.moveTo(textOffsetToPosition(paragraph, 0));
    await gesture.up();
    await tester.pump();
    expect(content, isNotNull);
    expect(content!.plainText, 'How');
  });

  testWidgets('stopping drag of end handle will show the toolbar', (WidgetTester tester) async {
    final FocusNode focusNode = FocusNode();
    addTearDown(focusNode.dispose);

    // Regression test for https://github.com/flutter/flutter/issues/119314
    await tester.pumpWidget(
      MaterialApp(
        theme: ThemeData(useMaterial3: false),
        home: Scaffold(
          body: Padding(
            padding: const EdgeInsets.only(top: 64),
            child: Column(
              children: <Widget>[
                const Text('How are you?'),
                SelectionArea(
                  focusNode: focusNode,
                  child: const Text('Good, and you?'),
                ),
                const Text('Fine, thank you.'),
              ],
            ),
          ),
        ),
      ),
    );
    await tester.pumpAndSettle();
    final RenderParagraph paragraph2 = tester.renderObject<RenderParagraph>(find.descendant(of: find.text('Good, and you?'), matching: find.byType(RichText)));
    final TestGesture gesture = await tester.startGesture(textOffsetToPosition(paragraph2, 7)); // at the 'a'
    addTearDown(gesture.removePointer);
    await tester.pump(const Duration(milliseconds: 500));
    await gesture.up();
    final List<TextBox> boxes = paragraph2.getBoxesForSelection(paragraph2.selections[0]);
    expect(boxes.length, 1);
    await tester.pumpAndSettle();
    // There is a selection now.
    // We check the presence of the copy button to make sure the selection toolbar
    // is showing.
    expect(find.text('Copy'), findsOneWidget);

    // This is the position of the selection handle displayed at the end.
    final Offset handlePos = paragraph2.localToGlobal(boxes[0].toRect().bottomRight);
    await gesture.down(handlePos);
    await gesture.moveTo(textOffsetToPosition(paragraph2, 11) + Offset(0, paragraph2.size.height / 2));
    await tester.pump();

    await gesture.up();
    await tester.pump();

    // After lifting the finger up, the selection toolbar should be showing again.
    expect(find.text('Copy'), findsOneWidget);
  },
    variant: TargetPlatformVariant.all(),
    skip: kIsWeb, // [intended]
  );
}