// 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 'dart:ui' as ui;

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/semantics.dart';
import 'package:flutter_test/flutter_test.dart';

typedef SemanticsNodeUpdateObservation = ({
  String label,
  List<StringAttribute>? labelAttributes,
  String value,
  List<StringAttribute>? valueAttributes,
  String hint,
  List<StringAttribute>? hintAttributes,
  Int32List childrenInTraversalOrder,
  Float64List transform,
});

void main() {
  SemanticsUpdateTestBinding();

  testWidgets('Semantics update does not send update for merged nodes.', (
    WidgetTester tester,
  ) async {
    final SemanticsHandle handle = tester.ensureSemantics();
    // Pumps a placeholder to trigger the warm up frame.
    await tester.pumpWidget(
      const Placeholder(),
      // Stops right after the warm up frame.
      phase: EnginePhase.build,
    );
    // The warm up frame will send update for an empty semantics tree. We
    // ignore this one time update.
    SemanticsUpdateBuilderSpy.observations.clear();

    // Builds the real widget tree.
    await tester.pumpWidget(
      Directionality(
        textDirection: TextDirection.ltr,
        child: MergeSemantics(
          child: Semantics(
            label: 'outer',
            // This semantics node should not be part of the semantics update
            // because it is under another semantics container.
            child: Semantics(label: 'inner', container: true, child: const Text('text')),
          ),
        ),
      ),
    );

    expect(SemanticsUpdateBuilderSpy.observations.length, 2);

    expect(SemanticsUpdateBuilderSpy.observations.containsKey(0), isTrue);
    expect(SemanticsUpdateBuilderSpy.observations[0]!.childrenInTraversalOrder.length, 1);
    expect(SemanticsUpdateBuilderSpy.observations[0]!.childrenInTraversalOrder[0], 1);

    expect(SemanticsUpdateBuilderSpy.observations.containsKey(1), isTrue);
    expect(SemanticsUpdateBuilderSpy.observations[1]!.childrenInTraversalOrder.length, 0);
    expect(SemanticsUpdateBuilderSpy.observations[1]!.label, 'outer\ninner\ntext');

    SemanticsUpdateBuilderSpy.observations.clear();

    // Updates the inner semantics label and verifies it only sends update for
    // the merged parent.
    await tester.pumpWidget(
      Directionality(
        textDirection: TextDirection.ltr,
        child: MergeSemantics(
          child: Semantics(
            label: 'outer',
            // This semantics node should not be part of the semantics update
            // because it is under another semantics container.
            child: Semantics(label: 'inner-updated', container: true, child: const Text('text')),
          ),
        ),
      ),
    );
    expect(SemanticsUpdateBuilderSpy.observations.length, 1);

    expect(SemanticsUpdateBuilderSpy.observations.containsKey(1), isTrue);
    expect(SemanticsUpdateBuilderSpy.observations[1]!.childrenInTraversalOrder.length, 0);
    expect(SemanticsUpdateBuilderSpy.observations[1]!.label, 'outer\ninner-updated\ntext');

    SemanticsUpdateBuilderSpy.observations.clear();
    handle.dispose();
  });

  testWidgets('Semantics update receives attributed text', (WidgetTester tester) async {
    final SemanticsHandle handle = tester.ensureSemantics();
    // Pumps a placeholder to trigger the warm up frame.
    await tester.pumpWidget(
      const Placeholder(),
      // Stops right after the warm up frame.
      phase: EnginePhase.build,
    );
    // The warm up frame will send update for an empty semantics tree. We
    // ignore this one time update.
    SemanticsUpdateBuilderSpy.observations.clear();

    // Builds the real widget tree.
    await tester.pumpWidget(
      Directionality(
        textDirection: TextDirection.ltr,
        child: Semantics(
          attributedLabel: AttributedString(
            'label',
            attributes: <StringAttribute>[
              SpellOutStringAttribute(range: const TextRange(start: 0, end: 5)),
            ],
          ),
          attributedValue: AttributedString(
            'value',
            attributes: <StringAttribute>[
              LocaleStringAttribute(
                range: const TextRange(start: 0, end: 5),
                locale: const Locale('en', 'MX'),
              ),
            ],
          ),
          attributedHint: AttributedString(
            'hint',
            attributes: <StringAttribute>[
              SpellOutStringAttribute(range: const TextRange(start: 1, end: 2)),
            ],
          ),
          child: const Placeholder(),
        ),
      ),
    );

    expect(SemanticsUpdateBuilderSpy.observations.length, 2);

    expect(SemanticsUpdateBuilderSpy.observations.containsKey(0), isTrue);
    expect(SemanticsUpdateBuilderSpy.observations[0]!.childrenInTraversalOrder.length, 1);
    expect(SemanticsUpdateBuilderSpy.observations[0]!.childrenInTraversalOrder[0], 1);

    expect(SemanticsUpdateBuilderSpy.observations.containsKey(1), isTrue);
    expect(SemanticsUpdateBuilderSpy.observations[1]!.childrenInTraversalOrder.length, 0);
    expect(SemanticsUpdateBuilderSpy.observations[1]!.label, 'label');
    expect(SemanticsUpdateBuilderSpy.observations[1]!.labelAttributes!.length, 1);
    expect(
      SemanticsUpdateBuilderSpy.observations[1]!.labelAttributes![0] is SpellOutStringAttribute,
      isTrue,
    );
    expect(
      SemanticsUpdateBuilderSpy.observations[1]!.labelAttributes![0].range,
      const TextRange(start: 0, end: 5),
    );

    expect(SemanticsUpdateBuilderSpy.observations[1]!.value, 'value');
    expect(SemanticsUpdateBuilderSpy.observations[1]!.valueAttributes!.length, 1);
    expect(
      SemanticsUpdateBuilderSpy.observations[1]!.valueAttributes![0] is LocaleStringAttribute,
      isTrue,
    );
    final localeAttribute =
        SemanticsUpdateBuilderSpy.observations[1]!.valueAttributes![0] as LocaleStringAttribute;
    expect(localeAttribute.range, const TextRange(start: 0, end: 5));
    expect(localeAttribute.locale, const Locale('en', 'MX'));

    expect(SemanticsUpdateBuilderSpy.observations[1]!.hint, 'hint');
    expect(SemanticsUpdateBuilderSpy.observations[1]!.hintAttributes!.length, 1);
    expect(
      SemanticsUpdateBuilderSpy.observations[1]!.hintAttributes![0] is SpellOutStringAttribute,
      isTrue,
    );
    expect(
      SemanticsUpdateBuilderSpy.observations[1]!.hintAttributes![0].range,
      const TextRange(start: 1, end: 2),
    );

    expect(
      tester.widget(find.byType(Semantics)).toString(),
      'Semantics('
      'container: false, '
      'properties: SemanticsProperties, '
      'attributedLabel: "label" [SpellOutStringAttribute(TextRange(start: 0, end: 5))], '
      'attributedValue: "value" [LocaleStringAttribute(TextRange(start: 0, end: 5), en-MX)], '
      'attributedHint: "hint" [SpellOutStringAttribute(TextRange(start: 1, end: 2))]' // ignore: missing_whitespace_between_adjacent_strings
      ')',
    );

    SemanticsUpdateBuilderSpy.observations.clear();
    handle.dispose();
  });

  testWidgets('Semantics update receives correct traversal transform with nested OverlayPortals', (
    WidgetTester tester,
  ) async {
    final SemanticsHandle handle = tester.ensureSemantics();
    // Pumps a placeholder to trigger the warm up frame.
    await tester.pumpWidget(
      const Placeholder(),
      // Stops right after the warm up frame.
      phase: EnginePhase.build,
    );
    // The warm up frame will send update for an empty semantics tree. We
    // ignore this one time update.
    SemanticsUpdateBuilderSpy.observations.clear();
    final controller1 = OverlayPortalController()..show();
    final controller2 = OverlayPortalController()..show();

    final entry = OverlayEntry(
      builder: (BuildContext context) {
        return OverlayPortal(
          controller: controller1,
          child: TextButton(onPressed: () {}, child: const Text('a')),
          overlayChildBuilder: (BuildContext context) {
            return Positioned(
              left: 10,
              top: 11,
              child: OverlayPortal(
                controller: controller2,
                child: TextButton(onPressed: () {}, child: const Text('b')),
                overlayChildBuilder: (BuildContext context) {
                  // (100, 200) in 'b's coordinates.
                  return Positioned(
                    left: 110,
                    top: 211,
                    child: TextButton(onPressed: () {}, child: const Text('c')),
                  );
                },
              ),
            );
          },
        );
      },
    );
    addTearDown(() {
      entry
        ..remove()
        ..dispose();
    });

    // Builds the real widget tree.
    await tester.pumpWidget(
      Directionality(
        textDirection: TextDirection.ltr,
        child: Overlay(initialEntries: <OverlayEntry>[entry]),
      ),
    );

    // traversal parent of 'b',
    expect(
      SemanticsUpdateBuilderSpy.observations[4]!.transform,
      Matrix4.translationValues(10.0, 11.0, 0.0).storage,
    );
    // 'b'
    expect(SemanticsUpdateBuilderSpy.observations[5]!.transform, Matrix4.identity().storage);
    // parent of 'c', inverse of node#4's transform.
    expect(
      SemanticsUpdateBuilderSpy.observations[6]!.transform,
      Matrix4.translationValues(-10.0, -11.0, 0.0).storage,
    );
    // 'c'
    expect(
      SemanticsUpdateBuilderSpy.observations[7]!.transform,
      Matrix4.translationValues(110.0, 211.0, 0.0).storage,
    );
    SemanticsUpdateBuilderSpy.observations.clear();
    handle.dispose();
  }, skip: kIsWeb); // intended: the web engine handles the transform calculation itself.
}

class SemanticsUpdateTestBinding extends AutomatedTestWidgetsFlutterBinding {
  @override
  ui.SemanticsUpdateBuilder createSemanticsUpdateBuilder() {
    return SemanticsUpdateBuilderSpy();
  }
}

class SemanticsUpdateBuilderSpy extends Fake implements ui.SemanticsUpdateBuilder {
  final SemanticsUpdateBuilder _builder = ui.SemanticsUpdateBuilder();

  static Map<int, SemanticsNodeUpdateObservation> observations =
      <int, SemanticsNodeUpdateObservation>{};

  @override
  void updateNode({
    required int id,
    required SemanticsFlags flags,
    required int actions,
    required int maxValueLength,
    required int currentValueLength,
    required int textSelectionBase,
    required int textSelectionExtent,
    required int platformViewId,
    required int scrollChildren,
    required int scrollIndex,
    required int? traversalParent,
    required double scrollPosition,
    required double scrollExtentMax,
    required double scrollExtentMin,
    required Rect rect,
    required String identifier,
    required String label,
    List<StringAttribute>? labelAttributes,
    required String value,
    List<StringAttribute>? valueAttributes,
    required String increasedValue,
    List<StringAttribute>? increasedValueAttributes,
    required String decreasedValue,
    List<StringAttribute>? decreasedValueAttributes,
    required String hint,
    List<StringAttribute>? hintAttributes,
    String? tooltip,
    TextDirection? textDirection,
    required Float64List transform,
    required Float64List hitTestTransform,
    required Int32List childrenInTraversalOrder,
    required Int32List childrenInHitTestOrder,
    required Int32List additionalActions,
    int headingLevel = 0,
    String? linkUrl,
    SemanticsRole role = SemanticsRole.none,
    required List<String>? controlsNodes,
    SemanticsValidationResult validationResult = SemanticsValidationResult.none,
    ui.SemanticsHitTestBehavior hitTestBehavior = ui.SemanticsHitTestBehavior.defer,
    required ui.SemanticsInputType inputType,
    required ui.Locale? locale,
    required String minValue,
    required String maxValue,
  }) {
    // Makes sure we don't send the same id twice.
    assert(!observations.containsKey(id));
    observations[id] = (
      label: label,
      labelAttributes: labelAttributes,
      hint: hint,
      hintAttributes: hintAttributes,
      value: value,
      valueAttributes: valueAttributes,
      childrenInTraversalOrder: childrenInTraversalOrder,
      transform: transform,
    );
  }

  @override
  void updateCustomAction({required int id, String? label, String? hint, int overrideId = -1}) =>
      _builder.updateCustomAction(id: id, label: label, hint: hint, overrideId: overrideId);

  @override
  ui.SemanticsUpdate build() => _builder.build();
}