// 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/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter_api_samples/widgets/overscroll_indicator/glowing_overscroll_indicator.1.dart'
    as example;
import 'package:flutter_test/flutter_test.dart';

void main() {
  testWidgets('Displays widget tree when the example app is run', (WidgetTester tester) async {
    await tester.pumpWidget(const example.GlowingOverscrollIndicatorExampleApp());

    expect(
      find.descendant(
        of: find.byType(Scaffold),
        matching: find.widgetWithText(AppBar, 'GlowingOverscrollIndicator Sample'),
      ),
      findsOne,
    );

    expect(
      find.descendant(
        of: find.byType(NestedScrollView),
        matching: find.widgetWithText(SliverAppBar, 'Custom NestedScrollViews'),
      ),
      findsOne,
    );

    expect(
      find.descendant(
        of: find.byType(NestedScrollView),
        matching: find.widgetWithText(Center, 'Glow all day!'),
      ),
      findsOne,
    );

    final Finder customScrollViewFinder = find.byType(CustomScrollView);

    expect(
      find.descendant(of: customScrollViewFinder, matching: find.byType(SliverToBoxAdapter)),
      findsOne,
    );

    expect(
      find.descendant(
        of: customScrollViewFinder,
        matching: find.widgetWithIcon(SliverFillRemaining, Icons.sunny),
      ),
      findsOne,
    );

    expect(
      find.descendant(
        of: customScrollViewFinder,
        matching: find.byType(GlowingOverscrollIndicator),
      ),
      findsOne,
    );

    // Check if GlowingOverscrollIndicator starts just after the SliverAppBar.
    final RenderBox overscrollIndicator = tester.renderObject<RenderBox>(
      find.descendant(
        of: customScrollViewFinder,
        matching: find.byType(GlowingOverscrollIndicator),
      ),
    );
    final RenderSliver sliverAppBar = tester.renderObject<RenderSliver>(
      find.widgetWithText(SliverAppBar, 'Custom NestedScrollViews'),
    );
    final Matrix4 transform = overscrollIndicator.getTransformTo(sliverAppBar);
    final Offset? offset = MatrixUtils.getAsTranslation(transform);
    expect(offset?.dy, sliverAppBar.geometry?.paintExtent);
  });
}