// Copyright 2020 The Flutter team. 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:animations/src/misc/animated_list.dart';
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';

Widget createAnimatedListDemoScreen() =>
    const MaterialApp(home: AnimatedListDemo());

void main() {
  group('Animated List Tests', () {
    testWidgets('Initial length of list', (tester) async {
      await tester.pumpWidget(createAnimatedListDemoScreen());

      // Get the initial length of list.
      var initialLength = tester.widgetList(find.byType(ListTile)).length;

      // Initial length of list should be equal to 5.
      expect(initialLength, equals(5));
    });

    testWidgets('Length of list increases on Add Icon Button tap', (
      tester,
    ) async {
      await tester.pumpWidget(createAnimatedListDemoScreen());

      // Get the initial length of list.
      var initialLength = tester.widgetList(find.byType(ListTile)).length;

      // Tap on the Add Icon Button.
      await tester.tap(find.byIcon(Icons.add));
      await tester.pumpAndSettle();

      // Get the new length of list.
      var newLength = tester.widgetList(find.byType(ListTile)).length;

      // New length should be greater than initial length by one.
      expect(newLength, equals(initialLength + 1));
    });

    testWidgets(
      'Length of list decreases on Delete Icon Button tap at middle index',
      (tester) async {
        await tester.pumpWidget(createAnimatedListDemoScreen());

        // Get the initial length of list.
        var initialLength = tester.widgetList(find.byType(ListTile)).length;

        // Tap on the Delete Icon Button at middle index.
        await tester.tap(find.byIcon(Icons.delete).at(initialLength ~/ 2));
        await tester.pumpAndSettle();

        // Get the new length of list.
        var newLength = tester.widgetList(find.byType(ListTile)).length;

        // New length should be less than initial length by one.
        expect(newLength, equals(initialLength - 1));
      },
    );

    testWidgets(
      'Length of list decreases on Delete Icon Button tap at start index',
      (tester) async {
        await tester.pumpWidget(createAnimatedListDemoScreen());

        // Get the initial length of list.
        var initialLength = tester.widgetList(find.byType(ListTile)).length;

        // Tap on the Delete Icon Button at start index.
        await tester.tap(find.byIcon(Icons.delete).at(0));
        await tester.pumpAndSettle();

        // Get the new length of list.
        var newLength = tester.widgetList(find.byType(ListTile)).length;

        // New length should be less than initial length by one.
        expect(newLength, equals(initialLength - 1));
      },
    );

    testWidgets(
      'Length of list decreases on Delete Icon Button tap at end index',
      (tester) async {
        await tester.pumpWidget(createAnimatedListDemoScreen());

        // Get the initial length of list.
        var initialLength = tester.widgetList(find.byType(ListTile)).length;

        // Tap on the Delete Icon Button at end index.
        await tester.tap(find.byIcon(Icons.delete).at(initialLength - 1));
        await tester.pumpAndSettle();

        // Get the new length of list.
        var newLength = tester.widgetList(find.byType(ListTile)).length;

        // New Length should be less than initial length by one.
        expect(newLength, equals(initialLength - 1));
      },
    );

    testWidgets('All ListTiles deleted', (tester) async {
      await tester.pumpWidget(createAnimatedListDemoScreen());

      // Get the initial length of list.
      var initialLength = tester.widgetList(find.byType(ListTile)).length;

      // Iterating over all the Delete Icon Buttons.
      for (var i = 0; i < initialLength; i++) {
        // Tap on the Delete Icon
        await tester.tap(find.byIcon(Icons.delete).first);
        await tester.pumpAndSettle();
      }

      // Get the final length of list.
      var finalLength = tester.widgetList(find.byType(ListTile)).length;

      // New length should be zero.
      expect(finalLength, equals(0));
    });
  });
}
