import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:http/http.dart' as http;
import 'package:http/testing.dart';
import 'package:kouyu_english/core/ai_service.dart';
import 'package:kouyu_english/core/app_state.dart';
import 'package:kouyu_english/core/models.dart';
import 'package:kouyu_english/core/courses/courses.dart';
import 'package:kouyu_english/features/lesson/lesson_flow.dart';

void main() {
  group('independentShortfall', () {
    test('is null when the attempt passes', () {
      expect(independentShortfall('a0-04-a', 'zero, one, two'), isNull);
      expect(
        independentShortfall('a0-01-a', "My name is Alex. Nice to meet you."),
        isNull,
      );
    });

    test('names the missing part of a single-segment task', () {
      final message = independentShortfall('a0-01-a', 'My name is Alex.');
      expect(message, contains('nice to meet you'));
      expect(message, isNot(contains('my name is')));
    });

    test('counts the numbers still needed', () {
      expect(
        independentShortfall('a0-04-a', 'zero, one'),
        contains('目前用上 2 个'),
      );
    });

    test('lists the taught expressions of a split segment', () {
      expect(
        independentShortfall('a0-08-b', 'It is Monday.'),
        contains('friday'),
      );
    });
  });

  group('assessmentAnswerGuide', () {
    final pack = a0AssessmentPacks.first;

    test('shows the correct choice', () {
      final task = pack.forSkill(AssessmentSkill.listening).first;
      expect(assessmentAnswerGuide(task, '买东西'), '正确答案：自我介绍');
      expect(assessmentAnswerGuide(task, '自我介绍'), contains('没有播放音频'));
    });

    test('explains open speaking and writing tasks', () {
      final speaking = pack.forSkill(AssessmentSkill.speaking)[3];
      expect(
        assessmentAnswerGuide(speaking, 'my mother'),
        contains('This is my'),
      );
      final writing = pack.forSkill(AssessmentSkill.writing).first;
      expect(assessmentAnswerGuide(writing, 'abc'), isNotEmpty);
    });
  });

  testWidgets('finishing step 6 after an AI correction counts as assisted', (
    tester,
  ) async {
    final messenger = tester.binding.defaultBinaryMessenger;
    for (final name in const [
      'com.llfbandit.record/messages',
      'xyz.luan/audioplayers',
      'xyz.luan/audioplayers.global',
    ]) {
      messenger.setMockMethodCallHandler(
        MethodChannel(name),
        (_) async => null,
      );
    }
    messenger.setMockStreamHandler(
      const EventChannel('xyz.luan/audioplayers.global/events'),
      MockStreamHandler.inline(onListen: (_, _) {}),
    );
    final reportError = FlutterError.onError;
    FlutterError.onError = (details) {
      if (details.exception is! MissingPluginException) {
        reportError?.call(details);
      }
    };
    addTearDown(() => FlutterError.onError = reportError);
    AiService.instance.setFallbackApiKey('test-key');
    final state = AppState()
      ..aiProvider = AiProviderType.compatible
      ..aiEndpoint = 'https://api.deepseek.com'
      ..aiModel = 'deepseek-flash'
      ..activeLessonId = 'a0-01'
      ..lessonStep = LessonStep.independent;
    final segmentId = lessonById('a0-01').segments.first.id;
    final check = jsonEncode({
      'schemaVersion': 'writing-feedback-1',
      'verdict': 'rewrite',
      'feedback': '内容完整，有一个语法错误。',
      'suggestion': 'My name is Alex. Nice to meet you. I am happy.',
      'missing': ['I is 应为 I am'],
      'lessonId': segmentId,
    });
    final prompts = <String>[];

    await http.runWithClient(
      () async {
        await tester.pumpWidget(
          MaterialApp(
            home: LessonFlow(
              state: state,
              onOpenDialogue: () {},
              onFinish: () {},
            ),
          ),
        );
        await tester.pump();
        expect(find.text('独立完成'), findsOneWidget);
        await tester.enterText(
          find.byType(TextField),
          'My name is Alex. Nice to meet you. I is happy.',
        );
        await tester.pump();
        final aiButton = find.text('提交前 AI 检查语法和拼写（可选）');
        await tester.ensureVisible(aiButton);
        await tester.tap(aiButton);
        await tester.runAsync(
          () => Future<void>.delayed(const Duration(milliseconds: 50)),
        );
        await tester.pump();

        expect(find.text('· I is 应为 I am'), findsOneWidget);
        final finish = find.text('带帮助完成');
        await tester.ensureVisible(finish);
        await tester.tap(finish);
        await tester.pump();
      },
      () => MockClient((request) async {
        prompts.add(request.body);
        return http.Response(
          jsonEncode({
            'choices': [
              {
                'message': {'content': check},
              },
            ],
          }),
          200,
          headers: {'content-type': 'application/json; charset=utf-8'},
        );
      }),
    );

    expect(prompts.single, contains('I is happy'));
    expect(state.lessonStep, LessonStep.complete);
    expect(state.independentAttemptAssisted, isTrue);
  });
}