import 'dart:convert';
import 'dart:io';

import 'package:crypto/crypto.dart' show sha256;
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:http/http.dart' as http;
import 'package:http/testing.dart';
import 'package:observer/camera/model_catalog_section.dart';
import 'package:observer/models/model_manager.dart';

const _modelBytes = [1, 2, 3, 4, 5, 6, 7, 8];
String _shaHex(List<int> bytes) => sha256.convert(bytes).toString();

/// 分两段到达的下载流（中间 50ms 停顿，供取消测试在下载中触发）
Stream<List<int>> _delayedChunks() async* {
  yield [1, 2, 3, 4];
  await Future<void>.delayed(const Duration(milliseconds: 50));
  yield [5, 6, 7, 8];
}

Map<String, dynamic> _item() => {
      'datasetId': 7,
      'datasetName': '环颈雉鸡数据集',
      'version': 'v1.0.0',
      'labels': ['pheasant', 'suspect'],
      'sizeBytes': _modelBytes.length,
      'sha256': _shaHex(_modelBytes),
      'downloadUrl': '/download/models/7/latest.tflite',
      'coverUrl': '/api/v1/app/cover?namePrefix=RNPHE',
    };

void main() {
  late Directory root;

  setUp(() async {
    root = await Directory.systemTemp.createTemp('catalog-section-test');
  });

  tearDown(() => root.delete(recursive: true));

  ModelManager manager() => ModelManager(
        baseUrl: 'http://test.local',
        client: MockClient((req) async {
          if (req.url.path == '/api/v1/app/update') {
            return http.Response.bytes(
                utf8.encode(jsonEncode({
                  'code': 0,
                  'message': 'ok',
                  'data': {'models': [_item()]}
                })),
                200);
          }
          if (req.url.path.startsWith('/download/models/')) {
            return http.Response.bytes(_modelBytes, 200);
          }
          return http.Response('not found', 404);
        }),
        rootDir: () async => root,
      );

  Future<void> pumpSection(WidgetTester tester, ModelManager m) async {
    await tester.pumpWidget(MaterialApp(
        home: Scaffold(
            body: ModelCatalogSection(manager: m))));
    await tester.pumpAndSettle();
  }

  testWidgets('未下载：显示使用按钮，点击后下载完成自动变为已使用', (tester) async {
    final m = manager();
    await m.refresh();
    await pumpSection(tester, m);

    expect(find.text('环颈雉鸡数据集'), findsOneWidget);
    expect(find.text('使用'), findsOneWidget);

    await tester.tap(find.text('使用'));
    await tester.pumpAndSettle();

    expect(m.isDownloaded(7), isTrue);
    expect(m.isActive(7), isTrue);
    expect(find.text('已使用'), findsOneWidget);
  });

  testWidgets('已激活：再次点击取消使用', (tester) async {
    final m = manager();
    await m.refresh();
    await m.downloadModel(m.catalog.first);
    await pumpSection(tester, m);

    expect(find.text('已使用'), findsOneWidget);
    await tester.tap(find.text('已使用'));
    await tester.pumpAndSettle();

    expect(m.isActive(7), isFalse);
    expect(find.text('使用'), findsOneWidget);
  });

  testWidgets('目录为空：显示暂无已发布模型', (tester) async {
    final m = ModelManager(
      baseUrl: 'http://test.local',
      client: MockClient((_) async => http.Response.bytes(
          utf8.encode(jsonEncode(
              {'code': 0, 'message': 'ok', 'data': {'models': []}})),
          200)),
      rootDir: () async => root,
    );
    await m.refresh();
    await pumpSection(tester, m);

    expect(find.text('暂无已发布模型'), findsOneWidget);
  });

  testWidgets('下载中：显示进度和取消按钮，取消后恢复使用', (tester) async {
    final m = ModelManager(
      baseUrl: 'http://test.local',
      client: MockClient((req) async {
        if (req.url.path == '/api/v1/app/update') {
          return http.Response.bytes(
              utf8.encode(jsonEncode({
                'code': 0,
                'message': 'ok',
                'data': {'models': [_item()]}
              })),
              200);
        }
        if (req.url.path.startsWith('/download/models/')) {
          return http.Response.fromStream(http.StreamedResponse(
              _delayedChunks(), 200,
              contentLength: _modelBytes.length));
        }
        return http.Response('not found', 404);
      }),
      rootDir: () async => root,
    );
    await m.refresh();
    await pumpSection(tester, m);

    await tester.tap(find.text('使用'));
    await tester.pump(); // 首个分块到达，进度条与取消按钮出现
    expect(find.text('取消'), findsOneWidget);

    await tester.tap(find.text('取消'));
    await tester.pumpAndSettle();

    expect(m.isDownloaded(7), isFalse);
    expect(m.isActive(7), isFalse);
    expect(find.text('使用'), findsOneWidget);
  });
}