cyberhybridhub/server/test/spelling/spelling_audio_handler_test.dart

import 'dart:io';

import 'package:cyberhybridhub_server/handlers/spelling_audio_handler.dart';
import 'package:http/http.dart' as http;
import 'package:http/testing.dart';
import 'package:shelf/shelf.dart';
import 'package:test/test.dart';

void main() {
  group('SpellingAudioHandler tests', () {
    late Directory tempCacheDir;
    late File logFile;

    setUp(() {
      tempCacheDir = Directory('spelling_audio_cache');
      if (tempCacheDir.existsSync()) {
        try {
          tempCacheDir.deleteSync(recursive: true);
        } catch (_) {}
      }
      logFile = File('spelling_audio_errors.log');
      if (logFile.existsSync()) {
        try {
          logFile.deleteSync();
        } catch (_) {}
      }
    });

    tearDown(() {
      if (tempCacheDir.existsSync()) {
        try {
          tempCacheDir.deleteSync(recursive: true);
        } catch (_) {}
      }
      if (logFile.existsSync()) {
        try {
          logFile.deleteSync();
        } catch (_) {}
      }
    });

    test('serves cached file if exists', () async {
      tempCacheDir.createSync(recursive: true);
      final File localFile = File('${tempCacheDir.path}/hello.mp3');
      localFile.writeAsBytesSync([1, 2, 3, 4]);

      final handler = spellingAudioHandler();
      final request = Request('GET', Uri.parse('http://localhost/v1/spelling/audio/hello.mp3'));
      final response = await handler(request);

      expect(response.statusCode, 200);
      expect(response.headers['Content-Type'], 'audio/mpeg');
      expect(await response.read().first, [1, 2, 3, 4]);
    });

    test('downloads, caches and serves file on-demand if not cached', () async {
      final mockClient = MockClient((request) async {
        if (request.url.path.contains('/entries/en/hello')) {
          const jsonResponse = '''
          [
            {
              "word": "hello",
              "phonetics": [
                {
                  "audio": "https://example.com/hello.mp3"
                }
              ]
            }
          ]
          ''';
          return http.Response(jsonResponse, 200);
        }
        if (request.url.toString() == 'https://example.com/hello.mp3') {
          return http.Response.bytes([5, 6, 7, 8], 200);
        }
        return http.Response('Not found', 404);
      });

      final handler = spellingAudioHandler(httpClient: mockClient);
      final request = Request('GET', Uri.parse('http://localhost/v1/spelling/audio/hello.mp3'));
      final response = await handler(request);

      expect(response.statusCode, 200);
      expect(response.headers['Content-Type'], 'audio/mpeg');
      expect(await response.read().first, [5, 6, 7, 8]);

      // Check if file is saved locally
      final File localFile = File('${tempCacheDir.path}/hello.mp3');
      expect(localFile.existsSync(), isTrue);
      expect(localFile.readAsBytesSync(), [5, 6, 7, 8]);
    });

    test('returns 404 if dictionary api fails or has no audio', () async {
      final mockClient = MockClient((request) async {
        return http.Response('[]', 200);
      });

      final handler = spellingAudioHandler(httpClient: mockClient);
      final request = Request('GET', Uri.parse('http://localhost/v1/spelling/audio/nonexistent.mp3'));
      final response = await handler(request);

      expect(response.statusCode, 404);
    });

    test('falls back to Merriam-Webster Collegiate API if dictionaryapi.dev returns empty/fails', () async {
      final mockClient = MockClient((request) async {
        if (request.url.path.contains('/entries/en/apple')) {
          return http.Response('[]', 200); // dictionaryapi.dev returns no entries
        }
        if (request.url.path.contains('/references/collegiate/json/apple')) {
          expect(request.url.queryParameters['key'], 'TEST_KEY');
          const mwResponse = '''
          [
            {
              "hwi": {
                "prs": [
                  {
                    "sound": {
                      "audio": "apple"
                    }
                  }
                ]
              }
            }
          ]
          ''';
          return http.Response(mwResponse, 200);
        }
        if (request.url.toString() == 'https://media.merriam-webster.com/audio/prons/en/us/mp3/a/apple.mp3') {
          return http.Response.bytes([9, 10, 11, 12], 200);
        }
        return http.Response('Not found', 404);
      });

      final handler = spellingAudioHandler(merriamWebsterApiKey: 'TEST_KEY', httpClient: mockClient);
      final request = Request('GET', Uri.parse('http://localhost/v1/spelling/audio/apple.mp3'));
      final response = await handler(request);

      expect(response.statusCode, 200);
      expect(response.headers['Content-Type'], 'audio/mpeg');
      expect(await response.read().first, [9, 10, 11, 12]);

      final File localFile = File('${tempCacheDir.path}/apple.mp3');
      expect(localFile.existsSync(), isTrue);
      expect(localFile.readAsBytesSync(), [9, 10, 11, 12]);
    });

    test('logs failures to spelling_audio_errors.log when APIs return non-200 or empty data', () async {
      final mockClient = MockClient((request) async {
        if (request.url.path.contains('/entries/en/failedword')) {
          return http.Response('Server Error', 500);
        }
        return http.Response('Not found', 404);
      });

      final handler = spellingAudioHandler(httpClient: mockClient);
      final request = Request('GET', Uri.parse('http://localhost/v1/spelling/audio/failedword.mp3'));
      final response = await handler(request);

      expect(response.statusCode, 404);
      expect(logFile.existsSync(), isTrue);
      final String logContents = logFile.readAsStringSync();
      expect(logContents, contains('=== Audio Fetch Failure ==='));
      expect(logContents, contains('Word: failedword'));
      expect(logContents, contains('API: dictionaryapi.dev'));
      expect(logContents, contains('Status Code: 500'));
      expect(logContents, contains('Response Body: Server Error'));
    });

    test('falls back to Google Cloud TTS if both dictionaries return empty/fails', () async {
      final mockClient = MockClient((request) async {
        if (request.url.path.contains('/entries/en/orange')) {
          return http.Response('[]', 200);
        }
        if (request.url.path.contains('/references/collegiate/json/orange')) {
          return http.Response('[]', 200);
        }
        if (request.url.path.contains('/text:synthesize')) {
          expect(request.url.queryParameters['key'], 'GOOGLE_KEY');
          expect(request.body, contains('"text":"orange"'));
          const gcResponse = '''
          {
            "audioContent": "ZGVtb2J5dGVz"
          }
          ''';
          return http.Response(gcResponse, 200);
        }
        return http.Response('Not found', 404);
      });

      final handler = spellingAudioHandler(
        merriamWebsterApiKey: 'TEST_KEY',
        googleCloudApiKey: 'GOOGLE_KEY',
        httpClient: mockClient,
      );
      final request = Request('GET', Uri.parse('http://localhost/v1/spelling/audio/orange.mp3'));
      final response = await handler(request);

      expect(response.statusCode, 200);
      expect(response.headers['Content-Type'], 'audio/mpeg');
      // base64Decode("ZGVtb2J5dGVz") -> "demobytes" -> [100, 101, 109, 111, 98, 121, 116, 101, 115]
      expect(await response.read().first, [100, 101, 109, 111, 98, 121, 116, 101, 115]);

      final File localFile = File('${tempCacheDir.path}/orange.mp3');
      expect(localFile.existsSync(), isTrue);
      expect(localFile.readAsBytesSync(), [100, 101, 109, 111, 98, 121, 116, 101, 115]);
    });
  });
}