open_indexing_services_impl.dart

class OpenAIIndexingServicesImpl extends OpenAIIndexingServices {
  late final http.Client client;
  late final Connection connection;

  OpenAIIndexingServicesImpl({
    required this.client,
    required this.connection,
  });
  Future<String> getCompletionFromMessages(messages,
      {model = "gpt-3.5-turbo-1106", temperature = 0, maxtokens = 1000}) async {
    final response = await client.post(
      Uri.parse("https://api.openai.com/v1/chat/completions"),
      headers: {
        'Content-Type': 'application/json',
        'Authorization': 'Bearer ${dotenv.env['OPENAI_API_KEY']!}',
      },
      body: jsonEncode({
        'model': model,
        'messages': messages,
        'max_tokens': maxtokens,
      }),
    );
    if (response.statusCode == 200) {
      final Map<String, dynamic> responseData = jsonDecode(response.body);
      String content = responseData\['choices'\][0]\['message'\]['content'];
      return content;
    } else {
      throw response.body;
    }
  }

  Future<List<double>> getQueryEmbeddings(String query) async {
    debugPrint("Embedding ....");
    final response = await http.post(
      Uri.parse("https://api.openai.com/v1/embeddings"),
      headers: {
        'Content-Type': 'application/json',
        'Authorization': 'Bearer ${dotenv.env['OPENAI_API_KEY']!}',
      },
      body: jsonEncode({
        'model': 'babbage-002',
        'input': query,
      }),
    );
    if (response.statusCode == 200) {
      final Map<String, dynamic> responseData = jsonDecode(response.body);
      List<dynamic> embedding = responseData\['data'\][0]['embedding'];
      List<double> embeddingdouble = embedding.map((item) {
        if (item is double) {
          return item;
        } else {
          throw const FormatException('Invalid format');
        }
      }).toList();
      debugPrint("Embedding complete....");
      return embeddingdouble;
    } else {
      throw response.body;
    }
  }
  @override
  Future<String> queryNeonTable(String tableName, String query) async {
    print("Query started ...");
    String delimiter = "```";
    final embedQuery = await getQueryEmbeddings(query);
    List<List<dynamic>> getSimilar = await connection.execute(
        "SELECT *, 1 - (embedding <=> '$embedQuery') AS cosine_similarity FROM $tableName WHERE (1 - (embedding <=> '$embedQuery')) BETWEEN 0.3 AND 1.00 ORDER BY cosine_similarity DESC LIMIT 3;");
    List<Metadata> csvMetadata = getSimilar
        .map((item) => Metadata.fromJson(
              json.decode(item[1]),
            ))
        .toList();
    if (csvMetadata.isNotEmpty) {
      final concatPageContent = csvMetadata.map((e) {
        return e.pageContent;
      }).join(' ');
      print(concatPageContent);
      String systemMessage = """
      You are a friendly chatbot. \n
      You can answer questions about  Implementing OAuth2 Clients with Flutter and Appwrite. \n
      You respond in a concise, technically credible tone. \n
      """;
      List<Map<String, String>> messages = [
        {"role": "system", "content": systemMessage},
        {"role": "user", "content": "$delimiter$query$delimiter"},
        {
          "role": "assistant",
          "content":
              "Relevant Appwrite OAuth2 case studies \n $concatPageContent"
        }
      ];
      final finalResponse = await getCompletionFromMessages(messages);
      print("Query Recieved: $finalResponse");
      return finalResponse;
    } else {
      return "Couldn't find anything on that topic";
    }
  }
}
void debugPrint(String message) {
  if (kDebugMode) {
    print(message);
  }
}