Add function message role and function name

.gitignore

@@ -9,4 +9,5 @@ example/.env
 env.g.dart
 .env
 *.mp3
-*.png
+*.png
+.idea/

example/lib/chat_example_with_function_call.dart

@@ -1,3 +1,5 @@
+import 'dart:convert';
+
 import 'package:dart_openai/dart_openai.dart';
 
 import 'env/env.dart';
@@ -5,39 +7,100 @@ import 'env/env.dart';
 Future<void> main() async {
   OpenAI.apiKey = Env.apiKey;
 
-  final chatRes = await OpenAI.instance.chat.create(
-    model: "gpt-3.5-turbo-0613",
-    messages: [
-      OpenAIChatCompletionChoiceMessageModel(
-        content:
-            "send an email with a message asking about weather in Marrakech",
-        role: OpenAIChatMessageRole.user,
-      ),
-    ],
-    functions: [
-      OpenAIFunctionModel(
-        name: "sendEmail",
-        description: "sends an email with the given message",
-        parameters: OpenAIFunctionParameters.fromProperties(
-          [
-            OpenAIFunctionProperty(
-              name: "message",
-              type: 'string',
-            ),
-          ],
+  final function = OpenAIFunctionModel(
+    name: "getCurrentWeather",
+    description: "Get the current weather in a given location",
+    parameters: OpenAIFunctionParameters.fromProperties(
+      [
+        OpenAIFunctionProperty(
+          name: "location",
+          description: 'The city and state, e.g. San Francisco, CA',
+          type: OpenAIFunctionProperty.functionTypeString,
+          isRequired: true,
         ),
-      ),
-    ],
+        OpenAIFunctionProperty(
+          name: "unit",
+          description: 'The unit of temperature to return',
+          type: OpenAIFunctionProperty.functionTypeString,
+          enumValues: ["celsius", "fahrenheit"],
+        ),
+      ],
+    ),
   );
 
-  final funcCall = chatRes.choices.first.message.functionCall;
+  final userMsg = OpenAIChatCompletionChoiceMessageModel(
+    content: "What’s the weather like in Boston right now?",
+    role: OpenAIChatMessageRole.user,
+  );
 
-  if (funcCall != null && funcCall.name == "sendEmail") {
-    final message = funcCall.arguments["message"];
-    sendEmail(message);
+  final chatRes1 = await OpenAI.instance.chat.create(
+    model: "gpt-3.5-turbo-0613",
+    messages: [userMsg],
+    functions: [function],
+  );
+
+  final assistantMsg1 = chatRes1.choices.first.message;
+  final funcCall = assistantMsg1.functionCall;
+
+  if (funcCall == null || funcCall.name != "getCurrentWeather") {
+    print(assistantMsg1.content);
+    return;
+  }
+
+  final weather = getCurrentWeather(
+    location: funcCall.arguments["location"],
+    unit: funcCall.arguments["unit"],
+  );
+
+  final functionMsg = OpenAIChatCompletionChoiceMessageModel(
+    functionName: function.name,
+    content: json.encode(weather.toMap()),
+    role: OpenAIChatMessageRole.function,
+  );
+
+  final chatRes2 = await OpenAI.instance.chat.create(
+    model: "gpt-3.5-turbo-0613",
+    messages: [
+      userMsg,
+      assistantMsg1,
+      functionMsg,
+    ],
+    functions: [function],
+  );
+
+  final assistantMsg2 = chatRes2.choices.first.message;
+
+  print(assistantMsg2.content);
+  // The weather in Boston right now is sunny with a temperature of 22 degrees Celsius.
+}
+
+Weather getCurrentWeather({
+  required String location,
+  String? unit = "celsius",
+}) {
+  return Weather(
+    temperature: 22,
+    unit: unit ?? "celsius",
+    description: "Sunny",
+  );
+}
+
+class Weather {
+  final int temperature;
+  final String unit;
+  final String description;
+
+  const Weather({
+    required this.temperature,
+    required this.unit,
+    required this.description,
+  });
+
+  Map<String, dynamic> toMap() {
+    return {
+      'temperature': temperature,
+      'unit': unit,
+      'description': description,
+    };
   }
 }
-
-void sendEmail(String message) {
-  print("message: $message... is sent successfully.");
-}

lib/src/core/models/chat/sub_models/choices/sub_models/message.dart

@@ -11,11 +11,20 @@ final class OpenAIChatCompletionChoiceMessageModel {
   /// The [content] of the message.
   final String content;
 
+  /// The function that the model is requesting to call.
   final FunctionCallResponse? functionCall;
 
+  /// The name of the function that was called.
+  final String? functionName;
+
+  bool get hasFunctionCall => functionCall != null;
+
   @override
   int get hashCode {
-    return role.hashCode ^ content.hashCode;
+    return role.hashCode ^
+        content.hashCode ^
+        functionCall.hashCode ^
+        functionName.hashCode;
   }
 
   /// {@macro openai_chat_completion_choice_message_model}
@@ -23,10 +32,9 @@ final class OpenAIChatCompletionChoiceMessageModel {
     required this.role,
     required this.content,
     this.functionCall,
+    this.functionName,
   });
 
-  bool get hasFunctionCall => functionCall != null;
-
   /// This is used  to convert a [Map<String, dynamic>] object to a [OpenAIChatCompletionChoiceMessageModel] object.
   factory OpenAIChatCompletionChoiceMessageModel.fromMap(
     Map<String, dynamic> json,
@@ -47,15 +55,24 @@ final class OpenAIChatCompletionChoiceMessageModel {
       "role": role.name,
       "content": content,
       if (functionCall != null) "function_call": functionCall!.toMap(),
+      if (functionName != null) "name": functionName,
     };
   }
 
   @override
   String toString() {
+    String str = 'OpenAIChatCompletionChoiceMessageModel('
+        'role: $role, '
+        'content: $content, ';
     if (functionCall != null) {
-      return 'OpenAIChatCompletionChoiceMessageModel(role: $role, content: $content, functionCall: $functionCall)';
+      str += 'functionCall: $functionCall, ';
     }
-    return 'OpenAIChatCompletionChoiceMessageModel(role: $role, content: $content)';
+    if (functionName != null) {
+      str += 'functionName: $functionName, ';
+    }
+    str += ')';
+
+    return str;
   }
 
   @override
@@ -65,6 +82,7 @@ final class OpenAIChatCompletionChoiceMessageModel {
     return other is OpenAIChatCompletionChoiceMessageModel &&
         other.role == role &&
         other.content == content &&
-        other.functionCall == functionCall;
+        other.functionCall == functionCall &&
+        other.functionName == functionName;
   }
 }

lib/src/core/models/functions/functions.dart

@@ -140,7 +140,7 @@ class FunctionCallResponse {
   Map<String, dynamic> toMap() {
     return {
       'name': name,
-      'arguments': arguments,
+      'arguments': json.encode(arguments),
     };
   }
 

lib/src/core/models/image/enum.dart

@@ -4,4 +4,4 @@ enum OpenAIImageResponseFormat { url, b64Json }
 
 enum OpenAIAudioResponseFormat { json, text, srt, verbose_json, vtt }
 
-enum OpenAIChatMessageRole { system, user, assistant }
+enum OpenAIChatMessageRole { system, user, assistant, function }