Update ChatGPT model to accept ChatModel & use 4.1-mini for questions (#1376)

* Update ChatGPT model to GPT_5_MINI

* feat: add a chat model parameter to allow choice between models (speed vs quality)

* feat: create an enum to house the AI models

* update AI response footer to include model

* docs: add java docs

---------

Co-authored-by: Suraj Kumar <sk96.uk@gmail.com>

Author: tj-wazei

application/src/main/java/org/togetherjava/tjbot/features/chatgpt/ChatGptCommand.java

@@ -25,6 +25,7 @@
  * which it will respond with an AI generated answer.
  */
 public final class ChatGptCommand extends SlashCommandAdapter {
+    private static final ChatGptModel CHAT_GPT_MODEL = ChatGptModel.HIGH_QUALITY;
     public static final String COMMAND_NAME = "chatgpt";
     private static final String QUESTION_INPUT = "question";
     private static final int MAX_MESSAGE_INPUT_LENGTH = 200;
@@ -82,8 +83,8 @@ public void onModalSubmitted(ModalInteractionEvent event, List<String> args) {
 
         String question = event.getValue(QUESTION_INPUT).getAsString();
 
-        Optional<String> chatgptResponse =
-                chatGptService.ask(question, "You may use markdown syntax for the response");
+        Optional<String> chatgptResponse = chatGptService.ask(question,
+                "You may use markdown syntax for the response", CHAT_GPT_MODEL);
         if (chatgptResponse.isPresent()) {
             userIdToAskedAtCache.put(event.getMember().getId(), Instant.now());
         }
@@ -96,7 +97,8 @@ public void onModalSubmitted(ModalInteractionEvent event, List<String> args) {
         String response = chatgptResponse.orElse(errorResponse);
         SelfUser selfUser = event.getJDA().getSelfUser();
 
-        MessageEmbed responseEmbed = helper.generateGptResponseEmbed(response, selfUser, question);
+        MessageEmbed responseEmbed =
+                helper.generateGptResponseEmbed(response, selfUser, question, CHAT_GPT_MODEL);
 
         event.getHook().sendMessageEmbeds(responseEmbed).queue();
     }

application/src/main/java/org/togetherjava/tjbot/features/chatgpt/ChatGptModel.java

@@ -0,0 +1,45 @@
+package org.togetherjava.tjbot.features.chatgpt;
+
+import com.openai.models.ChatModel;
+
+/**
+ * Logical abstraction over OpenAI chat models.
+ * <p>
+ * This enum allows the application to select models based on performance/quality intent rather than
+ * hard-coding specific OpenAI model versions throughout the codebase.
+ *
+ */
+public enum ChatGptModel {
+    /**
+     * Fastest response time with the lowest computational cost.
+     */
+    FASTEST(ChatModel.GPT_3_5_TURBO),
+
+    /**
+     * Balanced option between speed and quality.
+     */
+    FAST(ChatModel.GPT_4_1_MINI),
+
+    /**
+     * Highest quality responses with increased reasoning capability.
+     */
+    HIGH_QUALITY(ChatModel.GPT_5_MINI);
+
+    private final ChatModel chatModel;
+
+    ChatGptModel(ChatModel chatModel) {
+        this.chatModel = chatModel;
+    }
+
+    /**
+     * @return the underlying OpenAI model used by this enum.
+     */
+    public ChatModel toChatModel() {
+        return chatModel;
+    }
+
+    @Override
+    public String toString() {
+        return chatModel.toString();
+    }
+}

application/src/main/java/org/togetherjava/tjbot/features/chatgpt/ChatGptService.java

@@ -2,7 +2,6 @@
 
 import com.openai.client.OpenAIClient;
 import com.openai.client.okhttp.OpenAIOkHttpClient;
-import com.openai.models.ChatModel;
 import com.openai.models.responses.Response;
 import com.openai.models.responses.ResponseCreateParams;
 import com.openai.models.responses.ResponseOutputText;
@@ -51,11 +50,12 @@ public ChatGptService(Config config) {
      * @param question The question being asked of ChatGPT. Max is {@value MAX_TOKENS} tokens.
      * @param context The category of asked question, to set the context(eg. Java, Database, Other
      *        etc).
+     * @param chatModel The AI model to use for this request.
      * @return response from ChatGPT as a String.
      * @see <a href="https://platform.openai.com/docs/guides/chat/managing-tokens">ChatGPT
      *      Tokens</a>.
      */
-    public Optional<String> ask(String question, @Nullable String context) {
+    public Optional<String> ask(String question, @Nullable String context, ChatGptModel chatModel) {
         if (isDisabled) {
             return Optional.empty();
         }
@@ -76,7 +76,7 @@ public Optional<String> ask(String question, @Nullable String context) {
         String response = null;
         try {
             ResponseCreateParams params = ResponseCreateParams.builder()
-                .model(ChatModel.GPT_5_NANO)
+                .model(chatModel.toChatModel())
                 .input(inputPrompt)
                 .maxOutputTokens(MAX_TOKENS)
                 .build();

application/src/main/java/org/togetherjava/tjbot/features/help/HelpSystemHelper.java

@@ -25,6 +25,7 @@
 import org.togetherjava.tjbot.db.generated.tables.HelpThreads;
 import org.togetherjava.tjbot.db.generated.tables.records.HelpThreadsRecord;
 import org.togetherjava.tjbot.features.chatgpt.ChatGptCommand;
+import org.togetherjava.tjbot.features.chatgpt.ChatGptModel;
 import org.togetherjava.tjbot.features.chatgpt.ChatGptService;
 import org.togetherjava.tjbot.features.componentids.ComponentIdInteractor;
 import org.togetherjava.tjbot.features.utils.Guilds;
@@ -55,6 +56,7 @@
  */
 public final class HelpSystemHelper {
     private static final Logger logger = LoggerFactory.getLogger(HelpSystemHelper.class);
+    private static final ChatGptModel CHAT_GPT_MODEL = ChatGptModel.FAST;
 
     static final Color AMBIENT_COLOR = new Color(255, 255, 165);
 
@@ -143,7 +145,7 @@ RestAction<Message> constructChatGptAttempt(ThreadChannel threadChannel,
         String context =
                 "Category %s on a Java Q&A discord server. You may use markdown syntax for the response"
                     .formatted(matchingTag.getName());
-        chatGptAnswer = chatGptService.ask(question, context);
+        chatGptAnswer = chatGptService.ask(question, context, CHAT_GPT_MODEL);
 
         if (chatGptAnswer.isEmpty()) {
             return useChatGptFallbackMessage(threadChannel);
@@ -168,7 +170,8 @@ RestAction<Message> constructChatGptAttempt(ThreadChannel threadChannel,
             answer = answer.substring(0, responseCharLimit);
         }
 
-        MessageEmbed responseEmbed = generateGptResponseEmbed(answer, selfUser, originalQuestion);
+        MessageEmbed responseEmbed =
+                generateGptResponseEmbed(answer, selfUser, originalQuestion, CHAT_GPT_MODEL);
         return post.flatMap(_ -> threadChannel.sendMessageEmbeds(responseEmbed)
             .addActionRow(generateDismissButton(componentIdInteractor, messageId.get())));
     }
@@ -178,11 +181,13 @@ RestAction<Message> constructChatGptAttempt(ThreadChannel threadChannel,
      *
      * @param answer The response text generated by AI.
      * @param selfUser The SelfUser representing the bot.
-     * @param title The title for the MessageEmbed.
+     * @param title The title for the MessageEmbed
+     * @param model The AI model that was used for the foot notes
      * @return A MessageEmbed that contains response generated by AI.
      */
-    public MessageEmbed generateGptResponseEmbed(String answer, SelfUser selfUser, String title) {
-        String responseByGptFooter = "- AI generated response";
+    public MessageEmbed generateGptResponseEmbed(String answer, SelfUser selfUser, String title,
+            ChatGptModel model) {
+        String responseByGptFooter = "- AI generated response using %s model".formatted(model);
 
         int embedTitleLimit = MessageEmbed.TITLE_MAX_LENGTH;
         String capitalizedTitle = Character.toUpperCase(title.charAt(0)) + title.substring(1);

application/src/main/java/org/togetherjava/tjbot/features/moderation/TransferQuestionCommand.java

@@ -31,6 +31,7 @@
 import org.togetherjava.tjbot.features.BotCommandAdapter;
 import org.togetherjava.tjbot.features.CommandVisibility;
 import org.togetherjava.tjbot.features.MessageContextCommand;
+import org.togetherjava.tjbot.features.chatgpt.ChatGptModel;
 import org.togetherjava.tjbot.features.chatgpt.ChatGptService;
 import org.togetherjava.tjbot.features.utils.StringDistances;
 
@@ -98,7 +99,8 @@ public void onMessageContext(MessageContextInteractionEvent event) {
         String chatGptTitleRequest =
                 "Summarize the following question into a concise title or heading not more than 5 words, remove quotations if any: %s"
                     .formatted(originalMessage);
-        Optional<String> chatGptTitle = chatGptService.ask(chatGptTitleRequest, null);
+        Optional<String> chatGptTitle =
+                chatGptService.ask(chatGptTitleRequest, null, ChatGptModel.FASTEST);
         String title = chatGptTitle.orElse(createTitle(originalMessage));
         if (title.startsWith("\"") && title.endsWith("\"")) {
             title = title.substring(1, title.length() - 1);