import { useState } from "react";
import { simulateTyping } from "../utils/simulateTyping";

// Handle chat completion logic, including settings, UI behavior, and error management
export function useChatCompletion(
  client,
  chatSettings,
  uiSettings,
  onMessageComplete
) {
  const [isLoading, setIsLoading] = useState(false);
  const [typingMessage, setTypingMessage] = useState("");
  const [error, setError] = useState(null);

  const sendMessage = async (message) => {
    if (!client) {
      setError({
        type: "MISSING_CLIENT",
        message: "Please login Hugging Face first.",
      });
      return;
    }

    setIsLoading(true);
    setError(null);
    setTypingMessage("");

    let result;

    try {
      result = await client.chatCompletion({
        model: "openai/gpt-oss-20b",
        messages: [
          { role: "system", content: chatSettings.system },
          { role: "user", content: message },
        ],
        temperature: chatSettings.temperature,
        top_p: chatSettings.top_p,
        max_tokens: chatSettings.max_tokens,
      });
    } catch (err) {
      setError({ type: "CHAT_ERROR", message: err.message });
      return;
    } finally {
      setIsLoading(false);
    }

    const assistantReply = result.choices[0].message.content;

    if (uiSettings.typingEnabled) {
      simulateTyping(assistantReply, setTypingMessage, () => {
        onMessageComplete({ user: message, assistant: assistantReply });
        setTypingMessage("");
      });
    } else {
      onMessageComplete({ user: message, assistant: assistantReply });
    }
  };

  return { sendMessage, isLoading, typingMessage, error };
}