# app.py
import gradio as gr
from openai import OpenAI

DEFAULT_SYSTEM_PROMPT = "You are a helpful, concise assistant."
DEFAULT_MODEL = "gpt-5-chat-latest"

def chat_fn(message, history, system_prompt, temperature, max_tokens, api_key, base_url, model):
    if not api_key:
        return "⚠️ Please provide an OpenAI API key (top of the page)."

    client = OpenAI(api_key=api_key, base_url=(base_url or "https://api.openai.com/v1").strip())

    messages = [{"role": "system", "content": (system_prompt or DEFAULT_SYSTEM_PROMPT).strip()}]
    for user_msg, assistant_msg in history:
        if user_msg:
            messages.append({"role": "user", "content": user_msg})
        if assistant_msg:
            messages.append({"role": "assistant", "content": assistant_msg})
    messages.append({"role": "user", "content": message})

    try:
        resp = client.chat.completions.create(
            model=(model or DEFAULT_MODEL).strip(),
            messages=messages,
            temperature=float(temperature) if temperature is not None else 0.7,
            max_tokens=int(max_tokens) if max_tokens else None,
        )
        return resp.choices[0].message.content
    except Exception as e:
        return f"❌ Error: {e}"

with gr.Blocks(title="OpenAI Chat (Gradio)") as demo:
    gr.Markdown("## 🔑 OpenAI Chatbot\nPaste your API key, pick a model, and chat.")

    with gr.Row():
        api_key = gr.Textbox(label="OpenAI API Key", type="password", placeholder="sk-...", lines=1)
        base_url = gr.Textbox(label="Base URL", value="https://api.openai.com/v1", lines=1)

    with gr.Row():
        model = gr.Textbox(label="Model", value=DEFAULT_MODEL, lines=1)

    system_prompt = gr.Textbox(label="System prompt", value=DEFAULT_SYSTEM_PROMPT, lines=2)

    with gr.Row():
        temperature = gr.Slider(minimum=0.0, maximum=2.0, value=0.7, step=0.1, label="Temperature")
        max_tokens = gr.Slider(minimum=64, maximum=4096, value=512, step=32, label="Max tokens (response)")

    gr.Markdown("---")

    gr.ChatInterface(
        fn=chat_fn,
        title="OpenAI Chatbot",
        additional_inputs=[system_prompt, temperature, max_tokens, api_key, base_url, model],
    )

if __name__ == "__main__":
    demo.launch()