app.py

import gradio as gr
from huggingface_hub import InferenceClient
import os

ACCESS_TOKEN = os.getenv("myHFtoken")

print("Access token loaded.")

client = InferenceClient(api_key=ACCESS_TOKEN)

print("Client initialized.")

SYSTEM_PROMPTS = {
    "zh-HK": "必須用繁體字，香港廣東話語調對話. No chatty. Answer in simple but accurate way.",
    "zh-TW": "Chat by Traditional Chinese language of Taiwan (zh-TW). No chatty. Answer in simple but accurate way.",
    "EN: General Assistant": "You are a helpful, respectful and honest assistant. Always provide accurate information and admit when you're not sure about something.",
    "EN: Code Helper": "You are a programming assistant. Help users with coding questions, debugging, and best practices. Provide clear explanations and code examples when appropriate.",
    "EN: Creative Writer": "You are a creative writing assistant. Help users with storytelling, character development, and creative writing techniques. Be imaginative and encouraging."
}

def respond(
    message,
    history: list[tuple[str, str]],
    preset_prompt,
    custom_prompt,
    max_tokens,
    temperature,
    top_p,
    model_name,
):
    print(f"Received message: {message}")
    print(f"History: {history}")
    
    system_message = custom_prompt if custom_prompt.strip() else SYSTEM_PROMPTS[preset_prompt]
    
    print(f"System message: {system_message}")
    print(f"Max tokens: {max_tokens}, Temperature: {temperature}, Top-P: {top_p}")
    print(f"Selected model: {model_name}")

    messages = [{"role": "system", "content": system_message}]

    for val in history:
        if val[0]:
            messages.append({"role": "user", "content": val[0]})
            print(f"Added user message to context: {val[0]}")
        if val[1]:
            messages.append({"role": "assistant", "content": val[1]})
            print(f"Added assistant message to context: {val[1]}")

    messages.append({"role": "user", "content": message})

    response = ""
    print("Sending request to Hugging Face API.")
    
    stream = client.chat.completions.create(
        model=model_name,
        messages=messages,
        max_tokens=max_tokens,
        temperature=temperature,
        top_p=top_p,
        stream=True
    )

    for chunk in stream:
        try:
            # Handle Hugging Face's streaming format
            token = chunk.choices[0].delta.content
            
            if token:  # Skip empty tokens
                response += token
                yield response
                print(f"Streamed token: {token}")
        except AttributeError as e:
            print(f"Error processing chunk: {e}")
            continue

    print("Completed response generation.")

models = [
    #"microsoft/Phi-4-mini-instruct",
    "meta-llama/Llama-3.2-3B-Instruct",
    "deepseek-ai/DeepSeek-R1-Distill-Qwen-1.5B",
    "deepseek-ai/DeepSeek-R1-Distill-Qwen-7B",
    "deepseek-ai/DeepSeek-R1-Distill-Qwen-14B",
    "PowerInfer/SmallThinker-3B-Preview",
    "Qwen/QwQ-32B-Preview",
    "Qwen/Qwen2.5-Coder-32B-Instruct",
    "microsoft/Phi-3-mini-128k-instruct",
]

with gr.Blocks() as demo:
    gr.Markdown("# LLM Test")
    
    with gr.Row():
        model_dropdown = gr.Dropdown(
            choices=models, 
            value=models[0], 
            label="Select Model:"
        )

    chatbot = gr.Chatbot(height=500)
    msg = gr.Textbox(
        show_label=False,
        placeholder="Enter text and press enter",
        container=False
    )
    clear = gr.Button("Clear")

    with gr.Accordion("Configuration", open=False):
        preset_prompt = gr.Dropdown(
            choices=list(SYSTEM_PROMPTS.keys()),
            value=list(SYSTEM_PROMPTS.keys())[0],
            label="Select System Prompt:"
        )
        custom_prompt = gr.Textbox(
            value="",
            label="Custom System Prompt (leaves blank to use preset):",
            lines=2
        )
        max_tokens = gr.Slider(
            minimum=1,
            maximum=8192,
            value=2048,
            step=1,
            label="Max new tokens:"
        )
        temperature = gr.Slider(
            minimum=0.1,
            maximum=1.0,
            value=0.3,
            step=0.1,
            label="Temperature:"
        )
        top_p = gr.Slider(
            minimum=0.1,
            maximum=1.0,
            value=0.95,
            step=0.05,
            label="Top-P:"
        )

    def user(user_message, history):
        return "", history + [[user_message, None]]

    def bot(
        history,
        preset_prompt,
        custom_prompt,
        max_tokens,
        temperature,
        top_p,
        model_name
    ):
        history[-1][1] = ""
        for character in respond(
            history[-1][0],
            history[:-1],
            preset_prompt,
            custom_prompt,
            max_tokens,
            temperature,
            top_p,
            model_name
        ):
            history[-1][1] = character
            yield history

    msg.submit(
        user,
        [msg, chatbot],
        [msg, chatbot],
        queue=False
    ).then(
        bot,
        [chatbot, preset_prompt, custom_prompt, max_tokens, temperature, top_p, model_dropdown],
        chatbot
    )

    clear.click(lambda: None, None, chatbot, queue=False)

print("Gradio interface initialized.")

if __name__ == "__main__":
    print("Launching the demo application.")
    demo.launch()