import torch
from transformers import pipeline, TextStreamer
import gradio as gr
import threading
import time

# Global variable to store the model pipeline
model_pipeline = None
model_loading_lock = threading.Lock()
model_loaded = False  # Status flag to indicate if the model is loaded

def load_model(model_name="deepseek-ai/DeepSeek-R1-Distill-Qwen-1.5B"):
    global model_pipeline, model_loaded
    with model_loading_lock:
        if not model_loaded:
            print("Loading model...")
            pipe = pipeline(
                "text-generation",
                model=model_name,
                device_map="sequential",
                torch_dtype=torch.float16,
                trust_remote_code=True,
                truncation=True,
                max_new_tokens=2048,
                model_kwargs={
                    "low_cpu_mem_usage": True,
                    "offload_folder": "offload"
                }
            )
            model_pipeline = pipe
            model_loaded = True
            print("Model loaded successfully.")
        else:
            print("Model already loaded.")

def check_model_status():
    """Check if the model is loaded and reload if necessary."""
    global model_loaded
    if not model_loaded:
        print("Model not loaded. Reloading...")
        load_model()
    return model_loaded

def chat(message, history, temperature, max_new_tokens):
    global model_pipeline
    
    # Ensure the model is loaded before proceeding
    if not check_model_status():
        yield "Model is not ready. Please try again later."
        return
    
    prompt = f"Human: {message}\n\nAssistant:"
    
    # Stream the response
    start_time = time.time()
    generated_tokens = 0
    
    # Create a TextStreamer for token streaming
    tokenizer = model_pipeline.tokenizer
    streamer = TextStreamer(tokenizer, skip_prompt=True, skip_special_tokens=True)
    
    def generate():
        stop_tokens = ["<|endoftext|>", "<|im_end|>","|im_end|"]
        nonlocal generated_tokens
        response = model_pipeline(
            prompt,
            max_new_tokens=max_new_tokens,
            temperature=temperature,
            do_sample=True,
            truncation=True,
            pad_token_id=tokenizer.eos_token_id,
            streamer=streamer  # Use the TextStreamer here
        )
        for new_token in streamer:
            outputs.append(new_token)
            if new_token in stop_tokens:
                
                break
            yield "".join(outputs), "not implemented"
def reload_model_button():
    """Reload the model manually via a button."""
    global model_loaded
    model_loaded = False
    load_model()
    return "Model reloaded successfully."

# Function to periodically update the status text
def update_status_periodically(status_text):
    while True:
        time.sleep(5)  # Update every 5 seconds
        status = "Model is loaded and ready." if model_loaded else "Model is not loaded."
        status_text.value = status  # Update the value directly

# Gradio Interface
with gr.Blocks(theme=gr.themes.Soft()) as demo:
    gr.Markdown("# DeepSeek-R1 Chatbot")
    gr.Markdown("DeepSeek-R1-Distill-Qwen-1.5B 모델을 사용한 대화 테스트용 데모입니다.")
    
    with gr.Row():
        chatbot = gr.Chatbot(height=600)
        textbox = gr.Textbox(placeholder="Enter your message...", container=False, scale=7)
    
    with gr.Row():
        send_button = gr.Button("Send")
        clear_button = gr.Button("Clear")
        reload_button = gr.Button("Reload Model")
    
    with gr.Row():
        temperature_slider = gr.Slider(minimum=0.1, maximum=1.0, value=0.7, step=0.1, label="Temperature")
        max_tokens_slider = gr.Slider(minimum=32, maximum=2048, value=2048, step=32, label="Max New Tokens")
    
    status_text = gr.Textbox(label="Model Status", value="Model not loaded yet.", interactive=False)
    token_status = gr.Textbox(label="Token Generation Status", value="", interactive=False)
    
    def respond(message, chat_history, temperature, max_new_tokens):
        bot_message = ""
        status = ""
        for partial_response, partial_status in chat(message, chat_history, temperature, max_new_tokens):
            bot_message = partial_response
            status = partial_status
            token_status.update(value=status)
            yield "", chat_history + [(message, bot_message)]
    
    send_button.click(respond, inputs=[textbox, chatbot, temperature_slider, max_tokens_slider], outputs=[textbox, chatbot])
    clear_button.click(lambda: [], None, chatbot)
    reload_button.click(reload_model_button, None, status_text)
    
    # Start a background thread to update the status text periodically
    threading.Thread(target=update_status_periodically, args=(status_text,), daemon=True).start()

# Load the model when the server starts
if __name__ == "__main__":
    load_model()  # Pre-load the model
    demo.launch(server_name="0.0.0.0")