import spaces
import gradio as gr
from huggingface_hub import InferenceClient, login
from transformers import AutoModelForCausalLM, AutoTokenizer, BitsAndBytesConfig
from peft import PeftModel
import os
import torch
import time
import bitsandbytes
import traceback
import threading
from accelerate import Accelerator

@spaces.GPU  # Forces GPU allocation before execution
def force_gpu_allocation():
    pass  # Dummy function to trigger GPU setup

print(f"Is CUDA available: {torch.cuda.is_available()}")  # True
print(f"CUDA device: {torch.cuda.get_device_name(torch.cuda.current_device())}")

# Define the device correctly
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
print(f"Using device: {device}")  # Debugging info

# Base model (LLaMA 3.1 8B) from Meta
base_model_name = "meta-llama/Llama-3.1-8B"

# Your fine-tuned LoRA adapter (uploaded to Hugging Face)
lora_model_name = "starnernj/Early-Christian-Church-Fathers-LLaMA-3.1-Fine-Tuned"


# Function to generate responses
def chatbot_response(user_input):
    accelerator = Accelerator()

    # Login because LLaMA 3.1 8B is a gated model
    login(token=os.getenv("HuggingFaceFineGrainedReadToken"))

    # Load tokenizer
    tokenizer = AutoTokenizer.from_pretrained(base_model_name)
    
    model = AutoModelForCausalLM.from_pretrained(
        base_model_name,
    )
    
    # Load LoRA adapter
    model = PeftModel.from_pretrained(model, lora_model_name)
    
    model = accelerator.prepare(model)
    
    try:
        inputs = tokenizer(user_input, return_tensors="pt").to(device)
        outputs = model.generate(**inputs, max_length=200)
        return tokenizer.decode(outputs[0], skip_special_tokens=True)
    except Exception as e:
        error_message = f"AssertionError: {str(e)}\n{traceback.format_exc()}"
        print(error_message)  # ✅ Logs detailed error messages
        return "An error occurred. Check the logs for details."


# Launch the Gradio chatbot
interface = gr.Interface(
    fn=chatbot_response,
    inputs=gr.Textbox(lines=2, placeholder="Ask me about the Christian Church Fathers..."),
    outputs="text",
    title="Early Christian Church Fathers Fine-Tuned LLaMA 3.1 8B with LoRA",
    description="A chatbot using a fine-tuned LoRA adapter on LLaMA 3.1 8B, tuned on thousands of writings of the early Christian Church Fathers.",
)

interface.launch()