import os
import logging
import asyncio
from huggingface_hub import hf_hub_download
from llama_cpp import Llama

logger = logging.getLogger("nexari.chat")
BASE_DIR = "./models/chat"
model = None

REPO_ID = "bartowski/Meta-Llama-3.1-8B-Instruct-GGUF"
FILENAME = "Meta-Llama-3.1-8B-Instruct-Q4_K_M.gguf"

def download_if_needed(local_dir: str):
    os.makedirs(local_dir, exist_ok=True)
    local_path = os.path.join(local_dir, FILENAME)
    if os.path.exists(local_path):
        logger.info(f"Chat model already present: {local_path}")
        return local_path
    logger.info(f"Downloading chat model to {local_dir} ...")
    path = hf_hub_download(repo_id=REPO_ID, filename=FILENAME, local_dir=local_dir)
    logger.info(f"Downloaded chat: {path}")
    return path

def load_model(local_dir: str = None):
    global model
    if not local_dir:
        local_dir = BASE_DIR
    try:
        model_path = download_if_needed(local_dir)
        model = Llama(model_path=model_path, n_ctx=2048, verbose=False)
        logger.info("Chat model loaded")
        return model
    except Exception as e:
        logger.exception(f"Failed to load chat model: {e}")
        model = None
        raise

async def load_model_async():
    return await asyncio.to_thread(load_model)