import aiohttp
import ssl
import logging
from langchain_core.tools import tool
from tenacity import retry, stop_after_attempt, wait_exponential
from typing import Optional
import json
import os

logger = logging.getLogger(__name__)

@retry(stop=stop_after_attempt(3), wait=wait_exponential(multiplier=1, min=1, max=10))
async def fetch_hf_models(author: str) -> Optional[dict]:
    url = f"https://huggingface.co/api/models?author={author}&sort=downloads&direction=-1&limit=1"
    ssl_context = ssl.create_default_context()
    try:
        async with aiohttp.ClientSession() as session:
            async with session.get(url, ssl=ssl_context) as response:
                response.raise_for_status()
                return await response.json()
    except aiohttp.ClientError as e:
        logger.error(f"Failed to fetch models for {author}: {e}")
        raise

@tool
async def hub_stats_tool(author: str) -> str:
    """
    Fetch the most downloaded model from a specific author on Hugging Face Hub.
    
    Args:
        author (str): Hugging Face author username.
    
    Returns:
        str: Model information or error message.
    """
    try:
        # Check local cache
        cache_file = f"temp/hf_cache_{author}.json"
        if os.path.exists(cache_file):
            with open(cache_file, "r") as f:
                models = json.load(f)
            logger.debug(f"Loaded cached models for {author}")
        else:
            models = await fetch_hf_models(author)
            os.makedirs("temp", exist_ok=True)
            with open(cache_file, "w") as f:
                json.dump(models, f)
        
        if models and isinstance(models, list) and models:
            model = models[0]
            return f"The most downloaded model by {author} is {model['id']} with {model.get('downloads', 0):,} downloads."
        return f"No models found for author {author}."
    except Exception as e:
        logger.error(f"Error fetching models for {author}: {e}")
        return f"Error: {str(e)}"