import os
import uuid
import requests
from langchain_core.tools import tool
from typing import Optional
import tempfile
from urllib.parse import urlparse

@tool
def download_file(url: str, filename: Optional[str] = None) -> str:
    """
    Download a file from a URL and save it to a temporary location.
    Args:
        url (str): the URL of the file to download.
        filename (str, optional): the name of the file. If not provided, a random name file will be created.
    """
    try:
        # Parse URL to get filename if not provided
        if not filename:
            path = urlparse(url).path
            filename = os.path.basename(path)
            if not filename:
                filename = f"downloaded_{uuid.uuid4().hex[:8]}"

        # Create temporary file
        temp_dir = tempfile.gettempdir()
        filepath = os.path.join(temp_dir, filename)

        # Download the file
        response = requests.get(url, stream=True)
        response.raise_for_status()

        # Save the file
        with open(filepath, "wb") as f:
            for chunk in response.iter_content(chunk_size=8192):
                f.write(chunk)

        return f"File downloaded to {filepath}. You can read this file to process its contents."
    except Exception as e:
        return f"Error downloading file: {str(e)}"