"""Configuration management for Helium server."""

import os
from pathlib import Path
from dotenv import load_dotenv
import logging

# Load environment variables from .env file
env_path = Path(__file__).parent / '.env'
load_dotenv(dotenv_path=env_path)

# Database configuration
DB_URL = os.getenv('HELIUM_DB_URL', 'hf://datasets/Fred808/helium/storage.json')

# HuggingFace token configuration
def get_hf_token() -> str:
    """Get the HuggingFace token from environment variables."""
    token = os.getenv('HF_TOKEN')
    if not token:
        logging.error("HF_TOKEN environment variable not set")
        raise ValueError(
            "HF_TOKEN environment variable not set. "
            "Please set it in .env file or environment. "
            "Create a .env file in the project root with: HF_TOKEN=your_token_here"
        )
    return token

def get_db_url() -> str:
    """Get the database URL from environment variables."""
    if not DB_URL or not DB_URL.startswith('hf://datasets/'):
        logging.error(f"Invalid database URL: {DB_URL}")
        raise ValueError(
            f"Invalid database URL: {DB_URL}. "
            "URL must start with 'hf://datasets/' and be properly formatted"
        )
    return DB_URL

# Singleton instance for HF token to avoid reading env multiple times
_hf_token = None

def get_hf_token_cached() -> str:
    """Get the HuggingFace token with caching."""
    global _hf_token
    if _hf_token is None:
        _hf_token = get_hf_token()
    return _hf_token