"""
Utilities for persistent storage in Hugging Face Spaces.
"""
import os
from pathlib import Path
from typing import Optional


def get_persistent_data_dir() -> Optional[Path]:
    """Get the persistent data directory if available.
    
    Returns:
        Path to persistent storage directory if available, None otherwise.
    """
    if os.path.isdir("/data"):
        data_dir = Path("/data/app_data")
        data_dir.mkdir(exist_ok=True)
        return data_dir
    return None


def get_cache_dir() -> Path:
    """Get the appropriate cache directory (persistent if available, temp otherwise).
    
    Returns:
        Path to cache directory.
    """
    if os.path.isdir("/data"):
        cache_dir = Path("/data/.cache")
        cache_dir.mkdir(exist_ok=True)
        return cache_dir
    else:
        # Fallback to temp directory
        import tempfile
        return Path(tempfile.gettempdir()) / "app_cache"


def save_uploaded_file(uploaded_file, filename: str) -> Optional[Path]:
    """Save an uploaded file to persistent storage.
    
    Args:
        uploaded_file: Gradio uploaded file object
        filename: Name to save the file as
        
    Returns:
        Path to saved file if successful, None otherwise.
    """
    persistent_dir = get_persistent_data_dir()
    if persistent_dir and uploaded_file:
        save_path = persistent_dir / filename
        save_path.parent.mkdir(parents=True, exist_ok=True)
        
        # Copy the uploaded file to persistent storage
        import shutil
        shutil.copy2(uploaded_file, save_path)
        return save_path
    return None


def is_persistent_storage_available() -> bool:
    """Check if persistent storage is available.
    
    Returns:
        True if persistent storage is available, False otherwise.
    """
    return os.path.isdir("/data")


def get_persistent_results_dir() -> Optional[Path]:
    """Get the persistent results directory for storing pipeline results.
    
    Returns:
        Path to persistent results directory if available, None otherwise.
    """
    persistent_dir = get_persistent_data_dir()
    if persistent_dir:
        results_dir = persistent_dir / "results"
        results_dir.mkdir(exist_ok=True)
        return results_dir
    return None