"""Shadow environment setup utilities."""
import shutil
from pathlib import Path


def setup_shadow_files(target_dir: Path) -> tuple[str, bool, str]:
    """
    Copy shadow files to their target locations if they don't exist.
    - Copies .env.shadow to .env (if .env doesn't exist)
    - Copies event.shadow.json to event.json (if event.json doesn't exist)
    
    Args:
        target_dir: Path to the target directory (lambda or fargate)
    
    Returns:
        tuple: (target_name, success, error_message)
    """
    target_name = target_dir.name
    
    try:
        # Copy .env.shadow to .env if .env doesn't exist
        env_shadow = target_dir / ".env.shadow"
        env_target = target_dir / ".env"
        
        if env_shadow.exists() and not env_target.exists():
            shutil.copy2(env_shadow, env_target)
        
        # Copy event.shadow.json to event.json if event.json doesn't exist
        event_shadow = target_dir / "event.shadow.json"
        event_target = target_dir / "event.json"
        
        if event_shadow.exists() and not event_target.exists():
            shutil.copy2(event_shadow, event_target)
        
        return (target_name, True, "")
    except Exception as e:
        return (target_name, False, str(e))