"""
Encryption utilities for sensitive data (WiFi passwords, etc).

Uses Fernet (symmetric encryption) from cryptography library.
"""

from cryptography.fernet import Fernet

from app.config import settings


def get_cipher() -> Fernet:
    """Get Fernet cipher instance."""
    # Convert settings key to bytes if needed
    key = settings.ENCRYPTION_KEY
    if isinstance(key, str):
        key = key.encode()
    return Fernet(key)


def encrypt_password(plain_password: str) -> str:
    """
    Encrypt a password using Fernet.

    Args:
        plain_password: Plain text password

    Returns:
        Encrypted password as string (base64 encoded)
    """
    cipher = get_cipher()
    encrypted_bytes = cipher.encrypt(plain_password.encode())
    return encrypted_bytes.decode()


def decrypt_password(encrypted_password: str) -> str:
    """
    Decrypt a password using Fernet.

    Args:
        encrypted_password: Encrypted password (base64 encoded string)

    Returns:
        Decrypted plain text password
    """
    cipher = get_cipher()
    decrypted_bytes = cipher.decrypt(encrypted_password.encode())
    return decrypted_bytes.decode()