"""Encryption module."""

from abc import ABC, abstractmethod
from typing import Optional
from dataclasses import dataclass
import secrets


@dataclass
class CipherText:
    """Encrypted data."""
    ciphertext: bytes
    nonce: bytes
    tag: bytes


class EncryptionProvider(ABC):
    """Abstract encryption provider."""
    
    @abstractmethod
    async def encrypt(self, plaintext: str) -> CipherText:
        """Encrypt data."""
        pass
    
    @abstractmethod
    async def decrypt(self, ciphertext: CipherText) -> str:
        """Decrypt data."""
        pass


class AESEncryptionProvider(EncryptionProvider):
    """AES encryption provider."""
    
    def __init__(self, key: Optional[bytes] = None):
        self.key = key or secrets.token_bytes(32)
    
    async def encrypt(self, plaintext: str) -> CipherText:
        """Encrypt with AES-GCM."""
        # Placeholder - would use cryptography library
        return CipherText(
            ciphertext=plaintext.encode(),
            nonce=secrets.token_bytes(12),
            tag=secrets.token_bytes(16)
        )
    
    async def decrypt(self, ciphertext: CipherText) -> str:
        """Decrypt with AES-GCM."""
        # Placeholder
        return ciphertext.ciphertext.decode()
