"""
Basic QUIC Security implementation for Module 1.
This provides minimal TLS configuration for QUIC transport.
Full implementation will be in Module 5.
"""

from dataclasses import dataclass
import os
import tempfile
from typing import Optional

from libp2p.crypto.keys import PrivateKey
from libp2p.peer.id import ID

from .exceptions import QUICSecurityError


@dataclass
class TLSConfig:
    """TLS configuration for QUIC transport."""

    cert_file: str
    key_file: str
    ca_file: Optional[str] = None


def generate_libp2p_tls_config(private_key: PrivateKey, peer_id: ID) -> TLSConfig:
    """
    Generate TLS configuration with libp2p peer identity.

    This is a basic implementation for Module 1.
    Full implementation with proper libp2p TLS spec compliance
    will be provided in Module 5.

    Args:
        private_key: libp2p private key
        peer_id: libp2p peer ID

    Returns:
        TLS configuration

    Raises:
        QUICSecurityError: If TLS configuration generation fails

    """
    try:
        # TODO: Implement proper libp2p TLS certificate generation
        # This should follow the libp2p TLS specification:
        # https://github.com/libp2p/specs/blob/master/tls/tls.md

        # For now, create a basic self-signed certificate
        # This is a placeholder implementation

        # Create temporary files for cert and key
        with tempfile.NamedTemporaryFile(
            mode="w", suffix=".pem", delete=False
        ) as cert_file:
            cert_path = cert_file.name
            # Write placeholder certificate
            cert_file.write(_generate_placeholder_cert(peer_id))

        with tempfile.NamedTemporaryFile(
            mode="w", suffix=".key", delete=False
        ) as key_file:
            key_path = key_file.name
            # Write placeholder private key
            key_file.write(_generate_placeholder_key(private_key))

        return TLSConfig(cert_file=cert_path, key_file=key_path)

    except Exception as e:
        raise QUICSecurityError(f"Failed to generate TLS config: {e}") from e


def _generate_placeholder_cert(peer_id: ID) -> str:
    """
    Generate a placeholder certificate.

    This is a temporary implementation for Module 1.
    Real implementation will embed the peer ID in the certificate
    following the libp2p TLS specification.
    """
    # This is a placeholder - real implementation needed
    return f"""-----BEGIN CERTIFICATE-----
# Placeholder certificate for peer {peer_id}
# TODO: Implement proper libp2p TLS certificate generation
# This should embed the peer ID in a certificate extension
# according to the libp2p TLS specification
-----END CERTIFICATE-----"""


def _generate_placeholder_key(private_key: PrivateKey) -> str:
    """
    Generate a placeholder private key.

    This is a temporary implementation for Module 1.
    Real implementation will use the actual libp2p private key.
    """
    # This is a placeholder - real implementation needed
    return """-----BEGIN PRIVATE KEY-----
# Placeholder private key
# TODO: Convert libp2p private key to TLS-compatible format
-----END PRIVATE KEY-----"""


def cleanup_tls_config(config: TLSConfig) -> None:
    """
    Clean up temporary TLS files.

    Args:
        config: TLS configuration to clean up

    """
    try:
        if os.path.exists(config.cert_file):
            os.unlink(config.cert_file)
        if os.path.exists(config.key_file):
            os.unlink(config.key_file)
        if config.ca_file and os.path.exists(config.ca_file):
            os.unlink(config.ca_file)
    except Exception:
        # Ignore cleanup errors
        pass