"""Local Snowflake connection utilities for development."""

import json
import os
import os.path
from typing import Any

from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import serialization


def get_connection_parameters(account: str) -> dict[str, Any]:
    """
    Get Snowflake connection parameters for local development.

    Args:
        account: Connection profile name from connections.json

    Returns:
        Dictionary containing connection parameters with private key bytes
    """
    connections_file = os.path.join(os.path.dirname(__file__), "connections.json")
    with open(connections_file, "r") as file:
        connection_params = json.load(file)[account]
        private_key_file = connection_params["private_file"]
        # Get password if provided (optional)
        private_key_password = connection_params.get("private_key_password")

    # Expand ~ to home directory
    private_key_file = os.path.expanduser(private_key_file)

    # Convert password to bytes if provided
    password_bytes = None
    if private_key_password:
        password_bytes = private_key_password.encode("utf-8")

    with open(private_key_file, "rb") as key:
        p_key = serialization.load_pem_private_key(
            key.read(), password=password_bytes, backend=default_backend()
        )

    pkb = p_key.private_bytes(
        encoding=serialization.Encoding.DER,
        format=serialization.PrivateFormat.PKCS8,
        encryption_algorithm=serialization.NoEncryption(),
    )

    connection_parameters = {
        "account": connection_params["account"],
        "user": connection_params["user"],
        "role": connection_params["role"],
        "private_key": pkb,
        "warehouse": connection_params["warehouse"],
        "database": connection_params["database"],
        "schema": connection_params["schema"],
    }

    return connection_parameters