import argparse
from pathlib import Path

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


def run(parser: argparse.ArgumentParser, arguments: argparse.Namespace):
    # TODO(Faraphel): should NOT be named "client"
    print("creating new client...")

    directory_client = Path(f"./assets/client/{arguments.username}/")
    if directory_client.exists():
        raise ValueError("This client already exists !")

    directory_client.mkdir(parents=True)

    # Generate a private key
    private_key = rsa.generate_private_key(
        public_exponent=65537,
        key_size=2048,
        backend=default_backend(),
    )

    (directory_client / "private.key").write_bytes(
        private_key.private_bytes(
            encoding=serialization.Encoding.PEM,
            format=serialization.PrivateFormat.OpenSSH,
            encryption_algorithm=serialization.BestAvailableEncryption(arguments.password.encode()),
        )
    )
    (directory_client / "public.key").write_bytes(
        private_key.public_key().public_bytes(
            encoding=serialization.Encoding.PEM,
            format=serialization.PublicFormat.OpenSSH,
        )
    )