from __future__ import annotations

import json
from typing import Final

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


def service_account_json(project: str, token_url: str) -> str:
    private_key: Final = (
        rsa.generate_private_key(public_exponent=65537, key_size=2048)
        .private_bytes(
            serialization.Encoding.PEM,
            serialization.PrivateFormat.PKCS8,
            serialization.NoEncryption(),
        )
        .decode()
    )
    return json.dumps(
        {
            "type": "service_account",
            "project_id": project,
            "private_key_id": "scripted",
            "private_key": private_key,
            "client_email": f"scripted@{project}.iam.gserviceaccount.com",
            "client_id": "0",
            "auth_uri": f"{token_url}/_oauth/authorize",
            "token_uri": f"{token_url}/_oauth/token",
        }
    )