from types import SimpleNamespace
from unittest.mock import patch

from app.services.mail_sender import build_message, sign_message


def test_dkim_sign_uses_selector_before_domain():
    message = build_message(
        sender="user@ritoesis.com",
        recipients=["recipient@example.com"],
        cc=[],
        subject="Test",
        body_text="Hello",
        body_html=None,
    )
    domain = SimpleNamespace(
        domain_name="ritoesis.com",
        dkim_selector="agmail",
        dkim_private_key="private-key",
    )

    with patch(
        "app.services.mail_sender.dkim.sign",
        return_value=b"DKIM-Signature: test\r\n",
    ) as signer:
        sign_message(message, domain)

    assert signer.call_args.args[1] == b"agmail"
    assert signer.call_args.args[2] == b"ritoesis.com"