"""Credential handling for the mail module.

Both checks guard fixes for real defects: the account file used to be written at
the umask and chmodded afterwards, and the IMAP/SMTP connections used to take
Python's stdlib SSL context, which verifies nothing.
"""
import json
import os
import ssl
import stat

from modules.mail import backend as mail


def test_account_file_is_never_group_or_world_readable(tmp_path, monkeypatch):
    monkeypatch.setattr(mail, "_ACCOUNT_FILE", tmp_path / "mail_accounts.json")
    mail._write_accounts([{**mail._DEFAULTS, "id": "abc", "username": "u", "password": "secret"}])

    mode = stat.S_IMODE((tmp_path / "mail_accounts.json").stat().st_mode)
    assert mode == 0o600, f"account file is {oct(mode)}, expected 0o600"
    assert not list(tmp_path.glob("*.tmp")), "temp file left behind"

    # The password round-trips to disk but never to the API.
    assert mail.load_accounts()[0]["password"] == "secret"
    assert "password" not in mail.public_account(mail.get_account("abc"))
    assert mail.public_account(mail.get_account("abc"))["has_password"] is True
    assert json.loads((tmp_path / "mail_accounts.json").read_text())["accounts"]


def test_account_file_is_0600_while_it_is_being_written(tmp_path, monkeypatch):
    """The old code wrote at the umask and chmodded afterwards, so the file sat
    world-readable for the length of the write. Assert the handle it is written
    through is already 0600 -- the pre-fix version never wrote through a handle
    at all (json.dumps to a string, then write_text), so this fails against it."""
    monkeypatch.setattr(mail, "_ACCOUNT_FILE", tmp_path / "mail_accounts.json")
    seen = {}
    real_dump = mail.json.dump

    def spy(obj, fh, **kw):
        seen["mode"] = stat.S_IMODE(os.fstat(fh.fileno()).st_mode)
        return real_dump(obj, fh, **kw)

    monkeypatch.setattr(mail.json, "dump", spy)
    mail._write_accounts([{**mail._DEFAULTS, "id": "abc", "username": "u", "password": "secret"}])

    assert seen["mode"] == 0o600, f"written through a {oct(seen['mode'])} handle"


def test_tls_context_verifies_certificate_and_hostname():
    # ssl._create_stdlib_context(), the imaplib/smtplib fallback, gives
    # CERT_NONE + check_hostname False -- which is what this replaced.
    assert mail._TLS.verify_mode is ssl.CERT_REQUIRED
    assert mail._TLS.check_hostname is True
