import os
import tempfile
import unittest
from pathlib import Path

from bfos.identity import identity_for, read_dealer_id, validate_dealer_id
from bfos.preferences import load_preferences, save_dealer


class IdentityContractTests(unittest.TestCase):
    def test_only_eight_digits_are_valid(self):
        self.assertTrue(validate_dealer_id("12345678"))
        for value in ("1234567", "123456789", "1234abcd", ""):
            self.assertFalse(validate_dealer_id(value))

    def test_derived_identity_is_deterministic(self):
        self.assertEqual(
            identity_for("12345678"),
            {
                "dealer_id": "12345678",
                "username": "bf-12345678",
                "hostname": "bf-12345678",
                "device_id": "BF-12345678",
                "active_user": "bf-12345678",
            },
        )

    def test_preferences_use_write_once_dealer_file(self):
        with tempfile.TemporaryDirectory() as directory:
            path = Path(directory) / "dealer-id"
            os.environ["BF_DEALER_ID_FILE"] = str(path)
            try:
                self.assertEqual(save_dealer("12345678")["username"], "bf-12345678")
                self.assertEqual(read_dealer_id(path), "12345678")
                with self.assertRaises(PermissionError):
                    save_dealer("87654321")
                self.assertEqual(load_preferences()["active_user"], "bf-12345678")
            finally:
                os.environ.pop("BF_DEALER_ID_FILE", None)


if __name__ == "__main__":
    unittest.main()