import unittest

from core.dfp_sq0 import decode_sq0_string_fields, encode_sq0_device_info


class DfpSq0Tests(unittest.TestCase):
    def test_lite_encoding_preserves_known_tag_order(self):
        raw = encode_sq0_device_info({"k5": "a", "k14": "bc", "k113": "z"}, mode="lite")
        self.assertEqual(raw.hex(), "2a0161720262638a07017a")

        fields = decode_sq0_string_fields(raw)
        self.assertEqual(
            [(field["proto_tag"], field["value"]) for field in fields],
            [(5, "a"), (14, "bc"), (113, "z")],
        )

    def test_empty_values_are_not_encoded(self):
        raw = encode_sq0_device_info({"k5": "a", "k14": "", "k113": "z"}, mode="lite")
        fields = decode_sq0_string_fields(raw)
        self.assertEqual(
            [(field["proto_tag"], field["value"]) for field in fields],
            [(5, "a"), (113, "z")],
        )

    def test_unknown_key_is_rejected(self):
        with self.assertRaises(KeyError):
            encode_sq0_device_info({"k999": "x"}, mode="lite")


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