import unittest

from db import build_pg_config


class DatabaseConfigTests(unittest.TestCase):
    def test_complete_config_is_parsed(self):
        config = build_pg_config(
            {
                "PG_HOST": "db.example.test",
                "PG_PORT": "5544",
                "PG_DB": "warehouse",
                "PG_USER": "collector",
                "PG_PASSWORD": "secret",
            }
        )

        self.assertEqual(
            config,
            {
                "host": "db.example.test",
                "port": 5544,
                "dbname": "warehouse",
                "user": "collector",
                "password": "secret",
            },
        )

    def test_missing_final_config_is_rejected(self):
        with self.assertRaisesRegex(RuntimeError, "PG_HOST"):
            build_pg_config(
                {
                    "PG_PORT": "5432",
                    "PG_DB": "warehouse",
                    "PG_USER": "collector",
                    "PG_PASSWORD": "secret",
                }
            )


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