import tempfile
import unittest
from pathlib import Path
from audit_database import migration_manifest, compare_snapshots


class MigrationAuditTest(unittest.TestCase):
    def test_manifest_is_numerically_sorted_and_ignores_line_endings(self):
        with tempfile.TemporaryDirectory() as folder:
            root = Path(folder)
            (root / "V10__ten.sql").write_bytes(b"SELECT 10;\r\n")
            (root / "V2__two.sql").write_bytes(b"SELECT 2;\n")
            before = migration_manifest(root)
            self.assertEqual([2, 10], [r["version"] for r in before])
            (root / "V10__ten.sql").write_bytes(b"SELECT 10;\n")
            self.assertEqual(before, migration_manifest(root))
            (root / "V10__ten.sql").write_bytes(b"SELECT 11;\n")
            self.assertNotEqual(before, migration_manifest(root))

    def test_duplicate_versions_are_rejected(self):
        with tempfile.TemporaryDirectory() as folder:
            root = Path(folder)
            for name in ("V2__a.sql", "V2__b.sql"):
                (root / name).write_text("SELECT 1;", encoding="utf-8")
            with self.assertRaisesRegex(ValueError, "迁移版本重复"):
                migration_manifest(root)

    def test_structure_drift_is_detected_without_count_or_timestamp_noise(self):
        self.assertEqual([], compare_snapshots({"integrity": {"n": 1}}, {"integrity": {"n": 0}}))
        self.assertEqual(["indexes"], compare_snapshots({"indexes": []}, {"indexes": ["new"]}))


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