from __future__ import annotations

import importlib.util
from pathlib import Path
import sys
import tempfile
import unittest


ROOT = Path(__file__).resolve().parents[1]
SCRIPT = ROOT / "scripts" / "release-migration-audit.py"


def load_audit_module():
    spec = importlib.util.spec_from_file_location("release_migration_audit", SCRIPT)
    if spec is None or spec.loader is None:
        raise RuntimeError(f"Could not load {SCRIPT}")
    module = importlib.util.module_from_spec(spec)
    sys.modules[spec.name] = module
    spec.loader.exec_module(module)
    return module


class ReleaseMigrationAuditTests(unittest.TestCase):
    def test_typed_alembic_variables_are_parsed(self) -> None:
        audit = load_audit_module()
        with tempfile.TemporaryDirectory(prefix="migration-audit-test-") as directory:
            path = Path(directory) / "1234_example.py"
            path.write_text(
                """
from __future__ import annotations
from typing import Sequence, Union

revision: str = "1234"
down_revision: Union[str, None] = "base"
branch_labels: Union[str, Sequence[str], None] = None
""",
                encoding="utf-8",
            )

            migration = audit.parse_migration_file("govoplan-core", path)

        self.assertIsNotNone(migration)
        self.assertEqual(migration.revision, "1234")
        self.assertEqual(migration.down_revisions, ("base",))
        self.assertEqual(migration.branch_labels, ())

    def test_release_baseline_matches_current_heads_in_strict_report(self) -> None:
        audit = load_audit_module()
        migrations = [
            audit.Migration("govoplan-core", Path("base.py"), "base", (), ()),
            audit.Migration("govoplan-core", Path("head.py"), "head", ("base",), ()),
        ]
        report = audit.build_report(
            migrations,
            baseline={
                "version": 1,
                "releases": [
                    {
                        "release": "0.1.0",
                        "heads": [{"owner": "govoplan-core", "revision": "head"}],
                    }
                ],
            },
            baseline_file=Path("docs/migration-release-baselines.json"),
            workspace_root=Path("/workspace"),
        )

        self.assertEqual(report["current_heads"], ["head"])
        self.assertEqual(report["graph_errors"], [])
        self.assertEqual(report["strict_errors"], [])

    def test_owner_heads_are_accepted_for_subset_installs(self) -> None:
        audit = load_audit_module()
        migrations = [
            audit.Migration("govoplan-core", Path("base.py"), "base", (), ()),
            audit.Migration("govoplan-core", Path("core_head.py"), "core-head", ("base",), ()),
        ]
        report = audit.build_report(
            migrations,
            baseline={
                "version": 1,
                "releases": [
                    {
                        "release": "0.1.0",
                        "heads": [{"owner": "govoplan-files", "revision": "files-head"}],
                        "owner_heads": [{"owner": "govoplan-core", "revisions": ["core-head"]}],
                    }
                ],
            },
            baseline_file=Path("docs/migration-release-baselines.json"),
            workspace_root=Path("/workspace"),
        )

        self.assertEqual(report["current_heads"], ["core-head"])
        self.assertEqual(report["strict_errors"], [])

    def test_records_current_release_baseline(self) -> None:
        audit = load_audit_module()
        migrations = [
            audit.Migration("govoplan-core", Path("base.py"), "base", (), ()),
            audit.Migration("govoplan-core", Path("core_head.py"), "core-head", ("base",), ()),
            audit.Migration("govoplan-files", Path("files_head.py"), "files-head", ("core-head",), ()),
        ]
        report = audit.build_report(
            migrations,
            baseline={"version": 1, "releases": []},
            baseline_file=Path("docs/migration-release-baselines.json"),
            workspace_root=Path("/workspace"),
        )

        baseline = audit.record_release_baseline(
            {"version": 1, "releases": []},
            report,
            release="0.2.0",
            replace=False,
        )

        release = baseline["releases"][0]
        self.assertEqual(release["release"], "0.2.0")
        self.assertEqual(release["squash_policy"], "reviewed-manual")
        self.assertEqual(release["heads"], [{"owner": "govoplan-files", "revision": "files-head"}])
        self.assertIn({"owner": "govoplan-core", "revisions": ["core-head"]}, release["owner_heads"])

    def test_missing_down_revision_is_a_graph_error(self) -> None:
        audit = load_audit_module()
        migrations = [
            audit.Migration("govoplan-core", Path("head.py"), "head", ("missing",), ()),
        ]
        report = audit.build_report(
            migrations,
            baseline={"version": 1, "releases": []},
            baseline_file=Path("docs/migration-release-baselines.json"),
            workspace_root=Path("/workspace"),
        )

        self.assertIn("references missing down_revision", report["graph_errors"][0])


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