import hashlib
import importlib.util
import json
from pathlib import Path
import tempfile
import unittest


ROOT = Path(__file__).resolve().parents[1]
spec = importlib.util.spec_from_file_location(
    "verify_source_package", ROOT / "deploy" / "verify_source_package.py"
)
verify_source_package = importlib.util.module_from_spec(spec)
spec.loader.exec_module(verify_source_package)


COMMIT = "a" * 40
VERSION = "0.2.1"


class VerifySourcePackageTests(unittest.TestCase):
    def fixture(self, directory: str):
        root = Path(directory)
        archive = root / "GuestOps-0.2.1-aaaaaaaaaaaa.tar.gz"
        record = root / "GuestOps-0.2.1-aaaaaaaaaaaa.source.json"
        archive.write_bytes(b"committed source package")
        payload = {
            "artifact": {
                "name": archive.name,
                "sha256": hashlib.sha256(archive.read_bytes()).hexdigest(),
                "size": archive.stat().st_size,
            },
            "commit": COMMIT,
            "schemaVersion": 1,
            "version": VERSION,
        }
        record.write_text(json.dumps(payload), encoding="utf-8")
        return archive, record, payload

    def test_verifies_archive_record_and_expected_identity(self):
        with tempfile.TemporaryDirectory() as directory:
            archive, record, _ = self.fixture(directory)
            result = verify_source_package.validate(archive, record, COMMIT, VERSION)
            self.assertTrue(result["verified"])
            self.assertEqual(result["commit"], COMMIT)
            self.assertEqual(result["artifact"]["sha256"], hashlib.sha256(archive.read_bytes()).hexdigest())
            self.assertEqual(result["sourceRecord"]["sha256"], hashlib.sha256(record.read_bytes()).hexdigest())

    def test_rejects_changed_archive(self):
        with tempfile.TemporaryDirectory() as directory:
            archive, record, _ = self.fixture(directory)
            archive.write_bytes(b"changed source package")
            with self.assertRaisesRegex(ValueError, "size does not match"):
                verify_source_package.validate(archive, record, COMMIT, VERSION)

    def test_rejects_wrong_commit_version_and_filename(self):
        cases = [
            (lambda value: value.update(commit="b" * 40), "commit does not match"),
            (lambda value: value.update(version="0.3.0"), "version does not match"),
            (lambda value: value["artifact"].update(name="other.tar.gz"), "filename does not match"),
        ]
        for mutate, message in cases:
            with self.subTest(message=message), tempfile.TemporaryDirectory() as directory:
                archive, record, payload = self.fixture(directory)
                mutate(payload)
                record.write_text(json.dumps(payload), encoding="utf-8")
                with self.assertRaisesRegex(ValueError, message):
                    verify_source_package.validate(archive, record, COMMIT, VERSION)


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