import importlib.util
import pathlib
import subprocess
import tempfile
import unittest

ROOT = pathlib.Path(__file__).resolve().parents[1]
SPEC = importlib.util.spec_from_file_location("exporter", ROOT / "tools/export-private-modules.py")
MODULE = importlib.util.module_from_spec(SPEC)
SPEC.loader.exec_module(MODULE)


class ExportTest(unittest.TestCase):
    def test_committed_bytes_and_provenance_are_exact(self):
        with tempfile.TemporaryDirectory() as temporary:
            base = pathlib.Path(temporary)
            source, target = base / "source", base / "target"
            source.mkdir()
            target.mkdir()
            subprocess.run(["git", "init", "-q", str(source)], check=True)
            for path in MODULE.FILES:
                file = source / path
                file.parent.mkdir(parents=True, exist_ok=True)
                file.write_text("package main\n")
            subprocess.run(["git", "-C", str(source), "add", "."], check=True)
            subprocess.run(["git", "-C", str(source), "-c", "user.name=Fixture",
                            "-c", "user.email=fixture@example.invalid", "commit", "-qm", "fixture"], check=True)
            revision = MODULE.committed(source, "rev-parse", "HEAD").decode().strip()
            (source / next(iter(MODULE.FILES))).write_text("dirty worktree must be ignored")
            MODULE.export(source, target, revision)
            MODULE.export(source, target, revision, True)
            subprocess.run(["sha256sum", "-c", "tools/private-modules.sha256"],
                           cwd=target, check=True, stdout=subprocess.DEVNULL)
            destination = target / "tools/private-modules.go"
            self.assertEqual(destination.read_text(), "package main\n")
            destination.write_text("changed")
            with self.assertRaises(ValueError):
                MODULE.export(source, target, revision, True)
            destination.unlink()
            destination.symlink_to(source / next(iter(MODULE.FILES)))
            with self.assertRaises(ValueError):
                MODULE.export(source, target, revision)
            with self.assertRaises(ValueError):
                MODULE.export(source, target, "HEAD")


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