import importlib.util
import pathlib
import os
import json
import subprocess
import tempfile
import unittest
import zipfile

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_native_go_archive_excludes_nested_build_artifacts(self):
        with tempfile.TemporaryDirectory() as temporary:
            root = pathlib.Path(temporary)
            source = root / "source"
            source.mkdir()
            module = "example.invalid/fixture.git"
            (source / "go.mod").write_text("module " + module + "\n\ngo 1.27.0\n")
            (source / "provider.go").write_text("package fixture\n")
            boundary = source / "third_party/go-proxy"
            boundary.mkdir(parents=True)
            (boundary / "go.mod").write_text("module example.invalid/build-artifacts\n\ngo 1.27.0\n")
            (boundary / "provider.zip").write_bytes(b"must not enter the provider module archive")
            subprocess.run(["git", "init", "-q", str(source)], check=True)
            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)
            subprocess.run(["git", "-C", str(source), "tag", "v0.1.0"], check=True)
            config = root / "gitconfig"
            config.write_text('[url "' + source.as_uri() + '"]\n'
                              '\tinsteadOf = https://example.invalid/fixture\n')
            # Let Go select the synthetic VCS URL; Git still permits only the
            # rewritten local file protocol, with no network scheme allowed.
            env = dict(os.environ, GO111MODULE="on", GOTOOLCHAIN="local", GOFLAGS="", GOWORK="off",
                       GOPROXY="direct", GONOPROXY="none", GOSUMDB="off", GOVCS="*:git",
                       GOINSECURE="example.invalid",
                       GOMODCACHE=str(root / "cache"), GIT_CONFIG_GLOBAL=str(config),
                       GIT_CONFIG_NOSYSTEM="1", GIT_CONFIG_COUNT="0", GIT_ALLOW_PROTOCOL="file")
            probe = subprocess.run(["git", "ls-remote", "https://example.invalid/fixture"], env=env, capture_output=True)
            self.assertEqual(probe.returncode, 0, probe.stderr.decode())
            # Native Git accepts only the local file protocol: a missed rewrite
            # cannot turn this proof into a network or credential lookup.
            result = subprocess.run(["go", "mod", "download", "-json", module + "@v0.1.0"],
                                    cwd=root, env=env, capture_output=True)
            self.assertEqual(result.returncode, 0, result.stdout.decode() + result.stderr.decode())
            archive = json.loads(result.stdout)["Zip"]
            with zipfile.ZipFile(archive) as zipped:
                names = zipped.namelist()
            self.assertIn(module + "@v0.1.0/provider.go", names)
            self.assertFalse(any("third_party/go-proxy" in name for name in names))

    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()