"""Real Git migration regression; no network, user settings or player data."""
import importlib.util
import os
from pathlib import Path
import subprocess
import tempfile
import unittest
from unittest.mock import patch

SPEC = importlib.util.spec_from_file_location("airdef_build", Path(__file__).with_name("airdef.py"))
airdef = importlib.util.module_from_spec(SPEC)
SPEC.loader.exec_module(airdef)


def git(at, *args):
    return subprocess.check_output(["git", "-C", str(at), *args], text=True, stderr=subprocess.STDOUT).strip()


def init(at):
    at.mkdir()
    git(at, "init", "-q")
    git(at, "config", "user.name", "Test")
    git(at, "config", "user.email", "test@example.invalid")


def commit(at, text):
    (at / "engine.txt").write_text(text)
    git(at, "add", "engine.txt")
    git(at, "commit", "-qm", text)
    return git(at, "rev-parse", "HEAD")


class ForkMigrationTests(unittest.TestCase):
    def test_stale_local_url_is_synced_before_fetching_new_pin(self):
        with tempfile.TemporaryDirectory(prefix="airdef-fork-test-") as tmp, patch.dict(os.environ, {"GIT_ALLOW_PROTOCOL": "file"}):
            root = Path(tmp)
            source, parent = root / "source", root / "airdef"
            init(source)
            old = commit(source, "old")
            canonical = root / "canonical.git"
            git(root, "clone", "--bare", str(source), str(canonical))
            init(parent)
            git(parent, "submodule", "add", str(canonical), "horizon")
            child = parent / "horizon"
            new = commit(source, "new-fork-only-pin")
            git(source, "push", str(canonical), "HEAD")
            git(parent, "update-index", "--cacheinfo", f"160000,{new},horizon")
            stale = str(root / "missing-upstream.git")
            git(parent, "config", "submodule.horizon.url", stale)
            git(child, "remote", "set-url", "origin", stale)
            self.assertEqual(git(child, "rev-parse", "HEAD"), old)
            with patch.object(airdef, "ROOT", parent), patch.object(airdef, "FORK", child):
                airdef.fork()
                self.assertEqual(git(child, "rev-parse", "HEAD"), new)
                self.assertEqual(git(child, "remote", "get-url", "origin"), str(canonical))
                # The fast path must also repair stale configuration for the next update.
                git(child, "remote", "set-url", "origin", stale)
                airdef.fork()
                self.assertEqual(git(child, "remote", "get-url", "origin"), str(canonical))


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