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

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


class InstallerTests(unittest.TestCase):
    def setUp(self):
        self.temp = tempfile.TemporaryDirectory()
        self.addCleanup(self.temp.cleanup)
        self.home = Path(self.temp.name) / "codex-home"
        self.home.mkdir()

    def test_preview_never_writes(self):
        result = installer.install(ROOT, self.home, include_prompt=True)
        self.assertTrue(result["changed_paths"])
        self.assertFalse(result["applied"])
        self.assertEqual(list(self.home.iterdir()), [])

    def test_apply_preserves_user_files_and_backs_up(self):
        prompt = self.home / "AGENTS.md"
        prompt.write_text("user prompt\n")
        config = self.home / "config.toml"
        config.write_text('model = "user-selected"\n')
        skill = self.home / "skills/codex-subagent-router"
        skill.mkdir(parents=True)
        custom = skill / "custom.md"
        custom.write_text("local extension")
        result = installer.install(ROOT, self.home, include_prompt=True, apply=True)
        self.assertEqual((Path(result["backup"]) / "AGENTS.md").read_text(), "user prompt\n")
        self.assertEqual(config.read_text(), 'model = "user-selected"\n')
        self.assertEqual(custom.read_text(), "local extension")
        self.assertEqual(prompt.read_bytes(), (ROOT / "prompts/AGENTS.md").read_bytes())
        again = installer.install(ROOT, self.home, include_prompt=True, apply=True)
        self.assertEqual(again["changed_paths"], [])
        self.assertIsNone(again["backup"])

    def test_skill_only_does_not_replace_global_prompt(self):
        prompt = self.home / "AGENTS.md"
        prompt.write_text("keep")
        installer.install(ROOT, self.home, apply=True)
        self.assertEqual(prompt.read_text(), "keep")

    def test_symlink_target_is_rejected(self):
        outside = Path(self.temp.name) / "outside"
        outside.mkdir()
        (self.home / "skills").symlink_to(outside, target_is_directory=True)
        with self.assertRaisesRegex(ValueError, "symlink"):
            installer.install(ROOT, self.home, apply=True)
        self.assertEqual(list(outside.iterdir()), [])

    def test_conflicting_directory_is_rejected_before_writes(self):
        (self.home / "AGENTS.md").mkdir()
        with self.assertRaisesRegex(ValueError, "regular file"):
            installer.install(ROOT, self.home, include_prompt=True, apply=True)
        self.assertFalse((self.home / "skills").exists())


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