from __future__ import annotations

import hashlib
import json
import tempfile
import unittest
from pathlib import Path

from vpn_egressctl.errors import ValidationError
from vpn_egressctl.installcheck import verify_install_state


class InstallCheckTests(unittest.TestCase):
    def test_empty_install_root_is_allowed(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            verify_install_state(root / "policy.json", root / "state", root / "config.json")

    def test_legacy_policy_is_rejected_instead_of_migrated(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            raw = json.loads(Path("config/policy.json").read_text(encoding="utf-8"))
            raw["sing_box"]["required_version"] = "1.13.19"
            policy = root / "policy.json"
            policy.write_text(json.dumps(raw), encoding="utf-8")
            with self.assertRaisesRegex(ValidationError, "exactly 1.14.0"):
                verify_install_state(policy, root / "state", root / "config.json")

    def test_legacy_state_is_rejected(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            state_dir = root / "state"
            state_dir.mkdir()
            (state_dir / "state.json").write_text(
                json.dumps({"controller_version": "0.1.0"}), encoding="utf-8"
            )
            with self.assertRaisesRegex(ValidationError, "another vpn-egressctl release"):
                verify_install_state(root / "policy.json", state_dir, root / "config.json")

    def test_unmanaged_existing_config_is_rejected(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            config = root / "config.json"
            config.write_text("{}\n", encoding="utf-8")
            with self.assertRaisesRegex(ValidationError, "unmanaged"):
                verify_install_state(root / "policy.json", root / "state", config)

    def test_orphaned_legacy_backup_is_rejected(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            state_dir = root / "state"
            state_dir.mkdir()
            (state_dir / "last-good.json").write_text("{}\n", encoding="utf-8")
            with self.assertRaisesRegex(ValidationError, "Orphaned"):
                verify_install_state(root / "policy.json", state_dir, root / "config.json")

    def test_same_release_state_and_config_are_allowed(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            config = root / "config.json"
            config.write_bytes(b"{}\n")
            state_dir = root / "state"
            state_dir.mkdir()
            (state_dir / "state.json").write_text(
                json.dumps(
                    {
                        "controller_version": "0.2.0",
                        "sing_box_version": "1.14.0",
                        "config_sha256": hashlib.sha256(b"{}\n").hexdigest(),
                    }
                ),
                encoding="utf-8",
            )
            verify_install_state(root / "policy.json", state_dir, config)


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