from __future__ import annotations

import json
import tempfile
import unittest
from pathlib import Path

from vpn_egressctl.errors import ApplyError, UnsupportedVersionError, ValidationError
from vpn_egressctl.renderer_1_13_19 import render_bytes
from vpn_egressctl.transaction import Controller
from vpn_egressctl.uri import parse_hysteria2_uri

from tests.helpers import FakeResponse, FakeRunner, VERSION_OUTPUT, make_policy


OLD_CONFIG = b'{"log":{"level":"error"}}\n'
URI_OLD = "hysteria2://OLD@example.com:443/?obfs=salamander&obfs-password=OLDOBFS"
URI_NEW = "hysteria2://NEW@example.com:443/?obfs=salamander&obfs-password=NEWOBFS"


class TransactionTests(unittest.TestCase):
    def make(self, directory: str, *, runner: FakeRunner | None = None) -> tuple[Controller, FakeRunner, object]:
        root = Path(directory)
        policy = make_policy(root)
        Path(policy.sing_box.config_path).parent.mkdir(parents=True)
        Path(policy.runtime.uri_path).write_text(URI_NEW + "\n", encoding="utf-8")
        selected = runner or FakeRunner()
        controller = Controller(
            policy,
            runner=selected,
            urlopen=lambda *args, **kwargs: FakeResponse(),
            sleeper=lambda _: None,
        )
        return controller, selected, policy

    def test_sync_applies_and_records_last_good(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            controller, runner, policy = self.make(directory)
            Path(policy.sing_box.config_path).write_bytes(OLD_CONFIG)
            changed = controller.sync()
            self.assertTrue(changed)
            installed = Path(policy.sing_box.config_path).read_bytes()
            self.assertIn(b'"password": "NEW"', installed)
            self.assertEqual(controller.last_good_path.read_bytes(), OLD_CONFIG)
            state_text = controller.state_path.read_text(encoding="utf-8")
            self.assertNotIn("NEWOBFS", state_text)
            self.assertNotIn('"NEW"', state_text)
            self.assertEqual(json.loads(state_text)["status"], "ok")
            self.assertTrue(any("restart" in call for call in runner.calls))

    def test_no_change_does_not_restart(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            controller, runner, policy = self.make(directory)
            endpoint = parse_hysteria2_uri(URI_NEW)
            Path(policy.sing_box.config_path).write_bytes(render_bytes(policy, endpoint))
            self.assertFalse(controller.sync())
            self.assertFalse(any("restart" in call for call in runner.calls))
            self.assertFalse(json.loads(controller.state_path.read_text())["changed"])

    def test_generated_config_rejection_is_non_mutating(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            controller, _, policy = self.make(directory, runner=FakeRunner(check_result=1))
            Path(policy.sing_box.config_path).write_bytes(OLD_CONFIG)
            with self.assertRaises(ValidationError):
                controller.sync()
            self.assertEqual(Path(policy.sing_box.config_path).read_bytes(), OLD_CONFIG)

    def test_version_gate_is_non_mutating(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            output = VERSION_OUTPUT.replace("1.13.19", "1.13.12", 1)
            controller, _, policy = self.make(directory, runner=FakeRunner(version=output))
            Path(policy.sing_box.config_path).write_bytes(OLD_CONFIG)
            with self.assertRaises(UnsupportedVersionError):
                controller.sync()
            self.assertEqual(Path(policy.sing_box.config_path).read_bytes(), OLD_CONFIG)

    def test_restart_failure_restores_config(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            runner = FakeRunner(restart_results=[1, 0])
            controller, _, policy = self.make(directory, runner=runner)
            Path(policy.sing_box.config_path).write_bytes(OLD_CONFIG)
            with self.assertRaises(ApplyError) as caught:
                controller.sync()
            self.assertTrue(caught.exception.rollback_ok)
            self.assertEqual(Path(policy.sing_box.config_path).read_bytes(), OLD_CONFIG)
            self.assertEqual(json.loads(controller.state_path.read_text())["status"], "apply_failed_rolled_back")

    def test_import_failure_restores_uri_and_config(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            runner = FakeRunner(restart_results=[1, 0])
            controller, _, policy = self.make(directory, runner=runner)
            Path(policy.runtime.uri_path).write_text(URI_OLD + "\n", encoding="utf-8")
            Path(policy.sing_box.config_path).write_bytes(OLD_CONFIG)
            with self.assertRaises(ApplyError):
                controller.import_uri(URI_NEW)
            self.assertEqual(Path(policy.runtime.uri_path).read_text().strip(), URI_OLD)
            self.assertEqual(Path(policy.sing_box.config_path).read_bytes(), OLD_CONFIG)

    def test_import_validation_does_not_store_uri(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            controller, _, policy = self.make(directory)
            Path(policy.runtime.uri_path).write_text(URI_OLD + "\n", encoding="utf-8")
            with self.assertRaises(ValidationError):
                controller.import_uri("hysteria2://secret@example.com?unknown=x")
            self.assertEqual(Path(policy.runtime.uri_path).read_text().strip(), URI_OLD)

    def test_manual_rollback_swaps_current_and_last_good(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            controller, _, policy = self.make(directory)
            current = render_bytes(policy, parse_hysteria2_uri(URI_NEW))
            previous = render_bytes(policy, parse_hysteria2_uri(URI_OLD))
            Path(policy.sing_box.config_path).write_bytes(current)
            controller.state_dir.mkdir(parents=True)
            controller.last_good_path.write_bytes(previous)
            controller.rollback()
            self.assertEqual(Path(policy.sing_box.config_path).read_bytes(), previous)
            self.assertEqual(controller.last_good_path.read_bytes(), current)
            self.assertEqual(json.loads(controller.state_path.read_text())["status"], "rolled_back")
            status = controller.status()
            self.assertEqual(status["status"], "rolled_back")
            self.assertFalse(status["source_drift"])

    def test_diff_never_contains_secrets(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            controller, _, policy = self.make(directory)
            Path(policy.sing_box.config_path).write_bytes(OLD_CONFIG)
            output = "\n".join(controller.diff())
            self.assertNotIn("NEWOBFS", output)
            self.assertNotIn('"NEW"', output)
            self.assertIn("REDACTED", output)

    def test_status_detects_source_drift(self) -> None:
        with tempfile.TemporaryDirectory() as directory:
            controller, _, policy = self.make(directory)
            endpoint = parse_hysteria2_uri(URI_NEW)
            Path(policy.sing_box.config_path).write_bytes(render_bytes(policy, endpoint))
            controller.sync()
            Path(policy.runtime.uri_path).write_text(URI_OLD + "\n", encoding="utf-8")
            status = controller.status()
            self.assertTrue(status["source_drift"])


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