import pytest
from unittest.mock import patch
from jianda_proxy.daemon import (
    read_pid,
    write_pid,
    remove_pid,
    is_process_alive,
    is_running,
    stop_daemon,
    get_status,
)


class TestPidFile:
    def test_write_and_read_pid(self, tmp_path, monkeypatch):
        pid_file = str(tmp_path / "test.pid")
        monkeypatch.setattr("jianda_proxy.daemon.get_pid_path", lambda: pid_file)
        write_pid(12345)
        assert read_pid() == 12345

    def test_read_missing_pid_returns_none(self, tmp_path, monkeypatch):
        pid_file = str(tmp_path / "nonexistent.pid")
        monkeypatch.setattr("jianda_proxy.daemon.get_pid_path", lambda: pid_file)
        assert read_pid() is None

    def test_remove_pid(self, tmp_path, monkeypatch):
        pid_file = str(tmp_path / "test.pid")
        monkeypatch.setattr("jianda_proxy.daemon.get_pid_path", lambda: pid_file)
        write_pid(12345)
        remove_pid()
        assert read_pid() is None


class TestProcessCheck:
    @patch("os.kill")
    def test_alive_on_unix(self, mock_kill):
        mock_kill.return_value = None
        assert is_process_alive(12345) is True

    @patch("os.kill", side_effect=ProcessLookupError)
    def test_dead_on_unix(self, mock_kill):
        assert is_process_alive(12345) is False

    @patch("os.kill", side_effect=PermissionError)
    def test_permission_means_alive(self, mock_kill):
        assert is_process_alive(12345) is True


class TestIsRunning:
    @patch("jianda_proxy.daemon.is_process_alive", return_value=True)
    @patch("jianda_proxy.daemon.read_pid", return_value=12345)
    def test_running_when_pid_and_alive(self, mock_read, mock_alive):
        assert is_running() is True

    @patch("jianda_proxy.daemon.is_process_alive", return_value=False)
    @patch("jianda_proxy.daemon.read_pid", return_value=12345)
    def test_not_running_when_pid_dead(self, mock_read, mock_alive):
        assert is_running() is False

    @patch("jianda_proxy.daemon.read_pid", return_value=None)
    def test_not_running_when_no_pid(self, mock_read):
        assert is_running() is False


class TestStopDaemon:
    @patch("jianda_proxy.daemon.is_process_alive", return_value=True)
    @patch("jianda_proxy.daemon.read_pid", return_value=12345)
    @patch("time.sleep")
    @patch("os.kill")
    def test_stop_sends_sigterm(self, mock_kill, mock_sleep, mock_read, mock_alive):
        mock_alive.side_effect = [True, False]
        stop_daemon()
        mock_kill.assert_called_once_with(12345, 15)  # SIGTERM=15

    @patch("jianda_proxy.daemon.remove_pid")
    @patch("jianda_proxy.daemon.is_process_alive", return_value=False)
    @patch("jianda_proxy.daemon.read_pid", return_value=None)
    def test_stop_noop_when_not_running(self, mock_read, mock_alive, mock_remove):
        result = stop_daemon()
        assert result == "not_running"


class TestGetStatus:
    @patch("jianda_proxy.daemon.is_process_alive", return_value=True)
    @patch("jianda_proxy.daemon.read_pid", return_value=12345)
    def test_status_running(self, mock_read, mock_alive):
        status = get_status()
        assert status["running"] is True
        assert status["pid"] == 12345

    @patch("jianda_proxy.daemon.read_pid", return_value=None)
    def test_status_not_running(self, mock_read):
        status = get_status()
        assert status["running"] is False