"""Mock API 内嵌启停的真实端口生命周期回归（缺陷回归守卫）。

背景：uvicorn 0.30+ 的 Server 已无 startup_error 属性，旧实现访问它会抛 AttributeError，
使 POST /api/mock-api/start 恒定返回 500（而服务其实已启动），端口被占用时也无法如实报错。
既有测试全部走进程内 TestClient，覆盖不到真实绑定路径——本文件用真实端口补齐该盲区。
"""
from __future__ import annotations

import asyncio
import socket

import pytest

import app  # noqa: E402  conftest 已把模拟器根目录加入 sys.path


def _free_port() -> int:
    """取一个当前空闲的端口（绑定 0 由 OS 分配后立即释放）。"""
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
        s.bind(("127.0.0.1", 0))
        return s.getsockname()[1]


@pytest.fixture()
def mock_port(monkeypatch):
    """把 mockApiPort 指向空闲端口；启停在用例内完成，夹具只复位全局句柄。"""
    port = _free_port()
    monkeypatch.setitem(app.CONFIG, "mockApiPort", port)
    yield port
    app.MOCK_HANDLE.server = None
    app.MOCK_HANDLE.task = None
    app.MOCK_HANDLE.last_error = ""


def test_start_binds_real_port_and_is_idempotent(mock_port):
    """启动成功须返回 running=true、端口真实可连通、重复调用幂等，且不抛异常（不再 500）。"""

    async def scenario():
        result = await app._start_mock_api()
        try:
            assert result["running"] is True, result
            assert result["port"] == mock_port
            assert app._mock_running() is True
            assert app.MOCK_HANDLE.last_error == ""
            # 端口必须真实可连通，不能只是内部状态为真
            with socket.create_connection(("127.0.0.1", mock_port), timeout=2):
                pass
            again = await app._start_mock_api()
            assert again.get("alreadyRunning") is True, again
        finally:
            await app._stop_mock_api()

    asyncio.run(scenario())
    assert app._mock_running() is False


def test_start_on_occupied_port_reports_error_not_raise(mock_port):
    """端口被占用须返回 {running:false, error} 并写入 lastError，而不是抛 AttributeError。"""
    blocker = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    blocker.bind(("127.0.0.1", mock_port))
    blocker.listen(1)

    async def scenario():
        try:
            return await app._start_mock_api()
        finally:
            blocker.close()

    result = asyncio.run(scenario())
    assert result["running"] is False, result
    assert str(mock_port) in result["error"]
    assert app.MOCK_HANDLE.last_error  # /api/status 的 lastError 诊断字段恢复有效
    assert app._mock_running() is False