"""浏览器池 driver 断链自动恢复逻辑的单元测试（不启动真实 Chromium）。

覆盖本次修复的核心：
- is_disconnect_error 对 WriteUnixTransport "the handler is closed" 等断链错误的识别
- _run_with_reconnect 在断链后重建一次并重试成功
- _browser_generation 守卫：并发下他人已重建时不重复重建
"""
from __future__ import annotations

import pytest

from app.core.config import Settings
from app.services.browser_pool import BrowserPool


class _FakeBrowser:
    def __init__(self, connected: bool = True):
        self._connected = connected

    def is_connected(self) -> bool:
        return self._connected


def _make_pool(**overrides) -> BrowserPool:
    settings = Settings(**overrides)
    pool = BrowserPool(settings)
    pool._browser = _FakeBrowser()
    pool._started = True
    pool._browser_generation = 1
    return pool


# 复现线上崩溃日志里的真实报错文本
_HANDLER_CLOSED = (
    "Stealth.hooked_new_context_async: unable to perform operation on "
    "<WriteUnixTransport closed=True reading=False 0x7f9a27185a40>; the handler is closed"
)


def test_is_disconnect_error_recognizes_closed_transport():
    assert BrowserPool.is_disconnect_error(RuntimeError(_HANDLER_CLOSED)) is True
    assert BrowserPool.is_disconnect_error(Exception("connection closed")) is True
    # 业务异常不应被误判为断链
    assert BrowserPool.is_disconnect_error(ValueError("invalid selector")) is False


@pytest.mark.asyncio
async def test_run_with_reconnect_rebuilds_then_retries(monkeypatch):
    """首次因断链失败 → 重建一次 → 第二次成功。"""
    pool = _make_pool()
    rebuilt: list[str] = []

    async def fake_restart(reason, *, observed_generation=None):
        rebuilt.append(reason)
        pool._browser_generation += 1  # 模拟 start() 自增代次

    monkeypatch.setattr(pool, "_restart_browser", fake_restart)

    attempts = {"n": 0}

    async def factory():
        attempts["n"] += 1
        if attempts["n"] == 1:
            raise RuntimeError(_HANDLER_CLOSED)
        return "ok"

    result = await pool._run_with_reconnect(factory, "测试操作")

    assert result == "ok"
    assert attempts["n"] == 2
    assert len(rebuilt) == 1


@pytest.mark.asyncio
async def test_run_with_reconnect_gives_up_after_one_retry(monkeypatch):
    """连续两次断链：只重试一次，第二次仍失败则抛出。"""
    pool = _make_pool()

    async def fake_restart(reason, *, observed_generation=None):
        pool._browser_generation += 1

    monkeypatch.setattr(pool, "_restart_browser", fake_restart)

    attempts = {"n": 0}

    async def factory():
        attempts["n"] += 1
        raise RuntimeError(_HANDLER_CLOSED)

    with pytest.raises(RuntimeError):
        await pool._run_with_reconnect(factory, "测试操作")

    assert attempts["n"] == 2  # 初次 + 一次重试


@pytest.mark.asyncio
async def test_run_with_reconnect_passes_through_non_disconnect(monkeypatch):
    """非断链异常不触发重建，直接抛出。"""
    pool = _make_pool()
    rebuilt: list[str] = []

    async def fake_restart(reason, *, observed_generation=None):
        rebuilt.append(reason)

    monkeypatch.setattr(pool, "_restart_browser", fake_restart)

    async def factory():
        raise ValueError("业务错误")

    with pytest.raises(ValueError):
        await pool._run_with_reconnect(factory, "测试操作")

    assert rebuilt == []


@pytest.mark.asyncio
async def test_restart_browser_skips_when_generation_changed():
    """持锁后代次已变化（他人已重建）→ 直接返回，不重复重建。"""
    pool = _make_pool()

    closed: list[str] = []

    async def fake_close():
        closed.append("close")

    pool.close = fake_close  # type: ignore[method-assign]

    # 调用方观察到的是旧代次，而当前代次已被他人推进
    await pool._restart_browser("stale", observed_generation=pool._browser_generation - 1)

    assert closed == []  # 未触发关闭/重建


@pytest.mark.asyncio
async def test_open_context_and_page_closes_context_on_page_failure(monkeypatch):
    """页面创建失败时关闭半开上下文，避免泄漏。"""
    pool = _make_pool()

    class _Ctx:
        def __init__(self):
            self.closed = False

        async def new_page(self):
            raise RuntimeError("new_page boom")

    ctx = _Ctx()

    async def fake_new_context_raw(storage_state):
        return ctx

    closed: list[object] = []

    async def fake_close_context(c):
        closed.append(c)

    monkeypatch.setattr(pool, "_new_context_raw", fake_new_context_raw)
    monkeypatch.setattr(pool, "close_context", fake_close_context)

    with pytest.raises(RuntimeError, match="new_page boom"):
        await pool._open_context_and_page(None)

    assert closed == [ctx]