# -*- coding: utf-8 -*-
"""auth_system 异步栈的读写并发验证：读不持锁、写仍串行（WAL）。"""
import asyncio
import sqlite3
import threading

import pytest

import auth_system


@pytest.fixture()
def temp_site(tmp_path, monkeypatch):
    monkeypatch.setattr(auth_system.db, 'DATA_DIR', tmp_path)
    monkeypatch.setattr(auth_system.db, 'DB_PATH', tmp_path / 'site.db')
    monkeypatch.setattr(auth_system.db, 'BACKUP_DIR', tmp_path / 'backups')
    monkeypatch.setattr(auth_system.db, 'SECRET_KEY_PATH', tmp_path / 'secret.key')
    asyncio.run(auth_system.init_db())
    return tmp_path / 'site.db'


def test_q_does_not_hold_lock(temp_site):
    """_q 读不应获取写锁（否则读会被写挡住）。"""

    async def _main():
        # 已在写锁内：读仍应立即返回（读路径不取写锁）
        async with auth_system.db._write_lock():
            rows = await auth_system._q('SELECT COUNT(*) AS n FROM users')
            assert rows is not None
            assert rows[0]['n'] >= 0

    asyncio.run(_main())


def test_concurrent_reads_and_writes(temp_site):
    """多读线程 + 一个写线程并发：无异常、结果一致。"""
    errors = []
    stop = threading.Event()

    def writer():
        try:
            for i in range(50):
                asyncio.run(auth_system.set_setting(f'k{i}', str(i)))
        except Exception as e:
            errors.append(('w', e))
        finally:
            stop.set()

    def reader():
        while not stop.is_set():
            try:
                asyncio.run(auth_system.get_setting('k0'))
            except Exception as e:
                errors.append(('r', e))

    ws = threading.Thread(target=writer, daemon=True)
    rs = [threading.Thread(target=reader, daemon=True) for _ in range(4)]
    ws.start()
    for r in rs:
        r.start()
    ws.join(20)
    for r in rs:
        r.join(2)

    assert not errors, f'并发读写异常: {errors[:3]}'
    assert asyncio.run(auth_system.get_setting('k49')) == '49'


def test_wal_enabled(temp_site):
    conn = sqlite3.connect(str(temp_site))
    try:
        mode = conn.execute('PRAGMA journal_mode').fetchone()[0]
    finally:
        conn.close()
    assert str(mode).lower() == 'wal'