"""utils/captcha.py 验证码校验：原子消费（get→del→compare）杜绝重放与无限试错。

fakeredis 不支持 Lua eval，这里用 Python 复刻 Lua 语义（原子 get→del→compare，
无论对错都消费验证码）作为 fake，验证业务层行为；另断言生产代码确实调用
_CAPTCHA_VERIFY_LUA 脚本。
"""
import pytest
import fakeredis.aioredis


@pytest.fixture
def _captcha_redis(monkeypatch):
    from core import redis_client as rc

    redis = fakeredis.aioredis.FakeRedis(decode_responses=True)

    async def fake_eval(script, numkeys, key, user_input):
        # 复刻 _CAPTCHA_VERIFY_LUA 语义：原子 get→del→compare，无论对错都消费
        stored = await redis.get(key)
        if not stored:
            return 0
        await redis.delete(key)
        if str(stored).upper().strip() == str(user_input).upper().strip():
            return 1
        return 0

    monkeypatch.setattr(redis, 'eval', fake_eval)
    monkeypatch.setattr(rc, 'get_redis', lambda: redis)
    return redis


@pytest.mark.asyncio
async def test_verify_captcha_correct_then_consumed(_captcha_redis):
    from utils.captcha import verify_captcha

    await _captcha_redis.set('k1', 'Ab3X')
    # 大小写不敏感比较通过
    assert await verify_captcha('k1', 'ab3x') is True
    # 已消费：同一验证码无法再次使用（防重放）
    assert await verify_captcha('k1', 'Ab3X') is False


@pytest.mark.asyncio
async def test_verify_captcha_wrong_input_burns_captcha(_captcha_redis):
    from utils.captcha import verify_captcha

    await _captcha_redis.set('k2', 'Ab3X')
    # 错误输入 → False，且验证码被消费（失败即失效，防无限试错）
    assert await verify_captcha('k2', 'wrong') is False
    # 随后即使用正确输入也无法通过
    assert await verify_captcha('k2', 'Ab3X') is False
    assert await _captcha_redis.get('k2') is None


@pytest.mark.asyncio
async def test_verify_captcha_missing_key(_captcha_redis):
    from utils.captcha import verify_captcha

    assert await verify_captcha('missing', 'any') is False


@pytest.mark.asyncio
async def test_verify_captcha_empty_input(_captcha_redis):
    from utils.captcha import verify_captcha

    assert await verify_captcha('k', '') is False
    assert await verify_captcha('', 'x') is False


@pytest.mark.asyncio
async def test_verify_captcha_uses_atomic_lua_script(_captcha_redis, monkeypatch):
    from utils.captcha import verify_captcha, _CAPTCHA_VERIFY_LUA

    await _captcha_redis.set('k1', 'Ab3X')
    calls = []
    original = _captcha_redis.eval

    async def spy_eval(script, numkeys, key, user_input):
        calls.append((script, numkeys))
        return await original(script, numkeys, key, user_input)

    monkeypatch.setattr(_captcha_redis, 'eval', spy_eval)

    assert await verify_captcha('k1', 'Ab3X') is True
    # 生产代码调用原子 Lua 脚本（numkeys=1）
    assert calls and calls[0] == (_CAPTCHA_VERIFY_LUA, 1)