"""真实驱动池的会话隔离与容量验证；只连接显式隔离测试库。"""

from concurrent.futures import ThreadPoolExecutor
from threading import Event

import pytest

from muse.共享.调用身份 import 用途
from muse.基础设施.数据库.连接 import 数据库工厂, 连接池耗尽

pytestmark = pytest.mark.数据库


@pytest.mark.case_id("NC-O06-POOL-PG-ISOLATION")
def test_真实池只读与自动提交失败后不串用(应用测试库):
    provider = 数据库工厂(应用测试库[用途.生产].引用, 用途.生产, 常驻=True, 最大连接=1)
    provider.打开()
    try:
        with pytest.raises(ValueError):
            with provider.连接(只读=True) as conn:
                assert conn.execute("SHOW transaction_read_only").fetchone()[0] == "on"
                assert conn.execute("SELECT current_user").fetchone()[0] == "muse_app"
                raise ValueError("synthetic rollback")
        with provider.连接(autocommit=True) as conn:
            assert conn.autocommit
            assert conn.execute("SHOW transaction_read_only").fetchone()[0] == "off"
            assert (
                conn.execute("SELECT current_setting('app.purpose')").fetchone()[0] == "production"
            )
        with provider.连接(只读=True, autocommit=True) as conn:
            assert conn.execute("SHOW transaction_read_only").fetchone()[0] == "on"
    finally:
        provider.关闭()


@pytest.mark.case_id("NC-O06-POOL-PG-CAPACITY")
def test_真实池超容量按期限拒绝且释放后可再借(应用测试库):
    provider = 数据库工厂(应用测试库[用途.生产].引用, 用途.生产, 常驻=True, 最大连接=1, 等待秒=1)
    provider.打开()
    持有 = Event()
    释放 = Event()

    def occupy():
        with provider.连接() as conn:
            conn.execute("SELECT 1")
            持有.set()
            assert 释放.wait(10)

    try:
        with ThreadPoolExecutor(max_workers=1) as executor:
            future = executor.submit(occupy)
            try:
                assert 持有.wait(5)
                with pytest.raises(连接池耗尽):
                    with provider.连接():
                        pytest.fail("容量一的池不得借出第二条")
            finally:
                释放.set()
            future.result()
        with provider.连接() as conn:
            assert conn.execute("SELECT 1").fetchone()[0] == 1
    finally:
        provider.关闭()