"""集成测试 fixture：连接本地 PostgreSQL 16，按事务隔离并回滚。

需要可连接的数据库（DATABASE_URL）。无法连接时跳过整组集成测试。
"""

from __future__ import annotations

import pytest
from sqlalchemy import text
from sqlalchemy.exc import OperationalError

from app.db import get_engine


@pytest.fixture(scope="session")
def db_available() -> bool:
    try:
        with get_engine().connect() as conn:
            conn.execute(text("SELECT 1"))
        return True
    except OperationalError:
        return False


@pytest.fixture()
def session(db_available):
    if not db_available:
        pytest.skip("数据库不可用，跳过集成测试")
    engine = get_engine()
    connection = engine.connect()
    trans = connection.begin()
    from sqlalchemy.orm import Session

    sess = Session(bind=connection)
    try:
        yield sess
    finally:
        sess.close()
        if trans.is_active:
            trans.rollback()
        connection.close()