"""
DAO 写库回归测试：验证 upsert（INSERT ... ON DUPLICATE KEY UPDATE）而非 pandas replace，
确保不 DROP 表、不丢失数据、DELETE+INSERT 不再分事务。
不使用真实 DB（用假 engine 捕获 SQL）。
"""
import sys
import os
sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

import pandas as pd
import pytest
from unittest.mock import patch

from database import dao
from database.models import StockDaily
from sqlalchemy.dialects import mysql


class _RecConn:
    """记录最近一次执行的 SQL。"""
    def __init__(self):
        self.sql = None
    def begin(self):
        return self
    def __enter__(self):
        return self
    def __exit__(self, *a):
        pass
    def execute(self, stmt):
        self.sql = str(stmt.compile(dialect=mysql.dialect(), compile_kwargs={"literal_binds": True}))
        return type("R", (), {"rowcount": 2})()


class _RecEngine:
    def __init__(self):
        self.conn = _RecConn()
    def begin(self):
        return self.conn


def _daily_df():
    return pd.DataFrame({
        'ts_code': ['000001.SZ', '600519.SH'],
        'trade_date': ['20260601', '20260601'],
        'open': [10.1, 99.0], 'high': [10.8, 101.0], 'low': [10.0, 98.0],
        'close': [10.5, 100.0], 'pre_close': [10.2, 99.5],
        'change': [0.3, 0.5], 'pct_chg': [2.94, 0.50], 'vol': [100, 200],
        'amount': [1050, 19900], 'turnover_rate': [0.5, 0.2],
    })


def test_save_daily_generates_upsert_not_replace():
    eng = _RecEngine()
    with patch('database.dao.get_engine', return_value=eng):
        dao.save_daily(_daily_df())
    sql = eng.conn.sql
    assert "INSERT INTO" in sql and "mac_stock_daily" in sql
    assert "ON DUPLICATE KEY UPDATE" in sql, "save_daily 必须用 upsert，避免旧版 DELETE+INSERT"
    # 确保不会走 pandas replace（整表重建）
    assert "DROP TABLE" not in sql.upper()


def test_save_daily_no_multi_transaction():
    """save_daily 只构造一次 upsert 语句，DELETE 与 INSERT 合并为原子语句。"""
    eng = _RecEngine()
    with patch('database.dao.get_engine', return_value=eng):
        dao.save_daily(_daily_df())
    # 生成的 SQL 不含独立 DELETE，确保无"删除已发生但插入失败"的非原子风险
    assert "DELETE" not in eng.conn.sql.upper()