"""「单据账户标识 → 平台交易账号」换算（`OffsiteFundService._platform_account`）的回归测试。

## 为什么必须守住这条缝

场外核对的 NL2SQL 查询计划按 `fin_holding.trade_account = <单据上的账户标识>` 过滤
（`nl2sql_yc.py:509-514`），而库里存的是平台交易账号 `FSA{客户号:06d}`。两者**不同值**时：

```
JOIN fin_holding h ... WHERE h.trade_account = '10002'  → 0 行
→ 「申请前持有份额」= null → 规则判「无法判断」→ 单据状态 query_failed
```

2026-09-14 实测就是这样：客户 10002 **明明持有 15911 共 1000 份**，核对却报"查询无可用数据"，
页面上"单据核对与运营动作"因此是空的 —— 看起来像"缺数据"，实为**账户口径没桥接**。
本文件把换算规则钉死：命中就换算，认不出来就**原样返回（失败关闭，不猜不造）**。
"""

from __future__ import annotations

from typing import Any

import pytest

from app.service.offsite_fund_service import OffsiteFundService


class _StubSession:
    """按调用顺序返回预置结果的 session 替身；记录被执行的查询，不发真实 SQL。"""

    def __init__(self, results: list[Any]) -> None:
        self._results = list(results)
        self.queries: list[str] = []

    async def scalar(self, statement: Any) -> Any:
        self.queries.append(str(statement))
        return self._results.pop(0) if self._results else None


def _service(results: list[Any]) -> tuple[OffsiteFundService, _StubSession]:
    session = _StubSession(results)
    return OffsiteFundService(session), session  # type: ignore[arg-type]


@pytest.mark.asyncio
async def test_account_no_is_used_as_is() -> None:
    """已经是库里的交易账号：原样使用，且**只查一次**（不需要按客户号回退）。"""
    service, session = _service(["FSA010002"])

    assert await service._platform_account("FSA010002") == "FSA010002"
    assert len(session.queries) == 1


@pytest.mark.asyncio
async def test_numeric_customer_id_is_translated_to_trade_account() -> None:
    """单据上印的是客户号（演示单据就是 `10002`）⇒ 换算成该客户的交易账号。"""
    service, session = _service([None, "FSA010002"])

    assert await service._platform_account("10002") == "FSA010002"
    assert len(session.queries) == 2  # 先按 account_no 找、再按 customer_id 找


@pytest.mark.asyncio
async def test_unknown_identifier_is_returned_unchanged() -> None:
    """认不出来就原样返回：宁可继续查不到（暴露给人工），也不构造"看起来对"的账号。"""
    service, _session = _service([None, None])

    assert await service._platform_account("SL-UNKNOWN-001") == "SL-UNKNOWN-001"


@pytest.mark.asyncio
async def test_numeric_identifier_without_account_is_not_invented() -> None:
    """数字但是个不存在的客户号 ⇒ 不得凭空造出 `FSA099999` 这类账号。"""
    service, _session = _service([None, None])

    assert await service._platform_account("99999") == "99999"


@pytest.mark.asyncio
async def test_blank_identifier_needs_no_query() -> None:
    """空值不查库。"""
    service, session = _service([])

    assert await service._platform_account(None) is None
    assert await service._platform_account("") is None
    assert session.queries == []