"""T-3 读侧单测 + T-10 普通申赎批次维护（开发计划 §5.1 / §8 DoD）。

sqlite 内存库（conftest.sqlite_engine 单一事实源建表 + C×R 矩阵种子），
数据由本文件自建，不依赖真 MySQL。

覆盖：
1. get_nav_as_of（D10：nav_date <= 交易日降序取 1）
2. get_redeem_fee_rules（仅 redeem 档、按持有期升序）
3. list_share_lots（S1：同 confirmed_at 以 lot_id 升序兜底、max_lots 截断）
4. sum_remain_qty（仅统计 remain_qty > 0，归零批不计入）
5. get_holding（单行 / 不存在 None）
6. ShareLotRepository.select_for_convert（FIFO 贪心选批、不足额返回全部可用）
7. **T-10 普通申赎批次维护（FR-C16）**：申购建批次 / 赎回 FIFO 扣减 /
   无批次有持仓 → D8 兜底补建后再扣 / 降级两条（无净值、无批次无持仓）/
   `rebuild_lots.py` 入口 / **D18 同源断言**（两侧 confirmed_at 逐一相等）

R-c(2) 覆盖率补偿：第 7 组的真实路径**全部自建完整种子**
（`core_holding` + `core_share_lot` + `core_product_nav`），
**不得让降级路径充当测试覆盖**（降级是数据不全时的兜底，不是被测对象）。
"""

from __future__ import annotations

import importlib.util
import logging
from datetime import date, datetime, timedelta
from decimal import Decimal
from pathlib import Path

import pytest
from sqlalchemy import text

from _ddl import create_sqlite_engine
from app.gateway import trade_gateway as tg
from app.gateway.gateway_repository import GatewayRepository
from app.repository.core_ro import CoreReadOnlyRepository, _as_date
from app.repository.share_lot_repository import ShareLotRepository
from app.service.convert.errors import InsufficientShares
from app.service.convert.lot_bootstrap import bootstrap_lot_id, bootstrap_lots


def _as_dt(value: object) -> datetime:
    """sqlite TIMESTAMP 读回为字符串、MySQL 为 datetime —— 测试内统一规范化。"""
    if isinstance(value, datetime):
        return value
    return datetime.fromisoformat(str(value)[:19])


CUSTOMER = "CUST-T3"
PRODUCT_A = "PROD-T3A"
PRODUCT_B = "PROD-T3B"


def _seed_customer(engine, cid: str) -> None:
    with engine.begin() as conn:
        conn.execute(
            text(
                "INSERT INTO core_customer (customer_id, display_name) "
                "VALUES (:cid, '测试客户')"
            ),
            {"cid": cid},
        )


def _seed_product(engine, pid: str, ptype: str = "bond") -> None:
    with engine.begin() as conn:
        conn.execute(
            text(
                "INSERT INTO core_product (product_id, product_name, min_risk_code, "
                "product_type, can_subscribe, can_redeem) "
                "VALUES (:pid, '测试产品', 'R2', :ptype, 1, 1)"
            ),
            {"pid": pid, "ptype": ptype},
        )


def _seed_lot(
    engine, lot_id: str, cid: str, pid: str,
    remain: str, nav: str, confirmed_at: datetime, qty: str | None = None,
) -> None:
    # sqlite 不直接绑定 Decimal：统一转 float（与既有 Decimal(total) 读回约定一致）
    with engine.begin() as conn:
        conn.execute(
            text(
                "INSERT INTO core_share_lot (lot_id, customer_id, product_id, qty, "
                "remain_qty, nav, confirmed_at) "
                "VALUES (:lot_id, :cid, :pid, :qty, :remain, :nav, :confirmed_at)"
            ),
            {
                "lot_id": lot_id, "cid": cid, "pid": pid,
                "qty": float(qty or remain), "remain": float(remain),
                "nav": float(nav), "confirmed_at": confirmed_at,
            },
        )


# ── 1. get_nav_as_of（D10） ────────────────────────────────────────────

def test_get_nav_as_of_returns_latest_on_or_before_trade_date(sqlite_engine):
    d = date(2026, 9, 4)
    repo = CoreReadOnlyRepository(engine=sqlite_engine)
    with sqlite_engine.begin() as conn:
        for nav_date, nav in [
            (date(2026, 9, 2), 1.0100),
            (date(2026, 9, 3), 1.0200),
            (date(2026, 9, 5), 1.0300),
        ]:
            conn.execute(
                text(
                    "INSERT INTO core_product_nav (product_id, nav, daily_chg_pct, nav_date) "
                    "VALUES (:pid, :nav, 0, :nd)"
                ),
                {"pid": PRODUCT_A, "nav": nav, "nd": nav_date},
            )

    # 落在 9-4：应取 9-3（<= 的最近一期）
    row = repo.get_nav_as_of(PRODUCT_A, d)
    assert row is not None
    assert _as_date(row["nav_date"]) == date(2026, 9, 3)
    assert row["nav"] == 1.0200


def test_get_nav_as_of_after_latest_returns_newest(sqlite_engine):
    d = date(2026, 9, 10)
    repo = CoreReadOnlyRepository(engine=sqlite_engine)
    with sqlite_engine.begin() as conn:
        conn.execute(
            text(
                "INSERT INTO core_product_nav (product_id, nav, daily_chg_pct, nav_date) "
                "VALUES (:pid, :nav, 0, :nd)"
            ),
            {"pid": PRODUCT_A, "nav": 1.0300, "nd": date(2026, 9, 5)},
        )

    row = repo.get_nav_as_of(PRODUCT_A, d)
    assert row is not None
    assert _as_date(row["nav_date"]) == date(2026, 9, 5)


def test_get_nav_as_of_no_earlier_nav_returns_none(sqlite_engine):
    d = date(2026, 9, 1)
    repo = CoreReadOnlyRepository(engine=sqlite_engine)
    with sqlite_engine.begin() as conn:
        conn.execute(
            text(
                "INSERT INTO core_product_nav (product_id, nav, daily_chg_pct, nav_date) "
                "VALUES (:pid, :nav, 0, :nd)"
            ),
            {"pid": PRODUCT_A, "nav": 1.0300, "nd": date(2026, 9, 5)},
        )

    assert repo.get_nav_as_of(PRODUCT_A, d) is None


# ── 2. get_redeem_fee_rules ────────────────────────────────────────────

def test_get_redeem_fee_rules_only_redeem_and_ordered(sqlite_engine):
    repo = CoreReadOnlyRepository(engine=sqlite_engine)
    with sqlite_engine.begin() as conn:
        # 申购费档（本期不启用）应被排除
        conn.execute(
            text(
                "INSERT INTO core_fee_rule (product_id, fee_type, min_hold_days, "
                "max_hold_days, rate) VALUES (:pid, 'subscribe', 0, NULL, :rate)"
            ),
            {"pid": PRODUCT_A, "rate": 0.0080},
        )
        # 赎回费五档（乱序插入，断言按 min_hold_days 升序返回）
        for mh, mh_max, rate in [
            (180, 365, "0.0025"), (0, 7, "0.0150"),
            (30, 180, "0.0050"), (7, 30, "0.0100"), (365, None, "0.0000"),
        ]:
            conn.execute(
                text(
                    "INSERT INTO core_fee_rule (product_id, fee_type, min_hold_days, "
                    "max_hold_days, rate) VALUES (:pid, 'redeem', :mh, :mh_max, :rate)"
                ),
                {"pid": PRODUCT_A, "mh": mh, "mh_max": mh_max, "rate": float(rate)},
            )

    rules = repo.get_redeem_fee_rules(PRODUCT_A)
    assert len(rules) == 5
    assert [r["min_hold_days"] for r in rules] == [0, 7, 30, 180, 365]
    assert all(r["fee_type"] == "redeem" for r in rules)


def test_get_redeem_fee_rules_empty(sqlite_engine):
    repo = CoreReadOnlyRepository(engine=sqlite_engine)
    assert repo.get_redeem_fee_rules(PRODUCT_B) == []


# ── 3. list_share_lots（S1 确定性 + 截断） ─────────────────────────────

def test_list_share_lots_ordered_by_confirmed_at(sqlite_engine):
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    repo = CoreReadOnlyRepository(engine=sqlite_engine)
    # 乱序确认时间插入
    _seed_lot(sqlite_engine, "L3", CUSTOMER, PRODUCT_A, "50", "1.03",
              datetime(2026, 9, 3, 10, 0, 0))
    _seed_lot(sqlite_engine, "L1", CUSTOMER, PRODUCT_A, "100", "1.01",
              datetime(2026, 9, 1, 10, 0, 0))
    _seed_lot(sqlite_engine, "L2", CUSTOMER, PRODUCT_A, "80", "1.02",
              datetime(2026, 9, 2, 10, 0, 0))

    lots = repo.list_share_lots(CUSTOMER, PRODUCT_A)
    assert [l["lot_id"] for l in lots] == ["L1", "L2", "L3"]
    assert [_as_dt(l["confirmed_at"]) for l in lots] == [
        datetime(2026, 9, 1, 10, 0, 0),
        datetime(2026, 9, 2, 10, 0, 0),
        datetime(2026, 9, 3, 10, 0, 0),
    ]


def test_list_share_lots_same_confirmed_at_tiebreak_by_lot_id(sqlite_engine):
    """S1：同一 confirmed_at 多批次以 lot_id 升序兜底，顺序可复现。"""
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    repo = CoreReadOnlyRepository(engine=sqlite_engine)
    same = datetime(2026, 9, 1, 10, 0, 0)
    # 故意让 lot_id 顺序与插入顺序相反
    _seed_lot(sqlite_engine, "LOT-09", CUSTOMER, PRODUCT_A, "10", "1.00", same)
    _seed_lot(sqlite_engine, "LOT-02", CUSTOMER, PRODUCT_A, "10", "1.00", same)
    _seed_lot(sqlite_engine, "LOT-05", CUSTOMER, PRODUCT_A, "10", "1.00", same)

    lots = repo.list_share_lots(CUSTOMER, PRODUCT_A)
    assert [l["lot_id"] for l in lots] == ["LOT-02", "LOT-05", "LOT-09"]


def test_list_share_lots_max_lots_truncates(sqlite_engine):
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    repo = CoreReadOnlyRepository(engine=sqlite_engine)
    for i in range(3):
        _seed_lot(sqlite_engine, f"L{i}", CUSTOMER, PRODUCT_A, "10", "1.00",
                  datetime(2026, 9, 1 + i, 10, 0, 0))

    assert len(repo.list_share_lots(CUSTOMER, PRODUCT_A, max_lots=2)) == 2


# ── 4. sum_remain_qty（仅 >0） ─────────────────────────────────────────

def test_sum_remain_qty_excludes_zeroed_lots(sqlite_engine):
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    repo = CoreReadOnlyRepository(engine=sqlite_engine)
    # 已归零（D9 保留行）与正常批次混放
    _seed_lot(sqlite_engine, "L1", CUSTOMER, PRODUCT_A, "100", "1.00",
              datetime(2026, 9, 1, 10, 0, 0))
    _seed_lot(sqlite_engine, "L2", CUSTOMER, PRODUCT_A, "0", "1.00",
              datetime(2026, 9, 2, 10, 0, 0))  # 归零批
    _seed_lot(sqlite_engine, "L3", CUSTOMER, PRODUCT_A, "50", "1.00",
              datetime(2026, 9, 3, 10, 0, 0))

    assert repo.sum_remain_qty(CUSTOMER, PRODUCT_A) == Decimal("150")


def test_sum_remain_qty_only_zeros_returns_zero(sqlite_engine):
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    repo = CoreReadOnlyRepository(engine=sqlite_engine)
    _seed_lot(sqlite_engine, "L1", CUSTOMER, PRODUCT_A, "0", "1.00",
              datetime(2026, 9, 1, 10, 0, 0))

    assert repo.sum_remain_qty(CUSTOMER, PRODUCT_A) == Decimal("0")


# ── 5. get_holding ─────────────────────────────────────────────────────

def test_get_holding_returns_row(sqlite_engine):
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    repo = CoreReadOnlyRepository(engine=sqlite_engine)
    with sqlite_engine.begin() as conn:
        conn.execute(
            text(
                "INSERT INTO core_holding (customer_id, product_id, qty, cost_amount, "
                "market_value, pnl_pct, as_of) VALUES (:cid, :pid, :qty, 0, 0, 0, :as_of)"
            ),
            {"cid": CUSTOMER, "pid": PRODUCT_A, "qty": 100.0,
             "as_of": date(2026, 9, 4)},
        )

    row = repo.get_holding(CUSTOMER, PRODUCT_A)
    assert row is not None
    assert row["product_id"] == PRODUCT_A
    assert row["qty"] == 100.0


def test_get_holding_missing_returns_none(sqlite_engine):
    _seed_customer(sqlite_engine, CUSTOMER)
    repo = CoreReadOnlyRepository(engine=sqlite_engine)
    assert repo.get_holding(CUSTOMER, PRODUCT_B) is None


# ── 6. ShareLotRepository.select_for_convert（FIFO 选批） ────────────────

def test_select_for_convert_fifo_partial_covers_first_lots(sqlite_engine):
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_lot(sqlite_engine, "L1", CUSTOMER, PRODUCT_A, "100", "1.0000",
              datetime(2026, 9, 1, 10, 0, 0))
    _seed_lot(sqlite_engine, "L2", CUSTOMER, PRODUCT_A, "50", "1.1000",
              datetime(2026, 9, 2, 10, 0, 0))

    repo = ShareLotRepository(engine=sqlite_engine)
    selected = repo.select_for_convert(CUSTOMER, PRODUCT_A, Decimal("120"))
    # 先吃满 L1(100)，再从 L2 取 20
    assert [s["lot_id"] for s in selected] == ["L1", "L2"]
    assert selected[0]["qty"] == 100.0
    assert selected[1]["qty"] == Decimal("20")
    assert repo.available_qty(CUSTOMER, PRODUCT_A) == Decimal("150")


def test_select_for_convert_shortfall_returns_all_available(sqlite_engine):
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_lot(sqlite_engine, "L1", CUSTOMER, PRODUCT_A, "100", "1.0000",
              datetime(2026, 9, 1, 10, 0, 0))
    _seed_lot(sqlite_engine, "L2", CUSTOMER, PRODUCT_A, "50", "1.1000",
              datetime(2026, 9, 2, 10, 0, 0))

    repo = ShareLotRepository(engine=sqlite_engine)
    selected = repo.select_for_convert(CUSTOMER, PRODUCT_A, Decimal("1000"))
    # 不足额：返回全部可用批次，差额由调用方校验
    assert [s["lot_id"] for s in selected] == ["L1", "L2"]
    assert [s["qty"] for s in selected] == [100.0, Decimal("50")]


def test_select_for_convert_zero_qty_returns_empty(sqlite_engine):
    repo = ShareLotRepository(engine=sqlite_engine)
    assert repo.select_for_convert(CUSTOMER, PRODUCT_A, Decimal("0")) == []


# ═══════════════════════════════════════════════════════════════════════
# 7. T-10 普通申赎批次维护（FR-C16 · 含 D8 兜底补建）
# ═══════════════════════════════════════════════════════════════════════

#: 交易日（T 日）：批次 confirmed_at 与净值取数基准
NOW_T = datetime(2026, 9, 4, 14, 0, 0)
NAV_DATE = date(2026, 9, 4)


def _dec(value: object) -> Decimal:
    """sqlite 读回 DECIMAL 列是 float —— 统一转 Decimal 再比，避免二进制误差误判。"""
    return Decimal(str(value))


def _rows(engine, sql: str, params: dict | None = None) -> list[dict]:
    with engine.connect() as conn:
        return [dict(r) for r in conn.execute(text(sql), params or {}).mappings()]


def _seed_nav(engine, pid: str, nav: str, nav_date: date = NAV_DATE) -> None:
    with engine.begin() as conn:
        conn.execute(
            text(
                "INSERT INTO core_product_nav (product_id, nav, daily_chg_pct, nav_date) "
                "VALUES (:pid, :nav, 0, :nd)"
            ),
            {"pid": pid, "nav": float(nav), "nd": nav_date},
        )


def _seed_fee_rule(engine, pid: str, rate: str = "0.0050") -> None:
    """灌一档赎回费率（`[0, NULL)`）—— `_redeem_quote` 金额反算需要费率档。"""
    with engine.begin() as conn:
        conn.execute(
            text(
                "INSERT INTO core_fee_rule (product_id, fee_type, min_hold_days, "
                "max_hold_days, rate) VALUES (:pid, 'redeem', 0, NULL, :rate)"
            ),
            {"pid": pid, "rate": float(rate)},
        )


def _seed_holding(
    engine, cid: str, pid: str, qty: str, cost: str, as_of: date
) -> None:
    with engine.begin() as conn:
        conn.execute(
            text(
                "INSERT INTO core_holding (customer_id, product_id, qty, cost_amount, "
                "market_value, pnl_pct, as_of) "
                "VALUES (:cid, :pid, :qty, :cost, :cost, 0, :as_of)"
            ),
            {"cid": cid, "pid": pid, "qty": float(qty), "cost": float(cost), "as_of": as_of},
        )


def _maintain(
    engine,
    *,
    trade_id: str,
    trade_type: str,
    amount: str | None = None,
    qty: str | None = None,
    product_id: str = PRODUCT_A,
    customer_id: str = CUSTOMER,
    traded_at: datetime = NOW_T,
) -> None:
    """直调批次维护入口（单元级：可控、可断言语义，端到端接线见 test_trade_gateway.py）。

    **入参按申报方式分池（T-9 · D26/R-6）**：
    - `subscribe`（金额申购）传 `amount` —— 内部按净值折份额；
    - `redeem`（份额赎回）传 `qty` —— 直接复用申报份额，**不再 `amount ÷ nav` 反算**。
    """
    tg._maintain_lots(
        writer=GatewayRepository(engine=engine),
        core=CoreReadOnlyRepository(engine=engine),
        trade_id=trade_id,
        customer_id=customer_id,
        product_id=product_id,
        trade_type=trade_type,
        amount=Decimal(amount) if amount is not None else None,
        qty=Decimal(qty) if qty is not None else None,
        traded_at=traded_at,
    )


# ── 7.1 真实路径：申购建批次 ───────────────────────────────────────────

def test_subscribe_creates_lot_with_amount_over_nav(sqlite_engine):
    """申购：`qty = amount ÷ T 日净值`（2 位 HALF_UP），`confirmed_at = T`。"""
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_nav(sqlite_engine, PRODUCT_A, "1.2500")

    _maintain(
        sqlite_engine, trade_id="TRD-T10-SUB", trade_type="subscribe", amount="10000"
    )

    rows = _rows(sqlite_engine, "SELECT * FROM core_share_lot")
    assert len(rows) == 1
    row = rows[0]
    assert row["lot_id"] == "LOT-SUB-TRD-T10-SUB"
    assert row["customer_id"] == CUSTOMER and row["product_id"] == PRODUCT_A
    assert _dec(row["qty"]) == Decimal("8000.00")  # 10000 / 1.25
    assert _dec(row["remain_qty"]) == Decimal("8000.00")
    assert _dec(row["nav"]) == Decimal("1.25")
    assert _as_dt(row["confirmed_at"]) == NOW_T
    assert row["source_trade_id"] == "TRD-T10-SUB"


def test_subscribe_rounds_qty_half_up(sqlite_engine):
    """份额 2 位 HALF_UP：1000 ÷ 1.2 = 833.333… → 833.33（不是银行家舍入）。"""
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_nav(sqlite_engine, PRODUCT_A, "1.2000")

    _maintain(
        sqlite_engine, trade_id="TRD-T10-RND", trade_type="subscribe", amount="1000"
    )

    row = _rows(sqlite_engine, "SELECT * FROM core_share_lot")[0]
    assert _dec(row["remain_qty"]) == Decimal("833.33")


# ── 7.2 真实路径：赎回 FIFO 扣减 ───────────────────────────────────────

def test_redeem_deducts_fifo_across_lots(sqlite_engine):
    """赎回：按 `amount ÷ T 日净值` 折算份额后 FIFO 扣减，最老批次先扣。"""
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_nav(sqlite_engine, PRODUCT_A, "1.0000")
    _seed_lot(sqlite_engine, "L-OLD", CUSTOMER, PRODUCT_A, "100", "1.0000",
              datetime(2026, 9, 1, 10, 0, 0))
    _seed_lot(sqlite_engine, "L-NEW", CUSTOMER, PRODUCT_A, "50", "1.1000",
              datetime(2026, 9, 2, 10, 0, 0))

    # D26：申报 120 份（份额申报，不再 120 元 ÷ 1.0 折算）→ L-OLD 扣满 100 归零，L-NEW 再扣 20
    _maintain(
        sqlite_engine, trade_id="TRD-T10-RED", trade_type="redeem", qty="120"
    )

    rows = {
        r["lot_id"]: _dec(r["remain_qty"])
        for r in _rows(sqlite_engine, "SELECT * FROM core_share_lot")
    }
    assert rows == {"L-OLD": Decimal("0.00"), "L-NEW": Decimal("30.00")}
    # 归零批次**保留行不删**（D9/P2）
    assert len(rows) == 2
    # 不超扣：Σ remain = 初始 150 − 实际扣减 120
    assert sum(rows.values()) == Decimal("30.00")


def test_redeem_shortfall_deducts_available_only(sqlite_engine):
    """普通赎回不阻断：请求份额 > 可用份额时，按可用额度全部扣减、不报错。"""
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_nav(sqlite_engine, PRODUCT_A, "1.0000")
    _seed_lot(sqlite_engine, "L1", CUSTOMER, PRODUCT_A, "30", "1.0000",
              datetime(2026, 9, 1, 10, 0, 0))

    _maintain(
        sqlite_engine, trade_id="TRD-T10-SHORT", trade_type="redeem", qty="5000"
    )

    row = _rows(sqlite_engine, "SELECT * FROM core_share_lot")[0]
    assert _dec(row["remain_qty"]) == Decimal("0.00")


# ── 7.3 真实路径：无批次有持仓 → D8 兜底补建后再扣 ─────────────────────

def test_redeem_bootstraps_lot_from_holding_then_deducts(sqlite_engine):
    """D8 主场景：无批次但有持仓 → 按 `core_holding.as_of` 补建初始批次再扣。"""
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_nav(sqlite_engine, PRODUCT_A, "1.0000")
    _seed_holding(sqlite_engine, CUSTOMER, PRODUCT_A, "100", "100.00", date(2026, 8, 1))

    _maintain(
        sqlite_engine, trade_id="TRD-T10-D8", trade_type="redeem", qty="30"
    )

    rows = _rows(sqlite_engine, "SELECT * FROM core_share_lot")
    assert len(rows) == 1
    row = rows[0]
    assert row["lot_id"] == bootstrap_lot_id(CUSTOMER, PRODUCT_A)  # 确定性 id，防重复补建
    assert _dec(row["qty"]) == Decimal("100")  # 原份额 = 持仓快照
    assert _dec(row["remain_qty"]) == Decimal("70.00")  # 补建 100 后扣 30
    assert row["source_trade_id"] is None  # 兜底补建无来源流水（与 08 种子一致）


def test_redeem_zero_holding_skips_bootstrap(sqlite_engine, caplog):
    """持仓份额为 0（D9 归零行保留）→ 不补建、不抛异常。"""
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_nav(sqlite_engine, PRODUCT_A, "1.0000")
    _seed_holding(sqlite_engine, CUSTOMER, PRODUCT_A, "0", "0.00", date(2026, 8, 1))

    with caplog.at_level(logging.WARNING, logger="app.gateway.trade_gateway"):
        _maintain(
            sqlite_engine, trade_id="TRD-T10-ZERO", trade_type="redeem", qty="30"
        )

    assert _rows(sqlite_engine, "SELECT * FROM core_share_lot") == []
    assert "无可补建批次" in caplog.text


# ── 7.4 降级路径（R-c(1) · 保住既有 510 用例的关键）────────────────────

def test_subscribe_without_nav_skips_with_warning(sqlite_engine, caplog):
    """申购取不到 T 日净值 → warning + 不建批次 + 不抛异常。"""
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)  # 刻意不灌 core_product_nav

    with caplog.at_level(logging.WARNING, logger="app.gateway.trade_gateway"):
        _maintain(
            sqlite_engine, trade_id="TRD-T10-NONAV", trade_type="subscribe",
            amount="10000",
        )

    assert _rows(sqlite_engine, "SELECT * FROM core_share_lot") == []
    assert "申购取不到 T 日净值" in caplog.text


def test_redeem_without_lot_and_holding_skips_with_warning(sqlite_engine, caplog):
    """赎回既无批次也无持仓 → warning + 跳过扣减 + 不抛异常（R16 的兜底）。"""
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_nav(sqlite_engine, PRODUCT_A, "1.0000")  # 有净值，但仍无批次无持仓

    with caplog.at_level(logging.WARNING, logger="app.gateway.trade_gateway"):
        _maintain(
            sqlite_engine, trade_id="TRD-T10-EMPTY", trade_type="redeem", qty="1000"
        )

    assert _rows(sqlite_engine, "SELECT * FROM core_share_lot") == []
    assert "既无批次也无持仓" in caplog.text


def test_maintain_lots_never_raises_on_broken_writer(sqlite_engine, caplog):
    """兜底：维护过程抛任何异常都被吞掉（交易主流程不受影响）。"""
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_nav(sqlite_engine, PRODUCT_A, "1.0000")

    class BoomGateway(GatewayRepository):
        def insert_share_lots(self, lots):  # noqa: D102
            raise RuntimeError("boom")

    with caplog.at_level(logging.WARNING, logger="app.gateway.trade_gateway"):
        tg._maintain_lots(
            writer=BoomGateway(engine=sqlite_engine),
            core=CoreReadOnlyRepository(engine=sqlite_engine),
            trade_id="TRD-T10-BOOM",
            customer_id=CUSTOMER,
            product_id=PRODUCT_A,
            trade_type="subscribe",
            amount=Decimal("10000"),
            traded_at=NOW_T,
        )

    assert "批次维护失败" in caplog.text


# ═══════════════════════════════════════════════════════════════════════
# 8. `scripts/core/rebuild_lots.py`（D18 同源 + 幂等）
# ═══════════════════════════════════════════════════════════════════════

_REBUILD_PATH = Path(__file__).resolve().parents[1] / "scripts" / "core" / "rebuild_lots.py"


def _load_rebuild_lots():
    """按路径加载脚本模块（`scripts/` 非包，无法直接 import）。"""
    spec = importlib.util.spec_from_file_location("rebuild_lots_under_test", _REBUILD_PATH)
    module = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(module)
    return module


def test_rebuild_lots_bootstraps_missing_only(sqlite_engine):
    """缺省模式：只补建「无批次」的持仓行；已有批次的持仓不动。"""
    rebuild = _load_rebuild_lots()
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_product(sqlite_engine, PRODUCT_B)
    _seed_holding(sqlite_engine, CUSTOMER, PRODUCT_A, "100", "100.00", date(2026, 8, 1))
    _seed_holding(sqlite_engine, CUSTOMER, PRODUCT_B, "20", "22.00", date(2026, 8, 2))
    # PRODUCT_B 已有批次 → 应被跳过
    _seed_lot(sqlite_engine, "L-EXIST", CUSTOMER, PRODUCT_B, "20", "1.1000",
              datetime(2026, 8, 2, 10, 0, 0))

    stats = rebuild.rebuild_lots(sqlite_engine, customer_id=CUSTOMER)

    assert stats["holdings"] == 2
    assert stats["bootstrapped"] == 1
    assert stats["skipped_existing"] == 1
    assert stats["written"] == 1
    lot_ids = {r["lot_id"] for r in _rows(sqlite_engine, "SELECT * FROM core_share_lot")}
    assert lot_ids == {"L-EXIST", bootstrap_lot_id(CUSTOMER, PRODUCT_A)}

    # 幂等：再跑一次零写入
    again = rebuild.rebuild_lots(sqlite_engine, customer_id=CUSTOMER)
    assert again["written"] == 0 and again["bootstrapped"] == 0


def test_rebuild_lots_force_replaces_existing(sqlite_engine):
    """`--force`：先删后建，批次按持仓快照重建（L-7）。"""
    rebuild = _load_rebuild_lots()
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_holding(sqlite_engine, CUSTOMER, PRODUCT_A, "100", "100.00", date(2026, 8, 1))
    _seed_lot(sqlite_engine, "L-STALE", CUSTOMER, PRODUCT_A, "77", "9.9999",
              datetime(2026, 1, 1, 10, 0, 0))

    stats = rebuild.rebuild_lots(sqlite_engine, customer_id=CUSTOMER, force=True)

    assert stats["removed"] == 1 and stats["written"] == 1
    rows = _rows(sqlite_engine, "SELECT * FROM core_share_lot")
    assert [r["lot_id"] for r in rows] == [bootstrap_lot_id(CUSTOMER, PRODUCT_A)]
    assert _dec(rows[0]["remain_qty"]) == Decimal("100")


def test_rebuild_lots_dry_run_writes_nothing(sqlite_engine):
    """`--dry-run`：只报告，不写库。"""
    rebuild = _load_rebuild_lots()
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_holding(sqlite_engine, CUSTOMER, PRODUCT_A, "100", "100.00", date(2026, 8, 1))

    stats = rebuild.rebuild_lots(sqlite_engine, customer_id=CUSTOMER, dry_run=True)

    assert stats["bootstrapped"] == 1 and stats["written"] == 0
    assert _rows(sqlite_engine, "SELECT * FROM core_share_lot") == []


def test_d18_gateway_bootstrap_and_rebuild_lots_agree():
    """**D18 同源断言**：同一 `core_holding` 行，网关兜底补建与 `rebuild_lots.py`
    算出的批次必须**完全一致**（`confirmed_at` 逐一相等）。

    这是 D18 设立的唯一目的 —— 两处各写一份「由 `as_of` 反推」必然漂移，
    同一持仓会落到不同费率档（演示看不出、生产是错账）。故本用例同时验证
    「两侧都在调 `bootstrap_lots`」这一事实：任一侧改成自己实现即变红。
    """
    rebuild = _load_rebuild_lots()
    gateway_engine = create_sqlite_engine()
    script_engine = create_sqlite_engine()
    try:
        for engine in (gateway_engine, script_engine):
            _seed_customer(engine, CUSTOMER)
            _seed_product(engine, PRODUCT_A)
            _seed_nav(engine, PRODUCT_A, "1.0000")
            _seed_holding(engine, CUSTOMER, PRODUCT_A, "100", "123.45", date(2026, 8, 1))

        # 侧 A：网关 D8 兜底补建（经 redeem 触发；补建 100 后会扣 30）
        _maintain(
            gateway_engine, trade_id="TRD-T10-D18", trade_type="redeem", qty="30"
        )
        # 侧 B：rebuild_lots 快照重建（不扣减）
        rebuild.rebuild_lots(script_engine, customer_id=CUSTOMER)

        got = _rows(gateway_engine, "SELECT * FROM core_share_lot")[0]
        want = _rows(script_engine, "SELECT * FROM core_share_lot")[0]

        assert got["lot_id"] == want["lot_id"]
        assert got["confirmed_at"] == want["confirmed_at"]  # ← D18 的核心断言
        assert _dec(got["nav"]) == _dec(want["nav"])
        assert _dec(got["qty"]) == _dec(want["qty"])
        # 差异只应来自「侧 A 扣了 30 份」这件事本身
        assert _dec(got["remain_qty"]) == _dec(want["remain_qty"]) - Decimal("30")
    finally:
        gateway_engine.dispose()
        script_engine.dispose()


def test_rebuild_lots_uses_same_pure_function_as_gateway():
    """机制验证（防「两侧碰巧算出同值」的假绿）：脚本模块内的补建**必须**来自
    `bootstrap_lots`，而不是自带的第二份实现。"""
    rebuild = _load_rebuild_lots()
    assert rebuild.bootstrap_lots is bootstrap_lots
    row = {
        "customer_id": CUSTOMER,
        "product_id": PRODUCT_A,
        "qty": "100",
        "cost_amount": "123.45",
        "as_of": date(2026, 8, 1),
    }
    assert [lot.lot_id for lot in rebuild.bootstrap_lots(row)] == [
        lot.lot_id for lot in bootstrap_lots(row)
    ]


# ═══════════════════════════════════════════════════════════════════════
# 9. T-10 新增：T+2 可扣过滤（R-4 · FR-C25）+ 哨兵（R-6）+ 在途占用（R-3）
# ═══════════════════════════════════════════════════════════════════════

#: 固定日历：2026-09-04(五)/09-07(一)/09-08(二)/09-09(三) 为交易日（T/T+1/T+2/T+3）
CAL_DATES = [
    date(2026, 9, 4),
    date(2026, 9, 7),
    date(2026, 9, 8),
    date(2026, 9, 9),
]


def _seed_calendar(engine) -> None:
    """灌 T 日（0924? 用 CAL_DATES）交易日历（R-5 数据源）—— T+2 过滤依赖。"""
    with engine.begin() as conn:
        for d in CAL_DATES:
            conn.execute(
                text(
                    "INSERT INTO core_trade_calendar (cal_date, is_open) VALUES (:d, 1)"
                ),
                {"d": d},
            )


def _seed_request(
    engine, gid: str, cid: str, pid: str, qty: str, status: str = "accepted"
) -> None:
    """灌一张受理单（在途占用 · R-3 需要）。"""
    with engine.begin() as conn:
        conn.execute(
            text(
                "INSERT INTO core_convert_request (convert_group_id, customer_id, "
                "from_product_id, to_product_id, qty, status, requested_at, updated_at) "
                "VALUES (:gid, :cid, :pid, 'PROD-T3B', :qty, :status, :at, :at)"
            ),
            {
                "gid": gid, "cid": cid, "pid": pid,
                "qty": float(qty), "status": status, "at": datetime(2026, 9, 4, 10, 0, 0),
            },
        )


# 9.1 仓储层：T+2 可扣过滤透传（available_from 半开区间）─────────────────

def test_list_share_lots_t2_filter_half_open_interval(sqlite_engine):
    """T+2 过滤（R-4）：`available_from` 半开区间 `confirmed_at < af+1天`。

    T 日 = 9-04，确认日 T+1 = 9-07（前一日 = 9-04）→ `available_from` 取
    9-04：9-07 确认的转入批次（af+1=9-08 00:00 之前）**不可扣**。
    """
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_lot(sqlite_engine, "L-T1", CUSTOMER, PRODUCT_A, "10", "1.00",
              datetime(2026, 9, 4, 10, 0, 0))    # T 日
    _seed_lot(sqlite_engine, "L-T2", CUSTOMER, PRODUCT_A, "20", "1.00",
              datetime(2026, 9, 7, 10, 0, 0))    # T+1（9-07，确认日→不可扣）
    repo = CoreReadOnlyRepository(engine=sqlite_engine)

    # 业务日 D = 9-07（T+1）：前一交易日 = 9-04 → af+1 = 9-05 → 只含 L-T1
    only = repo.list_share_lots(CUSTOMER, PRODUCT_A, available_from=date(2026, 9, 4))
    assert [l["lot_id"] for l in only] == ["L-T1"]

    # 业务日 D = 9-08（T+2）：前一交易日 = 9-07 → af+1 = 9-08 → 含 L-T1 + L-T2
    both = repo.list_share_lots(CUSTOMER, PRODUCT_A, available_from=date(2026, 9, 7))
    assert [l["lot_id"] for l in both] == ["L-T1", "L-T2"]


def test_select_for_convert_t2_filter_skips_t1_lot(sqlite_engine):
    """`select_for_convert(available_from=…)` 透传：T+1 批次在 T+2 前不可选。"""
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_lot(sqlite_engine, "L-T1", CUSTOMER, PRODUCT_A, "100", "1.00",
              datetime(2026, 9, 4, 10, 0, 0))
    _seed_lot(sqlite_engine, "L-T2", CUSTOMER, PRODUCT_A, "50", "1.00",
              datetime(2026, 9, 7, 10, 0, 0))
    repo = ShareLotRepository(engine=sqlite_engine)

    # 请求 150 份 > 可扣 100 份（T+2 未到，T+2 批次不可扣）→ 只返回 100（差额由调用方判）
    sel = repo.select_for_convert(
        CUSTOMER, PRODUCT_A, Decimal("150"), available_from=date(2026, 9, 4)
    )
    assert [s["lot_id"] for s in sel] == ["L-T1"]
    assert len(sel) == 1


# 9.2 网关层：T+2 边界 + 在途占用 + 哨兵（真实路径，自建完整种子）────────

def test_redeem_t2_not_yet_available_blocks_t1_lot(sqlite_engine):
    """**验收 27**：T+1 确认的转入批次在 T+2 前**不可扣**。

    **区分度设计**：申报 150 > T 日批次余量 100 ——
      · T+2 过滤生效（业务日 9-07，af=9-04）：只扣 L-T1（100 全扣），L-T2（9-07
        确认、T+2 未到）**不动** → {L-T1: 0, L-T2: 50}；
      · 过滤失效：FIFO 继续扣到 L-T2 50 → {L-T1: 0, L-T2: 0}。
    断言前值可区分「过滤是否真的生效」（防假绿）。
    """
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_calendar(sqlite_engine)
    _seed_nav(sqlite_engine, PRODUCT_A, "1.0000")
    # T 日批次（9-04 确认）+ T+1 批次（9-07 确认，模拟 convert 转入）
    _seed_lot(sqlite_engine, "L-T1", CUSTOMER, PRODUCT_A, "100", "1.00",
              datetime(2026, 9, 4, 10, 0, 0))
    _seed_lot(sqlite_engine, "L-T2", CUSTOMER, PRODUCT_A, "50", "1.00",
              datetime(2026, 9, 7, 10, 0, 0))

    # 业务日 9-07（T+1）：申报 150 → 可扣上限 = min(150, 物理 150) = 150；
    # 但 T+2 过滤只放行 T 日批次（L-T1 100），逐批 FIFO 后 L-T2 未被选中
    _maintain(
        sqlite_engine, trade_id="TRD-T10-T2B", trade_type="redeem", qty="150",
        traded_at=datetime(2026, 9, 7, 14, 0, 0),
    )
    rows = {r["lot_id"]: _dec(r["remain_qty"])
            for r in _rows(sqlite_engine, "SELECT * FROM core_share_lot")}
    assert rows == {"L-T1": Decimal("0.00"), "L-T2": Decimal("50.00")}


def test_redeem_t2_available_includes_t1_lot(sqlite_engine):
    """**验收 27 反向**：T+2 起 T+1 转入批次**可扣**。"""
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_calendar(sqlite_engine)
    _seed_nav(sqlite_engine, PRODUCT_A, "1.0000")
    _seed_lot(sqlite_engine, "L-T1", CUSTOMER, PRODUCT_A, "100", "1.00",
              datetime(2026, 9, 4, 10, 0, 0))
    _seed_lot(sqlite_engine, "L-T2", CUSTOMER, PRODUCT_A, "50", "1.00",
              datetime(2026, 9, 7, 10, 0, 0))

    # 业务日 9-08（T+2）：T+1 批次已 T+2 可扣 → 先扣老批次再扣新批次（FIFO）
    _maintain(
        sqlite_engine, trade_id="TRD-T10-T2A", trade_type="redeem", qty="120",
        traded_at=datetime(2026, 9, 8, 14, 0, 0),
    )
    rows = {r["lot_id"]: _dec(r["remain_qty"])
            for r in _rows(sqlite_engine, "SELECT * FROM core_share_lot")}
    assert rows == {"L-T1": Decimal("0.00"), "L-T2": Decimal("30.00")}


def test_redeem_insufficient_from_t2_filter_raises(sqlite_engine):
    """T+2 过滤后余量不足 → `_redeem_quote` 抛 `InsufficientShares`（400）。

    金额侧**硬校验**（不静默裁剪改写客户指令）：请求 150 份，T+2 可扣只有 100 份
    （T+1 批次 9-07 未到 T+2）→ **显式拒绝**。`_redeem_quote` 是 `submit_trade`
    的金额入口，此异常沿错误映射出 400（见 CONVERT_ERROR_MATRIX）。
    """
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_calendar(sqlite_engine)
    _seed_nav(sqlite_engine, PRODUCT_A, "1.0000")
    _seed_fee_rule(engine=sqlite_engine, pid=PRODUCT_A)
    _seed_lot(sqlite_engine, "L-T1", CUSTOMER, PRODUCT_A, "100", "1.00",
              datetime(2026, 9, 4, 10, 0, 0))
    _seed_lot(sqlite_engine, "L-T2", CUSTOMER, PRODUCT_A, "50", "1.00",
              datetime(2026, 9, 7, 10, 0, 0))

    with pytest.raises(InsufficientShares):
        tg._redeem_quote(
            CoreReadOnlyRepository(engine=sqlite_engine),
            customer_id=CUSTOMER,
            product_id=PRODUCT_A,
            qty=Decimal("150"),
            traded_at=datetime(2026, 9, 7, 14, 0, 0),  # T+1：T+2 批次 9-07 未可扣
        )


def test_redeem_respects_inflight_occupation(sqlite_engine):
    """**在途占用（R-3）**：已被未终态受理单占用的份额**不可赎回**（裁剪语义）。

    `_maintain_lots` 的可扣上限 = min(申报 80, 可赎 100−30) = 70 → 只扣 70
    （而非扣满 80）。「申报 > 可赎」的**硬拒绝**在金额侧 `_redeem_quote`
    （见 test_trade_gateway.py 的全链路用例），这里是批次侧的截止。
    """
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_calendar(sqlite_engine)
    _seed_nav(sqlite_engine, PRODUCT_A, "1.0000")
    _seed_fee_rule(engine=sqlite_engine, pid=PRODUCT_A)
    _seed_lot(sqlite_engine, "L-IN", CUSTOMER, PRODUCT_A, "100", "1.00",
              datetime(2026, 9, 4, 10, 0, 0))
    # 30 份转出占用（在途）→ 可赎 = 100 − 30 = 70
    _seed_request(sqlite_engine, "CNV-IN1", CUSTOMER, PRODUCT_A, "30", "accepted")

    _maintain(
        sqlite_engine, trade_id="TRD-T10-IN1", trade_type="redeem", qty="80",
        traded_at=datetime(2026, 9, 4, 14, 0, 0),
    )
    # 只扣 70（可赎上限），L-IN 100 → 30；不是 100−80=20
    row = _rows(sqlite_engine, "SELECT * FROM core_share_lot")[0]
    assert _dec(row["remain_qty"]) == Decimal("30.00")


def test_redeem_inflight_released_after_terminal_state(sqlite_engine):
    """在途占用只计未终态：受理单转终态（confirmed/rejected/cancelled/expired）后
    占用自动释放，份额可再次赎回。"""
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_calendar(sqlite_engine)
    _seed_nav(sqlite_engine, PRODUCT_A, "1.0000")
    _seed_fee_rule(engine=sqlite_engine, pid=PRODUCT_A)
    _seed_lot(sqlite_engine, "L-TERM", CUSTOMER, PRODUCT_A, "100", "1.00",
              datetime(2026, 9, 4, 10, 0, 0))
    # 终态（cancelled）不占用 → 可赎 100
    _seed_request(sqlite_engine, "CNV-TERM", CUSTOMER, PRODUCT_A, "30", "cancelled")

    _maintain(
        sqlite_engine, trade_id="TRD-T10-TERM", trade_type="redeem", qty="90",
        traded_at=datetime(2026, 9, 4, 14, 0, 0),
    )
    rows = _rows(sqlite_engine, "SELECT * FROM core_share_lot")
    assert len(rows) == 1 and _dec(rows[0]["remain_qty"]) == Decimal("10.00")


def test_deduct_sentinel_blocks_overdraw(sqlite_engine):
    """**哨兵（R-6）**：扣减 `remain_qty >= :q` 不满足 → rowcount=0 → 抛错回滚。

    直测网关写侧（`deduct_share_lots`）：传入期望扣 150 但批次只剩 100 → ValueError。
    """
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_lot(sqlite_engine, "L-SENT", CUSTOMER, PRODUCT_A, "100", "1.00",
              datetime(2026, 9, 4, 10, 0, 0))
    writer = GatewayRepository(engine=sqlite_engine)

    with pytest.raises(ValueError, match="哨兵触发"):
        writer.deduct_share_lots([("L-SENT", Decimal("150"))])
    # 事务回滚：remain_qty 不变
    row = _rows(sqlite_engine, "SELECT * FROM core_share_lot")[0]
    assert _dec(row["remain_qty"]) == Decimal("100.00")


def test_redeem_after_convert_leaves_no_overdraw(sqlite_engine):
    """**验收 9（DoD 4）**：convert 转出后普通赎回 —— 批次已反映转出（remain 减少），
    普通赎回只从**剩余份额**扣、不超扣（remain 恒非负）。

    模拟 convert 确认段扣减后的状态（T-7 已测确认段扣减本身）：初始批次 100
    → 转出 30 → remain 70，holding 同步 70（真实场景两者由确认事务共同维护）。
    随后普通赎回只按 70 的余量选批扣减；申报超过余量 → 裁剪到可赎上限
    （`_maintain_lots` 三重裁剪 ③），归零也不越界。
    """
    _seed_customer(sqlite_engine, CUSTOMER)
    _seed_product(sqlite_engine, PRODUCT_A)
    _seed_calendar(sqlite_engine)
    _seed_nav(sqlite_engine, PRODUCT_A, "1.0000")
    # convert 确认段转出后：批次 remain 70（初始 100 − 30），holding 同步 70
    _seed_lot(sqlite_engine, "L-CNV", CUSTOMER, PRODUCT_A, "70", "1.00",
              datetime(2026, 9, 4, 10, 0, 0))
    _seed_holding(sqlite_engine, CUSTOMER, PRODUCT_A, "70", "70.00", date(2026, 9, 4))

    # 赎回 50 ≤ 剩余 70 → 只扣 50，剩 20（不超扣）
    _maintain(
        sqlite_engine, trade_id="TRD-T10-CNV-R1", trade_type="redeem", qty="50",
        traded_at=datetime(2026, 9, 8, 14, 0, 0),
    )
    row = _rows(sqlite_engine, "SELECT * FROM core_share_lot")[0]
    assert _dec(row["remain_qty"]) == Decimal("20.00")

    # 再赎回 30 > 剩 20 → 裁剪到可赎上限 20 → 归零（remain 恒非负，不超扣）
    _maintain(
        sqlite_engine, trade_id="TRD-T10-CNV-R2", trade_type="redeem", qty="30",
        traded_at=datetime(2026, 9, 8, 14, 0, 0),
    )
    row = _rows(sqlite_engine, "SELECT * FROM core_share_lot")[0]
    assert _dec(row["remain_qty"]) == Decimal("0.00")