"""fin_product 产品仓储：列表搜索（关键字/类型/风险/状态筛选 + 排序 + 分页）。"""
from __future__ import annotations

from sqlalchemy import or_, select

from model.fin_product import FinProduct
from repositories.base import BaseRepository
from utils.exceptions import ParamError

# 排序字段白名单：防止 sort_by 注入，字符串映射到 ORM 列（不拼 SQL）
SORTABLE_FIELDS = {
    "expected_return": FinProduct.expected_return,
    "nav": FinProduct.nav,
    "fee_rate": FinProduct.fee_rate,
    "risk_level": FinProduct.risk_level,
    "create_time": FinProduct.create_time,
}


class ProductRepo(BaseRepository):
    model = FinProduct

    async def get_by_code(self, product_code: str) -> FinProduct | None:
        return await self.db.scalar(
            select(FinProduct).where(FinProduct.product_code == product_code)
        )

    async def search(
        self,
        *,
        keyword: str | None = None,
        product_type: str | None = None,
        risk_level: str | None = None,
        status: str | None = "在售",
        sort_by: str = "create_time",
        sort_order: str = "desc",
        limit: int = 10,
        offset: int = 0,
    ) -> tuple[list[FinProduct], int]:
        conds = []
        if status and status != "全部":
            conds.append(FinProduct.status == status)
        if product_type:
            conds.append(FinProduct.product_type == product_type)
        if risk_level:
            conds.append(FinProduct.risk_level == risk_level)
        if keyword:
            like = f"%{keyword}%"
            conds.append(
                or_(
                    FinProduct.product_code.like(like),
                    FinProduct.product_name.like(like),
                    FinProduct.fund_manager.like(like),
                )
            )

        col = SORTABLE_FIELDS.get(sort_by)
        if col is None:
            raise ParamError(f"不支持的排序字段: {sort_by}")
        order_col = col.desc() if sort_order == "desc" else col.asc()

        stmt = (
            select(FinProduct)
            .where(*conds)
            .order_by(order_col)
            .limit(limit)
            .offset(offset)
        )
        items = list((await self.db.scalars(stmt)).all())
        total = await self.count(where=conds)
        return items, total