"""发货模型：发货单与发货产品明细。

- ship_date 是**回款天数计算基准日**（对照表 #1：发货日首日计第 1 天），
  回款指定本发货单后由 formula.payment_days 派生回款天数，不在本表落库
- 运费仅记录展示，不计入毛利润口径（对照表 #2）
- total_amount 为明细行汇总冗余，服务层事务内维护
"""

from datetime import date
from decimal import Decimal

from sqlalchemy import Date, ForeignKey, Index, Numeric, String
from sqlalchemy.orm import Mapped, mapped_column

from app.models.base import (
    BIGINT_UNSIGNED,
    Base,
    TimestampMixin,
    TPlusSyncMixin,
    mysql_table_args,
)


class Shipment(Base, TimestampMixin, TPlusSyncMixin):
    """发货单表（需求 2.2.2）：每笔发货对应一个业务，支持分批发货。"""

    __tablename__ = "shipments"
    __table_args__ = mysql_table_args(
        "发货单表（发货日为回款天数基准日，发货日首日计第 1 天）",
        Index("idx_shipments_business_id", "business_id"),
        Index("idx_shipments_ship_date", "ship_date"),
    )

    id: Mapped[int] = mapped_column(
        BIGINT_UNSIGNED, primary_key=True, autoincrement=True, comment="主键ID"
    )
    shipment_no: Mapped[str] = mapped_column(
        String(32),
        nullable=False,
        unique=True,
        comment="发货单号，自动生成 SH{YYYYMMDD}-{4位当日序号}（内部追溯用）",
    )
    business_id: Mapped[int] = mapped_column(
        BIGINT_UNSIGNED,
        ForeignKey("businesses.id", ondelete="RESTRICT"),
        nullable=False,
        comment="业务ID（businesses.id；终态业务禁止新发货）",
    )
    ship_date: Mapped[date] = mapped_column(
        Date, nullable=False, comment="发货日期（回款天数基准日，发货日首日=第 1 天）"
    )
    freight_amount: Mapped[Decimal | None] = mapped_column(
        Numeric(14, 2),
        nullable=True,
        comment="运费金额（仅记录展示；不计入毛利润口径，对照表 #2）",
    )
    total_amount: Mapped[Decimal] = mapped_column(
        Numeric(14, 2),
        nullable=False,
        server_default="0",
        comment="发货总金额（明细行汇总冗余，服务层事务内维护，禁手工直改）",
    )
    remark: Mapped[str | None] = mapped_column(String(255), comment="备注")


class ShipmentItem(Base, TimestampMixin):
    """发货产品明细表（需求 2.2.2）：记录发货的产品名称、规格、数量等。

    价格口径两可（T+ 供价或人工录入，待 IT 确认）：sale_price 可空人工补，
    amount 由服务层按 数量×单价 计算固化。
    """

    __tablename__ = "shipment_items"
    __table_args__ = mysql_table_args(
        "发货产品明细表",
        Index("idx_shipment_items_shipment_id", "shipment_id"),
        Index("idx_shipment_items_product_id", "product_id"),
    )

    id: Mapped[int] = mapped_column(
        BIGINT_UNSIGNED, primary_key=True, autoincrement=True, comment="主键ID"
    )
    shipment_id: Mapped[int] = mapped_column(
        BIGINT_UNSIGNED,
        ForeignKey("shipments.id", ondelete="RESTRICT"),
        nullable=False,
        comment="发货单ID（shipments.id）",
    )
    product_id: Mapped[int | None] = mapped_column(
        BIGINT_UNSIGNED,
        ForeignKey("products.id", ondelete="RESTRICT"),
        comment="产品ID（products.id；NULL=自由录入）",
    )
    product_name: Mapped[str] = mapped_column(
        String(128), nullable=False, comment="产品名称（引用产品时冗余固化）"
    )
    spec_model: Mapped[str] = mapped_column(
        String(128),
        nullable=False,
        server_default="''",
        comment="规格型号（冗余固化；空串对齐 products 组合唯一键口径）",
    )
    unit: Mapped[str | None] = mapped_column(String(16), comment="计量单位")
    quantity: Mapped[Decimal] = mapped_column(
        Numeric(14, 2), nullable=False, comment="发货数量（>0）"
    )
    sale_price: Mapped[Decimal | None] = mapped_column(
        Numeric(14, 4), comment="发货单价（元；T+ 同步或人工，口径待 IT 确认）"
    )
    amount: Mapped[Decimal] = mapped_column(
        Numeric(14, 2),
        nullable=False,
        comment="行金额 = 数量×单价（服务层计算固化，不信任前端传值）",
    )