"""产品模型"""
import uuid
from datetime import datetime
from sqlalchemy import String, DateTime, ForeignKey
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.models.base import Base
from app.core.time_utils import get_beijing_time


class Product(Base):
    __tablename__ = "products"

    id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True), primary_key=True, default=uuid.uuid4,
    )
    serial_number: Mapped[str] = mapped_column(
        String(16), unique=True, index=True, nullable=False, comment="产品序列号(16位)",
    )

    # ---- 物理外键（关联本库 production_orders）— 可选 ----
    order_id: Mapped[uuid.UUID | None] = mapped_column(
        UUID(as_uuid=True), ForeignKey("production_orders.id"), nullable=True, comment="所属订单ID(可选)",
    )

    # ---- 外部序列号（用户自定义，可选） ----
    external_serial: Mapped[str | None] = mapped_column(
        String(64), nullable=True, comment="用户自定义产品序列号(可选)",
    )

    # ---- 逻辑外键（关联老系统物料表，仅存储 ID，无物理约束） ----
    material_id: Mapped[str | None] = mapped_column(
        String(64), nullable=True, comment="物料ID(逻辑外键→老系统)",
    )
    # ---- MOM 物料快照字段（创产品时写入，防止老系统数据变动影响标签） ----
    material_name: Mapped[str | None] = mapped_column(
        String(255), nullable=True, comment="物料名称快照",
    )
    spec_model: Mapped[str | None] = mapped_column(
        String(255), nullable=True, comment="规格型号快照",
    )
    category: Mapped[str | None] = mapped_column(
        String(255), nullable=True, comment="物料分类快照",
    )
    material_type: Mapped[str | None] = mapped_column(
        String(100), nullable=True, comment="物料类型快照",
    )

    # ---- 物理外键（自引用：父产品） ----
    parent_product_id: Mapped[uuid.UUID | None] = mapped_column(
        UUID(as_uuid=True), ForeignKey("products.id"), nullable=True, comment="父产品ID",
    )

    # ---- 当前位置追踪（逻辑外键→用户ID 或 'virtual_warehouse'） ----
    current_location_id: Mapped[str | None] = mapped_column(
        String(64), nullable=True, comment="当前持有者ID 或 'virtual_warehouse'(仓库)",
    )

    status: Mapped[str] = mapped_column(
        String(50), nullable=False, default="pending", comment="产品状态",
    )
    # 宏观流转状态 — 首次扫码时强制设定：备货/生产/测试/维修/在库
    overall_status: Mapped[str | None] = mapped_column(
        String(20), nullable=True, comment="宏观状态: 备货/生产/测试/维修/在库",
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=get_beijing_time, comment="创建时间",
    )

    # ---- 关系 ----
    order: Mapped["ProductionOrder"] = relationship("ProductionOrder", lazy="selectin")
    parent_product: Mapped["Product | None"] = relationship(
        "Product", remote_side="Product.id", lazy="selectin",
    )

    def __repr__(self) -> str:
        return f"<Product {self.serial_number}>"