"""inventory 仓储域模型：仓库/库存/库存流水。"""
from sqlalchemy import Column, Integer, String, Text, DateTime, Boolean, Numeric, ForeignKey, UniqueConstraint, CheckConstraint
from sqlalchemy.sql import func
from sqlalchemy.orm import relationship

from shared.models.base import Base


class Warehouse(Base):
    """仓库表"""
    __tablename__ = "warehouses"

    id = Column(Integer, primary_key=True, index=True)
    code = Column(String(50), unique=True, index=True)
    name = Column(String(200), nullable=False)
    address = Column(Text, nullable=True)
    manager = Column(String(100), nullable=True)
    phone = Column(String(50), nullable=True)
    is_active = Column(Boolean, default=True)
    is_default = Column(Boolean, default=False)
    created_at = Column(DateTime, default=func.now())

    inventories = relationship("Inventory", back_populates="warehouse")

    def __repr__(self):
        return f"<Warehouse(id={self.id}, name='{self.name}')>"


class Inventory(Base):
    """库存表"""
    __tablename__ = "inventory"
    __table_args__ = (
        UniqueConstraint("product_id", "warehouse_id", name="uq_inventory_product_warehouse"),
        CheckConstraint("quantity >= 0 AND locked_quantity >= 0 AND locked_quantity <= quantity", name="ck_inventory_qty_nonnegative"),
    )

    id = Column(Integer, primary_key=True, index=True)
    product_id = Column(Integer, ForeignKey("products.id"), nullable=False, index=True)
    warehouse_id = Column(Integer, ForeignKey("warehouses.id"), nullable=False, index=True)
    quantity = Column(Numeric(12, 4), default=0)
    locked_quantity = Column(Numeric(12, 4), default=0)
    batch_number = Column(String(50), nullable=True)
    location = Column(String(100), nullable=True)
    updated_at = Column(DateTime, default=func.now(), onupdate=func.now())

    product = relationship("Product", back_populates="inventory")
    warehouse = relationship("Warehouse", back_populates="inventories")

    def __repr__(self):
        return f"<Inventory(product_id={self.product_id}, quantity={self.quantity})>"

    @property
    def available_quantity(self):
        return self.quantity - self.locked_quantity


class StockMovement(Base):
    """库存变动记录表"""
    __tablename__ = "stock_movements"

    id = Column(Integer, primary_key=True, index=True)
    product_id = Column(Integer, ForeignKey("products.id"), nullable=False, index=True)
    warehouse_id = Column(Integer, ForeignKey("warehouses.id"), nullable=False)
    movement_type = Column(String(20), nullable=False)
    quantity = Column(Numeric(12, 4), nullable=False)
    before_quantity = Column(Numeric(12, 4), default=0)
    after_quantity = Column(Numeric(12, 4), default=0)
    reference_type = Column(String(50), nullable=True)
    reference_id = Column(Integer, nullable=True)
    reference_no = Column(String(50), nullable=True)
    unit_price = Column(Numeric(12, 2), nullable=True)
    total_amount = Column(Numeric(12, 2), nullable=True)
    remark = Column(Text, nullable=True)
    operator_id = Column(Integer, ForeignKey("users.id"), nullable=True)
    created_at = Column(DateTime, default=func.now(), index=True)

    product = relationship("Product", back_populates="stock_movements")

    def __repr__(self):
        return f"<StockMovement(id={self.id}, type='{self.movement_type}', qty={self.quantity})>"