import datetime
from typing import TYPE_CHECKING, Optional

from sqlalchemy import ForeignKey
from sqlalchemy.orm import Mapped, mapped_column, relationship

from models import BaseModel

if TYPE_CHECKING:
    from models import Product, Client


class ResidualPallet(BaseModel):
    __tablename__ = 'residual_pallets'
    id: Mapped[int] = mapped_column(primary_key=True)
    created_at: Mapped[datetime.datetime] = mapped_column(nullable=False)

    client_id: Mapped[Optional[int]] = mapped_column(ForeignKey('clients.id'))
    client: Mapped['Client'] = relationship(back_populates='pallets')

    boxes: Mapped[list['ResidualBox']] = relationship(
        back_populates='pallet',
        uselist=True,
        lazy='joined',
        cascade='all, delete-orphan',
    )

    residual_products: Mapped[list['ResidualProduct']] = relationship(
        back_populates='pallet',
        uselist=True,
        lazy='joined',
        cascade='all, delete-orphan',
    )


class ResidualProduct(BaseModel):
    __tablename__ = 'residual_products'
    id: Mapped[int] = mapped_column(primary_key=True)
    quantity: Mapped[int] = mapped_column()

    product_id: Mapped[int] = mapped_column(ForeignKey('products.id'))
    product: Mapped['Product'] = relationship(lazy='joined')

    pallet_id: Mapped[Optional[int]] = mapped_column(ForeignKey('residual_pallets.id'))
    pallet: Mapped[ResidualPallet] = relationship(lazy='joined', back_populates="residual_products")

    box_id: Mapped[Optional[int]] = mapped_column(ForeignKey('residual_boxes.id'))
    box: Mapped['ResidualBox'] = relationship(back_populates='residual_products')


class ResidualBox(BaseModel):
    __tablename__ = 'residual_boxes'
    id: Mapped[int] = mapped_column(primary_key=True)
    created_at: Mapped[datetime.datetime] = mapped_column(nullable=False)

    pallet_id: Mapped[Optional[int]] = mapped_column(ForeignKey('residual_pallets.id'))
    pallet: Mapped[ResidualPallet] = relationship(back_populates='boxes')

    client_id: Mapped[Optional[int]] = mapped_column(ForeignKey('clients.id'))
    client: Mapped['Client'] = relationship(back_populates='boxes')

    residual_products: Mapped[list['ResidualProduct']] = relationship(back_populates='box')