from typing import TYPE_CHECKING, Optional

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

from models import BaseModel

if TYPE_CHECKING:
    from models import Deal


class DealGroup(BaseModel):
    __tablename__ = 'deal_groups'
    id: Mapped[int] = mapped_column(
        primary_key=True
    )
    name: Mapped[Optional[str]] = mapped_column(
        nullable=True
    )
    lexorank: Mapped[str] = mapped_column(
        nullable=False
    )
    deals: Mapped[list["Deal"]] = relationship(
        back_populates='group',
        secondary='deal_relations'
    )


deal_relations = Table(
    'deal_relations',
    BaseModel.metadata,
    Column('deal_id', ForeignKey('deals.id'), primary_key=True, unique=True),
    Column('group_id', ForeignKey('deal_groups.id'), primary_key=True)
)