feat: cards, attributes and modules

models/card_group.py

@@ -0,0 +1,39 @@
+from typing import TYPE_CHECKING, Optional
+
+from sqlalchemy import ForeignKey, Table, Column
+from sqlalchemy.orm import mapped_column, Mapped, relationship
+
+from models import BaseModel
+from models import GroupBillRequest
+
+if TYPE_CHECKING:
+    from models import Card
+
+
+class CardGroup(BaseModel):
+    __tablename__ = 'card_groups'
+    id: Mapped[int] = mapped_column(
+        primary_key=True
+    )
+    name: Mapped[Optional[str]] = mapped_column(
+        nullable=True
+    )
+    lexorank: Mapped[str] = mapped_column(
+        nullable=False
+    )
+    cards: Mapped[list["Card"]] = relationship(
+        back_populates='group',
+        secondary='card_relations'
+    )
+    bill_request: Mapped[Optional['GroupBillRequest']] = relationship(
+        back_populates='group',
+        lazy='joined'
+    )
+
+
+card_relations = Table(
+    'card_relations',
+    BaseModel.metadata,
+    Column('card_id', ForeignKey('cards.id'), primary_key=True, unique=True),
+    Column('group_id', ForeignKey('card_groups.id'), primary_key=True)
+)