from datetime import datetime
from sqlalchemy import DateTime, ForeignKey, Integer, String, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.db.base import Base
from app.models.document_line_item import DocumentLineItem


class DocumentLineItemSet(Base):
    __tablename__ = "document_line_item_sets"
    __table_args__ = (
        UniqueConstraint("document_id", name="uq_document_line_item_sets_document_id"),
    )

    id: Mapped[int] = mapped_column(primary_key=True, index=True)
    document_id: Mapped[int] = mapped_column(ForeignKey("documents.id"), nullable=False, index=True)
    schema_type: Mapped[str | None] = mapped_column(String(50), nullable=True)
    created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, nullable=False)
    updated_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow, nullable=False)

    document: Mapped["Document"] = relationship(back_populates="line_item_set")
    items: Mapped[list["DocumentLineItem"]] = relationship(
        back_populates="line_item_set",
        cascade="all, delete-orphan",
        order_by="DocumentLineItem.line_number",
    )