import uuid
from datetime import datetime, date, timezone
from sqlalchemy import String, Integer, Date, DateTime, Text, ForeignKey
from sqlalchemy.orm import Mapped, mapped_column, relationship
from app.core.database import Base


class BenefitTransaction(Base):
    __tablename__ = "benefit_transactions"

    id: Mapped[str] = mapped_column(
        String, primary_key=True, default=lambda: str(uuid.uuid4())
    )
    benefit_id: Mapped[str] = mapped_column(
        String, ForeignKey("benefits.id", ondelete="CASCADE"), nullable=False
    )
    employee_id: Mapped[str] = mapped_column(
        String, ForeignKey("employees.id", ondelete="CASCADE"), nullable=False
    )
    transaction_date: Mapped[date] = mapped_column(Date, nullable=False)
    description: Mapped[str] = mapped_column(Text, nullable=False)
    # debit = benefit paid out to employee (balance decreases)
    debit: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    # credit = benefit added to pool (balance increases)
    credit: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    # balance = running balance for this individual benefit
    balance: Mapped[int] = mapped_column(Integer, nullable=False)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
    )

    benefit: Mapped["Benefit"] = relationship("Benefit", back_populates="transactions")