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


class Loan(Base):
    __tablename__ = "loans"

    id: Mapped[str] = mapped_column(
        String, primary_key=True, default=lambda: str(uuid.uuid4())
    )
    employee_id: Mapped[str] = mapped_column(
        String, ForeignKey("employees.id", ondelete="CASCADE"), nullable=False
    )
    loan_date: Mapped[date] = mapped_column(Date, nullable=False)
    total_amount: Mapped[int] = mapped_column(Integer, nullable=False)
    monthly_deduction: Mapped[int] = mapped_column(Integer, nullable=False)
    description: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    remaining_balance: Mapped[int] = mapped_column(Integer, nullable=False)
    # status: "active" | "paid"
    status: Mapped[str] = mapped_column(String, default="active", nullable=False)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
    )

    employee: Mapped["Employee"] = relationship("Employee", back_populates="loans")
    transactions: Mapped[List["LoanTransaction"]] = relationship(
        "LoanTransaction",
        back_populates="loan",
        cascade="all, delete-orphan",
        order_by="LoanTransaction.transaction_date",
    )