from datetime import datetime, date
from decimal import Decimal
from sqlalchemy import String, Boolean, Numeric, ForeignKey, Date, DateTime, func
from sqlalchemy.orm import Mapped, mapped_column, relationship
from app.database import Base


class Budget(Base):
    __tablename__ = "budgets"

    id: Mapped[int] = mapped_column(primary_key=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id"), nullable=False, index=True)
    category_id: Mapped[int] = mapped_column(ForeignKey("categories.id"), nullable=False)
    name: Mapped[str] = mapped_column(String(200), nullable=False)
    amount: Mapped[Decimal] = mapped_column(Numeric(20, 2), nullable=False)
    currency_id: Mapped[int] = mapped_column(ForeignKey("currencies.id"), nullable=False)
    period_type: Mapped[str] = mapped_column(String(20), nullable=False)   # monthly | weekly | yearly | custom
    start_date: Mapped[date] = mapped_column(Date, nullable=False)
    end_date: Mapped[date | None] = mapped_column(Date)
    is_active: Mapped[bool] = mapped_column(Boolean, default=True, nullable=False)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())

    user: Mapped["User"] = relationship("User", back_populates="budgets")
    category: Mapped["Category"] = relationship("Category", back_populates="budgets")
    currency: Mapped["Currency"] = relationship("Currency", back_populates="budgets")