from datetime import UTC, datetime

from sqlalchemy import DateTime, Integer
from sqlalchemy.orm import Mapped, mapped_column

from database import Base


class PricingConfig(Base):
    """Pricing configuration for exchange trades.

    Singleton pattern: Only one record should exist in the database.
    Updates modify the existing record rather than creating new ones.
    """

    __tablename__ = "pricing_config"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)

    # Premium settings
    premium_buy: Mapped[int] = mapped_column(Integer, nullable=False)  # -100 to 100
    premium_sell: Mapped[int] = mapped_column(Integer, nullable=False)  # -100 to 100
    small_trade_threshold_eur: Mapped[int] = mapped_column(
        Integer, nullable=False
    )  # EUR cents, e.g., 20000 = €200
    small_trade_extra_premium: Mapped[int] = mapped_column(
        Integer, nullable=False
    )  # -100 to 100

    # Trade amount limits (EUR cents)
    eur_min_buy: Mapped[int] = mapped_column(Integer, nullable=False)
    eur_max_buy: Mapped[int] = mapped_column(Integer, nullable=False)
    eur_min_sell: Mapped[int] = mapped_column(Integer, nullable=False)
    eur_max_sell: Mapped[int] = mapped_column(Integer, nullable=False)

    # Timestamps
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(UTC)
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(UTC),
        onupdate=lambda: datetime.now(UTC),
    )