from datetime import UTC, datetime

from sqlalchemy import DateTime, Float, Integer, String, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column

from database import Base


class PriceHistory(Base):
    """Price history records from external exchanges."""

    __tablename__ = "price_history"
    __table_args__ = (
        UniqueConstraint("source", "pair", "timestamp", name="uq_price_source_pair_ts"),
    )

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    source: Mapped[str] = mapped_column(String(50), nullable=False, index=True)
    pair: Mapped[str] = mapped_column(String(20), nullable=False)
    price: Mapped[float] = mapped_column(Float, nullable=False)
    timestamp: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, index=True
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(UTC)
    )