from datetime import datetime, timezone
from sqlalchemy import Index, Integer, Text, DateTime, ForeignKey, text
from sqlalchemy.orm import mapped_column, Mapped
from app.database import Base


class UpstreamRateSnapshot(Base):
    __tablename__ = "upstream_rate_snapshots"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, index=True)
    upstream_id: Mapped[int] = mapped_column(Integer, ForeignKey("upstreams.id", ondelete="CASCADE"), index=True)
    snapshot_json: Mapped[str] = mapped_column(Text, nullable=False)
    captured_at: Mapped[datetime] = mapped_column(DateTime, default=lambda: datetime.now(timezone.utc), index=True)

    __table_args__ = (
        Index("ix_snapshot_upstream_captured", "upstream_id", text("captured_at DESC")),
    )