from datetime import date, datetime

from sqlalchemy import Date, DateTime, Float, ForeignKey, Index, String, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.database import Base


class EarningsEvent(Base):
    """Earnings calendar + surprise history, sourced from the DoltHub earnings repo.

    Forward rows (``announce_date`` > today) are the calendar; past rows are
    results. Rescheduling is handled in the importer's promotion transaction:
    this source's future-dated rows are deleted and re-inserted from the new
    snapshot so moved/cancelled dates never linger; past rows are never deleted.
    """

    __tablename__ = "earnings_events"
    __table_args__ = (
        UniqueConstraint("ticker_id", "announce_date", name="uq_earnings_ticker_announce"),
        Index("ix_earnings_events_announce_date", "announce_date"),
    )

    id: Mapped[int] = mapped_column(primary_key=True)
    ticker_id: Mapped[int] = mapped_column(
        ForeignKey("tickers.id", ondelete="CASCADE"), nullable=False
    )
    announce_date: Mapped[date] = mapped_column(Date, nullable=False)
    # bmo | amc | unknown (source coverage is partial)
    session: Mapped[str] = mapped_column(String(10), nullable=False, default="unknown")
    period_end: Mapped[date | None] = mapped_column(Date, nullable=True)
    eps_estimate: Mapped[float | None] = mapped_column(Float, nullable=True)
    eps_actual: Mapped[float | None] = mapped_column(Float, nullable=True)
    source: Mapped[str] = mapped_column(String(32), nullable=False)
    import_run_id: Mapped[int | None] = mapped_column(
        ForeignKey("data_import_runs.id", ondelete="SET NULL"), nullable=True
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=datetime.utcnow, nullable=False
    )

    ticker = relationship("Ticker", back_populates="earnings_events")