"""
PIT Ex-Dividend Calendar model — revisioned dividend announcements

Stores multiple revisions of the same (ticker, ex_dividend_date) with different
as_of_date values, enabling Point-in-Time backtesting without lookahead bias.
"""

from datetime import datetime, timezone
import uuid

from sqlalchemy import Column, String, Float, Index, UniqueConstraint
from sqlalchemy.dialects.postgresql import UUID, TIMESTAMP

from app.core.database import Base


class DividendCalendar(Base):
    __tablename__ = "dividend_calendar"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    ticker = Column(String(10), nullable=False, index=True)
    ex_dividend_date = Column(TIMESTAMP(timezone=True), nullable=False)
    amount = Column(Float, nullable=False)
    declaration_date = Column(TIMESTAMP(timezone=True), nullable=True)
    record_date = Column(TIMESTAMP(timezone=True), nullable=True)
    payment_date = Column(TIMESTAMP(timezone=True), nullable=True)
    currency = Column(String(10), default="USD")
    dividend_type = Column(String(20), default="regular")  # regular | special
    frequency = Column(String(20), nullable=True)  # quarterly | semi-annual | annual | monthly | irregular
    as_of_date = Column(TIMESTAMP(timezone=True), nullable=False)  # PIT key
    source = Column(String(50), nullable=False)  # "yfinance", "finra_orf", etc.
    source_file_date = Column(TIMESTAMP(timezone=True), nullable=True)

    created_at = Column(
        TIMESTAMP(timezone=True), default=lambda: datetime.now(timezone.utc)
    )
    updated_at = Column(
        TIMESTAMP(timezone=True),
        default=lambda: datetime.now(timezone.utc),
        onupdate=lambda: datetime.now(timezone.utc),
    )

    __table_args__ = (
        UniqueConstraint(
            "ticker", "ex_dividend_date", "as_of_date", "source",
            name="uq_dividend_calendar",
        ),
        Index("idx_dividend_ticker_exdate", "ticker", "ex_dividend_date"),
        Index("idx_dividend_exdate", "ex_dividend_date"),
        Index("idx_dividend_as_of", "as_of_date"),
        # Composite index directly supports DISTINCT ON (ticker, ex_dividend_date) ORDER BY as_of_date DESC
        Index("idx_dividend_pit_query", "ticker", "ex_dividend_date", "as_of_date"),
    )