"""Abstract base class for all trading strategies."""

from abc import ABC, abstractmethod

from shared.schemas.trading import MarketSnapshot, SentimentContext, TradeSignal


class BaseStrategy(ABC):
    """Base class that all trading strategies must inherit from.

    Subclasses implement :meth:`evaluate` to inspect market data and
    optionally sentiment, returning a :class:`TradeSignal` when the
    strategy has a directional opinion and ``None`` otherwise.
    """

    name: str

    @abstractmethod
    async def evaluate(
        self,
        ticker: str,
        market: MarketSnapshot,
        sentiment: SentimentContext | None = None,
    ) -> TradeSignal | None:
        """Return a signal if this strategy has an opinion, None otherwise."""
        ...