from abc import ABC, abstractmethod
from typing import Optional, Dict, Any


class StockAPIBase(ABC):
    """
    Abstract base class for stock price data providers.
    This design allows seamless switching between different stock APIs.
    """

    @abstractmethod
    def get_stock_price(self, ticker: str) -> Optional[Dict[str, Any]]:
        """
        Retrieve current stock price and related data for a given ticker.

        Args:
            ticker: Stock ticker symbol (e.g., 'PYPL', 'AAPL')

        Returns:
            Dictionary containing:
                - ticker: str
                - current_price: float
                - previous_close: float
                - change_dollar: float
                - change_percent: float
                - market_open: bool
            Returns None if ticker is invalid or data unavailable.
        """
        pass

    @abstractmethod
    def is_available(self) -> bool:
        """
        Check if the API service is currently available.

        Returns:
            True if API is accessible, False otherwise.
        """
        pass