"""
Base Fetcher class
"""
from abc import ABC, abstractmethod
import pandas as pd

class DataFetcher(ABC):
    def __init__(self, api_key: str):
        self.api_key = api_key

    @abstractmethod
    def get_income_statement(self, symbol: str) -> pd.DataFrame:
        pass

    @abstractmethod
    def get_balance_sheet(self, symbol: str) -> pd.DataFrame:
        pass

    @abstractmethod
    def get_cash_flow(self, symbol: str) -> pd.DataFrame:
        pass

    @abstractmethod
    def get_market_metrics(self, symbol: str) -> dict:
        pass

    def get_historical_metrics(self, symbol: str, dates: list) -> pd.DataFrame:
        """Optional method, not all fetchers need to implement"""
        return pd.DataFrame()

    def get_dividends(self, symbol: str) -> pd.DataFrame:
        """Optional method"""
        return pd.DataFrame()

    def get_repurchases(self, symbol: str) -> pd.DataFrame:
        """Optional method"""
        return pd.DataFrame()

    def get_employee_count(self, symbol: str) -> pd.DataFrame:
        """Optional method"""
        return pd.DataFrame()