#!/usr/bin/env python3
"""
Base classes for data connectors.
"""

import abc
from datetime import datetime
from typing import List, Optional, Dict, Any
from dataclasses import dataclass
from enum import Enum


class Interval(Enum):
    """Trading data intervals."""
    MINUTE_1 = "1m"
    MINUTE_5 = "5m"
    MINUTE_15 = "15m"
    MINUTE_30 = "30m"
    HOUR_1 = "1h"
    HOUR_4 = "4h"
    DAY_1 = "1d"
    WEEK_1 = "1w"
    MONTH_1 = "1M"


@dataclass
class OHLCV:
    """Standard OHLCV data point."""
    timestamp: datetime
    open: float
    high: float
    low: float
    close: float
    volume: float
    symbol: str
    interval: Interval
    
    def to_dict(self) -> Dict[str, Any]:
        return {
            "timestamp": self.timestamp.isoformat(),
            "open": self.open,
            "high": self.high,
            "low": self.low,
            "close": self.close,
            "volume": self.volume,
            "symbol": self.symbol,
            "interval": self.interval.value
        }


@dataclass
class InstrumentInfo:
    """Instrument metadata."""
    symbol: str
    name: str
    exchange: str
    currency: str
    lot_size: int
    min_price_increment: float
    trading_hours: Optional[str] = None
    is_tradable: bool = True


class DataConnector(abc.ABC):
    """Abstract base class for data connectors."""
    
    @abc.abstractmethod
    def connect(self) -> bool:
        """Establish connection to data source."""
        pass
    
    @abc.abstractmethod
    def disconnect(self):
        """Close connection."""
        pass
    
    @abc.abstractmethod
    def get_ohlcv(
        self,
        symbol: str,
        interval: Interval,
        start_date: datetime,
        end_date: datetime,
        limit: Optional[int] = None
    ) -> List[OHLCV]:
        """
        Fetch historical OHLCV data.
        
        Args:
            symbol: Trading symbol (e.g., "AAPL")
            interval: Time interval
            start_date: Start of period
            end_date: End of period
            limit: Maximum number of records to return
            
        Returns:
            List of OHLCV objects
        """
        pass
    
    @abc.abstractmethod
    def get_instrument_info(self, symbol: str) -> InstrumentInfo:
        """Get instrument metadata."""
        pass
    
    @abc.abstractmethod
    def subscribe_ohlcv(
        self,
        symbols: List[str],
        interval: Interval,
        callback
    ):
        """
        Subscribe to real-time OHLCV updates.
        
        Args:
            symbols: List of symbols to subscribe to
            interval: Interval for updates
            callback: Function to call with new OHLCV data
        """
        pass
    
    @abc.abstractmethod
    def unsubscribe(self, symbols: List[str]):
        """Cancel subscriptions."""
        pass
    
    @property
    @abc.abstractmethod
    def is_connected(self) -> bool:
        """Check if connector is currently connected."""
        pass
    
    @property
    @abc.abstractmethod
    def request_count(self) -> int:
        """Total number of API requests made."""
        pass