"""
Base classes for the strategy management system.

This module contains the fundamental building blocks for all trading strategies:
- StrategySignal: Represents trading signals with confidence and metadata
- StrategyBase: Abstract base class that all strategies must inherit from
"""

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


class StrategySignal:
    """
    Represents a trading signal from a strategy.
    
    A signal encapsulates the strategy's recommendation along with confidence
    level, optional price target, and additional metadata.
    
    Attributes:
        signal_type (str): Type of signal - "ENTRY", "EXIT", or "HOLD"
        confidence (float): Confidence level from 0.0 to 1.0
        price (Optional[float]): Optional specific price for the signal
        metadata (Dict): Additional signal data and context
    
    Example:
        # Entry signal with high confidence
        signal = StrategySignal("ENTRY", confidence=0.8)
        
        # Exit signal with stop loss price
        signal = StrategySignal("EXIT", confidence=1.0, price=50000, 
                              metadata={"type": "STOP_LOSS"})
    """
    
    def __init__(self, signal_type: str, confidence: float = 1.0, 
                 price: Optional[float] = None, metadata: Optional[Dict] = None):
        """
        Initialize a strategy signal.
        
        Args:
            signal_type: Type of signal ("ENTRY", "EXIT", "HOLD")
            confidence: Confidence level (0.0 to 1.0)
            price: Optional specific price for the signal
            metadata: Additional signal data and context
        """
        self.signal_type = signal_type
        self.confidence = max(0.0, min(1.0, confidence))  # Clamp to [0,1]
        self.price = price
        self.metadata = metadata or {}
    
    def __repr__(self) -> str:
        """String representation of the signal."""
        return (f"StrategySignal(type={self.signal_type}, "
                f"confidence={self.confidence:.2f}, "
                f"price={self.price}, metadata={self.metadata})")


class StrategyBase(ABC):
    """
    Abstract base class for all trading strategies.
    
    This class defines the interface that all strategies must implement:
    - initialize(): Setup strategy with backtester data
    - get_entry_signal(): Generate entry signals
    - get_exit_signal(): Generate exit signals
    - get_confidence(): Optional confidence calculation
    
    Attributes:
        name (str): Strategy name
        weight (float): Strategy weight for combination
        params (Dict): Strategy parameters
        initialized (bool): Whether strategy has been initialized
    
    Example:
        class MyStrategy(StrategyBase):
            def initialize(self, backtester):
                # Setup strategy indicators
                self.initialized = True
            
            def get_entry_signal(self, backtester, df_index):
                # Return StrategySignal based on analysis
                if should_enter:
                    return StrategySignal("ENTRY", confidence=0.7)
                return StrategySignal("HOLD", confidence=0.0)
    """
    
    def __init__(self, name: str, weight: float = 1.0, params: Optional[Dict] = None):
        """
        Initialize the strategy base.
        
        Args:
            name: Strategy name/identifier
            weight: Strategy weight for combination (default: 1.0)
            params: Strategy-specific parameters
        """
        self.name = name
        self.weight = weight
        self.params = params or {}
        self.initialized = False
    
    @abstractmethod
    def initialize(self, backtester) -> None:
        """
        Initialize strategy with backtester data.
        
        This method is called once before backtesting begins.
        Strategies should setup indicators, validate data, and
        set self.initialized = True when complete.
        
        Args:
            backtester: Backtest instance with data and configuration
        """
        pass
    
    @abstractmethod 
    def get_entry_signal(self, backtester, df_index: int) -> StrategySignal:
        """
        Generate entry signal for the given data index.
        
        Args:
            backtester: Backtest instance with current state
            df_index: Current index in the dataframe
            
        Returns:
            StrategySignal: Entry signal with confidence level
        """
        pass
    
    @abstractmethod
    def get_exit_signal(self, backtester, df_index: int) -> StrategySignal:
        """
        Generate exit signal for the given data index.
        
        Args:
            backtester: Backtest instance with current state
            df_index: Current index in the dataframe
            
        Returns:
            StrategySignal: Exit signal with confidence level
        """
        pass
    
    def get_confidence(self, backtester, df_index: int) -> float:
        """
        Get strategy confidence for the current market state.
        
        Default implementation returns 1.0. Strategies can override
        this to provide dynamic confidence based on market conditions.
        
        Args:
            backtester: Backtest instance with current state
            df_index: Current index in the dataframe
            
        Returns:
            float: Confidence level (0.0 to 1.0)
        """
        return 1.0
    
    def __repr__(self) -> str:
        """String representation of the strategy."""
        return (f"{self.__class__.__name__}(name={self.name}, "
                f"weight={self.weight}, initialized={self.initialized})")