"""Abstract base class for RL algorithms."""
from abc import ABC, abstractmethod
from typing import Dict, Any
import torch


class RLAlgorithm(ABC):
    """
    Abstract base class for reinforcement learning algorithms.
    
    Defines the interface that all RL algorithms must implement
    for training voice models.
    """
    
    def __init__(self, learning_rate: float, **kwargs):
        """
        Initialize the RL algorithm.
        
        Args:
            learning_rate: Learning rate for optimization
            **kwargs: Additional algorithm-specific parameters
        """
        self.learning_rate = learning_rate
        self.hyperparameters = kwargs
    
    @abstractmethod
    def compute_loss(
        self,
        states: torch.Tensor,
        actions: torch.Tensor,
        rewards: torch.Tensor,
        next_states: torch.Tensor,
        **kwargs
    ) -> torch.Tensor:
        """
        Compute the loss for the current batch.
        
        Args:
            states: Current states
            actions: Actions taken
            rewards: Rewards received
            next_states: Next states
            **kwargs: Additional algorithm-specific inputs
        
        Returns:
            Loss tensor
        """
        pass
    
    @abstractmethod
    def update_policy(self, loss: torch.Tensor) -> Dict[str, Any]:
        """
        Update the policy based on computed loss.
        
        Args:
            loss: Computed loss tensor
        
        Returns:
            Dictionary containing update metrics (e.g., gradient norms)
        """
        pass
    
    def get_hyperparameters(self) -> Dict[str, Any]:
        """
        Get the hyperparameters for this algorithm.
        
        Returns:
            Dictionary of hyperparameter names and values
        """
        return {
            'learning_rate': self.learning_rate,
            **self.hyperparameters
        }
    
    def set_hyperparameter(self, name: str, value: Any) -> None:
        """
        Set a hyperparameter value.
        
        Args:
            name: Hyperparameter name
            value: New value
        """
        if name == 'learning_rate':
            self.learning_rate = value
        else:
            self.hyperparameters[name] = value