from abc import ABC, abstractmethod
from datetime import datetime
import xml.etree.ElementTree as ET

class Entry(ABC):
    """
    Abstract base class for all entry types in the working memory.
    
    Attributes:
        id: Unique identifier for the entry
        timestamp: When the entry was created
    """
    
    def __init__(self, id: str, timestamp: datetime):
        """
        Initialize a new entry with provided id and timestamp.
        
        Args:
            id: Unique identifier for this entry
            timestamp: Creation timestamp for this entry
        """
        self.id = id
        self.timestamp = timestamp
    
    @abstractmethod
    def update(self) -> None:
        """
        Update the entry's state.
        Must be implemented by concrete classes.
        """
        pass
    
    @abstractmethod
    def generate_context(self) -> ET.Element:
        """
        Generate an XML Element representing this entry's context.
        Must be implemented by concrete classes.
        
        Returns:
            ET.Element: XML element containing the entry's data
        """
        pass

    def cleanup(self) -> None:
        """
        Clean up any resources used by this entry.
        Should be overridden by classes that need cleanup.
        Default implementation does nothing.
        """
        pass