"""
Base table class for database operations.

This module provides the base Table class that handles cursor management
and common database operations for table-specific implementations.
"""

import sqlite3
from typing import Optional, Any


class Table:
    """
    Base class for database table operations.
    
    Attributes:
        connection: SQLite database connection
        cursor: Database cursor for executing queries
    """
    
    def __init__(self, connection: sqlite3.Connection):
        """
        Initialize the table with a database connection.
        
        Args:
            connection: SQLite database connection
        """
        self.connection = connection
        self.cursor = self.connection.cursor()
    
    def create(self):
        """Create the table structure. To be implemented by subclasses."""
        raise NotImplementedError("Subclasses must implement create() method")
    
    def exists(self, pk_value: Any) -> bool:
        """
        Check if a record exists by primary key.
        
        Args:
            pk_value: Primary key value to check
            
        Returns:
            True if record exists, False otherwise
        """
        raise NotImplementedError("Subclasses must implement exists() method")
    
    def save(self, obj: Any) -> bool:
        """
        Save a single object to the database.
        
        Args:
            obj: Object to save
            
        Returns:
            True if object was saved, False if it already exists
        """
        raise NotImplementedError("Subclasses must implement save() method")
    
    def load(self, pk_value: Any) -> Optional[Any]:
        """
        Load a single object from the database by primary key.
        
        Args:
            pk_value: Primary key value to load
            
        Returns:
            Object if found, None otherwise
        """
        raise NotImplementedError("Subclasses must implement load() method")
    
    def commit(self):
        """Commit pending changes to the database."""
        self.connection.commit()
    
    def close(self):
        """Close the cursor."""
        self.cursor.close()