// List.java

public class List
{
	private ListNode firstNode;
	private ListNode lastNode;
	private int size = 0;
	private String name;


	// constructor creates empty list with name
	public List()
	{
		this( "list" );
	} // end constructor


	// constructor creates empty list with a name
	public List( String listName )
	{
		firstNode = lastNode = null;
		name = listName;
	} // end constructor

	// get first node
	public ListNode getFirstNode()
	{
		return firstNode;
	} // end method getFirstNode


	// get last node
	public ListNode getLastNode()
	{
		return lastNode;
	} // end method getLastNode


	// get size
	public int getSize()
	{
		return size;
	} // end method getSize


	// insert a node at the front of the list
	public void insertAtFront( Object insertItem )
	{
		if( isEmpty() )
			firstNode = lastNode = new ListNode( insertItem );
		else
			firstNode = new ListNode( insertItem, firstNode );

		size++;
	} // end method insertAtFront


	// insert a node at the back of the list
	public void insertAtBack( Object insertItem )
	{
		if( isEmpty() )
			firstNode = lastNode = new ListNode( insertItem );
		else
			lastNode = lastNode.nextNode = new ListNode( insertItem );

		size++;
	} // end method insertAtBack


	// remove node at specified position or original list
	public Object removeNodeAt( int position, int removedNodes ) throws EmptyListException
	{
		ListNode current = firstNode;
		ListNode removed = null;
		if ( position > 1 && position <= size )
		{
			for( int i = 1; i < position - 1; i++ )
				current = current.nextNode;

			removed = current.nextNode;
			current.nextNode = current.nextNode.nextNode;
			size--;
			System.out.printf( "Node at %d removed\n\n", position + removedNodes );
		} // end if
		else if ( position == 1 && position <= size)
		{
			removed = firstNode;
			firstNode = firstNode.nextNode;
			size--;
			System.out.printf( "Node at %d removed\n\n", position + removedNodes );
		}
		else if ( position < 1 && position < size )
			System.out.printf( "Cannot remove node at %d, does not exist\n\n", position + removedNodes );
		else if ( isEmpty() )
			System.out.printf( "No elements to be removed.\n\n" );
		else if ( position > size )
			System.out.printf( "Cannot remove node at %d, does not exist.\n\n", position + removedNodes );
		return removed;
	} // end method removeNodeAt


	public boolean isEmpty()
	{
		return firstNode == null;
	} // end method isEmpty


	// output list contents
	public void print()
	{
		if( isEmpty() )
		{
			System.out.printf( "Empty %s\n", name );
			return;
		} // end if

		System.out.printf( "The list %s is: ", name );
		ListNode current = firstNode;

		// while not at the end of list output current node's data
		while( current != null )
		{
			System.out.printf( "%s ", current.data );
			current = current.nextNode;
	 	} // end while

		System.out.println();
		System.out.printf ( "The size of list is %d\n", size );
	 	System.out.println( "\n" );
	} // end method print
} // end class List