import org.jastadd.plugin.compiler.ast.ICompletionNode;

import org.eclipse.jface.text.contentassist.CompletionProposal;
import org.eclipse.swt.graphics.Image;

import java.util.Comparator;
import java.util.Collection;
import java.util.Collections;

aspect Completion {

	/*
	 * The ICompletionNode interface must be implemented by ASTNode for 
	 * the AST to provide completion proposals
	 */
	ASTNode implements ICompletionNode;

	/*
	 * Default behavior for the getCompletionProposal(...) method in the
	 * ICompletionNode interface is to put together attribute values
	 * into a CompletionProposal.
	 */
	syn CompletionProposal ASTNode.getCompletionProposal(String filter, int documentOffset, boolean keepDot) {
		String label = completionLabel();
		Image image = contentOutlineImage();
		String proposal = completionProposal();
		String comment = completionComment();
		int cursorOffset = completionProposalOffset();
		
		if(keepDot) {
			return new CompletionProposal(proposal, documentOffset - filter.length(), 
				      filter.length(), cursorOffset, image, label, null, comment);
		}
		return new CompletionProposal(proposal, documentOffset - filter.length(), 
                 filter.length(), cursorOffset, image, label, null, comment);
	}

	/* 
	 * Default behavior for completionLabel() is to return the name of the node class
	 */
	syn String ASTNode.completionLabel() = this.getClass().getName();
	
	/*
	 * Default behavior is to return class name
	 */
	syn String ASTNode.completionProposal() = this.getClass().getName();
	
	/*
	 * Default behavior is to equal the offset with the length of the
	 * String value from completionProposal()
	 */
   	syn int ASTNode.completionProposalOffset() = completionProposal().length();
   	
    /*
     * Default behavior is an empty list
     */	
	syn Collection ASTNode.completion(String filter) = Collections.EMPTY_LIST;
	
	/*
	 * Default completion comment is null
	 */
	syn String ASTNode.completionComment() = null;
}