/*******************************************************************************
 * Copyright (c) 2005, 2008 Wind River Systems, Inc.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Eclipse Public License v1.0 
 * which accompanies this distribution, and is available at 
 * http://www.eclipse.org/legal/epl-v10.html  
 * 
 * Contributors: 
 *    Markus Schorn - initial API and implementation 
 ******************************************************************************/ 
package org.eclipse.cdt.internal.ui.refactoring.rename;

import org.eclipse.cdt.core.dom.ast.ASTVisitor;
import org.eclipse.cdt.core.dom.ast.IASTFileLocation;
import org.eclipse.cdt.core.dom.ast.IASTName;
import org.eclipse.cdt.core.dom.ast.IASTNode;
import org.eclipse.cdt.core.dom.ast.IASTNodeLocation;
import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTQualifiedName;

/**
 * Visitor to prefer simple ASTNames over the qualified ones. This is different
 * to the strategy used within the dom-package. 
 */
abstract public class ASTNameVisitor extends ASTVisitor {
    private int fOffset= -1;
    private String fFileName;

    public ASTNameVisitor(String fileName) {
        this(fileName, -1);
    }
    
    public ASTNameVisitor(String fileName, int offset) {
        fFileName= fileName;
        fOffset= offset;
        shouldVisitNames=true;
    }
    
    abstract protected int visitName(IASTName name);
    
    @Override
	final public int visit(IASTName name) {
        if (name instanceof ICPPASTQualifiedName) {
            ICPPASTQualifiedName qn= (ICPPASTQualifiedName) name;
            IASTName[] names= qn.getNames();
            boolean visited= false;
            for (int i = 0; i < names.length; i++) {
                if (checkLocation(names[i])) {
                    if (visitName(names[i]) == PROCESS_ABORT) {
                        return PROCESS_ABORT;
                    }
                    visited= true;
                }
            }
            if (!visited && names.length>0) {
                if (checkLocation(name)) {
                    return visitName(names[names.length-1]);
                }
            }
        }
        else if (checkLocation(name)) {
            return visitName(name);
        }
        return PROCESS_CONTINUE;
    }
        
    private boolean checkLocation(IASTNode node) {
        if (fFileName==null) {
            return true;
        }
        if (!fFileName.equals(node.getContainingFilename())) {
            return false;
        }
        IASTFileLocation loc= null;
        if (node instanceof IASTName) {
        	loc= ASTManager.getImageFileLocation((IASTName) node);
        }
        else {
            IASTNodeLocation[] locs= node.getNodeLocations();
            if (locs!=null && locs.length==1) {
            	if (locs[0] instanceof IASTFileLocation) {
            		loc= (IASTFileLocation) locs[0];
            	}
            }
        }
        if (loc==null) {
            return false;
        }
        if (fOffset==-1) {
            return true;
        }
        int off= loc.getNodeOffset();
        int len = loc.getNodeLength();
        return off <= fOffset && fOffset < off+len;
    }
}