/*******************************************************************************
 * Copyright (c) 2005, 2014 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.ICPPASTNameSpecifier;
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. 
 */
public abstract class ASTNameVisitor extends ASTVisitor {
    private final int fOffset;
    private final 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
	public final int visit(IASTName name) {
        if (name instanceof ICPPASTQualifiedName) {
            ICPPASTQualifiedName qn= (ICPPASTQualifiedName) name;
            ICPPASTNameSpecifier[] segments= qn.getQualifier();
            boolean visited= false;
            for (int i = 0; i <= segments.length; i++) {
                IASTNode segment = i < segments.length ? segments[i] : qn.getLastName();
				if (segment instanceof IASTName && checkLocation(segment)) {
                    if (visitName((IASTName) segment) == PROCESS_ABORT) {
                        return PROCESS_ABORT;
                    }
                    visited= true;
                }
            }
            if (!visited) {
                if (checkLocation(name)) {
                    return visitName(name.getLastName());
                }
            }
        } 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;
    }
}