Copyright (c) 2013, 2016 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2013, 2016 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.compiler.lookup;

import org.eclipse.jdt.internal.compiler.ast.Wildcard;
import org.eclipse.jdt.internal.compiler.util.SimpleLookupTable;


public class TypeBindingVisitor {

	private SimpleLookupTable visitedCache;

	public void reset() {
		this.visitedCache = null;
	}

	public boolean visit(BaseTypeBinding baseTypeBinding)  {
		return true;  // continue traversal.
	}

	public boolean visit(ArrayBinding arrayBinding) {
		return true;  // continue traversal.
	}
	
	public boolean visit(TypeVariableBinding typeVariable) {
		return true;  // continue traversal.
	}
	
	public boolean visit(ReferenceBinding referenceBinding) {
		return true;  // continue traversal.
	}
	
	public boolean visit(WildcardBinding wildcardBinding) {
		return true;  // continue traversal.
	}
	
	public boolean visit(ParameterizedTypeBinding parameterizedTypeBinding) {
		return true;  // continue traversal.
	}
	
	public boolean visit(IntersectionTypeBinding18 intersectionTypeBinding18) {
		return true;  // continue traversal.
	}
	
	public boolean visit(RawTypeBinding rawTypeBinding) {
		return true;  // continue traversal.
	}
	
	public boolean visit(PolyTypeBinding polyTypeBinding) {
		return true;  // continue traversal.
	}

	public static void visit(TypeBindingVisitor visitor, ReferenceBinding[] types) {
		for (int i = 0, length = types == null ? 0 : types.length; i < length; i++) {
	        visit(visitor, types[i]);
	    }
	}

	public static void visit(TypeBindingVisitor visitor, TypeBinding type) {

		if (type == null) 
			return;
		
		SimpleLookupTable visitedCache = visitor.visitedCache;
		if (visitedCache == null) {
			visitor.visitedCache = new SimpleLookupTable(3);
			visitedCache = visitor.visitedCache;
		}

		Object result = visitedCache.get(type);
		if (result == Boolean.TRUE)
			return;
		visitedCache.put(type, Boolean.TRUE);
		switch (type.kind()) {
			
			case Binding.TYPE_PARAMETER:
				TypeVariableBinding typeVariableBinding = (TypeVariableBinding) type;
				if (visitor.visit(typeVariableBinding)) {
					visit(visitor, typeVariableBinding.firstBound);
					visit(visitor, typeVariableBinding.superclass);
					visit(visitor, typeVariableBinding.superInterfaces);
				}
	            break;
	            
			case Binding.PARAMETERIZED_TYPE:
				ParameterizedTypeBinding parameterizedTypeBinding = (ParameterizedTypeBinding) type;
				if (visitor.visit(parameterizedTypeBinding)) {
					visit(visitor, parameterizedTypeBinding.enclosingType());
					visit(visitor, parameterizedTypeBinding.arguments);
				}
				break;

			case Binding.ARRAY_TYPE:
				ArrayBinding arrayBinding = (ArrayBinding) type;
				if (visitor.visit(arrayBinding))
					visit(visitor, arrayBinding.leafComponentType);
				break;

			case Binding.WILDCARD_TYPE:
			case Binding.INTERSECTION_TYPE:
		        WildcardBinding wildcard = (WildcardBinding) type;
		        if (visitor.visit(wildcard)) {
		        	if (wildcard.boundKind != Wildcard.UNBOUND) {
		        		visit(visitor, wildcard.bound);
		        		visit(visitor, wildcard.otherBounds);
		        	}
		        }
				break;
			
			case Binding.BASE_TYPE:
				visitor.visit((BaseTypeBinding) type);
				break;
			
			case Binding.RAW_TYPE:
				visitor.visit((RawTypeBinding) type);
				break;
				
			case Binding.TYPE:
			case Binding.GENERIC_TYPE:
				ReferenceBinding referenceBinding = (ReferenceBinding) type;
				if (visitor.visit(referenceBinding)) {
					visit(visitor, referenceBinding.enclosingType());
					visit(visitor, referenceBinding.typeVariables());
				}
				break;
			
			case Binding.INTERSECTION_TYPE18:
				IntersectionTypeBinding18 intersectionTypeBinding18 = (IntersectionTypeBinding18) type;
				if (visitor.visit(intersectionTypeBinding18))
					visit(visitor, intersectionTypeBinding18.intersectingTypes);
				break;
				
			case Binding.POLY_TYPE:
				visitor.visit((PolyTypeBinding) type);
				break;
				
			default:
				throw new InternalError("Unexpected binding type"); //$NON-NLS-1$
		}
	}

	public static void visit(TypeBindingVisitor visitor, TypeBinding[] types) {
		for (int i = 0, length = types == null ? 0 : types.length; i < length; i++) {
	        visit(visitor, types[i]);
	    }
	}
}