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 * Copyright 2013, Google Inc.
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 * modification, are permitted provided that the following conditions are
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 *
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 * notice, this list of conditions and the following disclaimer.
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 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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package org.jf.dexlib2.analysis.util;

import org.jf.dexlib2.analysis.TypeProto;
import org.jf.dexlib2.analysis.UnresolvedClassException;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.Iterator;
import java.util.NoSuchElementException;

public class TypeProtoUtils {
    
Get the chain of superclasses of the given class. The first element will be the immediate superclass followed by
it's superclass, etc. up to java.lang.Object.
Returns an empty iterable if called on java.lang.Object or a primitive.
If any class in the superclass chain can't be resolved, the iterable will return Ujava/lang/Object; to represent
the unknown class.
Returns:
An iterable containing the superclasses of this class./**
     * Get the chain of superclasses of the given class. The first element will be the immediate superclass followed by
     * it's superclass, etc. up to java.lang.Object.
     *
     * Returns an empty iterable if called on java.lang.Object or a primitive.
     *
     * If any class in the superclass chain can't be resolved, the iterable will return Ujava/lang/Object; to represent
     * the unknown class.
     *
     * @return An iterable containing the superclasses of this class.
     */
    @Nonnull
    public static Iterable<TypeProto> getSuperclassChain(@Nonnull final TypeProto typeProto) {
        return new Iterable<TypeProto>() {

            @Override public Iterator<TypeProto> iterator() {
                return new Iterator<TypeProto>() {
                    @Nullable private TypeProto type = getSuperclassAsTypeProto(typeProto);

                    @Override public boolean hasNext() {
                        return type != null;
                    }

                    @Override public TypeProto next() {
                        TypeProto type = this.type;
                        if (type == null) {
                            throw new NoSuchElementException();
                        }

                        this.type = getSuperclassAsTypeProto(type);
                        return type;
                    }

                    @Override public void remove() {
                        throw new UnsupportedOperationException();
                    }
                };
            }
        };
    }

    @Nullable
    public static TypeProto getSuperclassAsTypeProto(@Nonnull TypeProto type) {
        try {
            String next = type.getSuperclass();
            if (next != null) {
                return type.getClassPath().getClass(next);
            } else {
                return null;
            }
        } catch (UnresolvedClassException ex) {
            return type.getClassPath().getUnknownClass();
        }
    }

    public static boolean extendsFrom(@Nonnull TypeProto candidate, @Nonnull String possibleSuper) {
        if (candidate.getType().equals(possibleSuper)) {
            return true;
        }
        for (TypeProto superProto: getSuperclassChain(candidate)) {
            if (superProto.getType().equals(possibleSuper)) {
                return true;
            }
        }
        return false;
    }
}