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/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright (c) 2013-2020 Madz. All rights reserved.
 * 
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License"). You
 * may not use this file except in compliance with the License. You can
 * obtain a copy of the License at
 * https://raw.github.com/zhongdj/Lifecycle/master/License.txt
 * . See the License for the specific
 * language governing permissions and limitations under the License.
 * 
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 * 
 * Modifications:
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 * enclosed by brackets [] replaced by your own identifying information:
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 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
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 * recipient has the option to distribute your version of this file under
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package net.imadz.util;

import java.lang.reflect.Method;
import java.util.ArrayList;

public class MethodScanner {

    private static final ArrayList> SHOULD_TERMINATE_SCAN = new ArrayList>();

    private MethodScanner() {}

    public static void scanMethodsOnClasses(Class klass, final MethodScanCallback scanner) {
        scanMethodsOnClasses(new Class[] { klass }, scanner);
    }

    private static void scanMethodsOnClasses(Class[] klasses, final MethodScanCallback scanner) {
        if ( 0 == klasses.length ) {
            return;
        }
        ArrayList> superclasses = null;
        for ( final Class klass : klasses ) {
            superclasses = scanClass(scanner, klass);
            if ( 0 >= superclasses.size() ) {
                return;
            }
        }
        scanMethodsOnClasses(superclasses.toArray(new Class[superclasses.size()]), scanner);
    }

    private static ArrayList> scanClass(final MethodScanCallback scanner, Class klass) {
        if ( processDeclaredMethods(scanner, klass) ) {
            return SHOULD_TERMINATE_SCAN;
        } else {
            return populateSuperclasses(klass);
        }
    }

    private static boolean processDeclaredMethods(final MethodScanCallback scanner, Class klass) {
        for ( Method method : klass.getDeclaredMethods() ) {
            if (method.isBridge()) continue;
            if ( scanner.onMethodFound(method) ) {
                return true;
            }
        }
        return false;
    }

    private static ArrayList> populateSuperclasses(Class klass) {
        final ArrayList> superclasses = new ArrayList>();
        if ( hasSuperclass(klass) ) {
            superclasses.add(klass.getSuperclass());
        }
        for ( Class interfaze : klass.getInterfaces() ) {
            superclasses.add(interfaze);
        }
        return superclasses;
    }

    private static boolean hasSuperclass(Class klass) {
        return null != klass.getSuperclass() && Object.class != klass;
    }
}