/*

 * Copyright (c) 2009, 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

package invokeinterface;

import java.lang.reflect.Method;

import java.lang.reflect.Modifier;

public class Checker extends shared.Checker {

    private Class interfaceClass;

    public Checker(Class interfaceClass, Class dynamicTargetClass) {

        super(interfaceClass, dynamicTargetClass);

        if (staticTargetClass.isInterface()) {

            this.interfaceClass = staticTargetClass;

        } else {

            throw new RuntimeException("Static target class should be an interface.");

        }

    }

    public String check (Class callerClass) {

        // Check access rights to interface for caller

        if (!checkAccess(interfaceClass, callerClass)) {

            return "java.lang.IllegalAccessError";

        }

        // NSME is thrown when interface doesn't declare the method

        if (getDeclaredMethod(interfaceClass) == null) {

            return "java.lang.NoSuchMethodError";

        }

        // 9.1.5 Access to Interface Member Names

        // "All interface members are implicitly public. They are

        // accessible outside the package where the interface is

        // declared if the interface is also declared public or

        // protected, in accordance with the rules of 6.6."

        // Search for method declaration in the hierarchy

        Class klass = dynamicTargetClass;

        while (klass != Object.class) {

            Method method = getDeclaredMethod(klass);

            if (method != null) {

                int modifiers = method.getModifiers();

                // Check whether obtained method is public and isn't abstract

                if ( Modifier.isPublic(modifiers)) {

                    if (Modifier.isAbstract(modifiers)) {

                        return "java.lang.AbstractMethodError";

                    } else {

                        return String.format("%s.%s",

                            method.getDeclaringClass().getSimpleName(),

                            methodName);

                    }

                } else {

                    // IAE is thrown when located method isn't PUBLIC

                    // or private.  Private methods are skipped when

                    // looking for an interface method.

                    if (!Modifier.isPrivate(modifiers)) {

                        return "java.lang.IllegalAccessError";

                    }

                }

            }

            klass = klass.getSuperclass();

        }

        // No method declaration is found

        return "java.lang.AbstractMethodError";

    }

}