/**
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package org.apache.isis.core.unittestsupport.utils;

import java.lang.reflect.Field;
import java.lang.reflect.Method;

import javax.jdo.annotations.PersistenceCapable;
import javax.jdo.annotations.Persistent;

import com.google.common.base.Predicate;
import com.google.common.base.Strings;

public class ReflectUtils {

    public static <T> Predicate<Field> withTypeAssignableFrom(final Class<T> type) {
        return new Predicate<Field>() {
            public boolean apply(Field input) {
                return input != null && input.getType().isAssignableFrom(type);
            }
        };
    }

    public static <T> Predicate<Method> withReturnTypeAssignableFrom(final Class<T> type) {
        return new Predicate<Method>() {
            public boolean apply(Method input) {
                return input != null && input.getReturnType().isAssignableFrom(type);
            }
        };
    }

    public static Predicate<Method> withParametersAssignableFrom(final Class<?>... types) {
        return new Predicate<Method>() {
            public boolean apply(Method input) {
                if (input != null) {
                    Class<?>[] parameterTypes = input.getParameterTypes();
                    if (parameterTypes.length == types.length) {
                        for (int i = 0; i < parameterTypes.length; i++) {
                            if (!parameterTypes[i].isAssignableFrom(types[i])) {
                                return false;
                            }
                        }
                        return true;
                    }
                }
                return false;
            }
        };
    }

    public static final Predicate<? super Field> persistentMappedBy = new Predicate<Field>() {
        public boolean apply(Field f) {
            final Persistent annotation = f.getAnnotation(Persistent.class);
            return annotation!=null && !Strings.isNullOrEmpty(annotation.mappedBy());
        }
    };

    public static Predicate<? super Method> withEntityParameter() {
        return new Predicate<Method>() {
            public boolean apply(Method m) {
                final Class<?> parameterType = m.getParameterTypes()[0];
                return parameterType.isAnnotationPresent(PersistenceCapable.class);
            }
        };
    }

}
