/*
 * Copyright © 2016-2018 European Support Limited
 *
 * Licensed 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.openecomp.sdc.externalupload.utils;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.common.collect.ImmutableSet;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import java.util.Set;
import org.apache.commons.beanutils.BeanUtils;

public class ServiceUtils {

    private static ImmutableSet<Class> collectionClasses = ImmutableSet.of(Map.class, List.class, Set.class);
    private static ImmutableSet<Class> primitiveTypesClasses = ImmutableSet.of(String.class, Integer.class, Double.class, Float.class);

    private ServiceUtils() {
    }

    public static <T> Optional<T> createObjectUsingSetters(Object objectCandidate, Class<T> classToCreate) throws Exception {
        if (Objects.isNull(objectCandidate)) {
            return Optional.empty();
        }
        Map<String, Object> objectAsMap = getObjectAsMap(objectCandidate);
        T result = classToCreate.newInstance();
        List<Field> declaredFields = getAllFields(classToCreate);
        for (Field field : declaredFields) {
            if (isComplexClass(field)) {
                Optional<?> objectUsingSetters = createObjectUsingSetters(objectAsMap.get(field.getName()), field.getType());
                if (objectUsingSetters.isPresent()) {
                    objectAsMap.remove(field.getName());
                    objectAsMap.put(field.getName(), objectUsingSetters.get());
                }
            }
        }
        BeanUtils.populate(result, objectAsMap);
        return Optional.of(result);
    }

    private static <T> List<Field> getAllFields(Class<T> clazz) {
        List<Field> fields = new ArrayList<>();
        for (Class<?> c = clazz; c != null; c = c.getSuperclass()) {
            fields.addAll(Arrays.asList(c.getDeclaredFields()));
        }
        return fields;
    }

    private static boolean isComplexClass(Field field) {
        return !isCollectionClass(field) && !isPrimitiveClass(field) && !field.getType().equals(Object.class);
    }

    private static boolean isCollectionClass(Field field) {
        return collectionClasses.contains(field.getType());
    }

    private static boolean isPrimitiveClass(Field field) {
        return primitiveTypesClasses.contains(field.getType());
    }

    public static Map<String, Object> getObjectAsMap(Object obj) {
        return new ObjectMapper().convertValue(obj, Map.class);
    }

    public static Set<String> getClassFieldNames(Class<? extends Object> classType) {
        Set<String> fieldNames = new HashSet<>();
        List<Field> allFields = getAllFields(classType);
        allFields.forEach(field -> fieldNames.add(field.getName()));
        return fieldNames;
    }
}