/**
 * Copyright 2005-2018 The Kuali Foundation
 *
 * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
 *
 * 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.kuali.rice.krad.data.provider.annotation;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import org.kuali.rice.krad.data.metadata.DataObjectCollection;

/**
 * Defines that the associated Collection field contains a collection of DataObjects.
 *
 * <p>Analog to the {@link DataObjectCollection} metadata.</p>
 *
 * @author Kuali Rice Team (rice.collab@kuali.org)
 */
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface CollectionRelationship {
	/**
	 * The element type of the collection.
     *
     * <p>If the collection contains Generics, it will be derived automatically.</p>
     *
     * @return the element type of the collection.
	 */
	Class<?> collectionElementClass() default Object.class;

	/**
	 * The list of attribute relationships linking the parent object and the collection objects.
     *
     * @return list of attribute relationships linking the parent object and the collection objects.
	 */
	AttributeRelationship[] attributeRelationships();

	/**
	 * The default sort order for the collection.
     *
     * @return the default sort order for the collection.
	 */
	CollectionSortAttribute[] sortAttributes() default {};

    /**
     * The minimum items that can appear in the collection.
     *
     * @return lhe minimum items that can appear in the collection.
     */
	long minItemsInCollection() default 0L;

    /**
     * The maximum items that can appear in the collection.
     *
     * @return lhe maximum items that can appear in the collection.
     */
	long maxItemsInCollection() default Long.MAX_VALUE;

	/**
	 * Whether this collection uses an indirection table between the parent and collection objects.
     *
     * <p>This has no function at present, but is here for informational purposes.</p>
     *
     * @return whether this collection uses an indirection table between the parent and collection objects.
	 */
	boolean indirectCollection() default false;

	/**
	 * When needed, how to label each element of the collection.
     *
     * <p>This is usually singular.  Will default to the label of the contained element type.</p>
     *
     * @return how to label each element of the collection.
	 */
	String elementLabel() default "";

	/**
	 * The label of the collection itself.
     *
     * <p>This is usually plural.</p>
     *
     * @return the label of the collection itself.
	 */
	String label() default "";
}
