/*
 * Copyright (c) 2015 Cisco Systems, Inc. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html.
 */
package org.opendaylight.controller.md.sal.binding.api;

import java.util.Collection;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import org.opendaylight.yangtools.yang.binding.Augmentation;
import org.opendaylight.yangtools.yang.binding.ChildOf;
import org.opendaylight.yangtools.yang.binding.DataObject;
import org.opendaylight.yangtools.yang.binding.Identifiable;
import org.opendaylight.yangtools.yang.binding.Identifier;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier.PathArgument;

/**
 * Modified Data Object.
 *
 * Represents modification of Data Object.
 *
 */
public interface DataObjectModification<T extends DataObject> extends org.opendaylight.yangtools.concepts.Identifiable<PathArgument> {

    enum ModificationType {
        /**
         *
         * Child node (direct or indirect) was modified.
         *
         */
        SUBTREE_MODIFIED,
        /**
         *
         * Node was explicitly created / overwritten.
         *
         */
        WRITE,
        /**
         *
         * Node was deleted.
         *
         */
        DELETE
    }

    @Override
    PathArgument getIdentifier();

    /**
     * Returns type of modified object.
     *
     * @return type of modified object.
     */
    @Nonnull Class<T> getDataType();

    /**
     *
     * Returns type of modification
     *
     * @return type Type of performed modification.
     */
    @Nonnull ModificationType getModificationType();

    /**
     * Returns after state of top level container.
     *
     * @param root Class representing data container
     * @return State of object after modification. Null if subtree is not present.
     */
    @Nullable T getDataAfter();

    /**
     * Returns unmodifiable collection of modified direct children.
     *
     * @return unmodifiable collection of modified direct children.
     */
    @Nonnull Collection<DataObjectModification<? extends DataObject>> getModifiedChildren();

    /**
     * Returns container child modification if {@code child} was modified by this
     * modification.
     *
     * For accessing all modified list items consider iterating over {@link #getModifiedChildren()}.
     *
     * @param child Type of child - must be only container
     * @return Modification of {@code child} if {@code child} was modified, null otherwise.
     * @throws IllegalArgumentException If supplied {@code child} class is not valid child according
     *         to generated model.
     */
    @Nullable <C extends ChildOf<? super T>> DataObjectModification<C> getModifiedChildContainer(@Nonnull Class<C> child);

    /**
     * Returns augmentation child modification if {@code augmentation} was modified by this
     * modification.
     *
     * For accessing all modified list items consider iterating over {@link #getModifiedChildren()}.
     *
     * @param augmentation Type of augmentation - must be only container
     * @return Modification of {@code augmentation} if {@code augmentation} was modified, null otherwise.
     * @throws IllegalArgumentException If supplied {@code augmentation} class is not valid augmentation
     *         according to generated model.
     */
    @Nullable <C extends Augmentation<T> & DataObject> DataObjectModification<C> getModifiedAugmentation(@Nonnull Class<C> augmentation);


    /**
     * Returns child list item modification if {@code child} was modified by this modification.
     *
     * @param listItem Type of list item - must be list item with key
     * @param listKey List item key
     * @return Modification of {@code child} if {@code child} was modified, null otherwise.
     * @throws IllegalArgumentException If supplied {@code listItem} class is not valid child according
     *         to generated model.
     */
    <C extends Identifiable<K> & ChildOf<? super T>, K extends Identifier<C>> DataObjectModification<C> getModifiedChildListItem(
            @Nonnull Class<C> listItem,@Nonnull  K listKey);

    /**
     * Returns a child modification if a node identified by {@code childArgument} was modified by
     * this modification.
     *
     * @param childArgument Path Argument of child node
     * @return Modification of child identified by {@code childArgument} if {@code childArgument}
     *         was modified, null otherwise.
     * @throws IllegalArgumentException If supplied path argument is not valid child according to
     *         generated model.
     *
     */
    @Nullable DataObjectModification<? extends DataObject> getModifiedChild(PathArgument childArgument);

}