/*
 * Copyright (C) 2006 Alfresco, Inc.
 *
 * Licensed under the Mozilla Public License version 1.1 
 * with a permitted attribution clause. You may obtain a
 * copy of the License at
 *
 *   http://www.alfresco.org/legal/license.txt
 *
 * 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.alfresco.service.cmr.avmsync;

import java.util.List;

/**
 * This service handles comparisons and synchronizations between
 * corresponding avm node trees.
 * @author britt
 */
public interface AVMSyncService
{
    /**
     * Get a difference list between two corresponding node trees.
     * @param srcVersion The version id for the source tree.
     * @param srcPath The avm path to the source tree.
     * @param dstVersion The version id for the destination tree.
     * @param dstPath The avm path to the destination tree.
     * @return A List of AVMDifference structs which can be used for
     * the update operation.
     */
    public List<AVMDifference> compare(int srcVersion, String srcPath, 
                                       int dstVersion, String dstPath);
    
    /**
     * Updates the destination nodes in the AVMDifferences
     * with the source nodes. Normally any conflicts or cases in
     * which the source of an AVMDifference is older than the destination
     * will cause the transaction to roll back.
     * @param diffList A List of AVMDifference structs.
     * @param ignoreConflicts If this is true the update will skip those 
     * AVMDifferences which are in conflict with
     * the destination.
     * @param ignoreOlder If this is true the update will skip those 
     * AVMDifferences which have the source older than the destination.
     * @param overrideConflicts If this is true the update will override conflicting
     * AVMDifferences and replace the destination with the conflicting source.
     * @param overrideOlder If this is true the update will override AVMDifferences
     * in which the source is older than the destination and overwrite the destination.
     * @param tag Short comment.
     * @param description Full update blurb.
     */
    public void update(List<AVMDifference> diffList, boolean ignoreConflicts, boolean ignoreOlder,
                       boolean overrideConflicts, boolean overrideOlder, String tag, String description);
    
    /**
     * Flattens a layer so that all all nodes under and including
     * <code>layerPath</code> become translucent to any nodes in the 
     * corresponding location under and including <code>underlyingPath</code>
     * that are the same version. 
     * @param layerPath The overlying layer path.
     * @param underlyingPath The underlying path.
     */
    public void flatten(String layerPath, String underlyingPath);
    
    /**
     * Takes a layer, deletes it and recreates it pointing at the same underlying
     * node. Any changes in the layer are lost (except to history if the layer has been 
     * snapshotted.)
     * @param layerPath
     */
    public void resetLayer(String layerPath);
}