// Copyright 2012 Citrix Systems, Inc. Licensed under the
// Apache License, Version 2.0 (the "License"); you may not use this
// file except in compliance with the License.  Citrix Systems, Inc.
// reserves all rights not expressly granted by 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.
// 
// Automatically generated by addcopyright.py at 04/03/2012
package com.cloud.ha.dao;

import java.util.List;

import com.cloud.ha.HaWorkVO;
import com.cloud.ha.HighAvailabilityManager.WorkType;
import com.cloud.utils.db.GenericDao;

public interface HighAvailabilityDao extends GenericDao<HaWorkVO, Long> {

    /**
     * Takes an available HA work item.
     * 
     * @param serverId server that is taking this.
     * @return WorkVO if there's one to work on; null if none.
     */
    HaWorkVO take(long serverId);

    /**
     * Finds all the work items related to this instance.
     * 
     * @param instanceId
     * @return list of WorkVO or empty list.
     */
    List<HaWorkVO> findPreviousHA(long instanceId);
    
    boolean delete(long instanceId, WorkType type);

    /**
     * Finds all the work items that were successful and is now ready to be purged.
     * 
     * @param time that the work item must be successful before.
     * @return list of WorkVO or empty list.
     */
    void cleanup(long time);
    
    void deleteMigrationWorkItems(final long hostId, final WorkType type, final long serverId);
    
    List<HaWorkVO> findTakenWorkItems(WorkType type);
    
    /**
     * finds out if a work item has been scheduled for this work type but has not been taken yet.
     * 
     * @param instanceId vm instance id
     * @param type type of work scheduled for it.
     * @return true if it has been scheduled and false if it hasn't.
     */
    boolean hasBeenScheduled(long instanceId, WorkType type);

    int releaseWorkItems(long nodeId);

    /**
     * Look for HA work that has been scheduled for a vm since a certain work id.
     * 
     * @param vmId virtual machine id.
     * @param workId work item id.
     * @return List of work items.
     */
    List<HaWorkVO> listFutureHaWorkForVm(long vmId, long workId);

    /**
     * Look for HA work that is being run right now for a VM.
     * 
     * @param vmId virtual machine id
     * @return List of work items
     */
    List<HaWorkVO> listRunningHaWorkForVm(long vmId);
}