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// Licensed to the Apache Software Foundation (ASF) under one
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// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you 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
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package com.cloud.hypervisor.xenserver.resource.wrapper.xenbase;


import com.cloud.agent.api.Answer;
import com.cloud.agent.api.storage.ResizeVolumeAnswer;
import com.cloud.agent.api.storage.ResizeVolumeCommand;
import com.cloud.hypervisor.xenserver.resource.CitrixResourceBase;
import com.cloud.resource.CommandWrapper;
import com.cloud.resource.ResourceWrapper;
import com.cloud.utils.exception.CloudRuntimeException;
import com.xensource.xenapi.Connection;
import com.xensource.xenapi.PBD;
import com.xensource.xenapi.SR;
import com.xensource.xenapi.VDI;

import java.util.HashSet;
import java.util.Set;

import static com.cloud.utils.NumbersUtil.toHumanReadableSize;

@ResourceWrapper(handles =  ResizeVolumeCommand.class)
public final class CitrixResizeVolumeCommandWrapper extends CommandWrapper<ResizeVolumeCommand, Answer, CitrixResourceBase> {

    @Override
    public Answer execute(final ResizeVolumeCommand command, final CitrixResourceBase citrixResourceBase) {
        Connection conn = citrixResourceBase.getConnection();

        String volId = command.getPath();
        long newSize = command.getNewSize();

        try {

            if (command.getCurrentSize() == newSize) {
                logger.info("No need to resize volume [{}], current size [{}] is same as new size [{}].", volId, toHumanReadableSize(command.getCurrentSize()), toHumanReadableSize(newSize));
                return new ResizeVolumeAnswer(command, true, "success", newSize);
            } else if (command.getCurrentSize() > newSize) {
                logger.error("XenServer does not support volume shrink. Volume [{}] current size [{}] is smaller than new size [{}]", volId, toHumanReadableSize(command.getCurrentSize()), toHumanReadableSize(newSize));
                return new ResizeVolumeAnswer(command, false, "operation not supported");
            }
            if (command.isManaged()) {
                resizeSr(conn, command);
            }

            VDI vdi = citrixResourceBase.getVDIbyUuid(conn, volId);

            vdi.resize(conn, newSize);

            return new ResizeVolumeAnswer(command, true, "success", newSize);
        } catch (Exception ex) {
            logger.warn("Unable to resize volume", ex);

            String error = "Failed to resize volume: " + ex;

            return new ResizeVolumeAnswer(command, false, error);
        }
    }

    private void resizeSr(Connection conn, ResizeVolumeCommand command) {
        // If this is managed storage, re-size the SR, too.
        // The logical unit/volume has already been re-sized, so the SR needs to fill up the new space.

        String iScsiName = command.get_iScsiName();

        try {
            Set<SR> srs = SR.getByNameLabel(conn, iScsiName);
            Set<PBD> allPbds = new HashSet<>();

            for (SR sr : srs) {
                if (!(CitrixResourceBase.SRType.LVMOISCSI.equals(sr.getType(conn))))  {
                    continue;
                }

                Set<PBD> pbds = sr.getPBDs(conn);

                if (pbds.size() <= 0) {
                    logger.debug("No PBDs found for the following SR: " + sr.getNameLabel(conn));
                }

                allPbds.addAll(pbds);
            }

            for (PBD pbd: allPbds) {
                PBD.Record pbdr = pbd.getRecord(conn);

                if (pbdr.currentlyAttached) {
                    pbd.unplug(conn);
                    pbd.plug(conn);
                }
            }
        }
        catch (Throwable ex) {
            throw new CloudRuntimeException("Unable to resize volume: " +  ex.getMessage());
        }
    }
}
