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// 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
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package com.cloud.vm;

import com.cloud.agent.api.StopAnswer;
import com.cloud.agent.manager.Commands;
import com.cloud.deploy.DeployDestination;
import com.cloud.exception.ResourceUnavailableException;

/**
 * A VirtualMachineGuru knows how to process a certain type of virtual machine.
 *
 */
public interface VirtualMachineGuru<T extends VirtualMachine> {
    /**
     * Find the virtual machine by name.
     * @param name
     * @return virtual machine.
     */
    T findByName(String name);
    
    T findById(long id);
    
    T persist(T vm);
    
    boolean finalizeVirtualMachineProfile(VirtualMachineProfile<T> profile, DeployDestination dest, ReservationContext context);
    
    /**
     * finalize the virtual machine deployment.
     * @param cmds commands that were created.
     * @param profile virtual machine profile.
     * @param dest destination to send the command.
     * @return true if everything checks out.  false if not and we should try again.
     */
    boolean finalizeDeployment(Commands cmds, VirtualMachineProfile<T> profile, DeployDestination dest, ReservationContext context) throws ResourceUnavailableException;
    
    /**
     * Check the deployment results.
     * @param cmds commands and answers that were sent.
     * @param profile virtual machine profile.
     * @param dest destination it was sent to.
     * @return true if deployment was fine; false if it didn't go well.
     */
    boolean finalizeStart(VirtualMachineProfile<T> profile, long hostId, Commands cmds, ReservationContext context);
    
    boolean finalizeCommandsOnStart(Commands cmds, VirtualMachineProfile<T> profile);
    
    void finalizeStop(VirtualMachineProfile<T> profile, StopAnswer answer);
    
    void finalizeExpunge(T vm);
    
    boolean recreateNeeded(VirtualMachineProfile<T> profile, long hostId, Commands cmds, ReservationContext context);
    
    /**
     * Returns the id parsed from the name.  If it cannot parse the name,
     * then return null.  This method is used to determine if this is
     * the right handler for this vm.
     * 
     * @param vmName vm name coming form the agent.
     * @return id if the handler works for this vm and can parse id.  null if not.
     */
    Long convertToId(String vmName);
}