/*
 * Copyright 2000-2013 JetBrains s.r.o.
 *
 * Licensed 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 under the License.
 */

package jetbrains.buildServer.clouds.vmware;

import com.intellij.openapi.diagnostic.Logger;
import java.util.Collection;
import jetbrains.buildServer.clouds.CloudException;
import jetbrains.buildServer.clouds.CloudInstanceUserData;
import jetbrains.buildServer.clouds.vmware.settings.VMImageInfo;
import jetbrains.buildServer.clouds.vmware.vmrun.VMRun;
import jetbrains.buildServer.clouds.vmware.vmrun.VMRunParameters;
import org.jetbrains.annotations.NotNull;

/**
 * @author Eugene Petrenko
 *         Created: 20.03.2010 18:08:18
 */
public class CachedVMRun implements VMRun {
  private static final Logger LOG = Logger.getInstance(CachedVMRun.class.getName());

  private final VMRun myVMRun;
  private volatile String myClientId;
  private volatile String myHostName;
  private volatile Integer myAllowedMachines;
  private volatile Integer myVersion;

  public CachedVMRun(@NotNull final VMRun VMRun) {
    myVMRun = VMRun;
  }

  @NotNull
  public String getHostName() {
    return myHostName != null ? myHostName : (myHostName = myVMRun.getHostName());
  }

  @NotNull
  public Collection<VMImageInfo> getLocalImages() {
    return myVMRun.getLocalImages();
  }

  public synchronized int getAllowedMachinesToRun() {
    if (myAllowedMachines != null) {
      return myAllowedMachines;
    } else {
      try {
        myAllowedMachines = myVMRun.getAllowedMachinesToRun();
      } catch (Throwable t) {
        warnObsoleteClient(t);
        myAllowedMachines = 1;
      }
      return myAllowedMachines;
    }
  }

  @NotNull
  public String getLocationId() {
    return myClientId != null ? myClientId : (myClientId = myVMRun.getLocationId());
  }

  @NotNull
  public Collection<VMImageInfo> getRunningImages() {
    return myVMRun.getRunningImages();
  }

  public void startMachine(@NotNull final VMRunParameters instance, @NotNull final CloudInstanceUserData data)
    throws CloudException {
    myVMRun.startMachine(instance, data);
  }

  public void terminateMachine(@NotNull final VMImageInfo image) {
    myVMRun.terminateMachine(image);
  }

  public synchronized int getVersion(final int serverVersion) {
    if (myVersion != null) {
      return myVersion;
    }

    try {
      myVersion = myVMRun.getVersion(serverVersion);
    } catch (Throwable t) {
      warnObsoleteClient(t);
      myVersion = 0;
    }
    return myVersion;
  }

  private void warnObsoleteClient(final Throwable t) {
    LOG.info("Client: " + getHostName() + " is obsolete");
    LOG.debug(t.getMessage(), t);
  }
}