/*
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
 * agreements. See the NOTICE file 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 under
 * the License.
 */
package org.apache.geode.internal.process;

import org.apache.geode.distributed.internal.DistributionConfig;

import java.io.File;
import java.io.IOException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

/**
 * Manages which implementation of {@link ProcessController} will be used and constructs the
 * instance.
 * 
 * @since GemFire 8.0
 */
public final class ProcessControllerFactory {

  public static final String PROPERTY_DISABLE_ATTACH_API =
      DistributionConfig.GEMFIRE_PREFIX + "test.ProcessControllerFactory.DisableAttachApi";

  private final boolean disableAttachApi;

  public ProcessControllerFactory() {
    this.disableAttachApi = Boolean.getBoolean(PROPERTY_DISABLE_ATTACH_API);
  }

  public ProcessController createProcessController(final ProcessControllerParameters arguments,
      final int pid) {
    if (arguments == null) {
      throw new NullPointerException("ProcessControllerParameters must not be null");
    }
    if (pid < 1) {
      throw new IllegalArgumentException("Invalid pid '" + pid + "' specified");
    }
    try {
      if (isAttachAPIFound()) {
        return new MBeanProcessController((MBeanControllerParameters) arguments, pid);
      } else {
        return new FileProcessController((FileControllerParameters) arguments, pid);
      }
    } catch (final ExceptionInInitializerError e) {
      // LOGGER.warn("Attach API class not found", e);
    }
    return null;
  }

  public ProcessController createProcessController(final ProcessControllerParameters arguments,
      final File pidFile, final long timeout, final TimeUnit unit)
      throws IOException, InterruptedException, TimeoutException {
    if (arguments == null) {
      throw new NullPointerException("ProcessControllerParameters must not be null");
    }
    if (pidFile == null) {
      throw new NullPointerException("Pid file must not be null");
    }
    return createProcessController(arguments, new PidFile(pidFile).readPid(timeout, unit));
  }

  public ProcessController createProcessController(final ProcessControllerParameters arguments,
      final File directory, final String pidFilename, final long timeout, final TimeUnit unit)
      throws IOException, InterruptedException, TimeoutException {
    if (arguments == null) {
      throw new NullPointerException("ProcessControllerParameters must not be null");
    }
    if (directory == null) {
      throw new NullPointerException("Directory must not be null");
    }
    if (pidFilename == null) {
      throw new NullPointerException("Pid file name must not be null");
    }
    return createProcessController(arguments,
        new PidFile(directory, pidFilename).readPid(timeout, unit));
  }

  public boolean isAttachAPIFound() {
    if (this.disableAttachApi) {
      return false;
    }
    boolean found = false;
    try {
      final Class<?> virtualMachineClass = Class.forName("com.sun.tools.attach.VirtualMachine");
      found = virtualMachineClass != null;
    } catch (ClassNotFoundException e) {
    }
    return found;
  }
}