/*
 * Copyright 2013-present Facebook, Inc.
 *
 * 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 com.facebook.buck.util.environment;

import com.google.common.base.Optional;

public interface ExecutionEnvironment {

  /**
   * @return The current hostname or 'unknown'
   */
  public String getHostname();

  /**
   * @return The current username or 'unknown'
   */
  public String getUsername();

  /**
   * @return The number of cores on this machine.
   */
  public int getAvailableCores();

  /**
   * @return The amount of system memory on this machine.
   */
  public long getTotalMemoryInMb();

  /**
   * @return The current operating system.
   */
  public Platform getPlatform();

  /**
   * @return The SSID of the current wifi network if it can be determined.
   */
  public Optional<String> getWifiSsid() throws InterruptedException;

  /**
   * Gets the environment variable indicated by the specified key.
   */
  public String getenv(String key, String defaultValue);

  /**
   * Gets the java property indicated by the specified key.
   */
  public String getProperty(String key, String defaultValue);
}