#pragma once

#include <chrono>

#include "envoy/common/pure.h"

namespace Envoy {

/**

 * Less typing for common system time and steady time type.

 *

 * SystemTime should be used when getting a time to present to the user, e.g. for logging.

 * MonotonicTime should be used when tracking time for computing an interval.

 */

using Seconds = std::chrono::seconds;

using SystemTime = std::chrono::time_point<std::chrono::system_clock>;

using MonotonicTime = std::chrono::time_point<std::chrono::steady_clock>;

/**

 * Captures a system-time source, capable of computing both monotonically increasing

 * and real time.

 */

class TimeSource {

public:

  /**

   * @return the current system time; not guaranteed to be monotonically increasing.

   */

  virtual SystemTime systemTime() PURE;

  /**

   * @return the current monotonic time.

   */

  virtual MonotonicTime monotonicTime() PURE;

};

} // namespace Envoy