#ifndef __PROCESS_TIMEOUT_HPP__
#define __PROCESS_TIMEOUT_HPP__

#include <process/process.hpp>

#include <stout/duration.hpp>

namespace process {

class Timeout
{
public:
  Timeout()
    : timeout(Clock::now()) {}

  Timeout(const Duration& duration)
    : timeout(Clock::now() + duration.secs()) {}

  Timeout(const Timeout& that)
    : timeout(that.timeout) {}

  Timeout& operator = (const Timeout& that)
  {
    if (this != &that) {
      timeout = that.timeout;
    }

    return *this;
  }

  Timeout& operator = (const Duration& duration)
  {
    timeout = Clock::now() + duration.secs();
    return *this;
  }

  bool operator == (const Timeout& that) const
  {
    return timeout == that.timeout;
  }

  bool operator < (const Timeout& that) const
  {
    return timeout < that.timeout;
  }

  bool operator <= (const Timeout& that) const
  {
    return timeout <= that.timeout;
  }

  // Returns the value of the timeout as the number of seconds elapsed
  // since the epoch.
  double value() const
  {
    return timeout;
  }

  // Returns the amount of time remaining.
  Duration remaining() const
  {
    double seconds = timeout - Clock::now();
    return Seconds(seconds > 0 ? seconds : 0);
  }

  // Returns true if the timeout expired.
  bool expired() const
  {
    return (timeout - Clock::now()) <= 0;
  }

private:
  double timeout;
};

}  // namespace process {

#endif // __PROCESS_TIMEOUT_HPP__