#pragma once

#include <twist/stdlike/mutex.hpp>
#include <twist/stdlike/condition_variable.hpp>
#include <twist/support/locking.hpp>

namespace solutions {

class Semaphore {
 public:
  explicit Semaphore(const size_t count = 0) : counter_(count) {
  }

  void Acquire() {
    std::unique_lock<twist::mutex> lock(mutex_);
    while (counter_ == 0) {
      is_empty_.wait(lock);
    }
    --counter_;
  }

  void Release() {
    std::unique_lock<twist::mutex> lock(mutex_);
    ++counter_;
    is_empty_.notify_one();
  }

 private:
  size_t counter_;
  twist::mutex mutex_;
  twist::condition_variable is_empty_;
};

}  // namespace solutions