// Fig. 17.8: SharedBufferTest.cpp
// Concurrent threads correctly manipulating a synchronized buffer.
#include <chrono>
#include <fmt/format.h>
#include <iostream>
#include <mutex>
#include <random>
#include <thread>
#include "SynchronizedBuffer.h"

int main() {
   // set up random-number generation 
   std::random_device rd;
   std::default_random_engine engine{rd()};
   std::uniform_int_distribution ints{0, 3000};
   std::mutex intsMutex;

   // lambda for synchronized random sleep time generation
   auto getSleepTime{
      [&]() {
         std::lock_guard lock{intsMutex};
         return std::chrono::milliseconds{ints(engine)};
      }
   };

   // create SynchronizedBuffer to store ints       
   SynchronizedBuffer buffer;

   // lambda expression that produces the values 1-10 and sums them 
   auto produce{
      [&buffer, &getSleepTime]() {
         int sum{0};

         for (int count{1}; count <= 10; ++count) {
            // get random sleep time then sleep
            std::this_thread::sleep_for(getSleepTime());

            buffer.put(count); // set value in buffer
            sum += count; // add count to sum of values produced
         }

         std::cout << "Producer done producing\nTerminating Producer\n";
      }
   };

   // lambda expression that consumes the values 1-10 and sums them
   auto consume{
      [&buffer, &getSleepTime]() {
         int sum{0};

         for (int count{1}; count <= 10; ++count) {
            // get random sleep time then sleep
            std::this_thread::sleep_for(getSleepTime());

            sum += buffer.get(); // get buffer value and add to sum
         }

         std::cout << fmt::format("\n{} {}\n{}\n",
            "Consumer read values totaling", sum, "Terminating Consumer");
      }
   };

   std::cout << fmt::format("{:<40}{}\t\t{}\n{:<40}{}\t\t{}\n\n",
      "Operation", "Buffer", "Occupied",
      "---------", "------", "--------");

   std::jthread producer{produce}; // start producer thread
   std::jthread consumer{consume}; // start consumer thread 
}

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