#include <cstdio>
#include <cstdlib>
#include <unistd.h>
#include <semaphore.h>
#include <pthread.h>

const int BUFFER_SIZE = 10;
bool running = true;
int buffer[BUFFER_SIZE];
int product = 0;
int next_prod = 0, next_consume = 0;
sem_t empty, full;
pthread_mutex_t mutex;

void insert_item(int id){
    buffer[next_prod] = product;
    product++;
    printf("Producer %d produced: %d \n", id, buffer[next_prod]);
    next_prod = (next_prod + 1) % BUFFER_SIZE;
}

void* producer(void* id){

    int producer_id = *((int*)id);

    while(running){

        sem_wait(&empty);
        pthread_mutex_lock(&mutex, NULL);

        insert_item(producer_id);

        pthread_mutex_unlock(&mutex, NULL);
        sem_post(&full);
    }
}



int main(int argc, char *argv[]){

    if(argc != 4){
        fprintf(stderr, "usage: %s how_long_to_sleep producer_threads consumer_threads\n", argv[0]);
        exit(-1);
    }

    int sleep_time = atoi(argv[1]);
    int num_producers = atoi(argv[2]);
    int num_consumers = atoi(argv[3]);
    pthread_t producers[num_producers];
    pthread_t consumers[num_consumers];

    pthread_mutex_init(&mutex, NULL);
    sem_init(&empty, 0, BUFFER_SIZE);
    sem_init(&full, 0, 0);

    // create producers
    for(int i = 0; i < num_producers; i++){
        pthread_create(&producers[i], NULL, producer, (void*) &i);
    };

    // create consumers
    // or(int i = 0; i < num_consumers; i++){
    //  pthread_create(&consumers[i], NULL, consumer, (void*) &i);
    // };



    printf("going to sleep for %i seconds\n", sleep_time);
    sleep(sleep_time);
    running = false;

    sem_destroy(&full);
    sem_destroy(&empty);
    pthread_mutex_destroy(&mutex);
}