#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <pthread.h>

void* clientThread (void* arg);

int freeMugs = 0;
int beersDrank = 0;

int freeTaps = 0;
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

void* clientThread(void* arg) {
	int id = *((int*) arg);

	int i, tap, mug;
	int beers = 5;

	printf("[Klient %d]: Wejscie do pubu!\n", id);

	for (i = 0; i < beers; i++) {
		printf("FREE MUGS: %d \n", freeMugs);
		// SEKCJA KRYTYCZNA

		while(1) {
			pthread_mutex_lock(&mutex);
			if (freeMugs > 0) {
				freeMugs--; // ZAJECIE KUFLA
				// OPUSZCZENIE SEKCJI KRYTYCZNEJ
				pthread_mutex_unlock(&mutex);


				break;
			} else {
				pthread_mutex_unlock(&mutex);
			}
		}

		tap = 0;
		printf("[Klient %d]: Nalanie piwa z kranu %d!\n", id, tap);
		usleep(300);
		beersDrank++;
		printf("[Klient %d]: WYPICIE PIWA!\n", id);
		nanosleep((struct timespec[]){{0, 500000000L}}, NULL);
		printf("[Klient %d]: Zwrot kufla!\n", id);

		pthread_mutex_lock(&mutex);
		freeMugs++; // ZWROT KUFLA DO PULI
		pthread_mutex_unlock(&mutex);
	}

	printf("[Klient %d]: Wyjscie z pubu!\n", id);
	return(NULL);
}

main () {
	pthread_t* client;
	int* clientId;

	int clientsCount, mugsCount, tapsCount, i;

	// Initial data
	printf("\nLiczba klientow: "); scanf("%d", &clientsCount);
	printf("\nLiczba kufli: "); scanf("%d", &mugsCount);
	tapsCount = 3;

	// Spawn clients
	client = (pthread_t*) malloc(clientsCount * sizeof(pthread_t));
	clientId = (int*) malloc(clientsCount * sizeof(int));

	for (i = 0; i < clientsCount; i++) clientId[i] = i;

	// Start
	printf("Pub zostal otwarty!\n");
	freeMugs = mugsCount;
	freeTaps = tapsCount;
	printf("W pubie zostalo %d wolnych kufli!\n", freeMugs);

	for (i = 0; i < clientsCount; i++) {
		pthread_create(&client[i], NULL, clientThread, &clientId[i]);
	}

	for(i = 0; i < clientsCount; i++){
		pthread_join(client[i], NULL);
	}

	printf("DZISIAJ WYPITO %d KUFLI!\n", beersDrank);
	printf("Pub zostal zamkniety!\n");

}