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

#define OPERATOR_NUM 1
#define CUSTOMER_NUM 1






static struct{
	sem_t line_lock;
	int line_number;
	sem_t customers[CUSTOMER_NUM];
	sem_t oper_line_lock;
	int curr_customer;
	sem_t customer_ready;
} line_oper;



static struct{
	sem_t line_lock;
	int line_number;
	sem_t customers[CUSTOMER_NUM];
	sem_t customer_ready;
} line_cashier;


void * Cashier_FN(void * data){
	int i=0;
	for(; i<CUSTOMER_NUM; i++){
		sem_wait(&line_cashier.customer_ready);
		printf("cashier done queue %d\n", i);
		sem_post(&line_cashier.customers[i]);
	}
}

void * Operator_FN(void * data){
	int oper = *(int  *)data;
	printf("%d\n", oper);
	int curr_customer;
	while(1){
		sem_wait(&line_oper.customer_ready);
		sem_wait(&line_oper.oper_line_lock);
		curr_customer = line_oper.curr_customer++;
		sem_post(&line_oper.oper_line_lock);
		printf("operator %d done with queue %d\n", oper, curr_customer);
		sem_post(&line_oper.customers[curr_customer]);
		if(curr_customer == CUSTOMER_NUM)break;
	}

}



void * CUSTOMER_FN(void * data){
	int order;

	sem_wait(&line_oper.line_lock);
	order = line_oper.line_number;

	line_oper.line_number ++;
	printf("customer %d took queue number %d\n", *(int *)data,order);
	sem_post(&line_oper.line_lock);
	sem_post(&line_oper.customer_ready);
	sem_wait(&line_oper.customers[order]);

	sem_wait(&line_cashier.line_lock);
	order = line_cashier.line_number++;
	printf("customer %d took queue for cashier%d\n",*(int *)data, order);
	sem_post(&line_cashier.line_lock);
	sem_post(&line_cashier.customer_ready);
	sem_wait(&line_cashier.customers[order]);


}

void init_setup(){
	sem_init(&line_oper.line_lock, 0, 1);
	line_oper.line_number = 0;
	int i=0;
	for(; i<CUSTOMER_NUM; i++){
		sem_init(&line_oper.customers[i], 0, 0);
	}
	sem_init(&line_oper.oper_line_lock, 0, 1);
	line_oper.curr_customer = 0;
	sem_init(&line_oper.customer_ready, 0, 0);

	sem_init(&line_cashier.line_lock, 0, 1);
	line_cashier.line_number = 0;
	i=0;
	for(; i<CUSTOMER_NUM; i++){
		sem_init(&line_cashier.customers[i], 0, 0);
	}
	line_oper.curr_customer = 0;
	sem_init(&line_cashier.customer_ready, 0, 0);
}


int main(){
	init_setup();

	pthread_t cashier;
	pthread_create(&cashier, NULL, Cashier_FN, NULL);
	pthread_t t[OPERATOR_NUM];
	pthread_t tx[CUSTOMER_NUM];
	int i=0;
	for(; i<OPERATOR_NUM; i++){
		int x = i+1;
		pthread_create(&t[i], NULL, Operator_FN, &x);
	}

	i=0;
	for(; i<CUSTOMER_NUM; i++){
		int x = i+1;
		pthread_create(&tx[i], NULL, CUSTOMER_FN, &x);
	}



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

for(i=0; i<OPERATOR_NUM; i++){
	pthread_join(t[i], NULL);
}
pthread_join(cashier, NULL);
	return 0;
}