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

typedef enum Shape {PAPER = 2, ROCK = 1, SCISSORS = 0} Shape;
char* shapeNames[] = { "scissors", "rock", "paper" };

// return 1 if shape1 beats shape2
// return 2 if shape2 beats shape1
// return 0 if shape1 and shape2 are the same shape
int game(Shape shape1, Shape shape2) {
	int diff = shape1 - shape2;
	return diff < 0 ? diff + 3 : diff;
}


Shape playerShape[2];
int playing = 1;
sem_t readyToPlay[2], readyToJudge;

void* player(void* param) {
	int playerNo = *(int*)param;
	while(playing) {
		sem_wait(&readyToPlay[playerNo]);
		printf("%d\n", playerNo);
		playerShape[playerNo] = rand() % 3;
		sem_post(&readyToJudge);
	}
}

void* judge(void* param) {
	int points1 = 0, points2 = 0;
	while(points1 != 3 && points2 != 3) {
		sleep(1);
		sem_wait(&readyToJudge);
		sem_wait(&readyToJudge);
		int ret = game(playerShape[0], playerShape[1]);
		printf("%s vs %s\n", shapeNames[playerShape[0]], shapeNames[playerShape[1]]);
		if(ret == 1) {
			points1++;
			printf("Player1 wins the round - %d : %d\n", points1, points2);		
		}
		if(ret == 2) {
			points2++;
			printf("Player2 wins the round - %d : %d\n", points1, points2);		
		}
		if(points1 == 3 || points2 == 3)
			playing = 0;
		sem_post(&readyToPlay[0]);
		sem_post(&readyToPlay[1]);
	}
}

int main() {
	pthread_t player1, player2, moderator;
	int indexPlayer1 = 0, indexPlayer2 = 1;
	srand(time(0));
	
	sem_init(&readyToJudge, 0, 0);
	sem_init(&readyToPlay[0], 0, 1);
	sem_init(&readyToPlay[1], 0, 1);

	pthread_create(&player1, 0, player, &indexPlayer1);
	pthread_create(&player2, 0, player, &indexPlayer2);
	pthread_create(&moderator, 0, judge, 0);

	pthread_join(player1, 0);
	pthread_join(player2, 0);

	sem_destroy(&readyToJudge);
	sem_destroy(&readyToPlay[0]);
	sem_destroy(&readyToPlay[1]);
}