#include<stdio.h>
#define HAVE_STRUCT_TIMESPEC
#pragma comment(lib, "pthreadVC2.lib")
#include <pthread.h>
#include <semaphore.h>
#include<stdlib.h>
#include <time.h>
#include <stdbool.h>
#include <Windows.h>

#define vMax 50       // maximum visitor threads
#define dMax 5        // maximum doctor threads
#define roomMax 4     // maximum visitors in a room
#define MAX 100
#define pshared 0 // 0:threads   1+:process
#define key 1 // 1+:unlocked   0:locked

#define BUFFER_SIZE 5 // 50 visitors + 3 doctors
int buffer[BUFFER_SIZE];
pthread_t visitorQueue[vMax];
pthread_t doctorQueue[dMax];
int visitorCursor, doctorCursor = 0;
int visitorCount, doctorCount = 0;
int peopleInside = 0;
sem_t s;
int i, number = 0;
bool isDisplay = false; // Check if the display thread is created

// Critical section, a thread enters the room
void* enterRoom() {
    // enter room
    // pause a random perid
    // exit room
    int wait = 42; // generateTime();
    srand(time(0));
    printf("Visitor %lu wishes to enter.\n", pthread_self());
    printf("Visitor %lu entered the patient's room, waited for 42 ms.\n", GetThreadId());
    Sleep(wait);
    printf("Visitor %lu exited the patient's room, stayed for %d ms.\n", GetThreadId(), wait);
    sem_post(&s);
    exit(0);
}


//void* display() {
//    printf("Display -> In the room: %d doctors [ %d ], and %d visitors [ %d, %d]\n");
//    return NULL;
//}

// Specifies the thread type
void type(){
    sem_wait(&s);
    if (visitorCount < vMax) {
        visitorCount++;
        visitorQueue[visitorCursor] = pthread_self(); // Add the thread to the visitor queue;
        visitorCursor = ++visitorCursor % vMax; // Increment circular cursor
        enterRoom();
    }
    else if (doctorCount < dMax) { // < 4 or < 5 if there's a doctor in the room
        doctorCount++;
        doctorQueue[doctorCursor] = pthread_self(); // Add the thread to the visitor queue;
        doctorCursor = ++doctorCursor % dMax; // Increment circular cursor
    }
}

int main() {
    pthread_t TID[BUFFER_SIZE + 1]; // one for display
    sem_init(&s, pshared, key);
    //pthread_create(&TID[i], NULL, (void*)display, NULL); // create a display thread
    for (i = 0; i < BUFFER_SIZE + 1; i++) {
        // create thread
        pthread_create(&TID[i], NULL, (void*)type, NULL);
    }
    for (i = 0; i < +1; i++) {
        //printf("Contents of visitor queue: %lu\n", visitorQueue[i]);
    }
    for (i = 0; i < BUFFER_SIZE + 1; i++) {
        // join thread (wait)
        pthread_join(TID[i], NULL);
    }
    // destory thread
    pthread_exit(0);

    // destroy semaphore
    sem_destroy(&s);

    return 0;
}

//
//
//int generateNumber(int max){
//    int num = (rand() % (max) + 1);
//    return num;
//}