/* I pledge my Honor that I have abided by the Stevens Honor System -Paul Chua
 * cs392_thread.c
 *
 *  Created on: Apr 17, 2019
 *      Author: StevensUser
 */

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

int item1_counter,item2_counter,item3_counter = 0;
pthread_mutex_t m;


void* cs392_run_thread(void * arg){
	//Read each line
	FILE *fp;
	int s;
	char * buffer;
	ssize_t line;
	size_t line_buf_size = 0;

	//Open file and give error if you can't open it
	fp = fopen(arg,"r");
	if(fp ==NULL){
		perror("Error opening file");
	}
	pthread_mutex_lock(&m);
	line = getline(&buffer, &line_buf_size, fp);
	//While there is still content in the file, adjust counters based off of what it reads
	while(line >= 0){
		if (strcmp(buffer,"+item3\n") == 0){
			item3_counter++;;
		}
		else if( strcmp(buffer,"-item3\n") == 0){
			item3_counter--;
		}
		else if( strcmp(buffer,"+item2\n") == 0){
					item2_counter++;
				}
		else if( strcmp(buffer,"-item2\n") == 0){
					item2_counter--;
				}
		else if( strcmp(buffer,"+item1\n") == 0){
					item1_counter++;
				}
		else if( strcmp(buffer,"-item1\n") == 0){
					item1_counter--;
				}
		//If for some reason, you dont get the +item1 stuff, exit the program and tell the user something is unreadable
		else{
			printf("Content is wrong");
			exit(1);
		}
		//Move onto the next line
		line = getline(&buffer, &line_buf_size, fp);
	}

	pthread_mutex_unlock(&m);
	pthread_exit(NULL);
	return NULL;
}

int main(int argc, char **argv){
	//Error for when not enough arguments
	if (argc != 4){
		perror("Not enough arguments");
	}
	//Error if mutex fails
	if(pthread_mutex_init(&m, NULL) != 0){
		printf("Mutex init failed");
	}
	//Create threads and run the threads using the various arguments
	pthread_t thread1,thread2,thread3;
		int iret1,iret2,iret3;
		iret1 = pthread_create(&thread1,NULL,cs392_run_thread,argv[1]);
		iret2 = pthread_create(&thread2,NULL,cs392_run_thread,argv[2]);
		iret3 = pthread_create(&thread3,NULL,cs392_run_thread,argv[3]);

		//Join them
		pthread_join(thread1,NULL);
		pthread_join(thread2,NULL);
		pthread_join(thread3,NULL);
		//Print the result and destroy mutex
		pthread_mutex_destroy(&m);
		printf("The final value of item1_counter, item2_counter, and item3_counter are %d, %d, and %d", item1_counter, item2_counter, item3_counter);


}