#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/inotify.h>
#include <limits.h>

#define MAX_EVENTS	1024								// MAX NUMBER OF PROCESS AT ONE ROUTINE
#define LEN_NAME	32									// FILE NAME LENGTH LIMIT
#define EVENT_SIZE	(sizeof(struct inotify_event))		// SIZE OF ONE EVENT
#define BUF_LEN		(MAX_EVENTS*(EVENT_SIZE+LEN_NAME))	// BUFFER TO STORE THE DATA OF EVENTS


int main(int argc, char **argv) {
	int length, i = 0, wd;
	int fd;
	char buffer[BUF_LEN];

	// INITIALIZE INOTIFY
	fd = inotify_init();
	if(fd < 0)
		perror("INOTIFY INITIALIZATION FAIL");

	// WATCH FOR STARTING DIRECTORY
	wd = inotify_add_watch(fd, argv[1], IN_CREATE | IN_MODIFY | IN_DELETE);

	if(wd == -1)
		printf("FAIL TO ADD WATCH TO %s\n", argv[1]);
	else
		printf("WATCHING DIRECTORY %s\n", argv[1]);

	// LOOP
	while(1) {
		i = 0;
		length = read(fd, buffer, BUF_LEN);

		if(length < 0)
			perror("read");

		while(i < length) {
			struct inotify_event *event = (struct inotify_event *)&buffer[i];
			if(event->len) {
				if(event->mask & IN_CREATE) {
					if(event->mask & IN_ISDIR)
						printf("DIRECTORY %s WAS CREATED\n", event->name);
					else
						printf("FILE %s WAS CREATED WITH WD %d\n", event->name, event->wd);
				}
				if(event->mask & IN_MODIFY) {
					if(event->mask & IN_ISDIR)
						printf("DIRECTORY %s WAS MODIFIED\n", event->name);
					else
						printf("FILE %s WAS MODIFIED WITH WD %d\n", event->name, event->wd);
				}
				if(event->mask & IN_DELETE) {
					if(event->mask & IN_ISDIR)
						printf("DIRECTORY %s WAS DELETED\n", event->name);
					else
						printf("FILE %s WAS DELETED WITH WD %d\n", event->name, event->wd);
				}
				i += EVENT_SIZE + event->len;
			}
		}
	}

	// CLEANING UP
	inotify_rm_watch(fd, wd);
	close(fd);

	return 0;
}