#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <linux/input.h>

void dump_event(struct timespec* start, struct input_event* event);
int stream_events(char* device_path);

static inline void timespec_diff(struct timespec* a, struct timespec* b, struct timespec* result) {
	result->tv_sec = a->tv_sec - b->tv_sec;
	result->tv_nsec = a->tv_nsec - b->tv_nsec;
	if (result->tv_nsec < 0) {
		--result->tv_sec;
		result->tv_nsec += 1000000000L;
	}
}
	
void dump_event(struct timespec* start, struct input_event* event) {
    unsigned char button, bLeft, bMiddle, bRight;
	unsigned char *ptr = (unsigned char*)event;
	int i;       
    char x, y;
	struct timespec now;
	struct timespec diff;

	clock_gettime(CLOCK_MONOTONIC, &now);
	timespec_diff(&now, start, &diff);

	button = ptr[0];
	bLeft = button & 0x1;
	bMiddle = ( button & 0x4 ) > 0;
	bRight = ( button & 0x2 ) > 0;
   	x=(char) ptr[1];y=(char) ptr[2];
	printf("%ld.%ld,m,l%d,m%d,r%d,x%d,y%d\n",
		diff.tv_sec,
		diff.tv_nsec,
		bLeft, bMiddle, bRight, x, y);
	
	//
	// comment to disable the display of raw event structure datas
	//
	// for(i=0; i<sizeof(event); i++)
	// {
		// printf("%02X ", *ptr++);
	// }
}
int main(int argc, char* argv[]) {
	if(argc < 2) {
		fprintf(stderr, "You must specify a mouse input to track like /dev/input/mouse1.");
		exit(EXIT_FAILURE);
	}
	int result = stream_events(argv[1]);
	exit(result);
}

int stream_events(char* device_path) {
    int device_fd;
	struct timespec start;
    struct input_event event;
    if((device_fd = open(device_path, O_RDONLY)) == -1) {
        fprintf(stderr, "Failed to open %s. Are you running as root?\n", device_path);
		return 1;
    }
    else {
        fprintf(stderr, "Device open OK\n");
    }
	clock_gettime(CLOCK_MONOTONIC, &start);
    while(read(device_fd, &event, sizeof(struct input_event)))
    {
		dump_event(&start, &event);
	}
}