#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/mman.h>

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include <linux/unistd.h>
#include <linux/types.h>

#define PAGE_SIZE	4096
#include <linux/ukevent.h>

#define _syscall3(type,name,type1,arg1,type2,arg2,type3,arg3) \
type name (type1 arg1, type2 arg2, type3 arg3) \
{\
	return syscall(__NR_##name, arg1, arg2, arg3);\
}

#define _syscall4(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4) \
type name (type1 arg1, type2 arg2, type3 arg3, type4 arg4) \
{\
	return syscall(__NR_##name, arg1, arg2, arg3, arg4);\
}

#define _syscall5(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4, \
	  type5,arg5) \
type name (type1 arg1,type2 arg2,type3 arg3,type4 arg4,type5 arg5) \
{\
	return syscall(__NR_##name, arg1, arg2, arg3, arg4, arg5);\
}

#define _syscall6(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4, \
	  type5,arg5,type6,arg6) \
type name (type1 arg1,type2 arg2,type3 arg3,type4 arg4,type5 arg5, type6 arg6) \
{\
	return syscall(__NR_##name, arg1, arg2, arg3, arg4, arg5, arg6);\
}

_syscall4(int, kevent_ctl, int, arg1, unsigned int, argv2, unsigned int, argv3, void *, argv4);
_syscall6(int, kevent_get_events, int, arg1, unsigned int, argv2, unsigned int, argv3, __u64, argv4, void *, argv5, unsigned, arg6);
_syscall4(int, kevent_wait, int, arg1, unsigned int, arg2, unsigned int, argv3, __u64, argv4);

#define ulog(f, a...) fprintf(stderr, "%8u: "f, time(NULL), ##a)
#define ulog_err(f, a...) ulog(f ": %s [%d].\n", ##a, strerror(errno), errno)

static void usage(char *p)
{
	ulog("Usage: %s -t type -e event -o oneshot -p path -n wait_num -f kevent_file -r ready_num -h\n", p);
}

static int evtest_mmap(int fd, struct kevent_mring **ring, int number)
{
	int i;
	off_t o = 0;

	for (i=0; i<number; ++i) {
		ring[i] = mmap(NULL, PAGE_SIZE, PROT_READ, MAP_SHARED, fd, o);
		if (ring[i] == MAP_FAILED) {
			ulog_err("Failed to mmap: i: %d, number: %u, offset: %lu", i, number, o);
			return -ENOMEM;
		}

		printf("mmap: %d: number: %u, offset: %lu.\n", i, number, o);
		o += PAGE_SIZE;
	}
	
	return 0;
}

int main(int argc, char *argv[])
{
	int ch, fd, err, oneshot, wait_num;
	unsigned int i, ready_num, old_idx, new_idx, tm_sec, tm_nsec;
	char *file;
	char buf[4096];
	struct ukevent *uk;
	struct mukevent *m;
	struct kevent_mring *ring[KEVENT_MAX_PAGES];
	off_t offset;

	oneshot = 0;
	wait_num = 10;
	offset = 0;
	old_idx = 0;
	file = "/dev/kevent";
	tm_sec = 2;
	tm_nsec = 0;
	ready_num = 1;

	while ((ch = getopt(argc, argv, "r:f:t:T:o:n:h")) > 0) {
		switch (ch) {
			case 'f':
				file = optarg;
				break;
			case 'r':
				ready_num = atoi(optarg);
				break;
			case 'n':
				wait_num = atoi(optarg);
				break;
			case 't':
				tm_sec = atoi(optarg);
				break;
			case 'T':
				tm_nsec = atoi(optarg);
				break;
			case 'o':
				oneshot = atoi(optarg);
				break;
			default:
				usage(argv[0]);
				return -1;
		}
	}

	fd = open(file, O_RDWR);
	if (fd == -1) {
		ulog_err("Failed create kevent control block using file %s", file);
		return -1;
	}

	err = evtest_mmap(fd, ring, KEVENT_MAX_PAGES);
	if (err)
		return err;

	memset(buf, 0, sizeof(buf));
	
	for (i=0; i<ready_num; ++i) {
		uk = (struct ukevent *)buf;
		uk->event = KEVENT_TIMER_FIRED;
		uk->type = KEVENT_TIMER;
		if (oneshot)
			uk->req_flags |= KEVENT_REQ_ONESHOT;
		uk->user[0] = i;
		uk->id.raw[0] = tm_sec;
		uk->id.raw[1] = tm_nsec+i;

		err = kevent_ctl(fd, KEVENT_CTL_ADD, 1, uk);
		if (err < 0) {
			ulog_err("Failed to perform control operation: oneshot: %d, sec: %u, nsec: %u", 
					oneshot, tm_sec, tm_nsec);
			close(fd);
			return err;
		}
		if (err) {
			ulog("%d: %016llx: ret_flags: 0x%x, ret_data: %u %d.\n", 
					i, uk->id.raw_u64, 
					uk->ret_flags, uk->ret_data[0], (int)uk->ret_data[1]);
		}
	}

	old_idx = ready_num = 0;
	while (1) {
		new_idx = ring[0]->kidx;
		old_idx = ring[0]->uidx;
		if (new_idx != old_idx) {
			ready_num = (old_idx > new_idx)?(KEVENT_MAX_EVENTS - (old_idx - new_idx)):(new_idx - old_idx);

			ulog("mmap: new: %u, old: %u, ready: %u.\n", new_idx, old_idx, ready_num);

			for (i=0; i<ready_num; ++i) {
				int ridx = old_idx / KEVENTS_ON_PAGE;
				int idx = old_idx % KEVENTS_ON_PAGE;
				m = &ring[ridx]->event[idx % KEVENTS_ON_PAGE];
				ulog("%08x: %08x.%08x - %08x\n", 
					i, m->id.raw[0], m->id.raw[1], m->ret_flags);
			}
		}
		ulog("going to wait: old: %u, new: %u, ready_num: %u, uidx: %u, kidx: %u.\n", 
				old_idx, new_idx, ready_num, ring[0]->uidx, ring[0]->kidx);
		err = kevent_wait(fd, old_idx, ready_num, 10000000000ULL);
		if (err < 0) {
			if (errno != EAGAIN) {
				ulog_err("Failed to perform control operation: oneshot: %d, sec: %u, nsec: %u", 
						oneshot, tm_sec, tm_nsec);
				close(fd);
				return err;
			}
			old_idx = (old_idx + ready_num) % KEVENT_MAX_EVENTS;
			ready_num = 0;
		}
		ulog("wait: old: %u, ready: %u, ret: %d.\n", old_idx, ready_num, err);
	}

	close(fd);
	return 0;
}