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

#include "liburing.h"
#include "test.h"

#define BUF_SIZE 4096

static char buf[BUF_SIZE];
static char buf_tmp[BUF_SIZE];

static void io_uring_prep_my_cmd_lease(struct io_uring_sqe *sqe)
{
	io_uring_prep_rw(IORING_OP_URING_CMD, sqe, fd, 0, 0, 0);
	/* TODO */
	...
}

static void do_submit_wait1(struct io_uring *ring)
{
	struct io_uring_cqe *cqe;
	int ret;

	ret = io_uring_submit(ring);
	assert(ret == 1);
	ret = io_uring_wait_cqe(ring, &cqe);
	assert(ret >= 0);
	printf("cqe data %i res %i\n", (int)cqe->user_data, cqe->res);
	io_uring_cqe_seen(ring, cqe);
}

int main(int argc, char *argv[])
{
	unsigned long buf_offset = 0;
	unsigned slot = 0; /* reg buffer table index */
	struct io_uring_sqe *sqe;
	int pipe1[2], pipe2[2];
	struct io_uring ring;
	int ret, i;

	for (i = 0; i < BUF_SIZE; i++)
		buf[i] = (char)i;

	ret = pipe(pipe1);
	assert(ret == 0);
	ret = pipe(pipe2);
	assert(ret == 0);

	ret = io_uring_queue_init(8, &ring, 0);
	assert(ret == 0);
	ret = io_uring_register_buffers_sparse(&ring, 16);
	assert(ret >= 0);

	ret = write(pipe1[1], buf, BUF_SIZE);
	assert(ret == BUF_SIZE);

	sqe = io_uring_get_sqe(&ring);
	io_uring_prep_my_cmd_lease(sqe, bdev_fd, slot);
	sqe->user_data = 1;
	do_submit_wait1(&ring);

	// read data into the leased buffer
	sqe = io_uring_get_sqe(&ring);
	io_uring_prep_read_fixed(sqe, pipe1[0], (void *)buf_offset, BUF_SIZE, 0, slot);
	sqe->user_data = 2;
	do_submit_wait1(&ring);

	// write from the leased buffer into a pipe
	sqe = io_uring_get_sqe(&ring);
	io_uring_prep_write_fixed(sqe, pipe2[1], (void *)buf_offset, BUF_SIZE, 0, slot);
	sqe->user_data = 3;
	do_submit_wait1(&ring);

	// check the right data is in the pipe
	ret = read(pipe2[0], buf_tmp, BUF_SIZE);
	assert(ret == BUF_SIZE);
	for (i = 0; i < BUF_SIZE; i++) {
		assert(buf[i] == buf_tmp[i]);
	}

	struct iovec iovec = {};
	ret = io_uring_register_buffers_update_tag(&ring, 0, &iovec, NULL, 1);
	assert(ret >= 0);

	io_uring_queue_exit(&ring);
	return 0;
}