/* lib9p/tests/testclient-sess.c - Test the 9P `test_server`'s sessions
 *
 * Copyright (C) 2025  Luke T. Shumaker <lukeshu@lukeshu.com>
 * SPDX-License-Identifier: AGPL-3.0-or-later
 */

#include <arpa/inet.h> /* for htons(), inet_addr() */
#include <errno.h>
#include <error.h>
#include <netinet/in.h> /* for struct sockaddr{,_in} */
#include <stdlib.h> /* for atoi() */
#include <sys/socket.h> /* for socket(), connect() */
#include <sys/uio.h> /* for writev() */
#include <unistd.h> /* for read() */

#include <libmisc/assert.h>
#include <libmisc/endian.h>
#include <lib9p/9p.h>

#define MAX_MSG_SIZE (8*1024)

static void _send9p(int fd, struct lib9p_ctx *ctx, enum lib9p_msg_type typ, void *body) {
	struct lib9p_Tmsg_send_buf buf;
	bool err = lib9p_Tmsg_marshal(ctx, typ, body, &buf);
	assert(!err);
	size_t exp = 0;
	for (size_t i = 0; i < buf.iov_cnt; i++)
		exp += buf.iov[i].iov_len;
	ssize_t act = writev(fd, buf.iov, buf.iov_cnt);
	if (act < 0)
		error(1, errno, "writev");
	assert((size_t)act == exp);
}

#define send9p(typ, ...) _send9p(fd, &ctx, LIB9P_TYP_##typ, &((struct lib9p_msg_##typ){ __VA_ARGS__ }))

static void _recv9p(int fd) {
	uint8_t buf[MAX_MSG_SIZE];
	size_t goal = 4;
	size_t done = 0;
	while (done < goal) {
		ssize_t n = read(fd, &buf[done], goal-done);
		if (n < 0)
			error(1, errno, "read");
		done += n;
	}
	goal = uint32le_decode(buf);
	assert(goal <= MAX_MSG_SIZE);
	while (done < goal) {
		ssize_t n = read(fd, &buf[done], goal-done);
		if (n < 0)
			error(1, errno, "read");
		done += n;
	}
}

#define recv9p() _recv9p(fd)

int main(int argc, char *argv[]) {
	if (argc != 2)
		error(2, 0, "Usage: %s SERVER_PORT", argv[0]);
	uint16_t server_port = atoi(argv[1]);

	union {
                struct sockaddr         gen;
                struct sockaddr_in      in;
	} server_addr = {};
	server_addr.in.sin_family = AF_INET;
	server_addr.in.sin_addr.s_addr = inet_addr("127.0.0.1");
	server_addr.in.sin_port = htons(server_port);

	int fd = socket(AF_INET, SOCK_STREAM, 0);
	if (fd < 0)
		error(1, errno, "socket");
	if (connect(fd, &server_addr.gen, sizeof(server_addr)) < 0)
		error(1, errno, "connect");

	struct lib9p_ctx ctx = {
		.max_msg_size = 16*1024,
	};

	struct lib9p_s wname[1];

	/* numeric downgrade, unknown ext *************************************/
	send9p(Tversion, .tag=0, .max_msg_size=57, .version=lib9p_str("9P2025.x"));
	recv9p(); /* Rversion */
	ctx.version = LIB9P_VER_9P2000;

	/* numeric downgrade, known ext ***************************************/
	send9p(Tversion, .tag=0, .max_msg_size=57, .version=lib9p_str("9P2025.u"));
	recv9p(); /* Rversion */
	ctx.version = LIB9P_VER_9P2000_u;

	/* ext version ********************************************************/
	send9p(Tversion, .tag=0, .max_msg_size=57, .version=lib9p_str("9P2000.u"));
	recv9p(); /* Rversion */
	ctx.version = LIB9P_VER_9P2000_u;

	/* main session *******************************************************/
	send9p(Tversion, .tag=0, .max_msg_size=(8*1024), .version=lib9p_str("9P2000"));
	recv9p(); /* Rversion */
	ctx.version = LIB9P_VER_9P2000;
	send9p(Tattach, .tag=0, .fid=0, .afid=LIB9P_FID_NOFID, .uname=lib9p_str("nobody"), .aname=lib9p_str(""));
	recv9p(); /* Rattach */

	/* flush, but original response comes back first */
	wname[0] = lib9p_str("slowread"); send9p(Twalk, .tag=0, .fid=0, .newfid=1, .nwname=1, .wname=wname);
	recv9p(); /* Rwalk */
	send9p(Topen, .tag=0, .fid=1, .mode=LIB9P_O_MODE_READ);
	recv9p(); /* Ropen */
	send9p(Tread, .tag=1, .fid=1, .offset=0, .count=6);
	send9p(Tflush, .tag=2, .oldtag=1);
	recv9p(); /* Rread */
	recv9p(); /* Rflush */

	/* flush, original request is aborted with error */
	wname[0] = lib9p_str("slowread-flushable"); send9p(Twalk, .tag=1, .fid=0, .newfid=2, .nwname=1, .wname=wname);
	recv9p(); /* Rwalk */
	send9p(Topen, .tag=0, .fid=2, .mode=LIB9P_O_MODE_READ);
	recv9p(); /* Ropen */
	send9p(Tread, .tag=1, .fid=2, .offset=0, .count=6);
	send9p(Tflush, .tag=2, .oldtag=1);
	recv9p(); /* Rerror */
	recv9p(); /* Rflush */

	/* flush, unknown tag */
	send9p(Tflush, .tag=0, .oldtag=99);
	recv9p(); /* Rflush */

	/* shutdown ***********************************************************/
	send9p(Tversion, .tag=0, .max_msg_size=(8*1024), .version=lib9p_str("9P2000"));
	recv9p(); /* Rversion */
	ctx.version = LIB9P_VER_9P2000;
	send9p(Tattach, .tag=0, .fid=0, .afid=LIB9P_FID_NOFID, .uname=lib9p_str("nobody"), .aname=lib9p_str(""));
	recv9p(); /* Rattach */
	/* check the newfid==fid case */
	wname[0] = lib9p_str("shutdown"); send9p(Twalk, .tag=0, .fid=0, .newfid=0, .nwname=1, .wname=wname);
	recv9p(); /* Rwalk */
	send9p(Topen, .tag=0, .fid=0, .mode=LIB9P_O_MODE_WRITE);
	recv9p(); /* Ropen */
	send9p(Twrite, .tag=0, .fid=0, .offset=0, .count=2, .data="1\n");
	recv9p(); /* Rwrite */
	return 0;
}