/* Copyright (c) 2017 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "array.h"
#include "hostpid.h"
#include "net.h"
#include "fd-set-nonblock.h"
#include "istream.h"
#include "ostream.h"
#include "ioloop.h"
#include "unlink-directory.h"
#include "test-common.h"
#include "imapc-client-private.h"

#include <stdio.h>
#include <unistd.h>
#include <signal.h>
#include <sys/stat.h>
#include <sys/wait.h>

#define IMAPC_COMMAND_STATE_INVALID (enum imapc_command_state)-1

typedef void test_server_init_t(void);
typedef void test_client_init_t(void);

struct test_server {
	in_port_t port;
	pid_t pid;

	int fd_listen, fd;
	struct istream *input;
	struct ostream *output;
};

static struct ip_addr bind_ip;
static struct test_server server;
static struct imapc_client *imapc_client;
static enum imapc_command_state imapc_login_last_reply;
static ARRAY(enum imapc_command_state) imapc_cmd_last_replies;
static bool debug = FALSE;

static struct imapc_client_settings test_imapc_default_settings = {
	.host = "127.0.0.1",
	.username = "testuser",
	.password = "testpass",

	.dns_client_socket_path = "",
	.temp_path_prefix = ".test-tmp/",
	.rawlog_dir = "",

	.connect_timeout_msecs = 500,
	.connect_retry_count = 3,
	.connect_retry_interval_msecs = 10,

	.max_idle_time = 10000,
};

static int test_open_server_fd(in_port_t *bind_port)
{
	int fd = net_listen(&bind_ip, bind_port, 128);
	if (debug)
		i_debug("server listening on %u", *bind_port);
	if (fd == -1) {
		i_fatal("listen(%s:%u) failed: %m",
			net_ip2addr(&bind_ip), *bind_port);
	}
	fd_set_nonblock(fd, FALSE);
	return fd;
}

static void
test_server_wait_connection(struct test_server *server, bool send_banner)
{
	server->fd = net_accept(server->fd_listen, NULL, NULL);
	i_assert(server->fd >= 0);

	fd_set_nonblock(server->fd, FALSE);
	server->input = i_stream_create_fd(server->fd, (size_t)-1, FALSE);
	server->output = o_stream_create_fd(server->fd, (size_t)-1, FALSE);
	o_stream_set_no_error_handling(server->output, TRUE);

	if (send_banner) {
		o_stream_nsend_str(server->output,
			"* OK [CAPABILITY IMAP4rev1] ready\r\n");
	}
}

static void test_server_disconnect(struct test_server *server)
{
	if (server->input != NULL)
		i_stream_unref(&server->input);
	if (server->output != NULL)
		o_stream_unref(&server->output);
	if (server->fd != -1)
		i_close_fd(&server->fd);
}

static void test_server_disconnect_and_wait(bool send_banner)
{
	test_server_disconnect(&server);
	test_server_wait_connection(&server, send_banner);
}

static void test_server_kill(void)
{
	if (server.pid != (pid_t)-1) {
		if (kill(server.pid, SIGKILL) < 0)
			i_fatal("kill(%ld) failed: %m", (long)server.pid);
		if (waitpid(server.pid, NULL, 0) < 0)
			i_fatal("waitpid(%ld) failed: %m", (long)server.pid);
		server.pid = -1;
	}
}

static void test_run_client_server(
	const struct imapc_client_settings *client_set,
	test_client_init_t *client_test,
	test_server_init_t *server_test)
{
	struct imapc_client_settings client_set_copy = *client_set;
	struct ioloop *ioloop;

	imapc_client_cmd_tag_counter = 0;
	imapc_login_last_reply = IMAPC_COMMAND_STATE_INVALID;
	t_array_init(&imapc_cmd_last_replies, 4);

	i_zero(&server);
	server.pid = (pid_t)-1;
	server.fd = -1;
	server.fd_listen = server_test == NULL ? -1 :
		test_open_server_fd(&server.port);
	client_set_copy.port = server.port;

	if (mkdir(client_set->temp_path_prefix, 0700) < 0 && errno != EEXIST)
		i_fatal("mkdir(%s) failed: %m", client_set->temp_path_prefix);

	if ((server.pid = fork()) == (pid_t)-1)
		i_fatal("fork() failed: %m");
	if (server.pid == 0) {
		server.pid = (pid_t)-1;
		hostpid_init();
		if (debug)
			i_debug("server: PID=%s", my_pid);
		/* child: server */
		ioloop = io_loop_create();
		server_test();
		test_server_disconnect(&server);
		io_loop_destroy(&ioloop);
		/* wait for it to be killed; this way, valgrind will not
		   object to this process going away inelegantly. */
		sleep(60);
		exit(1);
	}
	/* parent: client */

	usleep(100000); /* wait a little for server setup */

	ioloop = io_loop_create();
	imapc_client = imapc_client_init(&client_set_copy);
	client_test();
	test_assert(array_count(&imapc_cmd_last_replies) == 0);
	if (imapc_client != NULL)
		imapc_client_deinit(&imapc_client);
	io_loop_destroy(&ioloop);

	if (server.fd_listen != -1)
		i_close_fd(&server.fd_listen);
	test_server_kill();
	(void)unlink_directory(client_set->temp_path_prefix, UNLINK_DIRECTORY_FLAG_RMDIR);
}

static enum imapc_command_state test_imapc_cmd_last_reply_pop(void)
{
	const enum imapc_command_state *replies;
	enum imapc_command_state reply;
	unsigned int count;

	replies = array_get(&imapc_cmd_last_replies, &count);
	if (count == 0)
		return IMAPC_COMMAND_STATE_INVALID;
	reply = replies[0];
	array_delete(&imapc_cmd_last_replies, 0, 1);
	return reply;
}

static bool test_imapc_cmd_last_reply_expect(enum imapc_command_state state)
{
	if (array_count(&imapc_cmd_last_replies) == 0)
		imapc_client_run(imapc_client);
	return test_imapc_cmd_last_reply_pop() == state;
}

static bool test_imapc_server_expect(const char *expected_line)
{
	const char *line = i_stream_read_next_line(server.input);

	if (line == NULL) {
		printf("imapc client disconnected unexpectedly: %s\n",
		       i_stream_get_error(server.input));
		return FALSE;
	} else if (strcmp(line, expected_line) != 0) {
		printf("imapc client sent '%s' when expecting '%s'\n",
		       line, expected_line);
		return FALSE;
	} else {
		return TRUE;
	}
}

static void imapc_login_callback(const struct imapc_command_reply *reply,
				 void *context ATTR_UNUSED)
{
	if (debug) {
		i_debug("Login reply: %s %s",
			imapc_command_state_names[reply->state],
			reply->text_full);
	}
	imapc_login_last_reply = reply->state;
	imapc_client_stop(imapc_client);
}

static void imapc_command_callback(const struct imapc_command_reply *reply,
				   void *context ATTR_UNUSED)
{
	if (debug) {
		i_debug("Command reply: %s %s",
			imapc_command_state_names[reply->state],
			reply->text_full);
	}
	array_append(&imapc_cmd_last_replies, &reply->state, 1);
	imapc_client_stop(imapc_client);
}

static void imapc_reopen_callback(void *context)
{
	struct imapc_client_mailbox *box = context;
	struct imapc_command *cmd;

	cmd = imapc_client_mailbox_cmd(box, imapc_command_callback, NULL);
	imapc_command_set_flags(cmd, IMAPC_COMMAND_FLAG_SELECT);
	imapc_command_send(cmd, "SELECT");
}

static void test_imapc_connect_failed_client(void)
{
	imapc_client_set_login_callback(imapc_client,
					imapc_login_callback, NULL);
	imapc_client_login(imapc_client);
	/* connection refused & one reconnect */
	test_expect_errors(2);
	imapc_client_run(imapc_client);
	test_expect_no_more_errors();
	test_assert(imapc_login_last_reply == IMAPC_COMMAND_STATE_DISCONNECTED);
}

static void test_imapc_connect_failed(void)
{
	struct imapc_client_settings set = test_imapc_default_settings;

	test_begin("imapc connect failed");
	test_run_client_server(&set, test_imapc_connect_failed_client,
			       NULL);
	test_end();
}

static void test_imapc_banner_hangs_client(void)
{
	imapc_client_set_login_callback(imapc_client,
					imapc_login_callback, NULL);
	imapc_client_login(imapc_client);
	test_expect_errors(2);
	imapc_client_run(imapc_client);
	test_expect_no_more_errors();
	test_assert(imapc_login_last_reply == IMAPC_COMMAND_STATE_DISCONNECTED);
}

static void test_imapc_banner_hangs_server(void)
{
	struct test_server server2 = { .fd_listen = server.fd_listen };

	test_server_wait_connection(&server, FALSE);
	test_server_wait_connection(&server2, FALSE);
	test_assert(i_stream_read_next_line(server2.input) == NULL);
	test_server_disconnect(&server2);
}

static void test_imapc_banner_hangs(void)
{
	struct imapc_client_settings set = test_imapc_default_settings;

	test_begin("imapc banner hangs");
	test_run_client_server(&set, test_imapc_banner_hangs_client,
			       test_imapc_banner_hangs_server);
	test_end();
}

static void test_imapc_login_hangs_client(void)
{
	imapc_client_set_login_callback(imapc_client,
					imapc_login_callback, NULL);
	imapc_client_login(imapc_client);
	test_expect_errors(2);
	imapc_client_run(imapc_client);
	test_expect_no_more_errors();
	test_assert(imapc_login_last_reply == IMAPC_COMMAND_STATE_DISCONNECTED);
}

static void test_imapc_login_hangs_server(void)
{
	struct test_server server2 = { .fd_listen = server.fd_listen };

	test_server_wait_connection(&server, TRUE);
	test_assert(test_imapc_server_expect("1 LOGIN \"testuser\" \"testpass\""));

	test_server_wait_connection(&server2, TRUE);
	test_assert(test_imapc_server_expect("1 LOGIN \"testuser\" \"testpass\""));

	test_assert(i_stream_read_next_line(server2.input) == NULL);
	test_server_disconnect(&server2);
}

static void test_imapc_login_hangs(void)
{
	struct imapc_client_settings set = test_imapc_default_settings;

	test_begin("imapc login hangs");
	test_run_client_server(&set, test_imapc_login_hangs_client,
			       test_imapc_login_hangs_server);
	test_end();
}

static void test_imapc_reconnect_client(void)
{
	struct imapc_command *cmd;

	/* login to server */
	imapc_client_set_login_callback(imapc_client,
					imapc_login_callback, NULL);
	imapc_client_login(imapc_client);
	imapc_client_run(imapc_client);
	test_assert(imapc_login_last_reply == IMAPC_COMMAND_STATE_OK);
	imapc_login_last_reply = IMAPC_COMMAND_STATE_INVALID;

	/* disconnect */
	cmd = imapc_client_cmd(imapc_client, imapc_command_callback, NULL);
	imapc_command_send(cmd, "DISCONNECT");
	test_expect_error_string("reconnecting");
	imapc_client_run(imapc_client);
	test_expect_no_more_errors();
	test_assert(test_imapc_cmd_last_reply_pop() == IMAPC_COMMAND_STATE_DISCONNECTED);

	/* we should be reconnected now. try a command. */
	cmd = imapc_client_cmd(imapc_client, imapc_command_callback, NULL);
	imapc_command_send(cmd, "NOOP");
	imapc_client_run(imapc_client);
	test_assert(imapc_login_last_reply == IMAPC_COMMAND_STATE_INVALID);
	test_assert(test_imapc_cmd_last_reply_pop() == IMAPC_COMMAND_STATE_OK);
}

static void test_imapc_reconnect_server(void)
{
	test_server_wait_connection(&server, TRUE);
	test_assert(test_imapc_server_expect("1 LOGIN \"testuser\" \"testpass\""));
	o_stream_nsend_str(server.output, "1 OK \r\n");

	test_assert(test_imapc_server_expect("2 DISCONNECT"));
	test_server_disconnect_and_wait(TRUE);

	test_assert(test_imapc_server_expect("4 LOGIN \"testuser\" \"testpass\""));
	o_stream_nsend_str(server.output, "4 OK \r\n");
	test_assert(test_imapc_server_expect("3 NOOP"));
	o_stream_nsend_str(server.output, "3 OK \r\n");

	test_assert(test_imapc_server_expect("4 LOGOUT"));
}

static void test_imapc_reconnect(void)
{
	struct imapc_client_settings set = test_imapc_default_settings;

	test_begin("imapc reconnect");
	test_run_client_server(&set, test_imapc_reconnect_client,
			       test_imapc_reconnect_server);
	test_end();
}

static void test_imapc_reconnect_resend_cmds_client(void)
{
	struct imapc_command *cmd;

	/* login to server */
	imapc_client_set_login_callback(imapc_client,
					imapc_login_callback, NULL);
	imapc_client_login(imapc_client);
	imapc_client_run(imapc_client);
	test_assert(imapc_login_last_reply == IMAPC_COMMAND_STATE_OK);
	imapc_login_last_reply = IMAPC_COMMAND_STATE_INVALID;

	/* send two commands */
	cmd = imapc_client_cmd(imapc_client, imapc_command_callback, NULL);
	imapc_command_set_flags(cmd, IMAPC_COMMAND_FLAG_RETRIABLE);
	imapc_command_send(cmd, "RETRY1");
	cmd = imapc_client_cmd(imapc_client, imapc_command_callback, NULL);
	imapc_command_set_flags(cmd, IMAPC_COMMAND_FLAG_RETRIABLE);
	imapc_command_send(cmd, "RETRY2");

	/* disconnect & reconnect automatically */
	cmd = imapc_client_cmd(imapc_client, imapc_command_callback, NULL);
	imapc_command_send(cmd, "DISCONNECT");
	test_expect_error_string("reconnecting");
	imapc_client_run(imapc_client);
	test_expect_no_more_errors();
	test_assert(test_imapc_cmd_last_reply_expect(IMAPC_COMMAND_STATE_DISCONNECTED));

	/* continue reconnection */
	test_assert(test_imapc_cmd_last_reply_expect(IMAPC_COMMAND_STATE_OK));
	test_assert(test_imapc_cmd_last_reply_expect(IMAPC_COMMAND_STATE_OK));
}

static void test_imapc_reconnect_resend_cmds_server(void)
{
	test_server_wait_connection(&server, TRUE);
	test_assert(test_imapc_server_expect("1 LOGIN \"testuser\" \"testpass\""));
	o_stream_nsend_str(server.output, "1 OK \r\n");

	test_assert(test_imapc_server_expect("2 RETRY1"));
	test_assert(test_imapc_server_expect("3 RETRY2"));
	test_assert(test_imapc_server_expect("4 DISCONNECT"));
	test_server_disconnect_and_wait(TRUE);

	test_assert(test_imapc_server_expect("5 LOGIN \"testuser\" \"testpass\""));
	o_stream_nsend_str(server.output, "5 OK \r\n");
	test_assert(test_imapc_server_expect("2 RETRY1"));
	o_stream_nsend_str(server.output, "2 OK \r\n");
	test_assert(test_imapc_server_expect("3 RETRY2"));
	o_stream_nsend_str(server.output, "3 OK \r\n");

	test_assert(test_imapc_server_expect("4 LOGOUT"));
}

static void test_imapc_reconnect_resend_commands(void)
{
	struct imapc_client_settings set = test_imapc_default_settings;

	test_begin("imapc reconnect resend commands");
	test_run_client_server(&set, test_imapc_reconnect_resend_cmds_client,
			       test_imapc_reconnect_resend_cmds_server);
	test_end();
}

static void test_imapc_reconnect_resend_cmds_failed_client(void)
{
	struct imapc_command *cmd;

	/* login to server */
	imapc_client_set_login_callback(imapc_client,
					imapc_login_callback, NULL);
	imapc_client_login(imapc_client);
	imapc_client_run(imapc_client);
	test_assert(imapc_login_last_reply == IMAPC_COMMAND_STATE_OK);
	imapc_login_last_reply = IMAPC_COMMAND_STATE_INVALID;

	/* send two commands */
	cmd = imapc_client_cmd(imapc_client, imapc_command_callback, NULL);
	imapc_command_set_flags(cmd, IMAPC_COMMAND_FLAG_RETRIABLE);
	imapc_command_send(cmd, "RETRY1");
	cmd = imapc_client_cmd(imapc_client, imapc_command_callback, NULL);
	imapc_command_set_flags(cmd, IMAPC_COMMAND_FLAG_RETRIABLE);
	imapc_command_send(cmd, "RETRY2");

	/* disconnect & try to reconnect automatically */
	cmd = imapc_client_cmd(imapc_client, imapc_command_callback, NULL);
	imapc_command_send(cmd, "DISCONNECT");
	test_expect_error_string("reconnecting");
	imapc_client_run(imapc_client);
	test_expect_no_more_errors();
	test_assert(test_imapc_cmd_last_reply_expect(IMAPC_COMMAND_STATE_DISCONNECTED));
	test_expect_error_string("timed out");
	test_assert(test_imapc_cmd_last_reply_expect(IMAPC_COMMAND_STATE_DISCONNECTED));
	test_expect_no_more_errors();
	test_assert(test_imapc_cmd_last_reply_expect(IMAPC_COMMAND_STATE_DISCONNECTED));
}

static void test_imapc_reconnect_resend_cmds_failed_server(void)
{
	test_server_wait_connection(&server, TRUE);
	test_assert(test_imapc_server_expect("1 LOGIN \"testuser\" \"testpass\""));
	o_stream_nsend_str(server.output, "1 OK \r\n");

	test_assert(test_imapc_server_expect("2 RETRY1"));
	test_assert(test_imapc_server_expect("3 RETRY2"));
	test_assert(test_imapc_server_expect("4 DISCONNECT"));
	test_server_disconnect(&server);
}

static void test_imapc_reconnect_resend_commands_failed(void)
{
	struct imapc_client_settings set = test_imapc_default_settings;

	test_begin("imapc reconnect resend commands failed");
	test_run_client_server(&set, test_imapc_reconnect_resend_cmds_failed_client,
			       test_imapc_reconnect_resend_cmds_failed_server);
	test_end();
}

static void test_imapc_reconnect_mailbox_client(void)
{
	struct imapc_command *cmd;
	struct imapc_client_mailbox *box;

	/* login to server */
	imapc_client_set_login_callback(imapc_client,
					imapc_login_callback, NULL);
	imapc_client_login(imapc_client);
	imapc_client_run(imapc_client);
	test_assert(imapc_login_last_reply == IMAPC_COMMAND_STATE_OK);
	imapc_login_last_reply = IMAPC_COMMAND_STATE_INVALID;

	/* select a mailbox */
	box = imapc_client_mailbox_open(imapc_client, NULL);
	imapc_client_mailbox_set_reopen_cb(box, imapc_reopen_callback, box);

	cmd = imapc_client_mailbox_cmd(box, imapc_command_callback, NULL);
	imapc_command_set_flags(cmd, IMAPC_COMMAND_FLAG_SELECT);
	imapc_command_send(cmd, "SELECT");
	imapc_client_run(imapc_client);
	test_assert(test_imapc_cmd_last_reply_expect(IMAPC_COMMAND_STATE_OK));

	/* send a command */
	cmd = imapc_client_mailbox_cmd(box, imapc_command_callback, NULL);
	imapc_command_set_flags(cmd, IMAPC_COMMAND_FLAG_RETRIABLE);
	imapc_command_send(cmd, "RETRY");

	/* disconnect & reconnect automatically */
	cmd = imapc_client_cmd(imapc_client, imapc_command_callback, NULL);
	imapc_command_send(cmd, "DISCONNECT");
	test_expect_error_string("reconnecting");
	imapc_client_run(imapc_client);
	test_expect_no_more_errors();
	test_assert(test_imapc_cmd_last_reply_expect(IMAPC_COMMAND_STATE_DISCONNECTED));

	/* continue reconnection */
	test_assert(test_imapc_cmd_last_reply_expect(IMAPC_COMMAND_STATE_OK));
	test_assert(test_imapc_cmd_last_reply_expect(IMAPC_COMMAND_STATE_OK));

	imapc_client_mailbox_close(&box);
}

static void test_imapc_reconnect_mailbox_server(void)
{
	test_server_wait_connection(&server, TRUE);
	test_assert(test_imapc_server_expect("1 LOGIN \"testuser\" \"testpass\""));
	o_stream_nsend_str(server.output, "1 OK \r\n");

	test_assert(test_imapc_server_expect("2 SELECT"));
	o_stream_nsend_str(server.output, "2 OK \r\n");

	test_assert(test_imapc_server_expect("3 RETRY"));
	test_assert(test_imapc_server_expect("4 DISCONNECT"));
	test_server_disconnect_and_wait(TRUE);

	test_assert(test_imapc_server_expect("5 LOGIN \"testuser\" \"testpass\""));
	o_stream_nsend_str(server.output, "5 OK \r\n");
	test_assert(test_imapc_server_expect("6 SELECT"));
	o_stream_nsend_str(server.output, "6 OK \r\n");
	test_assert(test_imapc_server_expect("3 RETRY"));
	o_stream_nsend_str(server.output, "3 OK \r\n");
	i_info("retry");

	test_assert(test_imapc_server_expect("4 LOGOUT"));
}

static void test_imapc_reconnect_mailbox(void)
{
	struct imapc_client_settings set = test_imapc_default_settings;

	test_begin("imapc reconnect mailbox");
	test_run_client_server(&set, test_imapc_reconnect_mailbox_client,
			       test_imapc_reconnect_mailbox_server);
	test_end();
}

int main(int argc ATTR_UNUSED, char *argv[])
{
	static void (*test_functions[])(void) = {
		test_imapc_connect_failed,
		test_imapc_banner_hangs,
		test_imapc_login_hangs,
		test_imapc_reconnect,
		test_imapc_reconnect_resend_commands,
		test_imapc_reconnect_resend_commands_failed,
		test_imapc_reconnect_mailbox,
		NULL
	};

	debug = null_strcmp(argv[1], "-D") == 0;
	test_imapc_default_settings.debug = debug;

	/* listen on localhost */
	i_zero(&bind_ip);
	bind_ip.family = AF_INET;
	bind_ip.u.ip4.s_addr = htonl(INADDR_LOOPBACK);

	return test_run(test_functions);
}