/*
 irc-server.c : irssi

    Copyright (C) 1999-2000 Timo Sirainen

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include "module.h"

#include "net-nonblock.h"
#include "net-sendbuffer.h"
#include "line-split.h"
#include "signals.h"
#include "rawlog.h"
#include "misc.h"

#include "channels.h"
#include "queries.h"

#include "irc-servers-setup.h"
#include "irc-servers.h"
#include "channel-rejoin.h"
#include "servers-idle.h"
#include "servers-reconnect.h"
#include "servers-redirect.h"
#include "modes.h"

#include "settings.h"

#define DEFAULT_MAX_KICKS 1
#define DEFAULT_MAX_MODES 3
#define DEFAULT_MAX_WHOIS 4
#define DEFAULT_MAX_MSGS 1

#define DEFAULT_USER_MODE "+i"
#define DEFAULT_CMD_QUEUE_SPEED 2200
#define DEFAULT_CMDS_MAX_AT_ONCE 5
#define DEFAULT_MAX_QUERY_CHANS 1 /* more and more IRC networks are using stupid ircds.. */

void irc_servers_reconnect_init(void);
void irc_servers_reconnect_deinit(void);

static int cmd_tag;

static int isnickflag_func(char flag)
{
	return isnickflag(flag);
}

static int ischannel_func(SERVER_REC *server, const char *data)
{
	if (*data == '@') {
		/* @#channel, @+#channel */
		data++;
		if (*data == '+' && ischannel(data[1]))
			return 1;
	}
	return ischannel(*data);
}

static void send_message(SERVER_REC *server, const char *target,
			 const char *msg, int target_type)
{
        IRC_SERVER_REC *ircserver;
	char *str;

        ircserver = IRC_SERVER(server);
	g_return_if_fail(ircserver != NULL);
	g_return_if_fail(target != NULL);
	g_return_if_fail(msg != NULL);

	str = g_strdup_printf("PRIVMSG %s :%s", target, msg);
	irc_send_cmd_split(ircserver, str, 2, ircserver->max_msgs_in_cmd);
	g_free(str);
}

static void sig_server_looking(IRC_SERVER_REC *server)
{
	if (!IS_IRC_SERVER(server))
		return;

	server->isnickflag = isnickflag_func;
	server->ischannel = ischannel_func;
	server->send_message = send_message;
}

static void server_init(IRC_SERVER_REC *server)
{
	IRC_SERVER_CONNECT_REC *conn;
	char hostname[100], *address, *ptr, *username;

	g_return_if_fail(server != NULL);

	conn = server->connrec;

	if (conn->proxy != NULL && conn->proxy_password != NULL &&
	    *conn->proxy_password != '\0')
		irc_send_cmdv(server, "PASS %s", conn->proxy_password);

	if (conn->proxy != NULL && conn->proxy_string != NULL)
		irc_send_cmdv(server, conn->proxy_string, conn->address, conn->port);

	if (conn->password != NULL && *conn->password != '\0') {
                /* send password */
		server->cmdcount = 0;
		irc_send_cmdv(server, "PASS %s", conn->password);
	}

        /* send nick */
	server->cmdcount = 0;
	irc_send_cmdv(server, "NICK %s", conn->nick);

	/* send user/realname */
	server->cmdcount = 0;

	if (gethostname(hostname, sizeof(hostname)) != 0 || *hostname == '\0')
		strcpy(hostname, "xx");

	address = server->connrec->address;
        ptr = strrchr(address, ':');
	if (ptr != NULL) {
		/* IPv6 address .. doesn't work here, use the string after
		   the last : char */
                address = ptr+1;
	}

	/* Replace ':' with '_' in our own hostname (the same IPv6 problem) */
	for (ptr = hostname; *ptr != '\0'; ptr++) {
		if (*ptr == ':') *ptr = '_';
	}

	username = g_strdup(conn->username);
	ptr = strchr(username, ' ');
	if (ptr != NULL) *ptr = '\0';

	irc_send_cmdv(server, "USER %s %s %s :%s", username, hostname,
		      address, conn->realname);
	g_free(username);

	server->cmdcount = 0;

	if (conn->proxy != NULL && conn->proxy_string_after != NULL) {
		irc_send_cmdv(server, conn->proxy_string_after,
			      conn->address, conn->port);
	}

	server->cmdcount = 0;
}

IRC_SERVER_REC *irc_server_connect(IRC_SERVER_CONNECT_REC *conn)
{
	IRC_SERVER_REC *server;

	g_return_val_if_fail(IS_IRC_SERVER_CONNECT(conn), NULL);
	if (conn->address == NULL || *conn->address == '\0') return NULL;
	if (conn->nick == NULL || *conn->nick == '\0') return NULL;

	server = g_new0(IRC_SERVER_REC, 1);
	server->chat_type = IRC_PROTOCOL;

	server->connrec = conn;
        server_connect_ref(SERVER_CONNECT(conn));

	if (server->connrec->port <= 0)
		server->connrec->port = 6667;

	server->cmd_queue_speed = conn->cmd_queue_speed > 0 ?
		conn->cmd_queue_speed : settings_get_int("cmd_queue_speed");
	server->max_cmds_at_once = conn->max_cmds_at_once > 0 ?
		conn->max_cmds_at_once : settings_get_int("cmds_max_at_once");
	server->max_query_chans = conn->max_query_chans > 0 ?
		conn->max_query_chans : DEFAULT_MAX_QUERY_CHANS;

	server->max_kicks_in_cmd = conn->max_kicks > 0 ?
		conn->max_kicks : DEFAULT_MAX_KICKS;
	server->max_modes_in_cmd = conn->max_modes > 0 ?
		conn->max_modes : DEFAULT_MAX_MODES;
	server->max_whois_in_cmd = conn->max_whois > 0 ?
		conn->max_whois : DEFAULT_MAX_WHOIS;
	server->max_msgs_in_cmd = conn->max_msgs > 0 ?
		conn->max_msgs : DEFAULT_MAX_MSGS;

	if (!server_start_connect((SERVER_REC *) server)) {
                server_connect_unref(SERVER_CONNECT(conn));
		g_free(server);
		return NULL;
	}
	return server;
}

/* Returns TRUE if `command' is sent to `target' */
static int command_has_target(const char *cmd, const char *target)
{
	const char *p;
        int len;

        /* just assume the command is in form "<command> <target> <data>" */
        p = strchr(cmd, ' ');
	if (p == NULL) return FALSE;
	p++;

        len = strlen(target);
	return strncmp(p, target, len) == 0 && p[len] == ' ';
}

/* Purge server output, either all or for specified target */
void irc_server_purge_output(IRC_SERVER_REC *server, const char *target)
{
	GSList *tmp, *next, *link;
        REDIRECT_REC *redirect;
	char *cmd;

	if (target != NULL && *target == '\0')
                target = NULL;

	for (tmp = server->cmdqueue; tmp != NULL; tmp = next) {
		next = tmp->next->next;
		cmd = tmp->data;
                redirect = tmp->next->data;

		if ((target == NULL || command_has_target(cmd, target)) &&
		    g_strncasecmp(cmd, "PONG ", 5) != 0) {
                        /* remove the redirection */
                        link = tmp->next;
			server->cmdqueue =
				g_slist_remove_link(server->cmdqueue, link);
                        g_slist_free_1(link);

			if (redirect != NULL)
                                server_redirect_destroy(redirect);

                        /* remove the command */
			server->cmdqueue =
				g_slist_remove(server->cmdqueue, cmd);
                        g_free(cmd);
                        server->cmdcount--;
		}
	}
}

static void sig_connected(IRC_SERVER_REC *server)
{
	if (!IS_IRC_SERVER(server))
		return;

	server->splits = g_hash_table_new((GHashFunc) g_istr_hash, (GCompareFunc) g_istr_equal);

        if (!server->session_reconnect)
		server_init(server);
}

static void sig_disconnected(IRC_SERVER_REC *server)
{
	GSList *tmp;

	if (!IS_IRC_SERVER(server))
		return;

	for (tmp = server->cmdqueue; tmp != NULL; tmp = tmp->next->next) {
		g_free(tmp->data);
		if (tmp->next->data != NULL)
                        server_redirect_destroy(tmp->next->data);
	}
	g_slist_free(server->cmdqueue);
        server->cmdqueue = NULL;

	g_free_and_null(server->wanted_usermode);
	g_free_and_null(server->real_address);
	g_free_and_null(server->usermode);
	g_free_and_null(server->userhost);
	g_free_and_null(server->last_invite);
}

static void sig_server_quit(IRC_SERVER_REC *server, const char *msg)
{
	char *str;

	if (!IS_IRC_SERVER(server) || server->handle == NULL ||
	    server->buffer == NULL)
		return;

	str = g_strdup_printf("QUIT :%s", msg);
	irc_send_cmd_now(server, str);
	g_free(str);
}

void irc_server_send_data(IRC_SERVER_REC *server, const char *data, int len)
{
	if (net_sendbuffer_send(server->handle, data, len) == -1) {
		/* something bad happened */
		server->connection_lost = TRUE;
		return;
	}

	g_get_current_time(&server->last_cmd);

	/* A bit kludgy way to do the flood protection. In ircnet, there
	   actually is 1sec / 100 bytes penalty, but we rather want to deal
	   with the max. 1000 bytes input buffer problem. If we send more
	   than that with the burst, we'll get excess flooded. */
	if (len < 100)
		server->wait_cmd.tv_sec = 0;
	else {
		memcpy(&server->wait_cmd, &server->last_cmd, sizeof(GTimeVal));
		server->wait_cmd.tv_sec += 2 + len/100;
	}
}

static void server_cmd_timeout(IRC_SERVER_REC *server, GTimeVal *now)
{
	REDIRECT_REC *redirect;
        GSList *link;
	long usecs;
	char *cmd;
	int len;

	if (!IS_IRC_SERVER(server))
		return;

	if (server->cmdcount == 0 && server->cmdqueue == NULL)
		return;

	if (g_timeval_cmp(now, &server->wait_cmd) == -1)
		return;

	usecs = get_timeval_diff(now, &server->last_cmd);
	if (usecs < server->cmd_queue_speed)
		return;

	server->cmdcount--;
	if (server->cmdqueue == NULL) return;

        /* get command */
	cmd = server->cmdqueue->data;
        redirect = server->cmdqueue->next->data;

	/* send command */
	len = strlen(cmd);
	irc_server_send_data(server, cmd, len);

	/* add to rawlog without [CR+]LF (/RAWQUOTE might not have
	   added the CR) */
        if (len > 2 && cmd[len-2] == '\r')
		cmd[len-2] = '\0';
        else if (cmd[len-1] == '\n')
		cmd[len-1] = '\0';
	rawlog_output(server->rawlog, cmd);
	server_redirect_command(server, cmd, redirect);

	/* remove from queue */
	g_free(cmd);
	server->cmdqueue = g_slist_remove(server->cmdqueue, cmd);

        link = server->cmdqueue;
	server->cmdqueue = g_slist_remove_link(server->cmdqueue, link);
        g_slist_free_1(link);
}

/* check every now and then if there's data to be sent in command buffer */
static int servers_cmd_timeout(void)
{
	GTimeVal now;

	g_get_current_time(&now);
	g_slist_foreach(servers, (GFunc) server_cmd_timeout, &now);
	return 1;
}

/* Return a string of all channels (and keys, if any have them) in server,
   like "#a,#b,#c,#d x,b_chan_key,x,x" or just "#e,#f,#g" */
char *irc_server_get_channels(IRC_SERVER_REC *server)
{
	GSList *tmp;
	GString *chans, *keys;
	char *ret;
	int use_keys;

	g_return_val_if_fail(server != NULL, FALSE);

	chans = g_string_new(NULL);
	keys = g_string_new(NULL);
	use_keys = FALSE;

	/* get currently joined channels */
	for (tmp = server->channels; tmp != NULL; tmp = tmp->next) {
		CHANNEL_REC *channel = tmp->data;

		g_string_sprintfa(chans, "%s,", channel->name);
		g_string_sprintfa(keys, "%s,", channel->key == NULL ? "x" :
				  channel->key);
		if (channel->key != NULL)
			use_keys = TRUE;
	}

	/* get also the channels that are in rejoin list */
	for (tmp = server->rejoin_channels; tmp != NULL; tmp = tmp->next) {
		REJOIN_REC *rec = tmp->data;

		g_string_sprintfa(chans, "%s,", rec->channel);
		g_string_sprintfa(keys, "%s,", rec->key == NULL ? "x" :
				  rec->key);
		if (rec->key != NULL) use_keys = TRUE;
	}

	if (chans->len > 0) {
		g_string_truncate(chans, chans->len-1);
		g_string_truncate(keys, keys->len-1);
		if (use_keys) g_string_sprintfa(chans, " %s", keys->str);
	}

	ret = chans->str;
	g_string_free(chans, FALSE);
	g_string_free(keys, TRUE);

	return ret;
}

static int sig_set_user_mode(IRC_SERVER_REC *server)
{
	const char *mode;
	char *newmode, *args;

	if (g_slist_find(servers, server) == NULL)
		return 0; /* got disconnected */

	mode = server->connrec->usermode;
	newmode = server->usermode == NULL ? NULL :
		modes_join(server->usermode, mode, FALSE);

	if (newmode == NULL || strcmp(newmode, server->usermode) != 0) {
		/* change the user mode. we used to do some trickery to
		   get rid of unwanted modes at reconnect time, but that's
		   more trouble than worth. (eg. we don't want to remove
		   some good default server modes, but we don't want to
		   set back +r, etc..) */
		args = g_strdup_printf("%s %s", server->nick, mode);
		signal_emit("command mode", 3, args, server, NULL);
		g_free(args);
	}

	g_free_not_null(newmode);
	return 0;
}

static void event_connected(IRC_SERVER_REC *server, const char *data, const char *from)
{
	char *params, *nick;

	g_return_if_fail(server != NULL);

	params = event_get_params(data, 1, &nick);

	if (strcmp(server->nick, nick) != 0) {
		/* nick changed unexpectedly .. connected via proxy, etc. */
		g_free(server->nick);
		server->nick = g_strdup(nick);
	}

	/* set the server address */
	g_free(server->real_address);
	server->real_address = from == NULL ?
		g_strdup(server->connrec->address) : /* shouldn't happen.. */
		g_strdup(from);

	/* last welcome message found - commands can be sent to server now. */
	server->connected = 1;
	server->real_connect_time = time(NULL);

	if (server->connrec->usermode != NULL) {
		/* wait a second and then send the user mode */
		g_timeout_add(1000, (GSourceFunc) sig_set_user_mode, server);
	}

	signal_emit("event connected", 1, server);
	g_free(params);
}

static void event_server_info(IRC_SERVER_REC *server, const char *data)
{
	char *params, *ircd_version, *usermodes, *chanmodes;

	g_return_if_fail(server != NULL);

	params = event_get_params(data, 5, NULL, NULL, &ircd_version, &usermodes, &chanmodes);

	/* check if server understands I and e channel modes */
	if (strchr(chanmodes, 'I') && strchr(chanmodes, 'e'))
		server->emode_known = TRUE;

	/* save server version */
	g_free_not_null(server->version);
	server->version = g_strdup(ircd_version);

	g_free(params);
}

static void event_motd(IRC_SERVER_REC *server, const char *data, const char *from)
{
	if (server->connected)
		return;

	/* Stupid broken piece of shit ircd didn't send us 001,
	   you'd think they could at least get that right??
	   But no, then I'll have to go and add these idiotic kludges
	   to make them work. Maybe I should instead get the users of these
	   servers to complain about it to their admins. */
        event_connected(server, data, from);
}

static void event_channels_formed(IRC_SERVER_REC *server, const char *data)
{
	char *params, *channels;

	g_return_if_fail(server != NULL);

	params = event_get_params(data, 2, NULL, &channels);
        server->channels_formed = atoi(channels);
	g_free(params);
}

static void event_server_banned(IRC_SERVER_REC *server, const char *data)
{
	g_return_if_fail(server != NULL);

        server->banned = TRUE;
}

static void event_error(IRC_SERVER_REC *server, const char *data)
{
	g_return_if_fail(server != NULL);

	if (!server->connected && (stristr(data, "Unauthorized") != NULL ||
				   stristr(data, "K-lined") != NULL))
		server->banned = TRUE;
}

static void event_ping(IRC_SERVER_REC *server, const char *data)
{
	char *params, *origin, *target, *str;

	params = event_get_params(data, 2, &origin, &target);
	str = *target == '\0' ? g_strconcat("PONG :", origin, NULL) :
		g_strdup_printf("PONG %s :%s", target, origin);
	irc_send_cmd_now(server, str);
        g_free(str);
	g_free(params);
}

static void event_empty(void)
{
}

void irc_servers_init(void)
{
	settings_add_str("misc", "usermode", DEFAULT_USER_MODE);
	settings_add_int("flood", "cmd_queue_speed", DEFAULT_CMD_QUEUE_SPEED);
	settings_add_int("flood", "cmds_max_at_once", DEFAULT_CMDS_MAX_AT_ONCE);

	cmd_tag = g_timeout_add(500, (GSourceFunc) servers_cmd_timeout, NULL);

	signal_add_first("server looking", (SIGNAL_FUNC) sig_server_looking);
	signal_add_first("server connected", (SIGNAL_FUNC) sig_connected);
	signal_add_last("server disconnected", (SIGNAL_FUNC) sig_disconnected);
	signal_add_last("server quit", (SIGNAL_FUNC) sig_server_quit);
	signal_add("event 001", (SIGNAL_FUNC) event_connected);
	signal_add("event 004", (SIGNAL_FUNC) event_server_info);
	signal_add("event 375", (SIGNAL_FUNC) event_motd);
	signal_add("event 254", (SIGNAL_FUNC) event_channels_formed);
	signal_add("event 465", (SIGNAL_FUNC) event_server_banned);
	signal_add("event error", (SIGNAL_FUNC) event_error);
	signal_add("event ping", (SIGNAL_FUNC) event_ping);
	signal_add("event empty", (SIGNAL_FUNC) event_empty);

	irc_servers_setup_init();
	irc_servers_reconnect_init();
	servers_redirect_init();
	servers_idle_init();
}

void irc_servers_deinit(void)
{
	g_source_remove(cmd_tag);

	signal_remove("server looking", (SIGNAL_FUNC) sig_server_looking);
	signal_remove("server connected", (SIGNAL_FUNC) sig_connected);
	signal_remove("server disconnected", (SIGNAL_FUNC) sig_disconnected);
        signal_remove("server quit", (SIGNAL_FUNC) sig_server_quit);
	signal_remove("event 001", (SIGNAL_FUNC) event_connected);
	signal_remove("event 004", (SIGNAL_FUNC) event_server_info);
	signal_remove("event 375", (SIGNAL_FUNC) event_motd);
	signal_remove("event 254", (SIGNAL_FUNC) event_channels_formed);
	signal_remove("event 465", (SIGNAL_FUNC) event_server_banned);
	signal_remove("event error", (SIGNAL_FUNC) event_error);
	signal_remove("event ping", (SIGNAL_FUNC) event_ping);
	signal_remove("event empty", (SIGNAL_FUNC) event_empty);

	irc_servers_setup_deinit();
	irc_servers_reconnect_deinit();
	servers_redirect_deinit();
	servers_idle_deinit();
}