/***************************************************************************\
*                                                                           *
*  BitlBee - An IRC to IM gateway                                           *
*  Jabber module - Main file                                                *
*                                                                           *
*  Copyright 2006-2013 Wilmer van der Gaast <wilmer@gaast.net>              *
*                                                                           *
*  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.,  *
*  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.              *
*                                                                           *
\***************************************************************************/

#include <glib.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>
#include <stdio.h>

#include "ssl_client.h"
#include "xmltree.h"
#include "bitlbee.h"
#include "jabber.h"
#include "oauth.h"
#include "md5.h"

GSList *jabber_connections;

/* First enty is the default */
static const int jabber_port_list[] = {
	5222,
	5223,
	5220,
	5221,
	5224,
	5225,
	5226,
	5227,
	5228,
	5229,
	80,
	443,
	0
};

static jabber_subproto_desc_t jabber_subproto_list[] = {
	{ "jabber", JSUB_NONE, NULL, NULL },
	{ "gtalk", JSUB_GTALK, &oauth2_service_google, "talk.google.com" },
	{ "fb", JSUB_FACEBOOK, &oauth2_service_facebook, "chat.facebook.com" },
	{ "hipchat", JSUB_HIPCHAT, NULL, "chat.hipchat.com" },
	{ NULL },
};

static void jabber_init(account_t *acc)
{
	set_t *s;
	char str[16];
	jabber_subproto_desc_t *subproto = acc->prpl->data;

	s = set_add(&acc->set, "activity_timeout", "600", set_eval_int, acc);

	s = set_add(&acc->set, "display_name", NULL, NULL, acc);

	if (subproto->oauth2_service) {
		s = set_add(&acc->set, "oauth", "false", set_eval_oauth, acc);
	}

	g_snprintf(str, sizeof(str), "%d", jabber_port_list[0]);
	s = set_add(&acc->set, "port", str, set_eval_int, acc);
	s->flags |= ACC_SET_OFFLINE_ONLY;

	s = set_add(&acc->set, "priority", "0", set_eval_priority, acc);

	s = set_add(&acc->set, "proxy", "<local>;<auto>", NULL, acc);

	s = set_add(&acc->set, "resource", "BitlBee", NULL, acc);
	s->flags |= ACC_SET_OFFLINE_ONLY;

	s = set_add(&acc->set, "resource_select", "activity", NULL, acc);

	s = set_add(&acc->set, "sasl", "true", set_eval_bool, acc);
	s->flags |= ACC_SET_OFFLINE_ONLY | SET_HIDDEN_DEFAULT;

	s = set_add(&acc->set, "server", NULL, set_eval_account, acc);
	s->flags |= SET_NOSAVE | ACC_SET_OFFLINE_ONLY | SET_NULL_OK;

	s = set_add(&acc->set, "ssl", "false", set_eval_bool, acc);
	s->flags |= ACC_SET_OFFLINE_ONLY;

	s = set_add(&acc->set, "tls", "true", set_eval_tls, acc);
	s->flags |= ACC_SET_OFFLINE_ONLY;

	s = set_add(&acc->set, "tls_verify", "true", set_eval_bool, acc);
	s->flags |= ACC_SET_OFFLINE_ONLY;

	s = set_add(&acc->set, "user_agent", "BitlBee", NULL, acc);

	s = set_add(&acc->set, "xmlconsole", "false", set_eval_bool, acc);
	s->flags |= ACC_SET_OFFLINE_ONLY;

	acc->flags |= ACC_FLAG_AWAY_MESSAGE | ACC_FLAG_STATUS_MESSAGE |
	              ACC_FLAG_HANDLE_DOMAINS;

	if (subproto->server) {
		set_setstr(&acc->set, "server", (char *) subproto->server);
	}
}

static void jabber_generate_id_hash(struct jabber_data *jd);

static void jabber_login(account_t *acc)
{
	struct im_connection *ic = imcb_new(acc);
	struct jabber_data *jd = g_new0(struct jabber_data, 1);
	jabber_subproto_desc_t *subproto = acc->prpl->data;
	char *s;

	/* For now this is needed in the _connected() handlers if using
	   GLib event handling, to make sure we're not handling events
	   on dead connections. */
	jabber_connections = g_slist_prepend(jabber_connections, ic);

	jd->ic = ic;
	ic->proto_data = jd;
	jd->subproto = subproto->id;

	jabber_set_me(ic, acc->user);

	jd->fd = jd->r_inpa = jd->w_inpa = -1;

	if (jd->server == NULL) {
		imcb_error(ic, "Incomplete account name (format it like <username@jabberserver.name>)");
		imc_logout(ic, FALSE);
		return;
	}

	if ((s = strchr(jd->server, '/'))) {
		*s = 0;
		set_setstr(&acc->set, "resource", s + 1);

		/* Also remove the /resource from the original variable so we
		   won't have to do this again every time. */
		s = strchr(acc->user, '/');
		*s = 0;
	}

	jd->node_cache = g_hash_table_new_full(g_str_hash, g_str_equal, NULL, jabber_cache_entry_free);
	jd->buddies = g_hash_table_new(g_str_hash, g_str_equal);

	if (subproto->oauth2_service && set_getbool(&acc->set, "oauth")) {
		GSList *p_in = NULL;
		const char *tok;

		jd->fd = jd->r_inpa = jd->w_inpa = -1;

		jd->oauth2_service = subproto->oauth2_service;

		oauth_params_parse(&p_in, ic->acc->pass);

		/* First see if we have a refresh token, in which case any
		   access token we *might* have has probably expired already
		   anyway. */
		if ((tok = oauth_params_get(&p_in, "refresh_token"))) {
			sasl_oauth2_refresh(ic, tok);
		}
		/* If we don't have a refresh token, let's hope the access
		   token is still usable. */
		else if ((tok = oauth_params_get(&p_in, "access_token"))) {
			jd->oauth2_access_token = g_strdup(tok);
			jabber_connect(ic);
		}
		/* If we don't have any, start the OAuth process now. Don't
		   even open an XMPP connection yet. */
		else {
			sasl_oauth2_init(ic);
			ic->flags |= OPT_SLOW_LOGIN;
		}

		oauth_params_free(&p_in);
	} else {
		jabber_connect(ic);
	}
}

/* Separate this from jabber_login() so we can do OAuth first if necessary.
   Putting this in io.c would probably be more correct. */
void jabber_connect(struct im_connection *ic)
{
	account_t *acc = ic->acc;
	struct jabber_data *jd = ic->proto_data;
	int i;
	char *connect_to;
	struct ns_srv_reply **srvl = NULL, *srv = NULL;

	/* Figure out the hostname to connect to. */
	if (acc->server && *acc->server) {
		connect_to = acc->server;
	} else if ((srvl = srv_lookup("xmpp-client", "tcp", jd->server)) ||
	           (srvl = srv_lookup("jabber-client", "tcp", jd->server))) {
		/* Find the lowest-priority one. These usually come
		   back in random/shuffled order. Not looking at
		   weights etc for now. */
		srv = *srvl;
		for (i = 1; srvl[i]; i++) {
			if (srvl[i]->prio < srv->prio) {
				srv = srvl[i];
			}
		}

		connect_to = srv->name;
	} else {
		connect_to = jd->server;
	}

	imcb_log(ic, "Connecting");

	for (i = 0; jabber_port_list[i] > 0; i++) {
		if (set_getint(&acc->set, "port") == jabber_port_list[i]) {
			break;
		}
	}

	if (jabber_port_list[i] == 0) {
		imcb_log(ic, "Illegal port number");
		imc_logout(ic, FALSE);
		return;
	}

	/* For non-SSL connections we can try to use the port # from the SRV
	   reply, but let's not do that when using SSL, SSL usually runs on
	   non-standard ports... */
	if (set_getbool(&acc->set, "ssl")) {
		jd->ssl = ssl_connect(connect_to, set_getint(&acc->set, "port"), set_getbool(&acc->set,
		                                                                             "tls_verify"), jabber_connected_ssl,
		                      ic);
		jd->fd = jd->ssl ? ssl_getfd(jd->ssl) : -1;
	} else {
		jd->fd = proxy_connect(connect_to, srv ? srv->port : set_getint(&acc->set,
		                                                                "port"), jabber_connected_plain, ic);
	}
	srv_free(srvl);

	if (jd->fd == -1) {
		imcb_error(ic, "Could not connect to server");
		imc_logout(ic, TRUE);

		return;
	}

	if (set_getbool(&acc->set, "xmlconsole")) {
		jd->flags |= JFLAG_XMLCONSOLE;
		/* Shouldn't really do this at this stage already, maybe. But
		   I think this shouldn't break anything. */
		imcb_add_buddy(ic, JABBER_XMLCONSOLE_HANDLE, NULL);
	}

	jabber_generate_id_hash(jd);
}

/* This generates an unfinished md5_state_t variable. Every time we generate
   an ID, we finish the state by adding a sequence number and take the hash. */
static void jabber_generate_id_hash(struct jabber_data *jd)
{
	md5_byte_t binbuf[4];
	char *s;

	md5_init(&jd->cached_id_prefix);
	md5_append(&jd->cached_id_prefix, (unsigned char *) jd->username, strlen(jd->username));
	md5_append(&jd->cached_id_prefix, (unsigned char *) jd->server, strlen(jd->server));
	s = set_getstr(&jd->ic->acc->set, "resource");
	md5_append(&jd->cached_id_prefix, (unsigned char *) s, strlen(s));
	random_bytes(binbuf, 4);
	md5_append(&jd->cached_id_prefix, binbuf, 4);
}

static void jabber_logout(struct im_connection *ic)
{
	struct jabber_data *jd = ic->proto_data;

	while (jd->filetransfers) {
		imcb_file_canceled(ic, (( struct jabber_transfer *) jd->filetransfers->data)->ft, "Logging out");
	}

	while (jd->streamhosts) {
		jabber_streamhost_t *sh = jd->streamhosts->data;
		jd->streamhosts = g_slist_remove(jd->streamhosts, sh);
		g_free(sh->jid);
		g_free(sh->host);
		g_free(sh);
	}

	if (jd->fd >= 0) {
		jabber_end_stream(ic);
	}

	while (ic->groupchats) {
		jabber_chat_free(ic->groupchats->data);
	}

	if (jd->r_inpa >= 0) {
		b_event_remove(jd->r_inpa);
	}
	if (jd->w_inpa >= 0) {
		b_event_remove(jd->w_inpa);
	}

	if (jd->ssl) {
		ssl_disconnect(jd->ssl);
	}
	if (jd->fd >= 0) {
		closesocket(jd->fd);
	}

	if (jd->tx_len) {
		g_free(jd->txq);
	}

	if (jd->node_cache) {
		g_hash_table_destroy(jd->node_cache);
	}

	jabber_buddy_remove_all(ic);

	xt_free(jd->xt);

	md5_free(&jd->cached_id_prefix);

	g_free(jd->oauth2_access_token);
	g_free(jd->away_message);
	g_free(jd->internal_jid);
	g_free(jd->username);
	g_free(jd->me);
	g_free(jd);

	jabber_connections = g_slist_remove(jabber_connections, ic);
}

static int jabber_buddy_msg(struct im_connection *ic, char *who, char *message, int flags)
{
	struct jabber_data *jd = ic->proto_data;
	struct jabber_buddy *bud;
	struct xt_node *node;
	char *s;
	int st;

	if (g_strcasecmp(who, JABBER_XMLCONSOLE_HANDLE) == 0) {
		return jabber_write(ic, message, strlen(message));
	}

	if (g_strcasecmp(who, JABBER_OAUTH_HANDLE) == 0 &&
	    !(jd->flags & OPT_LOGGED_IN) && jd->fd == -1) {
		if (sasl_oauth2_get_refresh_token(ic, message)) {
			return 1;
		} else {
			imcb_error(ic, "OAuth failure");
			imc_logout(ic, TRUE);
			return 0;
		}
	}

	if ((s = strchr(who, '=')) && jabber_chat_by_jid(ic, s + 1)) {
		bud = jabber_buddy_by_ext_jid(ic, who, 0);
	} else {
		bud = jabber_buddy_by_jid(ic, who, GET_BUDDY_BARE_OK);
	}

	node = xt_new_node("body", message, NULL);
	node = jabber_make_packet("message", "chat", bud ? bud->full_jid : who, node);

	if (bud && (jd->flags & JFLAG_WANT_TYPING) &&
	    ((bud->flags & JBFLAG_DOES_XEP85) ||
	     !(bud->flags & JBFLAG_PROBED_XEP85))) {
		struct xt_node *act;

		/* If the user likes typing notification and if we don't know
		   (and didn't probe before) if this resource supports XEP85,
		   include a probe in this packet now. Also, if we know this
		   buddy does support XEP85, we have to send this <active/>
		   tag to tell that the user stopped typing (well, that's what
		   we guess when s/he pressed Enter...). */
		act = xt_new_node("active", NULL, NULL);
		xt_add_attr(act, "xmlns", XMLNS_CHATSTATES);
		xt_add_child(node, act);

		/* Just make sure we do this only once. */
		bud->flags |= JBFLAG_PROBED_XEP85;
	}

	st = jabber_write_packet(ic, node);
	xt_free_node(node);

	return st;
}

static GList *jabber_away_states(struct im_connection *ic)
{
	static GList *l = NULL;
	int i;

	if (l == NULL) {
		for (i = 0; jabber_away_state_list[i].full_name; i++) {
			l = g_list_append(l, (void *) jabber_away_state_list[i].full_name);
		}
	}

	return l;
}

static void jabber_get_info(struct im_connection *ic, char *who)
{
	struct jabber_buddy *bud;

	bud = jabber_buddy_by_jid(ic, who, GET_BUDDY_FIRST);

	while (bud) {
		imcb_log(ic, "Buddy %s (%d) information:", bud->full_jid, bud->priority);
		if (bud->away_state) {
			imcb_log(ic, "Away state: %s", bud->away_state->full_name);
		}
		imcb_log(ic, "Status message: %s", bud->away_message ? bud->away_message : "(none)");

		bud = bud->next;
	}

	jabber_get_vcard(ic, bud ? bud->full_jid : who);
}

static void jabber_set_away(struct im_connection *ic, char *state_txt, char *message)
{
	struct jabber_data *jd = ic->proto_data;

	/* state_txt == NULL -> Not away.
	   Unknown state -> fall back to the first defined away state. */
	if (state_txt == NULL) {
		jd->away_state = NULL;
	} else if ((jd->away_state = jabber_away_state_by_name(state_txt)) == NULL) {
		jd->away_state = jabber_away_state_list;
	}

	g_free(jd->away_message);
	jd->away_message = (message && *message) ? g_strdup(message) : NULL;

	presence_send_update(ic);
}

static void jabber_add_buddy(struct im_connection *ic, char *who, char *group)
{
	struct jabber_data *jd = ic->proto_data;

	if (g_strcasecmp(who, JABBER_XMLCONSOLE_HANDLE) == 0) {
		jd->flags |= JFLAG_XMLCONSOLE;
		imcb_add_buddy(ic, JABBER_XMLCONSOLE_HANDLE, NULL);
		return;
	}

	if (jabber_add_to_roster(ic, who, NULL, group)) {
		presence_send_request(ic, who, "subscribe");
	}
}

static void jabber_remove_buddy(struct im_connection *ic, char *who, char *group)
{
	struct jabber_data *jd = ic->proto_data;

	if (g_strcasecmp(who, JABBER_XMLCONSOLE_HANDLE) == 0) {
		jd->flags &= ~JFLAG_XMLCONSOLE;
		/* Not necessary for now. And for now the code isn't too
		   happy if the buddy is completely gone right after calling
		   this function already.
		imcb_remove_buddy( ic, JABBER_XMLCONSOLE_HANDLE, NULL );
		*/
		return;
	}

	/* We should always do this part. Clean up our administration a little bit. */
	jabber_buddy_remove_bare(ic, who);

	if (jabber_remove_from_roster(ic, who)) {
		presence_send_request(ic, who, "unsubscribe");
	}
}

static struct groupchat *jabber_chat_join_(struct im_connection *ic, const char *room, const char *nick,
                                           const char *password, set_t **sets)
{
	struct jabber_data *jd = ic->proto_data;
	char *final_nick;

	/* Ignore the passed nick parameter if we have our own default */
	if (!(final_nick = set_getstr(sets, "nick")) &&
	    !(final_nick = set_getstr(&ic->acc->set, "display_name"))) {
		/* Well, whatever, actually use the provided default, then */
		final_nick = (char *) nick;
	}

	if (strchr(room, '@') == NULL) {
		imcb_error(ic, "%s is not a valid Jabber room name. Maybe you mean %s@conference.%s?",
		           room, room, jd->server);
	} else if (jabber_chat_by_jid(ic, room)) {
		imcb_error(ic, "Already present in chat `%s'", room);
	} else {
		return jabber_chat_join(ic, room, final_nick, set_getstr(sets, "password"));
	}

	return NULL;
}

static struct groupchat *jabber_chat_with_(struct im_connection *ic, char *who)
{
	return jabber_chat_with(ic, who);
}

static void jabber_chat_msg_(struct groupchat *c, char *message, int flags)
{
	if (c && message) {
		jabber_chat_msg(c, message, flags);
	}
}

static void jabber_chat_topic_(struct groupchat *c, char *topic)
{
	if (c && topic) {
		jabber_chat_topic(c, topic);
	}
}

static void jabber_chat_leave_(struct groupchat *c)
{
	if (c) {
		jabber_chat_leave(c, NULL);
	}
}

static void jabber_chat_invite_(struct groupchat *c, char *who, char *msg)
{
	struct jabber_data *jd = c->ic->proto_data;
	struct jabber_chat *jc = c->data;
	gchar *msg_alt = NULL;

	if (msg == NULL) {
		msg_alt = g_strdup_printf("%s invited you to %s", jd->me, jc->name);
	}

	if (c && who) {
		jabber_chat_invite(c, who, msg ? msg : msg_alt);
	}

	g_free(msg_alt);
}

static void jabber_keepalive(struct im_connection *ic)
{
	/* Just any whitespace character is enough as a keepalive for XMPP sessions. */
	if (!jabber_write(ic, "\n", 1)) {
		return;
	}

	/* This runs the garbage collection every minute, which means every packet
	   is in the cache for about a minute (which should be enough AFAIK). */
	jabber_cache_clean(ic);
}

static int jabber_send_typing(struct im_connection *ic, char *who, int typing)
{
	struct jabber_data *jd = ic->proto_data;
	struct jabber_buddy *bud;

	/* Enable typing notification related code from now. */
	jd->flags |= JFLAG_WANT_TYPING;

	if ((bud = jabber_buddy_by_jid(ic, who, 0)) == NULL) {
		/* Sending typing notifications to unknown buddies is
		   unsupported for now. Shouldn't be a problem, I think. */
		return 0;
	}

	if (bud->flags & JBFLAG_DOES_XEP85) {
		/* We're only allowed to send this stuff if we know the other
		   side supports it. */

		struct xt_node *node;
		char *type;
		int st;

		if (typing & OPT_TYPING) {
			type = "composing";
		} else if (typing & OPT_THINKING) {
			type = "paused";
		} else {
			type = "active";
		}

		node = xt_new_node(type, NULL, NULL);
		xt_add_attr(node, "xmlns", XMLNS_CHATSTATES);
		node = jabber_make_packet("message", "chat", bud->full_jid, node);

		st = jabber_write_packet(ic, node);
		xt_free_node(node);

		return st;
	}

	return 1;
}

void jabber_chat_add_settings(account_t *acc, set_t **head)
{
	/* Meh. Stupid room passwords. Not trying to obfuscate/hide
	   them from the user for now. */
	set_add(head, "password", NULL, NULL, NULL);
}

void jabber_chat_free_settings(account_t *acc, set_t **head)
{
	set_del(head, "password");
}

GList *jabber_buddy_action_list(bee_user_t *bu)
{
	static GList *ret = NULL;

	if (ret == NULL) {
		static const struct buddy_action ba[2] = {
			{ "VERSION", "Get client (version) information" },
		};

		ret = g_list_prepend(ret, (void *) ba + 0);
	}

	return ret;
}

void *jabber_buddy_action(struct bee_user *bu, const char *action, char * const args[], void *data)
{
	if (g_strcasecmp(action, "VERSION") == 0) {
		struct jabber_buddy *bud;

		if ((bud = jabber_buddy_by_ext_jid(bu->ic, bu->handle, 0)) == NULL) {
			bud = jabber_buddy_by_jid(bu->ic, bu->handle, GET_BUDDY_FIRST);
		}
		for (; bud; bud = bud->next) {
			jabber_iq_version_send(bu->ic, bud, data);
		}
	}

	return NULL;
}

gboolean jabber_handle_is_self(struct im_connection *ic, const char *who)
{
	struct jabber_data *jd = ic->proto_data;

	return ((g_strcasecmp(who, ic->acc->user) == 0) ||
	        (jd->internal_jid &&
	         g_strcasecmp(who, jd->internal_jid) == 0));
}

void jabber_initmodule()
{
	int i;
	struct prpl funcs;

	memset(&funcs, 0, sizeof(funcs));

	funcs.mms = 0;                        /* no limit */
	funcs.login = jabber_login;
	funcs.init = jabber_init;
	funcs.logout = jabber_logout;
	funcs.buddy_msg = jabber_buddy_msg;
	funcs.away_states = jabber_away_states;
	funcs.set_away = jabber_set_away;
	funcs.get_info = jabber_get_info;
	funcs.add_buddy = jabber_add_buddy;
	funcs.remove_buddy = jabber_remove_buddy;
	funcs.chat_msg = jabber_chat_msg_;
	funcs.chat_topic = jabber_chat_topic_;
	funcs.chat_invite = jabber_chat_invite_;
	funcs.chat_leave = jabber_chat_leave_;
	funcs.chat_join = jabber_chat_join_;
	funcs.chat_with = jabber_chat_with_;
	funcs.chat_add_settings = jabber_chat_add_settings;
	funcs.chat_free_settings = jabber_chat_free_settings;
	funcs.keepalive = jabber_keepalive;
	funcs.send_typing = jabber_send_typing;
	funcs.handle_cmp = g_strcasecmp;
	funcs.handle_is_self = jabber_handle_is_self;
	funcs.transfer_request = jabber_si_transfer_request;
	funcs.buddy_action_list = jabber_buddy_action_list;
	funcs.buddy_action = jabber_buddy_action;

	for (i = 0; jabber_subproto_list[i].name; i++) {
		struct prpl *subproto = g_memdup(&funcs, sizeof(funcs));
		subproto->name = jabber_subproto_list[i].name;
		subproto->data = &jabber_subproto_list[i];
		register_protocol(subproto);
	}
}