source: protocols/twitter/twitter.c @ 489847f

/***************************************************************************\
*                                                                           *
*  BitlBee - An IRC to IM gateway                                           *
*  Simple module to facilitate twitter functionality.                       *
*                                                                           *
*  Copyright 2009-2010 Geert Mulders <g.c.w.m.mulders@gmail.com>            *
*  Copyright 2010-2013 Wilmer van der Gaast <wilmer@gaast.net>              *
*                                                                           *
*  This library is free software; you can redistribute it and/or            *
*  modify it under the terms of the GNU Lesser General Public               *
*  License as published by the Free Software Foundation, version            *
*  2.1.                                                                     *
*                                                                           *
*  This library 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        *
*  Lesser General Public License for more details.                          *
*                                                                           *
*  You should have received a copy of the GNU Lesser General Public License *
*  along with this library; if not, write to the Free Software Foundation,  *
*  Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA           *
*                                                                           *
****************************************************************************/

#include "nogaim.h"
#include "oauth.h"
#include "twitter.h"
#include "twitter_http.h"
#include "twitter_lib.h"
#include "url.h"

GSList *twitter_connections = NULL;
/**
 * Main loop function
 */
gboolean twitter_main_loop(gpointer data, gint fd, b_input_condition cond)
{
        struct im_connection *ic = data;

        // Check if we are still logged in...
        if (!g_slist_find(twitter_connections, ic))
                return FALSE;

        // Do stuff..
        return twitter_get_timeline(ic, -1) &&
               ((ic->flags & OPT_LOGGED_IN) == OPT_LOGGED_IN);
}

static void twitter_main_loop_start(struct im_connection *ic)
{
        struct twitter_data *td = ic->proto_data;

        /* Create the room now that we "logged in". */
        if (td->flags & TWITTER_MODE_CHAT)
                twitter_groupchat_init(ic);

        imcb_log(ic, "Getting initial statuses");

        // Run this once. After this queue the main loop function (or open the
        // stream if available).
        twitter_main_loop(ic, -1, 0);
        
        if (set_getbool(&ic->acc->set, "stream")) {
                /* That fetch was just to get backlog, the stream will give
                   us the rest. \o/ */
                twitter_open_stream(ic);
                
                /* Stream sends keepalives (empty lines) or actual data at
                   least twice a minute. Disconnect if this stops. */
                ic->flags |= OPT_PONGS;
        } else {
                /* Not using the streaming API, so keep polling the old-
                   fashioned way. :-( */
                td->main_loop_id =
                    b_timeout_add(set_getint(&ic->acc->set, "fetch_interval") * 1000,
                                  twitter_main_loop, ic);
        }
}

struct groupchat *twitter_groupchat_init(struct im_connection *ic)
{
        char *name_hint;
        struct groupchat *gc;
        struct twitter_data *td = ic->proto_data;
        GSList *l;

        if (td->timeline_gc)
                return td->timeline_gc;

        td->timeline_gc = gc = imcb_chat_new(ic, "twitter/timeline");

        name_hint = g_strdup_printf("%s_%s", td->prefix, ic->acc->user);
        imcb_chat_name_hint(gc, name_hint);
        g_free(name_hint);

        for (l = ic->bee->users; l; l = l->next) {
                bee_user_t *bu = l->data;
                if (bu->ic == ic)
                        imcb_chat_add_buddy(gc, bu->handle);
        }
        imcb_chat_add_buddy(gc, ic->acc->user);
        
        return gc;
}

static void twitter_oauth_start(struct im_connection *ic);

void twitter_login_finish(struct im_connection *ic)
{
        struct twitter_data *td = ic->proto_data;

        td->flags &= ~TWITTER_DOING_TIMELINE;

        if (set_getbool(&ic->acc->set, "oauth") && !td->oauth_info)
                twitter_oauth_start(ic);
        else if (!(td->flags & TWITTER_MODE_ONE) &&
                 !(td->flags & TWITTER_HAVE_FRIENDS)) {
                imcb_log(ic, "Getting contact list");
                twitter_get_friends_ids(ic, -1);
        } else
                twitter_main_loop_start(ic);
}

static const struct oauth_service twitter_oauth = {
        "https://api.twitter.com/oauth/request_token",
        "https://api.twitter.com/oauth/access_token",
        "https://api.twitter.com/oauth/authorize",
        .consumer_key = "xsDNKJuNZYkZyMcu914uEA",
        .consumer_secret = "FCxqcr0pXKzsF9ajmP57S3VQ8V6Drk4o2QYtqMcOszo",
};

static const struct oauth_service identica_oauth = {
        "https://identi.ca/api/oauth/request_token",
        "https://identi.ca/api/oauth/access_token",
        "https://identi.ca/api/oauth/authorize",
        .consumer_key = "e147ff789fcbd8a5a07963afbb43f9da",
        .consumer_secret = "c596267f277457ec0ce1ab7bb788d828",
};

static gboolean twitter_oauth_callback(struct oauth_info *info);

static const struct oauth_service *get_oauth_service(struct im_connection *ic)
{
        struct twitter_data *td = ic->proto_data;

        if (strstr(td->url_host, "identi.ca"))
                return &identica_oauth;
        else
                return &twitter_oauth;

        /* Could add more services, or allow configuring your own base URL +
           API keys. */
}

static void twitter_oauth_start(struct im_connection *ic)
{
        struct twitter_data *td = ic->proto_data;
        const char *url = set_getstr(&ic->acc->set, "base_url");

        imcb_log(ic, "Requesting OAuth request token");
        
        if (!strstr(url, "twitter.com") && !strstr(url, "identi.ca"))
                imcb_log(ic, "Warning: OAuth only works with identi.ca and "
                             "Twitter.");

        td->oauth_info = oauth_request_token(get_oauth_service(ic), twitter_oauth_callback, ic);

        /* We need help from the user to complete OAuth login, so don't time
           out on this login. */
        ic->flags |= OPT_SLOW_LOGIN;
}

static gboolean twitter_oauth_callback(struct oauth_info *info)
{
        struct im_connection *ic = info->data;
        struct twitter_data *td;

        if (!g_slist_find(twitter_connections, ic))
                return FALSE;

        td = ic->proto_data;
        if (info->stage == OAUTH_REQUEST_TOKEN) {
                char *name, *msg;

                if (info->request_token == NULL) {
                        imcb_error(ic, "OAuth error: %s", twitter_parse_error(info->http));
                        imc_logout(ic, TRUE);
                        return FALSE;
                }

                name = g_strdup_printf("%s_%s", td->prefix, ic->acc->user);
                msg = g_strdup_printf("To finish OAuth authentication, please visit "
                                      "%s and respond with the resulting PIN code.",
                                      info->auth_url);
                imcb_buddy_msg(ic, name, msg, 0, 0);
                g_free(name);
                g_free(msg);
        } else if (info->stage == OAUTH_ACCESS_TOKEN) {
                const char *sn;
                
                if (info->token == NULL || info->token_secret == NULL) {
                        imcb_error(ic, "OAuth error: %s", twitter_parse_error(info->http));
                        imc_logout(ic, TRUE);
                        return FALSE;
                }
                
                if ((sn = oauth_params_get(&info->params, "screen_name"))) {
                        if (ic->acc->prpl->handle_cmp(sn, ic->acc->user) != 0)
                                imcb_log(ic, "Warning: You logged in via OAuth as %s "
                                         "instead of %s.", sn, ic->acc->user);
                        g_free(td->user);
                        td->user = g_strdup(sn);
                }

                /* IM mods didn't do this so far and it's ugly but I should
                   be able to get away with it... */
                g_free(ic->acc->pass);
                ic->acc->pass = oauth_to_string(info);

                twitter_login_finish(ic);
        }

        return TRUE;
}

int twitter_url_len_diff(gchar *msg, unsigned int target_len)
{
        int url_len_diff = 0;

        static GRegex *regex = NULL;
        GMatchInfo *match_info;

        if (regex == NULL)
                regex = g_regex_new("(^|\\s)(http(s)?://[^\\s$]+)", 0, 0, NULL);
        
        g_regex_match(regex, msg, 0, &match_info);
        while (g_match_info_matches(match_info)) {
                gchar *url = g_match_info_fetch(match_info, 2);
                url_len_diff += target_len - g_utf8_strlen(url, -1);
                /* Add another character for https://t.co/... URLs */
                if (g_match_info_fetch(match_info, 3) != NULL)
                        url_len_diff += 1;
                g_free(url);
                g_match_info_next(match_info, NULL);
        }
        g_match_info_free(match_info);

        return url_len_diff;
}

static gboolean twitter_length_check(struct im_connection *ic, gchar * msg)
{
        int max = set_getint(&ic->acc->set, "message_length"), len;
        int target_len = set_getint(&ic->acc->set, "target_url_length");
        int url_len_diff = 0;

        if (target_len > 0)
                url_len_diff = twitter_url_len_diff(msg, target_len);

        if (max == 0 || (len = g_utf8_strlen(msg, -1) + url_len_diff) <= max)
                return TRUE;

        twitter_log(ic, "Maximum message length exceeded: %d > %d", len, max);

        return FALSE;
}

static char *set_eval_commands(set_t * set, char *value)
{
        if (g_strcasecmp(value, "strict") == 0 )
                return value;
        else
                return set_eval_bool(set, value);
}

static char *set_eval_mode(set_t * set, char *value)
{
        if (g_strcasecmp(value, "one") == 0 ||
            g_strcasecmp(value, "many") == 0 || g_strcasecmp(value, "chat") == 0)
                return value;
        else
                return NULL;
}

static void twitter_init(account_t * acc)
{
        set_t *s;
        char *def_url;
        char *def_tul;
        char *def_mentions;

        if (strcmp(acc->prpl->name, "twitter") == 0) {
                def_url = TWITTER_API_URL;
                def_tul = "22";
                def_mentions = "true";
        } else {                /* if( strcmp( acc->prpl->name, "identica" ) == 0 ) */
                def_url = IDENTICA_API_URL;
                def_tul = "0";
                def_mentions = "false";
        }

        s = set_add(&acc->set, "auto_reply_timeout", "10800", set_eval_int, acc);

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

        s = set_add(&acc->set, "commands", "true", set_eval_commands, acc);

        s = set_add(&acc->set, "fetch_interval", "60", set_eval_int, acc);
        s->flags |= ACC_SET_OFFLINE_ONLY;

        s = set_add(&acc->set, "fetch_mentions", def_mentions, set_eval_bool, acc);

        s = set_add(&acc->set, "message_length", "140", set_eval_int, acc);

        s = set_add(&acc->set, "target_url_length", def_tul, set_eval_int, acc);

        s = set_add(&acc->set, "mode", "chat", set_eval_mode, acc);
        s->flags |= ACC_SET_OFFLINE_ONLY;

        s = set_add(&acc->set, "oauth", "true", set_eval_oauth, acc);

        s = set_add(&acc->set, "show_ids", "true", set_eval_bool, acc);

        s = set_add(&acc->set, "show_old_mentions", "20", set_eval_int, acc);

        s = set_add(&acc->set, "strip_newlines", "false", set_eval_bool, acc);
        
        if (strcmp(acc->prpl->name, "twitter") == 0) {
                s = set_add(&acc->set, "stream", "true", set_eval_bool, acc);
                s->flags |= ACC_SET_OFFLINE_ONLY;
        }
}

/**
 * Login method. Since the twitter API works with separate HTTP request we
 * only save the user and pass to the twitter_data object.
 */
static void twitter_login(account_t * acc)
{
        struct im_connection *ic = imcb_new(acc);
        struct twitter_data *td;
        char name[strlen(acc->user) + 9];
        url_t url;
        char *s;
        
        if (!url_set(&url, set_getstr(&ic->acc->set, "base_url")) ||
            (url.proto != PROTO_HTTP && url.proto != PROTO_HTTPS)) {
                imcb_error(ic, "Incorrect API base URL: %s", set_getstr(&ic->acc->set, "base_url"));
                imc_logout(ic, FALSE);
                return;
        }

        if (!strstr(url.host, "twitter.com") &&
            set_getbool(&ic->acc->set, "stream")) {
                imcb_error(ic, "Warning: The streaming API is only supported by Twitter, "
                               "and you seem to be connecting to a different service.");
        }

        imcb_log(ic, "Connecting");

        twitter_connections = g_slist_append(twitter_connections, ic);
        td = g_new0(struct twitter_data, 1);
        ic->proto_data = td;
        td->user = g_strdup(acc->user);

        td->url_ssl = url.proto == PROTO_HTTPS;
        td->url_port = url.port;
        td->url_host = g_strdup(url.host);
        if (strcmp(url.file, "/") != 0)
                td->url_path = g_strdup(url.file);
        else {
                td->url_path = g_strdup("");
                if (g_str_has_suffix(url.host, "twitter.com"))
                        /* May fire for people who turned on HTTPS. */
                        imcb_error(ic, "Warning: Twitter requires a version number in API calls "
                                       "now. Try resetting the base_url account setting.");
        }
        
        /* Hacky string mangling: Turn identi.ca into identi.ca and api.twitter.com
           into twitter, and try to be sensible if we get anything else. */
        td->prefix = g_strdup(url.host);
        if (g_str_has_suffix(td->prefix, ".com"))
                td->prefix[strlen(url.host) - 4] = '\0';
        if ((s = strrchr(td->prefix, '.')) && strlen(s) > 4) {
                /* If we have at least 3 chars after the last dot, cut off the rest.
                   (mostly a www/api prefix or sth) */
                s = g_strdup(s + 1);
                g_free(td->prefix);
                td->prefix = s;
        }
        
        if (strstr(acc->pass, "oauth_token="))
                td->oauth_info = oauth_from_string(acc->pass, get_oauth_service(ic));

        sprintf(name, "%s_%s", td->prefix, acc->user);
        imcb_add_buddy(ic, name, NULL);
        imcb_buddy_status(ic, name, OPT_LOGGED_IN, NULL, NULL);

        td->log = g_new0(struct twitter_log_data, TWITTER_LOG_LENGTH);
        td->log_id = -1;
        
        s = set_getstr(&ic->acc->set, "mode");
        if (g_strcasecmp(s, "one") == 0)
                td->flags |= TWITTER_MODE_ONE;
        else if (g_strcasecmp(s, "many") == 0)
                td->flags |= TWITTER_MODE_MANY;
        else
                td->flags |= TWITTER_MODE_CHAT;

        twitter_login_finish(ic);
}

/**
 * Logout method. Just free the twitter_data.
 */
static void twitter_logout(struct im_connection *ic)
{
        struct twitter_data *td = ic->proto_data;

        // Set the status to logged out.
        ic->flags &= ~OPT_LOGGED_IN;

        // Remove the main_loop function from the function queue.
        b_event_remove(td->main_loop_id);

        if (td->timeline_gc)
                imcb_chat_free(td->timeline_gc);

        if (td) {
                http_close(td->stream);
                oauth_info_free(td->oauth_info);
                g_free(td->user);
                g_free(td->prefix);
                g_free(td->url_host);
                g_free(td->url_path);
                g_free(td->log);
                g_free(td);
        }

        twitter_connections = g_slist_remove(twitter_connections, ic);
}

static void twitter_handle_command(struct im_connection *ic, char *message);

/**
 *
 */
static int twitter_buddy_msg(struct im_connection *ic, char *who, char *message, int away)
{
        struct twitter_data *td = ic->proto_data;
        int plen = strlen(td->prefix);

        if (g_strncasecmp(who, td->prefix, plen) == 0 && who[plen] == '_' &&
            g_strcasecmp(who + plen + 1, ic->acc->user) == 0) {
                if (set_getbool(&ic->acc->set, "oauth") &&
                    td->oauth_info && td->oauth_info->token == NULL) {
                        char pin[strlen(message) + 1], *s;

                        strcpy(pin, message);
                        for (s = pin + sizeof(pin) - 2; s > pin && isspace(*s); s--)
                                *s = '\0';
                        for (s = pin; *s && isspace(*s); s++) {
                        }

                        if (!oauth_access_token(s, td->oauth_info)) {
                                imcb_error(ic, "OAuth error: %s",
                                           "Failed to send access token request");
                                imc_logout(ic, TRUE);
                                return FALSE;
                        }
                } else
                        twitter_handle_command(ic, message);
        } else {
                twitter_direct_messages_new(ic, who, message);
        }
        return (0);
}

static void twitter_get_info(struct im_connection *ic, char *who)
{
}

static void twitter_add_buddy(struct im_connection *ic, char *who, char *group)
{
        twitter_friendships_create_destroy(ic, who, 1);
}

static void twitter_remove_buddy(struct im_connection *ic, char *who, char *group)
{
        twitter_friendships_create_destroy(ic, who, 0);
}

static void twitter_chat_msg(struct groupchat *c, char *message, int flags)
{
        if (c && message)
                twitter_handle_command(c->ic, message);
}

static void twitter_chat_invite(struct groupchat *c, char *who, char *message)
{
}

static void twitter_chat_leave(struct groupchat *c)
{
        struct twitter_data *td = c->ic->proto_data;

        if (c != td->timeline_gc)
                return;         /* WTF? */

        /* If the user leaves the channel: Fine. Rejoin him/her once new
           tweets come in. */
        imcb_chat_free(td->timeline_gc);
        td->timeline_gc = NULL;
}

static void twitter_keepalive(struct im_connection *ic)
{
}

static void twitter_add_permit(struct im_connection *ic, char *who)
{
}

static void twitter_rem_permit(struct im_connection *ic, char *who)
{
}

static void twitter_add_deny(struct im_connection *ic, char *who)
{
}

static void twitter_rem_deny(struct im_connection *ic, char *who)
{
}

//static char *twitter_set_display_name( set_t *set, char *value )
//{
//      return value;
//}

static void twitter_buddy_data_add(struct bee_user *bu)
{
        bu->data = g_new0(struct twitter_user_data, 1);
}

static void twitter_buddy_data_free(struct bee_user *bu)
{
        g_free(bu->data);
}

/** Convert the given bitlbee tweet ID, bitlbee username, or twitter tweet ID
 *  into a twitter tweet ID.
 *
 *  Returns 0 if the user provides garbage.
 */
static guint64 twitter_message_id_from_command_arg(struct im_connection *ic, char *arg, bee_user_t **bu_) {
        struct twitter_data *td = ic->proto_data;
        struct twitter_user_data *tud;
        bee_user_t *bu = NULL;
        guint64 id = 0;
        
        if (bu_)
                *bu_ = NULL;
        if (!arg || !arg[0])
                return 0;
        
        if (arg[0] != '#' && (bu = bee_user_by_handle(ic->bee, ic, arg))) {
                if ((tud = bu->data))
                        id = tud->last_id;
        } else {
                if (arg[0] == '#')
                        arg++;
                if (sscanf(arg, "%" G_GINT64_MODIFIER "x", &id) == 1 &&
                    id < TWITTER_LOG_LENGTH) {
                        bu = td->log[id].bu;
                        id = td->log[id].id;
                        /* Beware of dangling pointers! */
                        if (!g_slist_find(ic->bee->users, bu))
                                bu = NULL;
                } else if (sscanf(arg, "%" G_GINT64_MODIFIER "d", &id) == 1) {
                        /* Allow normal tweet IDs as well; not a very useful
                           feature but it's always been there. Just ignore
                           very low IDs to avoid accidents. */
                        if (id < 1000000)
                                id = 0;
                }
        }
        if (bu_)
                *bu_ = bu;
        return id;
}

static void twitter_handle_command(struct im_connection *ic, char *message)
{
        struct twitter_data *td = ic->proto_data;
        char *cmds, **cmd, *new = NULL;
        guint64 in_reply_to = 0, id;
        gboolean allow_post =
                g_strcasecmp(set_getstr(&ic->acc->set, "commands"), "strict") != 0;
        bee_user_t *bu = NULL;

        cmds = g_strdup(message);
        cmd = split_command_parts(cmds);

        if (cmd[0] == NULL) {
                goto eof;
        } else if (!set_getbool(&ic->acc->set, "commands") && allow_post) {
                /* Not supporting commands if "commands" is set to true/strict. */
        } else if (g_strcasecmp(cmd[0], "undo") == 0) {
                if (cmd[1] == NULL)
                        twitter_status_destroy(ic, td->last_status_id);
                else if ((id = twitter_message_id_from_command_arg(ic, cmd[1], NULL)))
                        twitter_status_destroy(ic, id);
                else
                        twitter_log(ic, "Could not undo last action");

                goto eof;
        } else if (g_strcasecmp(cmd[0], "favourite") == 0 && cmd[1]) {
                if ((id = twitter_message_id_from_command_arg(ic, cmd[1], NULL))) {
                        twitter_favourite_tweet(ic, id);
                } else {
                        twitter_log(ic, "Please provide a message ID or username.");
                }
                goto eof;
        } else if (g_strcasecmp(cmd[0], "follow") == 0 && cmd[1]) {
                twitter_add_buddy(ic, cmd[1], NULL);
                goto eof;
        } else if (g_strcasecmp(cmd[0], "unfollow") == 0 && cmd[1]) {
                twitter_remove_buddy(ic, cmd[1], NULL);
                goto eof;
        } else if ((g_strcasecmp(cmd[0], "report") == 0 ||
                    g_strcasecmp(cmd[0], "spam") == 0) && cmd[1]) {
                char *screen_name;
                
                /* Report nominally works on users but look up the user who
                   posted the given ID if the user wants to do it that way */
                twitter_message_id_from_command_arg(ic, cmd[1], &bu);
                if (bu)
                        screen_name = bu->handle;
                else
                        screen_name = cmd[1];
                
                twitter_report_spam(ic, screen_name);
                goto eof;
        } else if (g_strcasecmp(cmd[0], "rt") == 0 && cmd[1]) {
                id = twitter_message_id_from_command_arg(ic, cmd[1], NULL);

                td->last_status_id = 0;
                if (id)
                        twitter_status_retweet(ic, id);
                else
                        twitter_log(ic, "User `%s' does not exist or didn't "
                                    "post any statuses recently", cmd[1]);

                goto eof;
        } else if (g_strcasecmp(cmd[0], "reply") == 0 && cmd[1] && cmd[2]) {
                id = twitter_message_id_from_command_arg(ic, cmd[1], &bu);
                if (!id || !bu) {
                        twitter_log(ic, "User `%s' does not exist or didn't "
                                    "post any statuses recently", cmd[1]);
                        goto eof;
                }
                message = new = g_strdup_printf("@%s %s", bu->handle, message + (cmd[2] - cmd[0]));
                in_reply_to = id;
                allow_post = TRUE;
        } else if (g_strcasecmp(cmd[0], "post") == 0) {
                message += 5;
                allow_post = TRUE;
        }

        if (allow_post) {
                char *s;

                if (!twitter_length_check(ic, message))
                        goto eof;

                s = cmd[0] + strlen(cmd[0]) - 1;
                if (!new && s > cmd[0] && (*s == ':' || *s == ',')) {
                        *s = '\0';

                        if ((bu = bee_user_by_handle(ic->bee, ic, cmd[0]))) {
                                struct twitter_user_data *tud = bu->data;

                                new = g_strdup_printf("@%s %s", bu->handle,
                                                      message + (s - cmd[0]) + 2);
                                message = new;

                                if (time(NULL) < tud->last_time +
                                    set_getint(&ic->acc->set, "auto_reply_timeout"))
                                        in_reply_to = tud->last_id;
                        }
                }

                /* If the user runs undo between this request and its response
                   this would delete the second-last Tweet. Prevent that. */
                td->last_status_id = 0;
                twitter_post_status(ic, message, in_reply_to);
        } else {
                twitter_log(ic, "Unknown command: %s", cmd[0]);
        }
eof:
        g_free(new);
        g_free(cmds);
}

void twitter_log(struct im_connection *ic, char *format, ... )
{
        struct twitter_data *td = ic->proto_data;
        va_list params;
        char *text;
        
        va_start(params, format);
        text = g_strdup_vprintf(format, params);
        va_end(params);
        
        if (td->timeline_gc)
                imcb_chat_log(td->timeline_gc, "%s", text);
        else
                imcb_log(ic, "%s", text);
        
        g_free(text);
}


void twitter_initmodule()
{
        struct prpl *ret = g_new0(struct prpl, 1);

        ret->options = OPT_NOOTR;
        ret->name = "twitter";
        ret->login = twitter_login;
        ret->init = twitter_init;
        ret->logout = twitter_logout;
        ret->buddy_msg = twitter_buddy_msg;
        ret->get_info = twitter_get_info;
        ret->add_buddy = twitter_add_buddy;
        ret->remove_buddy = twitter_remove_buddy;
        ret->chat_msg = twitter_chat_msg;
        ret->chat_invite = twitter_chat_invite;
        ret->chat_leave = twitter_chat_leave;
        ret->keepalive = twitter_keepalive;
        ret->add_permit = twitter_add_permit;
        ret->rem_permit = twitter_rem_permit;
        ret->add_deny = twitter_add_deny;
        ret->rem_deny = twitter_rem_deny;
        ret->buddy_data_add = twitter_buddy_data_add;
        ret->buddy_data_free = twitter_buddy_data_free;
        ret->handle_cmp = g_strcasecmp;

        register_protocol(ret);

        /* And an identi.ca variant: */
        ret = g_memdup(ret, sizeof(struct prpl));
        ret->name = "identica";
        register_protocol(ret);
}