/*
 * avatar.c
 * vim: expandtab:ts=4:sts=4:sw=4
 *
 * Copyright (C) 2019 - 2021 Michael Vetter <jubalh@iodoru.org>
 *
 * This file is part of Profanity.
 *
 * Profanity 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 3 of the License, or
 * (at your option) any later version.
 *
 * Profanity 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 Profanity.  If not, see <https://www.gnu.org/licenses/>.
 *
 * In addition, as a special exception, the copyright holders give permission to
 * link the code of portions of this program with the OpenSSL library under
 * certain conditions as described in each individual source file, and
 * distribute linked combinations including the two.
 *
 * You must obey the GNU General Public License in all respects for all of the
 * code used other than OpenSSL. If you modify file(s) with this exception, you
 * may extend this exception to your version of the file(s), but you are not
 * obligated to do so. If you do not wish to do so, delete this exception
 * statement from your version. If you delete this exception statement from all
 * source files in the program, then also delete it here.
 *
 */

#include "config.h"

#include <glib.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/stat.h>

#include "log.h"
#include "xmpp/connection.h"
#include "xmpp/iq.h"
#include "xmpp/message.h"
#include "xmpp/stanza.h"
#include "ui/ui.h"
#include "config/files.h"
#include "config/preferences.h"

typedef struct avatar_metadata
{
    char* type;
    char* id;
} avatar_metadata;

static GHashTable* looking_for = NULL; // contains nicks/barejids from who we want to get the avatar
static GHashTable* shall_open = NULL;  // contains a list of nicks that shall not just downloaded but also opened

static void _avatar_request_item_by_id(const char* jid, avatar_metadata* data);
static int _avatar_metadata_handler(xmpp_stanza_t* const stanza, void* const userdata);
static int _avatar_request_item_result_handler(xmpp_stanza_t* const stanza, void* const userdata);

static void
_free_avatar_data(avatar_metadata* data)
{
    if (data) {
        free(data->type);
        free(data);
    }
}

void
avatar_pep_subscribe(void)
{
    message_pubsub_event_handler_add(STANZA_NS_USER_AVATAR_METADATA, _avatar_metadata_handler, NULL, NULL);
    message_pubsub_event_handler_add(STANZA_NS_USER_AVATAR_DATA, _avatar_metadata_handler, NULL, NULL);

    // caps_add_feature(XMPP_FEATURE_USER_AVATAR_METADATA_NOTIFY);

    if (looking_for) {
        g_hash_table_destroy(looking_for);
    }
    looking_for = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, NULL);

    if (shall_open) {
        g_hash_table_destroy(shall_open);
    }
    shall_open = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, NULL);
}

gboolean
avatar_get_by_nick(const char* nick, gboolean open)
{
    // in case we set the feature, remove it
    caps_remove_feature(XMPP_FEATURE_USER_AVATAR_METADATA_NOTIFY);

    // save nick in list so we look for this one
    g_hash_table_insert(looking_for, strdup(nick), NULL);

    // add the feature. this will trigger the _avatar_metadata_notfication_handler handler
    caps_add_feature(XMPP_FEATURE_USER_AVATAR_METADATA_NOTIFY);

    if (open) {
        g_hash_table_insert(shall_open, strdup(nick), NULL);
    }

    return TRUE;
}

static int
_avatar_metadata_handler(xmpp_stanza_t* const stanza, void* const userdata)
{
    const char* from = xmpp_stanza_get_attribute(stanza, STANZA_ATTR_FROM);
    if (!from) {
        return 1;
    }

    if (!g_hash_table_contains(looking_for, from)) {
        return 1;
    }

    xmpp_stanza_t* root = NULL;
    xmpp_stanza_t* event = xmpp_stanza_get_child_by_ns(stanza, STANZA_NS_PUBSUB_EVENT);
    if (event) {
        root = event;
    }

    xmpp_stanza_t* pubsub = xmpp_stanza_get_child_by_ns(stanza, STANZA_NS_PUBSUB);
    if (pubsub) {
        root = pubsub;
    }

    if (!root) {
        return 1;
    }

    xmpp_stanza_t* items = xmpp_stanza_get_child_by_name(root, "items");
    if (!items) {
        return 1;
    }

    xmpp_stanza_t* item = xmpp_stanza_get_child_by_name(items, "item");
    if (item) {
        xmpp_stanza_t* metadata = xmpp_stanza_get_child_by_name(item, "metadata");
        if (metadata) {

            xmpp_stanza_t* info = xmpp_stanza_get_child_by_name(metadata, "info");
            if (info) {

                const char* id = xmpp_stanza_get_id(info);
                const char* type = xmpp_stanza_get_attribute(info, "type");

                if (id && type) {
                    log_debug("Avatar ID for %s is: %s", from, id);

                    avatar_metadata* data = malloc(sizeof(avatar_metadata));
                    if (data) {
                        data->type = strdup(type);
                        data->id = strdup(id);

                        // request the actual (image) data
                        _avatar_request_item_by_id(from, data);
                    }
                }
            }
        }
    }

    return 1;
}

static void
_avatar_request_item_by_id(const char* jid, avatar_metadata* data)
{
    caps_remove_feature(XMPP_FEATURE_USER_AVATAR_METADATA_NOTIFY);

    xmpp_ctx_t* const ctx = connection_get_ctx();

    char* uid = connection_create_stanza_id();

    xmpp_stanza_t* iq = stanza_create_avatar_retrieve_data_request(ctx, uid, data->id, jid);
    iq_id_handler_add(uid, _avatar_request_item_result_handler, (ProfIqFreeCallback)_free_avatar_data, data);

    free(uid);

    iq_send_stanza(iq);
    xmpp_stanza_release(iq);
}

static int
_avatar_request_item_result_handler(xmpp_stanza_t* const stanza, void* const userdata)
{
    const char* from_attr = xmpp_stanza_get_attribute(stanza, STANZA_ATTR_FROM);

    if (!from_attr) {
        return 1;
    }

    if (!g_hash_table_contains(looking_for, from_attr)) {
        return 1;
    }
    g_hash_table_remove(looking_for, from_attr);

    xmpp_stanza_t* pubsub = xmpp_stanza_get_child_by_ns(stanza, STANZA_NS_PUBSUB);
    if (!pubsub) {
        return 1;
    }

    xmpp_stanza_t* items = xmpp_stanza_get_child_by_name(pubsub, "items");
    if (!items) {
        return 1;
    }

    xmpp_stanza_t* item = xmpp_stanza_get_child_by_name(items, "item");
    if (!item) {
        return 1;
    }

    xmpp_stanza_t* st_data = xmpp_stanza_get_child_by_name_and_ns(item, "data", STANZA_NS_USER_AVATAR_DATA);
    if (!st_data) {
        return 1;
    }

    char* buf = xmpp_stanza_get_text(st_data);
    if (!buf) {
        return 1;
    }

    gsize size;
    gchar* de = (gchar*)g_base64_decode(buf, &size);
    free(buf);

    char* path = files_get_data_path("");
    GString* filename = g_string_new(path);
    free(path);

    g_string_append(filename, "avatars/");

    errno = 0;
    int res = g_mkdir_with_parents(filename->str, S_IRWXU);
    if (res == -1) {
        const char* errmsg = strerror(errno);
        if (errmsg) {
            log_error("Avatar: error creating directory: %s, %s", filename->str, errmsg);
        } else {
            log_error("Avatar: creating directory: %s", filename->str);
        }
    }

    gchar* from = str_replace(from_attr, "@", "_at_");
    g_string_append(filename, from);

    avatar_metadata* data = (avatar_metadata*)userdata;

    // check a few image types ourselves
    // if none matches we won't add an extension but linux will
    // be able to open it anyways
    // TODO: we could use /etc/mime-types
    if (g_strcmp0(data->type, "image/png") == 0) {
        g_string_append(filename, ".png");
    } else if (g_strcmp0(data->type, "image/jpeg") == 0) {
        g_string_append(filename, ".jpeg");
    } else if (g_strcmp0(data->type, "image/webp") == 0) {
        g_string_append(filename, ".webp");
    }

    free(from);

    GError* err = NULL;
    if (g_file_set_contents(filename->str, de, size, &err) == FALSE) {
        log_error("Unable to save picture: %s", err->message);
        cons_show("Unable to save picture %s", err->message);
        g_error_free(err);
    } else {
        cons_show("Avatar saved as %s", filename->str);
    }

    // if we shall open it
    if (g_hash_table_contains(shall_open, from_attr)) {
        gchar* argv[] = { prefs_get_string(PREF_AVATAR_CMD), filename->str, NULL };
        if (!call_external(argv, NULL, NULL)) {
            cons_show_error("Unable to display avatar: check the logs for more information.");
        }
        g_hash_table_remove(shall_open, from_attr);
    }

    g_string_free(filename, TRUE);
    free(de);

    return 1;
}