<?php
// This file is part of GNU social - https://www.gnu.org/software/social
//
// GNU social is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// GNU social 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with GNU social.  If not, see <http://www.gnu.org/licenses/>.

/**
 * A plugin to allow anonymous users to favorite notices
 *
 * If you want to keep certain users from having anonymous faving for their
 * notices initialize the plugin with the restricted array, e.g.:
 *
 * addPlugin(
 *     'AnonymousFave',
 *     ['restricted' => ['spock', 'kirk', 'bones']]
 * );
 *
 * @category  Plugin
 * @package   GNUsocial
 * @author    Zach Copley <zach@status.net>
 * @copyright 2010 StatusNet, Inc.
 * @license   https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
 */

defined('GNUSOCIAL') || die();

define('ANONYMOUS_FAVE_PLUGIN_VERSION', '0.1.0');

/**
 * Anonymous Fave plugin to allow anonymous (not logged in) users
 * to favorite notices
 *
 * @category  Plugin
 * @package   GNUsocial
 * @author    Zach Copley <zach@status.net>
 * @copyright 2010 StatusNet, Inc.
 * @license   https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
 */
class AnonymousFavePlugin extends Plugin
{
    // Array of users who should not have anon faving. The default is
    // that anonymous faving is allowed for all users.
    public $restricted = array();

    public function onArgsInitialize()
    {
        // We always want a session because we're tracking anon users
        common_ensure_session();
    }

    /**
     * Hook for ensuring our tables are created
     *
     * Ensures the fave_tally table is there and has the right columns
     *
     * @return boolean hook return
     */

    public function onCheckSchema()
    {
        $schema = Schema::get();

        // For storing total number of times a notice has been faved
        $schema->ensureTable('fave_tally', Fave_tally::schemaDef());

        return true;
    }

    public function onEndShowHTML($action)
    {
        if (!common_logged_in()) {
            // Set a place to return to when submitting forms
            common_set_returnto($action->selfUrl());
        }
    }

    public function onEndShowScripts($action)
    {
        // Setup ajax calls for favoriting. Usually this is only done when
        // a user is logged in.
        $action->inlineScript('SN.U.NoticeFavor();');
    }

    public function onStartInitializeRouter($m)
    {
        $m->connect('main/anonfavor', array('action' => 'AnonFavor'));
        $m->connect('main/anondisfavor', array('action' => 'AnonDisFavor'));

        return true;
    }

    public function onStartShowNoticeOptionItems(NoticeListItem $item): bool
    {
        if (!common_logged_in()) {
            $item->out->elementStart('div', 'notice-options');
            if (Event::handle('StartShowFaveForm', [$item])) {
                Event::handle('EndShowFaveForm', [$item]);
            }
            $item->out->elementEnd('div');
        }

        return true;
    }

    public function onStartShowFaveForm($item)
    {
        if (!common_logged_in() && $this->hasAnonFaving($item)) {
            $profile = AnonymousFavePlugin::getAnonProfile();
            if ($profile instanceof Profile) {
                if (Fave::existsForProfile($item->notice, $profile)) {
                    $disfavor = new AnonDisFavorForm($item->out, $item->notice);
                    $disfavor->show();
                } else {
                    $favor = new AnonFavorForm($item->out, $item->notice);
                    $favor->show();
                }
            }
        }

        return true;
    }

    public function onEndFavorNoticeForm($form, $notice)
    {
        $this->showTally($form->out, $notice);
    }

    public function onEndDisFavorNoticeForm($form, $notice)
    {
        $this->showTally($form->out, $notice);
    }

    private function showTally($out, Notice $notice): void
    {
        $tally = Fave_tally::ensureTally($notice->id);

        if (!empty($tally)) {
            $out->elementStart(
                'div',
                array(
                    'id' => 'notice-' . $notice->id . '-tally',
                    'class' => 'notice-tally'
                )
            );
            $out->elementStart('span', array('class' => 'fave-tally-title'));
            // TRANS: Label for tally for number of times a notice was favored.
            $out->raw(sprintf(_m("Favored")));
            $out->elementEnd('span');
            $out->elementStart('span', array('class' => 'fave-tally'));
            $out->raw($tally->count);
            $out->elementEnd('span');
            $out->elementEnd('div');
        }
    }

    public function onEndFavorNotice($profile, $notice)
    {
        $tally = Fave_tally::increment($notice->id);
    }

    public function onEndDisfavorNotice($profile, $notice)
    {
        $tally = Fave_tally::decrement($notice->id);
    }

    /**
     * Remove tally when the notice is deleted
     *
     * @param Notice $notice Notice being deleted
     * @return bool hook value
     */
    public function onNoticeDeleteRelated(Notice $notice): bool
    {
        $ft = Fave_tally::getKV('notice_id', $notice->id);

        if (!empty($ft)) {
            $ft->delete();
        }
        return true;
    }

    private static function createAnonProfile(): Profile
    {
        // Get the anon user's IP, and turn it into a nickname
        list($proxy, $ip) = common_client_ip();

        // IP + time + random number should help to avoid collisions
        $baseNickname = $ip . '-' . time() . '-' . common_random_hexstr(5);

        $profile = new Profile();
        $profile->nickname = $baseNickname;
        $id = $profile->insert();

        if (!$id) {
            // TRANS: Server exception.
            throw new ServerException(_m("Could not create anonymous user session."));
        }

        // Stick the Profile ID into the nickname
        $orig = clone($profile);

        $profile->nickname = 'anon-' . $id . '-' . $baseNickname;
        $result = $profile->update($orig);

        if (!$result) {
            // TRANS: Server exception.
            throw new ServerException(_m("Could not create anonymous user session."));
        }

        common_log(
            LOG_INFO,
            "AnonymousFavePlugin - created profile for anonymous user from IP: "
            . $ip
            . ', nickname = '
            . $profile->nickname
        );

        return $profile;
    }

    public static function getAnonProfile()
    {
        $token = $_SESSION['anon_token'];
        $anon = base64_decode($token);

        $profile = null;

        if (!empty($anon) && substr($anon, 0, 5) == 'anon-') {
            $parts = explode('-', $anon);
            $id = $parts[1];
            // Do Profile lookup by ID instead of nickname for safety/performance
            $profile = Profile::getKV('id', $id);
        } else {
            $profile = AnonymousFavePlugin::createAnonProfile();
            // Obfuscate so it's hard to figure out the Profile ID
            $_SESSION['anon_token'] = base64_encode($profile->nickname);
        }

        return $profile;
    }

    /**
     * Determine whether a given NoticeListItem should have the
     * anonymous fave/disfave form
     *
     * @param NoticeListItem $item
     *
     * @return boolean false if the profile associated with the notice is
     *                       in the list of restricted profiles, otherwise
     *                       return true
     */
    private function hasAnonFaving($item): bool
    {
        $profile = Profile::getKV('id', $item->notice->profile_id);
        if (in_array($profile->nickname, $this->restricted)) {
            return false;
        }

        return true;
    }

    /**
     * Provide plugin version information.
     *
     * This data is used when showing the version page.
     *
     * @param array &$versions array of version data arrays; see EVENTS.txt
     *
     * @return boolean hook value
     */
    public function onPluginVersion(array &$versions): bool
    {
        $url = GNUSOCIAL_ENGINE_REPO_URL . 'tree/master/plugins/AnonymousFave';

        $versions[] = array('name' => 'AnonymousFave',
            'version' => ANONYMOUS_FAVE_PLUGIN_VERSION,
            'author' => 'Zach Copley',
            'homepage' => $url,
            'rawdescription' =>
            // TRANS: Plugin description.
            _m('Allow anonymous users to favorite notices.'));

        return true;
    }
}