<?php
/*
 * StatusNet - the distributed open-source microblogging tool
 * Copyright (C) 2009-2010, StatusNet, Inc.
 *
 * This program 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.
 *
 * 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * @package FeedSubPlugin
 * @maintainer Brion Vibber <brion@status.net>
 */

/*
PuSH subscription flow:

    $profile->subscribe()
        generate random verification token
            save to verify_token
        sends a sub request to the hub...
    
    main/push/callback
        hub sends confirmation back to us via GET
        We verify the request, then echo back the challenge.
        On our end, we save the time we subscribed and the lease expiration
    
    main/push/callback
        hub sends us updates via POST
    
*/

class FeedDBException extends FeedSubException
{
    public $obj;

    function __construct($obj)
    {
        parent::__construct('Database insert failure');
        $this->obj = $obj;
    }
}

class Ostatus_profile extends Memcached_DataObject
{
    public $__table = 'ostatus_profile';

    public $id;
    public $profile_id;
    public $group_id;

    public $feeduri;
    public $homeuri;

    // PuSH subscription data
    public $huburi;
    public $secret;
    public $verify_token;
    public $sub_state; // subscribe, active, unsubscribe
    public $sub_start;
    public $sub_end;

    public $salmonuri;

    public $created;
    public $lastupdate;


    public /*static*/ function staticGet($k, $v=null)
    {
        return parent::staticGet(__CLASS__, $k, $v);
    }

    /**
     * return table definition for DB_DataObject
     *
     * DB_DataObject needs to know something about the table to manipulate
     * instances. This method provides all the DB_DataObject needs to know.
     *
     * @return array array of column definitions
     */

    function table()
    {
        return array('id' => DB_DATAOBJECT_INT + DB_DATAOBJECT_NOTNULL,
                     'profile_id' => DB_DATAOBJECT_INT,
                     'group_id' => DB_DATAOBJECT_INT,
                     'feeduri' => DB_DATAOBJECT_STR + DB_DATAOBJECT_NOTNULL,
                     'homeuri' => DB_DATAOBJECT_STR + DB_DATAOBJECT_NOTNULL,
                     'huburi' =>  DB_DATAOBJECT_STR,
                     'secret' => DB_DATAOBJECT_STR,
                     'verify_token' => DB_DATAOBJECT_STR,
                     'sub_state' => DB_DATAOBJECT_STR,
                     'sub_start' => DB_DATAOBJECT_STR + DB_DATAOBJECT_DATE + DB_DATAOBJECT_TIME,
                     'sub_end' => DB_DATAOBJECT_STR + DB_DATAOBJECT_DATE + DB_DATAOBJECT_TIME,
                     'salmonuri' =>  DB_DATAOBJECT_STR,
                     'created' => DB_DATAOBJECT_STR + DB_DATAOBJECT_DATE + DB_DATAOBJECT_TIME + DB_DATAOBJECT_NOTNULL,
                     'lastupdate' => DB_DATAOBJECT_STR + DB_DATAOBJECT_DATE + DB_DATAOBJECT_TIME + DB_DATAOBJECT_NOTNULL);
    }
    
    static function schemaDef()
    {
        return array(new ColumnDef('id', 'integer',
                                   /*size*/ null,
                                   /*nullable*/ false,
                                   /*key*/ 'PRI',
                                   /*default*/ '0',
                                   /*extra*/ null,
                                   /*auto_increment*/ true),
                     new ColumnDef('profile_id', 'integer',
                                   null, true, 'UNI'),
                     new ColumnDef('group_id', 'integer',
                                   null, true, 'UNI'),
                     new ColumnDef('feeduri', 'varchar',
                                   255, false, 'UNI'),
                     new ColumnDef('homeuri', 'varchar',
                                   255, false),
                     new ColumnDef('huburi', 'text',
                                   null, true),
                     new ColumnDef('verify_token', 'varchar',
                                   32, true),
                     new ColumnDef('secret', 'varchar',
                                   64, true),
                     new ColumnDef('sub_state', "enum('subscribe','active','unsubscribe')",
                                   null, true),
                     new ColumnDef('sub_start', 'datetime',
                                   null, true),
                     new ColumnDef('sub_end', 'datetime',
                                   null, true),
                     new ColumnDef('salmonuri', 'text',
                                   null, true),
                     new ColumnDef('created', 'datetime',
                                   null, false),
                     new ColumnDef('lastupdate', 'datetime',
                                   null, false));
    }

    /**
     * return key definitions for DB_DataObject
     *
     * DB_DataObject needs to know about keys that the table has; this function
     * defines them.
     *
     * @return array key definitions
     */

    function keys()
    {
        return array_keys($this->keyTypes());
    }

    /**
     * return key definitions for Memcached_DataObject
     *
     * Our caching system uses the same key definitions, but uses a different
     * method to get them.
     *
     * @return array key definitions
     */

    function keyTypes()
    {
        return array('id' => 'K', 'profile_id' => 'U', 'group_id' => 'U', 'feeduri' => 'U');
    }

    function sequenceKey()
    {
        return array('id', true, false);
    }

    /**
     * Fetch the StatusNet-side profile for this feed
     * @return Profile
     */
    public function localProfile()
    {
        if ($this->profile_id) {
            return Profile::staticGet('id', $this->profile_id);
        }
        return null;
    }

    /**
     * Fetch the StatusNet-side profile for this feed
     * @return Profile
     */
    public function localGroup()
    {
        if ($this->group_id) {
            return User_group::staticGet('id', $this->group_id);
        }
        return null;
    }

    /**
     * @param FeedMunger $munger
     * @param boolean $isGroup is this a group record?
     * @return Ostatus_profile
     */
    public static function ensureProfile($munger)
    {
        $profile = $munger->ostatusProfile();

        $current = self::staticGet('feeduri', $profile->feeduri);
        if ($current) {
            // @fixme we should probably update info as necessary
            return $current;
        }

        $profile->query('BEGIN');

        // Awful hack! Awful hack!
        $profile->verify = common_good_rand(16);
        $profile->secret = common_good_rand(32);

        try {
            $local = $munger->profile();

            if ($entity->isGroup()) {
                $group = new User_group();
                $group->nickname = $local->nickname . '@remote'; // @fixme
                $group->fullname = $local->fullname;
                $group->homepage = $local->homepage;
                $group->location = $local->location;
                $group->created = $local->created;
                $group->insert();
                if (empty($result)) {
                    throw new FeedDBException($group);
                }
                $profile->group_id = $group->id;
            } else {
                $result = $local->insert();
                if (empty($result)) {
                    throw new FeedDBException($local);
                }
                $profile->profile_id = $local->id;
            }

            $profile->created = sql_common_date();
            $profile->lastupdate = sql_common_date();
            $result = $profile->insert();
            if (empty($result)) {
                throw new FeedDBException($profile);
            }

            $entity->query('COMMIT');
        } catch (FeedDBException $e) {
            common_log_db_error($e->obj, 'INSERT', __FILE__);
            $entity->query('ROLLBACK');
            return false;
        }

        $avatar = $munger->getAvatar();
        if ($avatar) {
            try {
                $this->updateAvatar($avatar);
            } catch (Exception $e) {
                common_log(LOG_ERR, "Exception setting OStatus avatar: " .
                                    $e->getMessage());
            }
        }

        return $entity;
    }

    /**
     * Download and update given avatar image
     * @param string $url
     * @throws Exception in various failure cases
     */
    public function updateAvatar($url)
    {
        // @fixme this should be better encapsulated
        // ripped from oauthstore.php (for old OMB client)
        $temp_filename = tempnam(sys_get_temp_dir(), 'listener_avatar');
        copy($url, $temp_filename);
        $imagefile = new ImageFile($profile->id, $temp_filename);
        $filename = Avatar::filename($profile->id,
                                     image_type_to_extension($imagefile->type),
                                     null,
                                     common_timestamp());
        rename($temp_filename, Avatar::path($filename));
        if ($this->isGroup()) {
            $group = $this->localGroup();
            $group->setOriginal($filename);
        } else {
            $profile = $this->localProfile();
            $profile->setOriginal($filename);
        }
    }

    /**
     * Returns an XML string fragment with profile information as an
     * Activity Streams noun object with the given element type.
     *
     * Assumes that 'activity' namespace has been previously defined.
     *
     * @param string $element one of 'actor', 'subject', 'object', 'target'
     * @return string
     */
    function asActivityNoun($element)
    {
        $xs = new XMLStringer(true);

        $avatarHref = Avatar::defaultImage(AVATAR_PROFILE_SIZE);
        $avatarType = 'image/png';
        if ($this->isGroup()) {
            $type = 'http://activitystrea.ms/schema/1.0/group';
            $self = $this->localGroup();

            // @fixme put a standard getAvatar() interface on groups too
            if ($self->homepage_logo) {
                $avatarHref = $self->homepage_logo;
                $map = array('png' => 'image/png',
                             'jpg' => 'image/jpeg',
                             'jpeg' => 'image/jpeg',
                             'gif' => 'image/gif');
                $extension = pathinfo(parse_url($avatarHref, PHP_URL_PATH), PATHINFO_EXTENSION);
                if (isset($map[$extension])) {
                    $avatarType = $map[$extension];
                }
            }
        } else {
            $type = 'http://activitystrea.ms/schema/1.0/person';
            $self = $this->localProfile();
            $avatar = $self->getAvatar(AVATAR_PROFILE_SIZE);
            if ($avatar) {
                $avatarHref = $avatar->
                $avatarType = $avatar->mediatype;
            }
        }
        $xs->elementStart('activity:' . $element);
        $xs->element(
            'activity:object-type',
            null,
            $type
        );
        $xs->element(
            'id',
            null,
            $this->homeuri); // ?
        $xs->element('title', null, $self->getBestName());

        $xs->element(
            'link', array(
                'type' => $avatarType,
                'href' => $avatarHref
            ),
            ''
        );

        $xs->elementEnd('activity:' . $element);

        return $xs->getString();
    }

    /**
     * Damn dirty hack!
     */
    function isGroup()
    {
        return (strpos($this->feeduri, '/groups/') !== false);
    }

    /**
     * Send a subscription request to the hub for this feed.
     * The hub will later send us a confirmation POST to /main/push/callback.
     *
     * @return bool true on success, false on failure
     */
    public function subscribe($mode='subscribe')
    {
        if (common_config('feedsub', 'nohub')) {
            // Fake it! We're just testing remote feeds w/o hubs.
            return true;
        }
        // @fixme use the verification token
        #$token = md5(mt_rand() . ':' . $this->feeduri);
        #$this->verify_token = $token;
        #$this->update(); // @fixme
        try {
            $callback = common_local_url('pushcallback', array('feed' => $this->id));
            $headers = array('Content-Type: application/x-www-form-urlencoded');
            $post = array('hub.mode' => $mode,
                          'hub.callback' => $callback,
                          'hub.verify' => 'async',
                          'hub.verify_token' => $this->verify_token,
                          'hub.secret' => $this->secret,
                          //'hub.lease_seconds' => 0,
                          'hub.topic' => $this->feeduri);
            $client = new HTTPClient();
            $response = $client->post($this->huburi, $headers, $post);
            $status = $response->getStatus();
            if ($status == 202) {
                common_log(LOG_INFO, __METHOD__ . ': sub req ok, awaiting verification callback');
                return true;
            } else if ($status == 204) {
                common_log(LOG_INFO, __METHOD__ . ': sub req ok and verified');
                return true;
            } else if ($status >= 200 && $status < 300) {
                common_log(LOG_ERR, __METHOD__ . ": sub req returned unexpected HTTP $status: " . $response->getBody());
                return false;
            } else {
                common_log(LOG_ERR, __METHOD__ . ": sub req failed with HTTP $status: " . $response->getBody());
                return false;
            }
        } catch (Exception $e) {
            // wtf!
            common_log(LOG_ERR, __METHOD__ . ": error \"{$e->getMessage()}\" hitting hub $this->huburi subscribing to $this->feeduri");
            return false;
        }
    }

    /**
     * Save PuSH subscription confirmation.
     * Sets approximate lease start and end times and finalizes state.
     *
     * @param int $lease_seconds provided hub.lease_seconds parameter, if given
     */
    public function confirmSubscribe($lease_seconds=0)
    {
        $original = clone($this);

        $this->sub_state = 'active';
        $this->sub_start = common_sql_date(time());
        if ($lease_seconds > 0) {
            $this->sub_end = common_sql_date(time() + $lease_seconds);
        } else {
            $this->sub_end = null;
        }
        $this->lastupdate = common_sql_date();

        return $this->update($original);
    }

    /**
     * Save PuSH unsubscription confirmation.
     * Wipes active PuSH sub info and resets state.
     */
    public function confirmUnsubscribe()
    {
        $original = clone($this);

        $this->verify_token = null;
        $this->secret = null;
        $this->sub_state = null;
        $this->sub_start = null;
        $this->sub_end = null;
        $this->lastupdate = common_sql_date();

        return $this->update($original);
    }

    /**
     * Send a PuSH unsubscription request to the hub for this feed.
     * The hub will later send us a confirmation POST to /main/push/callback.
     *
     * @return bool true on success, false on failure
     */
    public function unsubscribe() {
        return $this->subscribe('unsubscribe');
    }

    /**
     * Send an Activity Streams notification to the remote Salmon endpoint,
     * if so configured.
     *
     * @param Profile $actor
     * @param $verb eg Activity::SUBSCRIBE or Activity::JOIN
     * @param $object object of the action; if null, the remote entity itself is assumed
     */
    public function notify(Profile $actor, $verb, $object=null)
    {
        if ($object == null) {
            $object = $this;
        }
        if ($this->salmonuri) {
            $text = 'update'; // @fixme
            $id = 'tag:' . common_config('site', 'server') . 
                ':' . $verb .
                ':' . $actor->id .
                ':' . time(); // @fixme

            $entry = new Atom10Entry();
            $entry->elementStart('entry');
            $entry->element('id', null, $id);
            $entry->element('title', null, $text);
            $entry->element('summary', null, $text);
            $entry->element('published', null, common_date_w3dtf());

            $entry->element('activity:verb', null, $verb);
            $entry->raw($profile->asAtomAuthor());
            $entry->raw($profile->asActivityActor());
            $entry->raw($object->asActivityNoun('object'));
            $entry->elmentEnd('entry');

            $feed = $this->atomFeed($actor);
            $feed->initFeed();
            $feed->addEntry($entry);
            $feed->renderEntries();
            $feed->endFeed();

            $xml = $feed->getString();
            common_log(LOG_INFO, "Posting to Salmon endpoint $salmon: $xml");

            $salmon = new Salmon(); // ?
            $salmon->post($this->salmonuri, $xml);
        }
    }

    function getBestName()
    {
        if ($this->isGroup()) {
            return $this->localGroup()->getBestName();
        } else {
            return $this->localProfile()->getBestName();
        }
    }

    function atomFeed($actor)
    {
        $feed = new Atom10Feed();
        // @fixme should these be set up somewhere else?
        $feed->addNamespace('activity', 'http://activitystrea.ms/spec/1.0/');
        $feed->addNamesapce('thr', 'http://purl.org/syndication/thread/1.0');
        $feed->addNamespace('georss', 'http://www.georss.org/georss');
        $feed->addNamespace('ostatus', 'http://ostatus.org/schema/1.0');

        $taguribase = common_config('integration', 'taguri');
        $feed->setId("tag:{$taguribase}:UserTimeline:{$actor->id}"); // ???

        $feed->setTitle($actor->getBestName() . ' timeline'); // @fixme
        $feed->setUpdated(time());
        $feed->setPublished(time());

        $feed->addLink(common_url('ApiTimelineUser',
                                  array('id' => $actor->id,
                                        'type' => 'atom')),
                       array('rel' => 'self',
                             'type' => 'application/atom+xml'));

        $feed->addLink(common_url('userbyid',
                                  array('id' => $actor->id)),
                       array('rel' => 'alternate',
                             'type' => 'text/html'));

        return $feed;
    }

    /**
     * Read and post notices for updates from the feed.
     * Currently assumes that all items in the feed are new,
     * coming from a PuSH hub.
     *
     * @param string $xml source of Atom or RSS feed
     * @param string $hmac X-Hub-Signature header, if present
     */
    public function postUpdates($xml, $hmac)
    {
        common_log(LOG_INFO, __METHOD__ . ": packet for \"$this->feeduri\"! $hmac $xml");

        if ($this->secret) {
            if (preg_match('/^sha1=([0-9a-fA-F]{40})$/', $hmac, $matches)) {
                $their_hmac = strtolower($matches[1]);
                $our_hmac = hash_hmac('sha1', $xml, $this->secret);
                if ($their_hmac !== $our_hmac) {
                    common_log(LOG_ERR, __METHOD__ . ": ignoring PuSH with bad SHA-1 HMAC: got $their_hmac, expected $our_hmac");
                    return;
                }
            } else {
                common_log(LOG_ERR, __METHOD__ . ": ignoring PuSH with bogus HMAC '$hmac'");
                return;
            }
        } else if ($hmac) {
            common_log(LOG_ERR, __METHOD__ . ": ignoring PuSH with unexpected HMAC '$hmac'");
            return;
        }

        require_once "XML/Feed/Parser.php";
        $feed = new XML_Feed_Parser($xml, false, false, true);
        $munger = new FeedMunger($feed);
        
        $hits = 0;
        foreach ($feed as $index => $entry) {
            // @fixme this might sort in wrong order if we get multiple updates

            $notice = $munger->notice($index);

            // Double-check for oldies
            // @fixme this could explode horribly for multiple feeds on a blog. sigh
            $dupe = new Notice();
            $dupe->uri = $notice->uri;
            if ($dupe->find(true)) {
                common_log(LOG_WARNING, __METHOD__ . ": tried to save dupe notice for entry {$notice->uri} of feed {$this->feeduri}");
                continue;
            }

            // @fixme need to ensure that groups get handled correctly
            $saved = Notice::saveNew($notice->profile_id,
                                     $notice->content,
                                     'ostatus',
                                     array('is_local' => Notice::REMOTE_OMB,
                                           'uri' => $notice->uri,
                                           'lat' => $notice->lat,
                                           'lon' => $notice->lon,
                                           'location_ns' => $notice->location_ns,
                                           'location_id' => $notice->location_id));

            /*
            common_log(LOG_DEBUG, "going to check group delivery...");
            if ($this->group_id) {
                $group = User_group::staticGet($this->group_id);
                if ($group) {
                    common_log(LOG_INFO, __METHOD__ . ": saving to local shadow group $group->id $group->nickname");
                    $groups = array($group);
                } else {
                    common_log(LOG_INFO, __METHOD__ . ": lost the local shadow group?");
                }
            } else {
                common_log(LOG_INFO, __METHOD__ . ": no local shadow groups");
                $groups = array();
            }
            common_log(LOG_DEBUG, "going to add to inboxes...");
            $notice->addToInboxes($groups, array());
            common_log(LOG_DEBUG, "added to inboxes.");
            */

            $hits++;
        }
        if ($hits == 0) {
            common_log(LOG_INFO, __METHOD__ . ": no updates in packet for \"$this->feeduri\"! $xml");
        }
    }
}