<?php

declare(strict_types = 1);

// {{{ License
// 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/>.
// }}}

/**
 * @author    Eliseu Amaro <mail@eliseuama.ro>
 * @author    Diogo Peralta Cordeiro <@diogo.site>
 * @copyright 2021-2022 Free Software Foundation, Inc http://www.fsf.org
 * @license   https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
 */

namespace Plugin\RepeatNote;

use App\Core\Cache;
use App\Core\DB;
use App\Core\Event;
use function App\Core\I18n\_m;
use App\Core\Modules\NoteHandlerPlugin;
use App\Core\Router;
use App\Entity\Activity;
use App\Entity\Actor;
use App\Entity\Note;
use App\Util\Common;
use App\Util\Exception\ClientException;
use App\Util\Exception\DuplicateFoundException;
use App\Util\Exception\ServerException;
use Component\Language\Entity\Language;
use Component\Notification\Entity\Attention;
use Component\Posting\Posting;
use DateTime;
use Plugin\RepeatNote\Entity\NoteRepeat as RepeatEntity;
use const SORT_REGULAR;
use Symfony\Component\HttpFoundation\Request;

class RepeatNote extends NoteHandlerPlugin
{
    /**
     * **Repeats a Note**
     *
     * This means the current Actor creates a new Note, cloning the contents of
     * the original Note provided as an argument.
     *
     * Bear in mind that, if it's a repeat, the **reply_to** should be to the
     * original, and **conversation** ought to be the same.
     *
     * In the end, the Activity is created, and a new notification for the
     * repeat Activity created
     *
     * @param Note $note     Note being repeated
     * @param int  $actor_id Actor id of whom is performing the repeat Activity
     *
     * @throws ClientException
     * @throws DuplicateFoundException
     * @throws ServerException
     */
    public static function repeatNote(Note $note, int $actor_id, string $source = 'web'): ?Activity
    {
        $note_repeat = RepeatEntity::getNoteActorRepeat($note, $actor_id);
        if (!\is_null($note_repeat)) {
            return null;
        }

        $original_note_id = $note->getId();

        // Create a new note with the same content as the original
        [, $repeat, ]     = Posting::storeLocalNote(
            actor: $actor = Actor::getById($actor_id),
            content: $note->getContent(),
            content_type: $note->getContentType(),
            locale: \is_null($lang_id = $note->getLanguageId()) ? null : Language::getById($lang_id)->getLocale(),
            // If it's a repeat, the reply_to should be to the original, conversation ought to be the same
            reply_to: $note->getReplyTo(),
            processed_attachments: $processed_attachments = $note->getAttachmentsWithTitle(),
            flush_and_notify: false,
            rendered: $note->getRendered(),
        );

        // Increment attachment lives, posting already handled actor_to_attachment relations for us,
        // and it obviously handled the attachment_to_note
        foreach ($processed_attachments as [$a, $fname]) {
            // We usually don't have to increment lives manually when storing an attachment, but we aren't re-storing it
            $a->livesIncrementAndGet();
        }

        DB::persist(RepeatEntity::create([
            'note_id'   => $repeat->getId(),
            'actor_id'  => $actor_id,
            'repeat_of' => $original_note_id,
        ]));
        Cache::delete(RepeatEntity::cacheKeys($note->getId(), $actor_id)['actor_repeat']);
        Cache::delete(RepeatEntity::cacheKeys($note->getId())['repeats']);

        // Log an activity
        $repeat_activity = Activity::create([
            'actor_id'    => $actor_id,
            'verb'        => 'repeat',
            'object_type' => 'note',
            'object_id'   => $note->getId(),
            'source'      => $source,
        ]);
        DB::persist($repeat_activity);
        DB::persist(Attention::create(['object_type' => Activity::schemaName(), 'object_id' => $repeat_activity->getId(), 'target_id' => $note->getActorId()]));

        foreach ($actor->getSubscribers() as $subscriber) {
            $target_id = $subscriber->getId();
            DB::persist(Attention::create(['object_type' => Activity::schemaName(), 'object_id' => $repeat_activity->getId(), 'target_id' => $target_id]));
            $effective_attentions[$target_id] = $subscriber;
        }

        return $repeat_activity;
    }

    /**
     * **Undoes a Repeat**
     *
     * Removes the Repeat from NoteRepeat table, and the deletes the Note
     * clone.
     *
     * Finally, creates a new Activity, undoing the repeat, and the respective
     * Notification is handled.
     *
     * @param int $note_id  Note id being unrepeated
     * @param int $actor_id Actor undoing repeat Activity
     *
     * @throws \App\Util\Exception\NotFoundException
     * @throws DuplicateFoundException
     * @throws ServerException
     */
    public static function unrepeatNote(int $note_id, int $actor_id, string $source = 'web'): ?Activity
    {
        $note_repeat = RepeatEntity::getNoteActorRepeat($note_id, $actor_id);

        if (!\is_null($note_repeat)) { // If it was repeated, then we can undo it
            // Find previous repeat activity
            $already_repeated_activity = DB::findOneBy(Activity::class, [
                'actor_id'    => $actor_id,
                'verb'        => 'repeat',
                'object_type' => 'note',
                'object_id'   => $note_repeat->getRepeatOf(),
            ], return_null: true);

            // Remove the clone note
            DB::findOneBy(Note::class, ['id' => $note_repeat->getNoteId()])->delete(actor: Actor::getById($actor_id));

            // Remove from the note_repeat table
            DB::removeBy(RepeatEntity::class, ['note_id' => $note_repeat->getNoteId()]);
            Cache::delete(RepeatEntity::cacheKeys($note_id, $actor_id)['actor_repeat']);
            Cache::delete(RepeatEntity::cacheKeys($note_repeat->getNoteId())['repeats']);

            // Log an activity
            $undo_repeat_activity = Activity::create([
                'actor_id'    => $actor_id,
                'verb'        => 'undo',
                'object_type' => 'activity',
                'object_id'   => $already_repeated_activity->getId(),
                'source'      => $source,
            ]);
            DB::persist($undo_repeat_activity);
            DB::persist(Attention::create(['object_type' => Activity::schemaName(), 'object_id' => $undo_repeat_activity->getId(), 'target_id' => Note::getById($note_id)->getActorId()]));

            foreach (Actor::getById($actor_id)->getSubscribers() as $subscriber) {
                $target_id = $subscriber->getId();
                DB::persist(Attention::create(['object_type' => Activity::schemaName(), 'object_id' => $undo_repeat_activity->getId(), 'target_id' => $target_id]));
                $effective_attentions[$target_id] = $subscriber;
            }

            return $undo_repeat_activity;
        } else {
            // Either was undoed already
            if (!\is_null($already_repeated_activity = DB::findOneBy(Activity::class, [
                'actor_id' => $actor_id,
                'verb' => 'repeat',
                'object_type' => 'note',
                'object_id' => $note_id,
            ], return_null: true))) {
                return DB::findOneBy(Activity::class, [
                    'actor_id'    => $actor_id,
                    'verb'        => 'undo',
                    'object_type' => 'activity',
                    'object_id'   => $already_repeated_activity->getId(),
                ], return_null: true); // null if not undoed
            } else {
                // or it's an attempt to undo something that wasn't repeated in the first place,
                return null;
            }
        }
    }

    /**
     * Filters repeats out of Conversations, and replaces a repeat with the
     * original Note on Actor feed
     *
     * @param array $notes List of Notes to be filtered
     *
     * @return bool Event hook, Event::next (true) is returned to allow Event to be handled by other handlers
     */
    public function onFilterNoteList(?Actor $actor, array &$notes, Request $request): bool
    {
        // Replaces repeat with original note on Actor feed
        // it's pretty cool
        if (str_starts_with($request->get('_route'), 'actor_view_')) {
            $notes = array_map(
                static fn (Note $note) => RepeatEntity::isNoteRepeat($note)
                    ? Note::getById(RepeatEntity::getByPK($note->getId())->getRepeatOf())
                    : $note,
                $notes,
            );
            return Event::next;
        }

        // Filter out repeats altogether
        $notes = array_filter($notes, static fn (Note $note) => !RepeatEntity::isNoteRepeat($note));
        return Event::next;
    }

    /**
     * HTML rendering event that adds the repeat form as a note
     * action, if a user is logged in
     *
     * @return bool Event hook, Event::next (true) is returned to allow Event to be handled by other handlers
     */
    public function onAddNoteActions(Request $request, Note $note, array &$actions): bool
    {
        // Only logged users can repeat notes
        if (\is_null($user = Common::user())) {
            return Event::next;
        }

        $note_repeat = RepeatEntity::getNoteActorRepeat($note, $user->getId());

        // If note is repeated, "is_repeated" is 1, 0 otherwise.
        $is_repeat = !\is_null($note_repeat);

        // Generating URL for repeat action route
        $args              = ['note_id' => !$is_repeat ? $note->getId() : $note_repeat->getRepeatOf()];
        $type              = Router::ABSOLUTE_PATH;
        $repeat_action_url = $is_repeat
            ? Router::url('repeat_remove', $args, $type)
            : Router::url('repeat_add', $args, $type);

        // Concatenating get parameter to redirect the user to where he came from
        $repeat_action_url .= '?from=' . urlencode($request->getRequestUri());

        $extra_classes = $is_repeat ? 'note-actions-set' : 'note-actions-unset';
        $repeat_action = [
            'url'     => $repeat_action_url,
            'title'   => $is_repeat ? 'Remove this repeat' : 'Repeat this note!',
            'classes' => "button-container repeat-button-container {$extra_classes}",
            'note_id' => 'repeat-button-container-' . $note->getId(),
        ];

        $actions[] = $repeat_action;
        return Event::next;
    }

    /**
     * Appends in Note information stating who and what user actions were
     * performed.
     *
     * @param array $vars   Contains the Note currently being rendered
     * @param array $result Rendered String containing anchors for Actors that
     *                      repeated the Note
     *
     * @return bool Event hook, Event::next (true) is returned to allow Event to be handled by other handlers
     */
    public function onAppendCardNote(array $vars, array &$result)
    {
        // If note is the original and user isn't the one who repeated, append on end "user repeated this"
        // If user is the one who repeated, append on end "you repeated this, remove repeat?"
        $check_user = !\is_null(Common::user());

        // The current Note being rendered
        $note = $vars['note'];

        // Will have actors array, and action string
        // Actors are the subjects, action is the verb (in the final phrase)
        $repeat_actors = [];
        $note_repeats  = RepeatEntity::getNoteRepeats($note);

        // Get actors who repeated the note
        foreach ($note_repeats as $repeat) {
            $repeat_actors[] = Actor::getByPK($repeat->getActorId());
        }
        if (\count($repeat_actors) < 1) {
            return Event::next;
        }

        // Filter out multiple replies from the same actor
        $repeat_actors = array_unique($repeat_actors, SORT_REGULAR);
        $result[]      = ['actors' => $repeat_actors, 'action' => 'repeated'];

        return Event::next;
    }

    /**
     * Deletes every repeat entity that is related to a deleted Note in its
     * respective table
     *
     * @param Note  $note  Note to be deleted
     * @param Actor $actor Who performed the Delete action
     *
     * @return bool Event hook, Event::next (true) is returned to allow Event to be handled by other handlers
     */
    public function onNoteDeleteRelated(Note &$note, Actor $actor): bool
    {
        $note_repeats_list = RepeatEntity::getNoteRepeats($note);
        foreach ($note_repeats_list as $note_repeat) {
            DB::remove($note_repeat);
        }

        return Event::next;
    }

    /**
     * Connects the following Routes to their respective Controllers:
     *
     * - **repeat_add**
     *  page containing the Note the user wishes to Repeat and a button to
     *  confirm it wishes to perform the action
     *
     * - **repeat_remove**
     *  same as above, except that it undoes the aforementioned action
     *
     * @return bool Event hook, Event::next (true) is returned to allow Event to be handled by other handlers
     */
    public function onAddRoute(Router $r): bool
    {
        // Add/remove note to/from repeats
        $r->connect(id: 'repeat_add', uri_path: '/object/note/{note_id<\d+>}/repeat', target: [Controller\Repeat::class, 'repeatAddNote']);
        $r->connect(id: 'repeat_remove', uri_path: '/object/note/{note_id<\d+>}/unrepeat', target: [Controller\Repeat::class, 'repeatRemoveNote']);

        return Event::next;
    }

    // ActivityPub handling and processing for Repeats is below

    /**
     * ActivityPub Inbox handler for Announces and Undo Announce activities
     *
     * @param Actor                                               $actor         Actor who authored the activity
     * @param \ActivityPhp\Type\AbstractObject                    $type_activity Activity Streams 2.0 Activity
     * @param mixed                                               $type_object   Activity's Object
     * @param null|\Plugin\ActivityPub\Entity\ActivitypubActivity $ap_act        Resulting ActivitypubActivity
     *
     * @throws \App\Util\Exception\NoSuchActorException
     * @throws \App\Util\Exception\NotFoundException
     * @throws \Symfony\Contracts\HttpClient\Exception\ClientExceptionInterface
     * @throws \Symfony\Contracts\HttpClient\Exception\RedirectionExceptionInterface
     * @throws \Symfony\Contracts\HttpClient\Exception\ServerExceptionInterface
     * @throws \Symfony\Contracts\HttpClient\Exception\TransportExceptionInterface
     * @throws ClientException
     * @throws DuplicateFoundException
     * @throws ServerException
     *
     * @return bool Returns `Event::stop` if handled, `Event::next` otherwise
     */
    private function activitypub_handler(Actor $actor, \ActivityPhp\Type\AbstractObject $type_activity, mixed $type_object, ?\Plugin\ActivityPub\Entity\ActivitypubActivity &$ap_act): bool
    {
        if (!\in_array($type_activity->get('type'), ['Announce', 'Undo']) || !$actor->isPerson()) {
            return Event::next;
        }
        if ($type_activity->get('type') === 'Announce') { // Repeat
            if ($type_object instanceof \ActivityPhp\Type\AbstractObject) {
                if ($type_object->get('type') === 'Note' || $type_object->get('type') === 'ChatMessage' || $type_object->get('type') === 'Article' || $type_object->get('type') === 'Page') {
                    $note    = \Plugin\ActivityPub\Util\Model\Note::fromJson($type_object);
                    $note_id = $note->getId();
                } else {
                    return Event::next;
                }
            } elseif ($type_object instanceof Note) {
                $note    = $type_object;
                $note_id = $note->getId();
            } else {
                return Event::next;
            }
            $activity = self::repeatNote($note, $actor->getId(), source: 'ActivityPub');
        } elseif ($type_activity->get('type') === 'Undo') { // Undo Repeat
            if ($type_object instanceof \ActivityPhp\Type\AbstractObject) {
                $ap_prev_repeat_act = \Plugin\ActivityPub\Util\Model\Activity::fromJson($type_object);
                $prev_repeat_act    = $ap_prev_repeat_act->getActivity();
                if ($prev_repeat_act->getVerb() === 'repeat' && $prev_repeat_act->getObjectType() === 'note') {
                    $note_id = $prev_repeat_act->getObjectId();
                } else {
                    return Event::next;
                }
            } elseif ($type_object instanceof Activity) {
                if ($type_object->getVerb() === 'repeat' && $type_object->getObjectType() === 'note') {
                    $note_id = $type_object->getObjectId();
                } else {
                    return Event::next;
                }
            } else {
                return Event::next;
            }
            $activity = self::unrepeatNote($note_id, $actor->getId(), source: 'ActivityPub');
        } else {
            return Event::next;
        }

        if (!\is_null($activity)) {
            // Store ActivityPub Activity
            $ap_act = \Plugin\ActivityPub\Entity\ActivitypubActivity::create([
                'activity_id'  => $activity->getId(),
                'activity_uri' => $type_activity->get('id'),
                'created'      => new DateTime($type_activity->get('published') ?? 'now'),
                'modified'     => new DateTime(),
            ]);
            DB::persist($ap_act);
        }
        return Event::stop;
    }

    public function onActivityPubNewNotification(Actor $sender, Activity $activity, array $targets, ?string $reason = null): bool
    {
        switch ($activity->getVerb()) {
            case 'repeat':
                Event::handle('NewNotification', [$sender, $activity, $targets, _m('{actor_id} repeated note {note_id}.', ['{actor_id}' => $sender->getId(), '{note_id}' => $activity->getObjectId()])]);
                return Event::stop;
            case 'undo':
                if ($activity->getObjectType() === 'activity') {
                    $undone_repeat = $activity->getObject();
                    if ($undone_repeat->getVerb() === 'repeat') {
                        Event::handle('NewNotification', [$sender, $activity, $targets, _m('{actor_id} unrepeated note {note_id}.', ['{actor_id}' => $sender->getId(), '{note_id}' => $undone_repeat->getObjectId()])]);
                        return Event::stop;
                    }
                }
        }
        return Event::next;
    }

    /**
     * Convert an Activity Streams 2.0 Announce or Undo Announce into the appropriate Repeat and Undo Repeat entities
     *
     * @param Actor                                               $actor         Actor who authored the activity
     * @param \ActivityPhp\Type\AbstractObject                    $type_activity Activity Streams 2.0 Activity
     * @param \ActivityPhp\Type\AbstractObject                    $type_object   Activity Streams 2.0 Object
     * @param null|\Plugin\ActivityPub\Entity\ActivitypubActivity $ap_act        Resulting ActivitypubActivity
     *
     * @throws \App\Util\Exception\NoSuchActorException
     * @throws \App\Util\Exception\NotFoundException
     * @throws \Symfony\Contracts\HttpClient\Exception\ClientExceptionInterface
     * @throws \Symfony\Contracts\HttpClient\Exception\RedirectionExceptionInterface
     * @throws \Symfony\Contracts\HttpClient\Exception\ServerExceptionInterface
     * @throws \Symfony\Contracts\HttpClient\Exception\TransportExceptionInterface
     * @throws ClientException
     * @throws DuplicateFoundException
     * @throws ServerException
     *
     * @return bool Returns `Event::stop` if handled, `Event::next` otherwise
     */
    public function onNewActivityPubActivity(Actor $actor, \ActivityPhp\Type\AbstractObject $type_activity, \ActivityPhp\Type\AbstractObject $type_object, ?\Plugin\ActivityPub\Entity\ActivitypubActivity &$ap_act): bool
    {
        return $this->activitypub_handler($actor, $type_activity, $type_object, $ap_act);
    }

    /**
     * Convert an Activity Streams 2.0 formatted activity with a known object into Entities
     *
     * @param Actor                                               $actor         Actor who authored the activity
     * @param \ActivityPhp\Type\AbstractObject                    $type_activity Activity Streams 2.0 Activity
     * @param mixed                                               $type_object   Object
     * @param null|\Plugin\ActivityPub\Entity\ActivitypubActivity $ap_act        Resulting ActivitypubActivity
     *
     * @throws \App\Util\Exception\NoSuchActorException
     * @throws \App\Util\Exception\NotFoundException
     * @throws \Symfony\Contracts\HttpClient\Exception\ClientExceptionInterface
     * @throws \Symfony\Contracts\HttpClient\Exception\RedirectionExceptionInterface
     * @throws \Symfony\Contracts\HttpClient\Exception\ServerExceptionInterface
     * @throws \Symfony\Contracts\HttpClient\Exception\TransportExceptionInterface
     * @throws ClientException
     * @throws DuplicateFoundException
     * @throws ServerException
     *
     * @return bool Returns `Event::stop` if handled, `Event::next` otherwise
     */
    public function onNewActivityPubActivityWithObject(Actor $actor, \ActivityPhp\Type\AbstractObject $type_activity, mixed $type_object, ?\Plugin\ActivityPub\Entity\ActivitypubActivity &$ap_act): bool
    {
        return $this->activitypub_handler($actor, $type_activity, $type_object, $ap_act);
    }

    /**
     * Translate GNU social internal verb 'repeat' to Activity Streams 2.0 'Announce'
     *
     * @param string      $verb                                GNU social's internal verb
     * @param null|string $gs_verb_to_activity_stream_two_verb Resulting Activity Streams 2.0 verb
     *
     * @return bool Returns `Event::stop` if handled, `Event::next` otherwise
     */
    public function onGSVerbToActivityStreamsTwoActivityType(string $verb, ?string &$gs_verb_to_activity_stream_two_verb): bool
    {
        if ($verb === 'repeat') {
            $gs_verb_to_activity_stream_two_verb = 'Announce';
            return Event::stop;
        }
        return Event::next;
    }
}