<?php

declare(strict_types=1);


/**
 * Nextcloud - Social Support
 *
 * This file is licensed under the Affero General Public License version 3 or
 * later. See the COPYING file.
 *
 * @author Maxence Lange <maxence@artificial-owl.com>
 * @copyright 2018, Maxence Lange <maxence@artificial-owl.com>
 * @license GNU AGPL version 3 or any later version
 *
 * 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/>.
 *
 */

namespace OCA\Social\Service;

use Exception;
use OCA\Social\Db\StreamRequest;
use OCA\Social\Exceptions\InvalidOriginException;
use OCA\Social\Exceptions\InvalidResourceException;
use OCA\Social\Exceptions\ItemUnknownException;
use OCA\Social\Exceptions\RedundancyLimitException;
use OCA\Social\Exceptions\SocialAppConfigException;
use OCA\Social\Exceptions\StreamNotFoundException;
use OCA\Social\Exceptions\UnauthorizedFediverseException;
use OCA\Social\Model\ActivityPub\ACore;
use OCA\Social\Model\ActivityPub\Actor\Person;
use OCA\Social\Model\ActivityPub\Object\Note;
use OCA\Social\Model\ActivityPub\OrderedCollection;
use OCA\Social\Model\ActivityPub\Stream;
use OCA\Social\Model\Client\Options\ProbeOptions;
use OCA\Social\Model\InstancePath;
use OCA\Social\Tools\Exceptions\DateTimeException;
use OCA\Social\Tools\Exceptions\MalformedArrayException;
use OCA\Social\Tools\Exceptions\RequestContentException;
use OCA\Social\Tools\Exceptions\RequestNetworkException;
use OCA\Social\Tools\Exceptions\RequestResultNotJsonException;
use OCA\Social\Tools\Exceptions\RequestResultSizeException;
use OCA\Social\Tools\Exceptions\RequestServerException;
use OCA\Social\Tools\Traits\TArrayTools;
use OCP\IURLGenerator;

class StreamService {
	use TArrayTools;

	private IUrlGenerator $urlGenerator;
	private StreamRequest $streamRequest;
	private ActivityService $activityService;
	private CacheActorService $cacheActorService;
	private ConfigService $configService;

	private const ANCESTOR_LIMIT = 5;

	public function __construct(
		IUrlGenerator $urlGenerator,
		StreamRequest $streamRequest,
		ActivityService $activityService,
		CacheActorService $cacheActorService,
		ConfigService $configService
	) {
		$this->urlGenerator = $urlGenerator;
		$this->streamRequest = $streamRequest;
		$this->activityService = $activityService;
		$this->cacheActorService = $cacheActorService;
		$this->configService = $configService;
	}


	/**
	 * @param Person $viewer
	 */
	public function setViewer(Person $viewer) {
		$this->streamRequest->setViewer($viewer);
	}


	/**
	 * @param ACore $stream
	 * @param Person $actor
	 * @param string $type
	 *
	 * @throws SocialAppConfigException
	 * @throws Exception
	 */
	public function assignItem(Acore $stream, Person $actor, string $type) {
		$stream->setId($this->configService->generateId('@' . $actor->getPreferredUsername()));
		$stream->setPublished(date("c"));

		$this->setRecipient($stream, $actor, $type);
		$stream->setLocal(true);

		if ($stream instanceof Stream) {
			$this->assignStream($stream);
		}
	}


	/**
	 * @param Stream $stream
	 *
	 * @throws Exception
	 */
	public function assignStream(Stream $stream) {
		$stream->convertPublished();
	}


	/**
	 * @param ACore $stream
	 * @param Person $actor
	 * @param string $type
	 */
	private function setRecipient(ACore $stream, Person $actor, string $type) {
		switch ($type) {
			case Stream::TYPE_UNLISTED:
				$stream->setTo($actor->getFollowers());
				$stream->addInstancePath(
					new InstancePath(
						$actor->getFollowers(), InstancePath::TYPE_FOLLOWERS,
						InstancePath::PRIORITY_LOW
					)
				);
				$stream->addCc(ACore::CONTEXT_PUBLIC);
				break;

			case Stream::TYPE_FOLLOWERS:
				$stream->setTo($actor->getFollowers());
				$stream->addInstancePath(
					new InstancePath(
						$actor->getFollowers(), InstancePath::TYPE_FOLLOWERS,
						InstancePath::PRIORITY_LOW
					)
				);
				break;

			case Stream::TYPE_ANNOUNCE:
				$stream->addInstancePath(
					new InstancePath(
						$actor->getFollowers(), InstancePath::TYPE_FOLLOWERS,
						InstancePath::PRIORITY_LOW
					)
				);
				$stream->addCc($actor->getFollowers());
				break;

			case Stream::TYPE_DIRECT:
				break;

			default:
				$stream->setTo(ACore::CONTEXT_PUBLIC);
				$stream->addCc($actor->getFollowers());
				$stream->addInstancePath(
					new InstancePath(
						$actor->getFollowers(), InstancePath::TYPE_FOLLOWERS,
						InstancePath::PRIORITY_LOW
					)
				);
				break;
		}
	}


	/**
	 * @param $stream
	 */
	public function detectType(Stream $stream) {
		if (in_array(ACore::CONTEXT_PUBLIC, $stream->getToAll())) {
			$stream->setTimeline(Stream::TYPE_PUBLIC);

			return;
		}

		if (in_array(ACore::CONTEXT_PUBLIC, $stream->getCcArray())) {
			$stream->setType(Stream::TYPE_UNLISTED);

			return;
		}

		try {
			$actor = $this->cacheActorService->getFromId($stream->getAttributedTo());
			echo json_encode($actor) . "\n";
		} catch (Exception $e) {
			return;
		}
	}


	/**
	 * @param Stream $stream
	 * @param string $type
	 * @param string $account
	 */
	public function addRecipient(Stream $stream, string $type, string $account) {
		if ($account === '') {
			return;
		}

		try {
			$actor = $this->cacheActorService->getFromAccount($account, true);
		} catch (Exception $e) {
			return;
		}

		$instancePath = new InstancePath(
			$actor->getInbox(), InstancePath::TYPE_INBOX, InstancePath::PRIORITY_MEDIUM
		);
		if ($type === Stream::TYPE_DIRECT) {
			$instancePath->setPriority(InstancePath::PRIORITY_HIGH);
			$stream->addToArray($actor->getId());
			$stream->setFilterDuplicate(true); // TODO: really needed ?
		} else {
			$stream->addCc($actor->getId());
		}

		$stream->addTag(
			[
				'type' => 'Mention',
				'href' => $actor->getId(),
				'name' => '@' . $account
			]
		);

		$stream->addInstancePath($instancePath);
	}


	/**
	 * @param Note $note
	 * @param string $hashtag
	 */
	public function addHashtag(Note $note, string $hashtag) {
		try {
			$note->addTag(
				[
					'type' => 'Hashtag',
					'href' => $this->configService->getSocialUrl() . 'tag/' . strtolower($hashtag),
					'name' => '#' . $hashtag
				]
			);
		} catch (SocialAppConfigException $e) {
		}
	}


	/**
	 * @param Stream $stream
	 * @param string $type
	 * @param array $accounts
	 */
	public function addRecipients(Stream $stream, string $type, array $accounts) {
		foreach ($accounts as $account) {
			$this->addRecipient($stream, $type, $account);
		}
	}


	/**
	 * @param Note $note
	 * @param array $hashtags
	 */
	public function addHashtags(Note $note, array $hashtags) {
		$note->setHashtags($hashtags);
		foreach ($hashtags as $hashtag) {
			$this->addHashtag($note, $hashtag);
		}
	}


	/**
	 * @param Note $note
	 * @param string $replyTo
	 *
	 * @throws InvalidOriginException
	 * @throws InvalidResourceException
	 * @throws ItemUnknownException
	 * @throws MalformedArrayException
	 * @throws RedundancyLimitException
	 * @throws RequestContentException
	 * @throws RequestNetworkException
	 * @throws RequestResultNotJsonException
	 * @throws RequestResultSizeException
	 * @throws RequestServerException
	 * @throws SocialAppConfigException
	 * @throws StreamNotFoundException
	 * @throws UnauthorizedFediverseException
	 */
	public function replyTo(Note $note, string $replyTo) {
		if ($replyTo === '') {
			return;
		}

		$author = $this->getAuthorFromPostId($replyTo);
		$note->setInReplyTo($replyTo);
		// TODO - type can be NOT public !
		$note->addInstancePath(
			new InstancePath(
				$author->getSharedInbox(), InstancePath::TYPE_INBOX, InstancePath::PRIORITY_HIGH
			)
		);
	}


	/**
	 * @param Stream $item
	 * @param string $type
	 *
	 * @throws Exception
	 */
	public function deleteLocalItem(Stream $item, string $type = '') {
		if (!$item->isLocal()) {
			return;
		}

		$item->setActorId($item->getAttributedTo());
		$this->activityService->deleteActivity($item);
		$this->streamRequest->deleteById($item->getId(), $type);
	}


	/**
	 * @param string $id
	 * @param bool $asViewer
	 *
	 * @return Stream
	 * @throws StreamNotFoundException
	 */
	public function getStreamById(
		string $id,
		bool $asViewer = false,
		int $format = ACore::FORMAT_ACTIVITYPUB
	): Stream {
		return $this->streamRequest->getStreamById($id, $asViewer, $format);
	}


	/**
	 * @param int $nid
	 *
	 * @return array
	 */
	public function getContextByNid(int $nid): array {
		$curr = $post = $this->streamRequest->getStreamByNid($nid);

		$ancestors = [];
		for ($i = 0; $i < self::ANCESTOR_LIMIT; $i++) {
			if ($curr->getInReplyTo() === '') {
				break;
			}

			try {
				$curr = $this->streamRequest->getStreamById($curr->getInReplyTo(), true);
				$curr->setExportFormat(ACore::FORMAT_LOCAL);
				$ancestors[] = $curr;
			} catch (StreamNotFoundException $e) {
				break; // ancestor might be out of range for viewer
			}
		}

		return [
			'ancestors' => array_reverse($ancestors),
			'descendants' => $this->streamRequest->getDescendants($post->getId())
		];
	}


	/**
	 * @param string $id
	 * @param bool $asViewer
	 *
	 * @return Stream
	 * @throws StreamNotFoundException
	 */
	public function getStreamByNid(int $nid): Stream {
		return $this->streamRequest->getStreamByNid($nid);
	}


	/**
	 * @param string $id
	 * @param int $since
	 * @param int $limit
	 * @param bool $asViewer
	 *
	 * @return Stream[]
	 * @throws StreamNotFoundException
	 * @throws DateTimeException
	 */
	public function getRepliesByParentId(
		string $id,
		int $since = 0,
		int $limit = 5,
		bool $asViewer = false
	): array {
		return $this->streamRequest->getRepliesByParentId($id, $since, $limit, $asViewer);
	}


	/**
	 * @param int $since
	 * @param int $limit
	 * @param int $format
	 *
	 * @return Note[]
	 * @throws DateTimeException
	 * @deprecated
	 */
	public function getStreamHome(
		int $since = 0,
		int $limit = 5,
		int $format = Stream::FORMAT_ACTIVITYPUB
	): array {
		return $this->streamRequest->getTimelineHome_dep($since, $limit, $format);
	}


	/**
	 * @param ProbeOptions $options
	 *
	 * @return Note[]
	 */
	public function getTimeline(ProbeOptions $options): array {
		return $this->streamRequest->getTimeline($options);
	}

	/**
	 * @param int $since
	 * @param int $limit
	 *
	 * @return Note[]
	 * @throws Exception
	 * @deprecated
	 */
	public function getStreamNotifications(int $since = 0, int $limit = 5): array {
		return $this->streamRequest->getTimelineNotifications_dep($since, $limit);
	}


	/**
	 * @param string $actorId
	 * @param int $since
	 * @param int $limit
	 *
	 * @return Note[]
	 * @throws Exception
	 * @deprecated
	 */
	public function getStreamAccount(string $actorId, int $since = 0, int $limit = 5): array {
		return $this->streamRequest->getTimelineAccount_dep($actorId, $since, $limit);
	}


	/**
	 * @param int $since
	 * @param int $limit
	 *
	 * @return Note[]
	 * @throws Exception
	 * @deprecated
	 */
	public function getStreamDirect(int $since = 0, int $limit = 5): array {
		return $this->streamRequest->getTimelineDirect_dep($since, $limit);
	}


	/**
	 * @param int $since
	 * @param int $limit
	 *
	 * @return Note[]
	 * @throws Exception
	 * @deprecated
	 */
	public function getStreamLocalTimeline(int $since = 0, int $limit = 5): array {
		return $this->streamRequest->getTimelineGlobal_dep($since, $limit, true);
	}


	/**
	 * @param string $hashtag
	 * @param int $since
	 * @param int $limit
	 *
	 * @return Note[]
	 * @throws Exception
	 */
	public function getStreamLocalTag(string $hashtag, int $since = 0, int $limit = 5): array {
		return $this->streamRequest->getTimelineTag($hashtag, $since, $limit);
	}


	/**
	 * @param int $since
	 * @param int $limit
	 *
	 * @return Note[]
	 */
	public function getStreamInternalTimeline(int $since = 0, int $limit = 5): array {
		// TODO - admin should be able to provide a list of 'friendly/internal' instance of ActivityPub
		return [];
	}


	/**
	 *
	 * @param int $since
	 * @param int $limit
	 *
	 * @return Note[]
	 * @throws Exception
	 */
	public function getStreamGlobalTimeline(int $since = 0, int $limit = 5): array {
		return $this->streamRequest->getTimelineGlobal_dep($since, $limit, false);
	}


	/**
	 *
	 * @param int $since
	 * @param int $limit
	 *
	 * @return Note[]
	 * @throws Exception
	 */
	public function getStreamLiked(int $since = 0, int $limit = 5): array {
		return $this->streamRequest->getTimelineLiked($since, $limit);
	}


	/**
	 * @param $noteId
	 *
	 * @return Person
	 * @throws InvalidOriginException
	 * @throws InvalidResourceException
	 * @throws MalformedArrayException
	 * @throws StreamNotFoundException
	 * @throws RedundancyLimitException
	 * @throws SocialAppConfigException
	 * @throws ItemUnknownException
	 * @throws RequestContentException
	 * @throws RequestNetworkException
	 * @throws RequestResultSizeException
	 * @throws RequestServerException
	 * @throws RequestResultNotJsonException
	 * @throws UnauthorizedFediverseException
	 */
	public function getAuthorFromPostId(string $noteId) {
		$note = $this->streamRequest->getStreamById($noteId);

		return $this->cacheActorService->getFromId($note->getAttributedTo());
	}


	/**
	 * @param Person $actor
	 *
	 * @return OrderedCollection
	 */
	public function getOutboxCollection(Person $actor): OrderedCollection {
		$collection = new OrderedCollection();
		$collection->setId($actor->getOutbox());
		$collection->setTotalItems($this->getInt('post', $actor->getDetails('count')));

		$link = $this->urlGenerator->linkToRouteAbsolute(
			'social.ActivityPub.outbox',
			['username' => $actor->getPreferredUsername()]
		);

		$collection->setFirst($link . '?page=1');
		$collection->setLast($link . '?page=1&min_id=0');

		return $collection;
	}
}