<?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\Model\ActivityPub;

use JsonSerializable;
use OCA\Social\Exceptions\ActivityCantBeVerifiedException;
use OCA\Social\Exceptions\InvalidOriginException;
use OCA\Social\Exceptions\InvalidResourceEntryException;
use OCA\Social\Exceptions\UrlCloudException;
use OCA\Social\Model\ActivityPub\Object\Document;
use OCA\Social\Model\LinkedDataSignature;
use OCA\Social\Tools\IQueryRow;
use OCA\Social\Tools\Traits\TArrayTools;
use OCA\Social\Tools\Traits\TPathTools;
use OCA\Social\Tools\Traits\TStringTools;

class ACore extends Item implements JsonSerializable, IQueryRow {
	use TArrayTools;
	use TStringTools;
	use TPathTools;


	public const CONTEXT_PUBLIC = 'https://www.w3.org/ns/activitystreams#Public';
	public const CONTEXT_ACTIVITYSTREAMS = 'https://www.w3.org/ns/activitystreams';
	public const CONTEXT_SECURITY = 'https://w3id.org/security/v1';

	public const AS_ID = 1;
	public const AS_TYPE = 2;
	public const AS_URL = 3;
	public const AS_DATE = 4;
	public const AS_USERNAME = 5;
	public const AS_ACCOUNT = 6;
	public const AS_STRING = 7;
	public const AS_CONTENT = 8;
	public const AS_TAGS = 10;

	public const FORMAT_ACTIVITYPUB = 1;
	public const FORMAT_LOCAL = 2;
	public const FORMAT_NOTIFICATION = 3;


	/** @var null Item */
	private $parent = null;

	private string $requestToken = '';
	private array $entries = [];
	private ?ACore $object = null;
	private ?Document $icon = null;

	private bool $displayW3ContextSecurity = false;
	private ?LinkedDataSignature $signature = null;
	private int $format = self::FORMAT_ACTIVITYPUB;


	/**
	 * Core constructor.
	 *
	 * @param ACore $parent
	 */
	public function __construct($parent = null) {
		if ($parent instanceof ACore) {
			$this->setParent($parent);
		}
	}


	/**
	 * @return string
	 */
	public function getRequestToken(): string {
		if ($this->isRoot()) {
			return $this->requestToken;
		} else {
			return $this->getRoot()
						->getRequestToken();
		}
	}

	/**
	 * @param string $token
	 *
	 * @return ACore
	 */
	public function setRequestToken(string $token): ACore {
		$this->requestToken = $token;

		return $this;
	}


	/**
	 * @param ACore $parent
	 *
	 * @return ACore
	 */
	public function setParent(ACore $parent): ACore {
		$this->parent = $parent;

		return $this;
	}

	/**
	 * @return ACore
	 */
	public function getParent(): ACore {
		return $this->parent;
	}


	/**
	 * @return bool
	 */
	public function hasObject(): bool {
		if ($this->object === null) {
			return false;
		}

		return true;
	}

	/**
	 * @return null|self
	 */
	public function getObject(): ?ACore {
		return $this->object;
	}

	/**
	 * @param ACore $object
	 *
	 * @return ACore
	 */
	public function setObject(ACore $object): self {
		$object->setParent($this);
		$this->object = $object;

		return $this;
	}

	/**
	 * @return string
	 */
	public function getObjectId(): string {
		if ($this->hasObject()) {
			return $this->getObject()
						->getId();
		}

		return parent::getObjectId();
	}


	/**
	 * @param bool $filter - will remove general url like Public
	 *
	 * @return array
	 */
	public function getRecipients(bool $filter = false): array {
		$recipients = array_merge($this->getToAll(), $this->getCcArray());

		if (!$filter) {
			return $recipients;
		}

		return array_diff($recipients, [self::CONTEXT_PUBLIC]);
	}


	/**
	 * @return bool
	 */
	public function hasIcon(): bool {
		return ($this->icon !== null);
	}

	public function getIcon(): ?Document {
		return $this->icon;
	}

	/**
	 * @param Document $icon
	 *
	 * @return ACore
	 */
	public function setIcon(Document $icon): ACore {
		$icon->setParent($this);
		$this->icon = $icon;

		return $this;
	}


	/**
	 * @return bool
	 */
	public function isDisplayW3ContextSecurity(): bool {
		return $this->displayW3ContextSecurity;
	}

	/**
	 * @param bool $display
	 *
	 * @return ACore
	 */
	public function setDisplayW3ContextSecurity(bool $display): ACore {
		$this->displayW3ContextSecurity = $display;

		return $this;
	}


	/**
	 * @return bool
	 */
	public function isPublic(): bool {
		return in_array(self::CONTEXT_PUBLIC, $this->getRecipients());
	}


	/**
	 * @return bool
	 */
	public function hasSignature(): bool {
		return ($this->signature !== null);
	}

	public function getSignature(): ?LinkedDataSignature {
		return $this->signature;
	}

	/**
	 * @param LinkedDataSignature $signature
	 *
	 * @return ACore
	 */
	public function setSignature(LinkedDataSignature $signature): Acore {
		$this->signature = $signature;

		return $this;
	}


	/**
	 * @param string $base
	 * @param bool $root
	 *
	 * @throws UrlCloudException
	 */
	public function generateUniqueId(string $base = '', bool $root = true) {
		$url = '';
		if ($root) {
			$url = $this->getUrlCloud();
			if ($url === '') {
				throw new UrlCloudException();
			}
		}

		if ($base !== '') {
			$base = $this->withoutEndSlash($this->withBeginSlash($base));
		}

		$this->setId($url . $base . '/' . $this->uuid());
	}


	/**
	 * @param string $id
	 *
	 * @throws InvalidOriginException
	 */
	public function checkOrigin(string $id) {
		$host = parse_url($id, PHP_URL_HOST);
		$origin = $this->getRoot()
					   ->getOrigin();

		if ($id !== '' && $origin === $host && $host !== '') {
			return;
		}

		throw new InvalidOriginException(
			'ACore::checkOrigin - id: ' . $id . ' - origin: ' . $origin
		);
	}


	/**
	 * @param string $url
	 *
	 * @throws ActivityCantBeVerifiedException
	 * @deprecated
	 *
	 */
	public function verify(string $url) {
		// TODO - Compare this with checkOrigin() - and delete this method.
		$url1 = parse_url($this->getId());
		$url2 = parse_url($url);

		if ($this->get('host', $url1, '1') !== $this->get('host', $url2, '2')) {
			throw new ActivityCantBeVerifiedException('activity cannot be verified');
		}

		if ($this->get('scheme', $url1, '1') !== $this->get('scheme', $url2, '2')) {
			throw new ActivityCantBeVerifiedException('activity cannot be verified');
		}

		if ($this->getInt('port', $url1, 1) !== $this->getInt('port', $url2, 1)) {
			throw new ActivityCantBeVerifiedException('activity cannot be verified');
		}
	}


	/**
	 * @return bool
	 */
	public function isRoot(): bool {
		return ($this->parent === null);
	}

	/**
	 * @param array $chain
	 *
	 * @return ACore
	 */
	public function getRoot(array &$chain = []): ACore {
		$chain[] = $this;
		if ($this->isRoot()) {
			return $this;
		}

		return $this->getParent()
					->getRoot($chain);
	}


	/**
	 * @param array $arr
	 *
	 * @return ACore
	 */
	public function setEntries(array $arr): ACore {
		$this->entries = $arr;

		return $this;
	}

	/**
	 * @return array
	 */
	public function getEntries(): array {
		return $this->entries;
	}

	/**
	 * @param string $k
	 * @param string $v
	 *
	 * @return ACore
	 */
	public function addEntry(string $k, string $v): ACore {
		if ($v === '') {
//			unset($this->entries[$k]);

			return $this;
		}

		$this->entries[$k] = $v;

		return $this;
	}

	/**
	 * @param string $k
	 * @param int $v
	 *
	 * @return ACore
	 */
	public function addEntryInt(string $k, int $v): ACore {
		if ($v === 0) {
			return $this;
		}

		$this->entries[$k] = $v;

		return $this;
	}

	/**
	 * @param string $k
	 * @param bool $v
	 *
	 * @return ACore
	 */
	public function addEntryBool(string $k, bool $v): ACore {
		if ($v === 0) {
			return $this;
		}

		$this->entries[$k] = $v;

		return $this;
	}

	/**
	 * @param string $k
	 * @param array $v
	 *
	 * @return ACore
	 */
	public function addEntryArray(string $k, array $v): ACore {
		if ($v === []) {
//			unset($this->entries[$k]);

			return $this;
		}

		$this->entries[$k] = $v;

		return $this;
	}


	/**
	 * @param string $k
	 * @param ACore $v
	 *
	 * @return ACore
	 */
	public function addEntryItem(string $k, ACore $v): ACore {
		if ($v === null) {
//			unset($this->entries[$k]);

			return $this;
		}

		$this->entries[$k] = $v;

		return $this;
	}


	/**
	 * @param int $as
	 * @param string $k
	 * @param array $arr
	 * @param string $default
	 *
	 * @return string
	 */
	public function validate(int $as, string $k, array $arr, string $default = ''): string {
		try {
			return $this->validateEntryString($as, $this->get($k, $arr, $default));
		} catch (InvalidResourceEntryException $e) {
			return $default;
		}
	}


	/**
	 * @param int $as
	 * @param string $k
	 * @param array $arr
	 * @param array $default
	 *
	 * @return array
	 */
	public function validateArray(int $as, string $k, array $arr, array $default = []): array {
		$values = $this->getArray($k, $arr, $default);

		$result = [];
		foreach ($values as $value) {
			try {
				if (is_array($value)) {
					$result[] = $this->validateEntryArray($as, $value);
				} else {
					$result[] = $this->validateEntryString($as, $value);
				}
			} catch (InvalidResourceEntryException $e) {
			}
		}

		return $result;
	}


	/**
	 * // TODO - better checks
	 *
	 * @param int $as
	 * @param string $value
	 * @param bool $exception
	 *
	 * @return string
	 * @throws InvalidResourceEntryException
	 */
	public function validateEntryString(int $as, string $value, bool $exception = true): string {
		switch ($as) {
			case self::AS_ID:
				if (parse_url($value) !== false) {
					return $value;
				}
				break;

			case self::AS_TYPE:
				return $value;

			case self::AS_URL:
				if (parse_url($value) !== false) {
					return $value;
				}
				break;

			case self::AS_DATE:
				return $value;

			case self::AS_STRING:
				$value = strip_tags($value);
				$value = html_entity_decode($value, ENT_QUOTES | ENT_HTML5);

				return $value;

			case self::AS_CONTENT:
				$value = strip_tags($value, ['a', 'p', 'span', 'br']);
				$value = html_entity_decode($value, ENT_QUOTES | ENT_HTML5);

				return $value;

			case self::AS_USERNAME:
				$value = strip_tags($value);

				return $value;

			case self::AS_ACCOUNT:
				$value = strip_tags($value);

				return $value;
		}

		if ($exception) {
			throw new InvalidResourceEntryException($as . ' ' . $value);
		} else {
			return '';
		}
	}


	/**
	 * @param int $as
	 * @param array $values
	 *
	 * @return array
	 * @throws InvalidResourceEntryException
	 */
	public function validateEntryArray(int $as, array $values): array {
		switch ($as) {
			case self::AS_TAGS:

				return [
					'type' => $this->validateEntryString(
						self::AS_TYPE, $this->get('type', $values, ''), false
					),
					'href' => $this->validateEntryString(
						self::AS_URL, $this->get('href', $values, ''), false
					),
					'name' => $this->validateEntryString(
						self::AS_STRING, $this->get('name', $values, ''), false
					)
				];
		}

		throw new InvalidResourceEntryException($as . ' ' . json_encode($values));
	}


	/**
	 * @param array $data
	 */
	public function import(array $data) {
		$this->setId($this->validate(self::AS_ID, 'id', $data, ''));
		$this->setType($this->validate(self::AS_TYPE, 'type', $data, ''));
		$this->setUrl($this->validate(self::AS_URL, 'url', $data, ''));
		$this->setSummary($this->get('summary', $data, ''));
		$this->setToArray($this->validateArray(self::AS_ID, 'to', $data, []));
		$this->setCcArray($this->validateArray(self::AS_ID, 'cc', $data, []));
		$this->setPublished($this->validate(self::AS_DATE, 'published', $data, ''));
		$this->setActorId($this->validate(self::AS_ID, 'actor', $data, ''));
		$this->setObjectId($this->validate(self::AS_ID, 'object', $data, ''));
		$this->setTags($this->validateArray(self::AS_TAGS, 'tag', $data, []));
	}


	/**
	 * @param array $data
	 */
	public function importFromDatabase(array $data) {
		// TODO: check if validate is needed when importing from database;
		$this->setNid($this->getInt('nid', $data));
		$this->setId($this->validate(self::AS_ID, 'id', $data, ''));
		$this->setType($this->validate(self::AS_TYPE, 'type', $data, ''));
		$this->setSubType($this->validate(self::AS_TYPE, 'subtype', $data, ''));
		$this->setUrl($this->validate(self::AS_URL, 'url', $data, ''));
		$this->setSummary($this->validate(self::AS_STRING, 'summary', $data, ''));
		$this->setTo($this->validate(self::AS_ID, 'to', $data, ''));
		$this->setToArray($this->validateArray(self::AS_ID, 'to_array', $data, []));
		$this->setCcArray($this->validateArray(self::AS_ID, 'cc', $data, []));
		$this->setBccArray($this->validateArray(self::AS_ID, 'bcc', $data, []));
		$this->setPublished($this->validate(self::AS_DATE, 'published', $data, ''));
		$this->setActorId($this->validate(self::AS_ID, 'actor_id', $data, ''));
		$this->setObjectId($this->validate(self::AS_ID, 'object_id', $data, ''));
		$this->setSource($this->get('source', $data, ''));
		$this->setLocal(($this->getInt('local', $data, 0) === 1));
	}

	/**
	 * based on json generated/exported as LOCAL
	 * @param array $data
	 */
	public function importFromLocal(array $data) {
		$this->setNid($this->getInt('id', $data));
	}

	/**
	 * @param int $format
	 *
	 * @return $this
	 */
	public function setExportFormat(int $format): self {
		$this->format = $format;

		return $this;
	}

	/**
	 * @return int
	 */
	public function getExportFormat(): int {
		return $this->format;
	}


	/**
	 * @return array
	 */
	public function jsonSerialize(): array {
		if ($this->getExportFormat() === self::FORMAT_LOCAL) {
			return $this->exportAsLocal();
		}

		if ($this->getExportFormat() === self::FORMAT_NOTIFICATION) {
			return $this->exportAsNotification();
		}

		return $this->exportAsActivityPub();
	}


	/**
	 * @return array
	 */
	public function exportAsActivityPub(): array {
		if ($this->hasSignature()) {
			$this->entries['signature'] = $this->getSignature();
		}

		if ($this->isRoot()) {
			$context = [self::CONTEXT_ACTIVITYSTREAMS];

			if ($this->hasSignature() || $this->isDisplayW3ContextSecurity()) {
				array_push($context, self::CONTEXT_SECURITY);
			}

			$this->addEntryArray('@context', $context);
		}

		$this->addEntry('id', $this->getId());
		$this->addEntry('type', $this->getType());
		$this->addEntry('subtype', $this->getSubType());
		$this->addEntry('url', $this->getUrl());
		$this->addEntry('to', $this->getTo());
		$this->addEntryArray('to', $this->getToArray());
		$this->addEntryArray('cc', $this->getCcArray());

		if ($this->hasActor()) {
			$this->addEntry(
				'actor', $this->getActor()
							  ->getId()
			);
			if ($this->isCompleteDetails()) {
				$this->addEntryItem('actor_info', $this->getActor());
			}
		} else {
			$this->addEntry('actor', $this->getActorId());
		}

		$this->addEntry('summary', $this->getSummary());
		$this->addEntry('published', $this->getPublished());
		$this->addEntryArray('tag', $this->getTags());

		if ($this->hasObject()) {
			$this->addEntryItem('object', $this->getObject());
		} else {
			$this->addEntry('object', $this->getObjectId());
		}

		// TODO - moving the $this->icon to Model/Person ?
		if ($this->hasIcon()) {
			$this->addEntryItem('icon', $this->getIcon());
		}

		if ($this->isCompleteDetails()) {
			$this->addEntry('source', $this->getSource());
		}

		if ($this->isLocal()) {
			$this->addEntryBool('local', $this->isLocal());
		}

		$result = $this->getEntries();
		$this->cleanArray($result);

		return $result;
	}


	/**
	 * @return array
	 */
	public function exportAsLocal(): array {
		$result = [
			'id' => $this->getId(),
		];

		if ($this->getNid() > 0) {
			$result['id'] = (string)$this->getNid();
		}

		return $result;
	}

	/**
	 * @return array
	 */
	public function exportAsNotification(): array {
		$result = [
			'id' => $this->getId()
		];

		if ($this->getNid() > 0) {
			$result['id'] = (string)$this->getNid();
		}

		return $result;
	}
}