<?php
/**
 * @copyright Copyright (C) 2020, Friendica
 *
 * @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 <https://www.gnu.org/licenses/>.
 *
 */

use Friendica\App;
use Friendica\Content\Pager;
use Friendica\Content\Text\BBCode;
use Friendica\Content\Text\HTML;
use Friendica\Core\ACL;
use Friendica\Core\Logger;
use Friendica\Core\Protocol;
use Friendica\Core\Renderer;
use Friendica\Core\Session;
use Friendica\Database\DBA;
use Friendica\DI;
use Friendica\Model\Contact;
use Friendica\Model\Item;
use Friendica\Model\Profile;
use Friendica\Module\Objects;
use Friendica\Network\HTTPException;
use Friendica\Protocol\ActivityPub;
use Friendica\Protocol\DFRN;
use Friendica\Util\Strings;

function display_init(App $a)
{
	if (ActivityPub::isRequest()) {
		Objects::rawContent(['guid' => $a->argv[1] ?? null]);
	}

	if (DI::config()->get('system', 'block_public') && !Session::isAuthenticated()) {
		return;
	}

	$nick = (($a->argc > 1) ? $a->argv[1] : '');

	$item = null;
	$item_user = local_user();

	$fields = ['id', 'parent', 'author-id', 'body', 'uid', 'guid', 'gravity'];

	// If there is only one parameter, then check if this parameter could be a guid
	if ($a->argc == 2) {
		$nick = "";

		// Does the local user have this item?
		if (local_user()) {
			$item = Item::selectFirstForUser(local_user(), $fields, ['guid' => $a->argv[1], 'uid' => local_user()]);
			if (DBA::isResult($item)) {
				$nick = $a->user["nickname"];
			}
		}

		// Is this item private but could be visible to the remove visitor?
		if (!DBA::isResult($item) && remote_user()) {
			$item = Item::selectFirst($fields, ['guid' => $a->argv[1], 'private' => Item::PRIVATE, 'origin' => true]);
			if (DBA::isResult($item)) {
				if (!Contact::isFollower(remote_user(), $item['uid'])) {
					$item = null;
				} else {
					$item_user = $item['uid'];
				}
			}
		}

		// Is it an item with uid=0?
		if (!DBA::isResult($item)) {
			$item = Item::selectFirstForUser(local_user(), $fields, ['guid' => $a->argv[1], 'private' => [Item::PUBLIC, Item::UNLISTED], 'uid' => 0]);
		}
	} elseif ($a->argc >= 3 && $nick == 'feed-item') {
		$item_id = $a->argv[2];
		if (substr($item_id, -5) == '.atom') {
			$item_id = substr($item_id, 0, -5);
		}
		$item = Item::selectFirstForUser(local_user(), $fields, ['id' => $item_id, 'private' => [Item::PUBLIC, Item::UNLISTED], 'uid' => 0]);
	}

	if (!DBA::isResult($item)) {
		return;
	}

	if ($a->argc >= 3 && $nick == 'feed-item') {
		displayShowFeed($item['id'], $a->argc > 3 && $a->argv[3] == 'conversation.atom');
	}

	if (!empty($_SERVER['HTTP_ACCEPT']) && strstr($_SERVER['HTTP_ACCEPT'], 'application/atom+xml')) {
		Logger::log('Directly serving XML for id '.$item['id'], Logger::DEBUG);
		displayShowFeed($item['id'], false);
	}

	if ($item['gravity'] != GRAVITY_PARENT) {
		$parent = Item::selectFirstForUser($item_user, $fields, ['id' => $item['parent']]);
		$item = $parent ?: $item;
	}

	$profiledata = display_fetchauthor($a, $item);

	if (strstr(Strings::normaliseLink($profiledata['url']), Strings::normaliseLink(DI::baseUrl()))) {
		$nickname = str_replace(Strings::normaliseLink(DI::baseUrl()) . '/profile/', '', Strings::normaliseLink($profiledata['url']));

		if (!empty($a->user['nickname']) && $nickname != $a->user['nickname']) {
			$profile = DBA::selectFirst('owner-view', [], ['nickname' => $nickname]);
			if (DBA::isResult($profile)) {
				$profiledata = $profile;
			}
			$profiledata["network"] = Protocol::DFRN;
		} else {
			$profiledata = [];
		}
	}

	Profile::load($a, $nick, $profiledata);
}

function display_fetchauthor($a, $item)
{
	$author = DBA::selectFirst('contact', ['name', 'nick', 'photo', 'network', 'url'], ['id' => $item['author-id']]);

	$profiledata = [];
	$profiledata['uid'] = -1;
	$profiledata['nickname'] = $author['nick'];
	$profiledata['name'] = $author['name'];
	$profiledata['picdate'] = '';
	$profiledata['photo'] = $author['photo'];
	$profiledata['url'] = $author['url'];
	$profiledata['network'] = $author['network'];

	// Check for a repeated message
	$shared = Item::getShareArray($item);
	if (!empty($shared) && empty($shared['comment'])) {
		if (!empty($shared['author'])) {
			$profiledata['name'] = $shared['author'];
		}

		if (!empty($shared['profile'])) {
			$profiledata['url'] = $shared['profile'];
		}

		if (!empty($shared['avatar'])) {
			$profiledata['photo'] = $shared['avatar'];
		}

		$profiledata["nickname"] = $profiledata["name"];
		$profiledata["network"] = Protocol::matchByProfileUrl($profiledata["url"]);

		$profiledata["address"] = "";
		$profiledata["about"] = "";
	}

	$profiledata = array_merge($profiledata, Contact::getByURLForUser($profiledata["url"], local_user()));

	if (!empty($profiledata["photo"])) {
		$profiledata["photo"] = DI::baseUrl()->remove($profiledata["photo"]);
	}

	return $profiledata;
}

function display_content(App $a, $update = false, $update_uid = 0)
{
	if (DI::config()->get('system','block_public') && !Session::isAuthenticated()) {
		throw new HTTPException\ForbiddenException(DI::l10n()->t('Public access denied.'));
	}

	$o = '';

	$item = null;

	$force = (bool)($_REQUEST['force'] ?? false);

	if ($update) {
		$item_id = $_REQUEST['item_id'];
		$item = Item::selectFirst(['uid', 'parent', 'parent-uri'], ['id' => $item_id]);
		if ($item['uid'] != 0) {
			$a->profile = ['uid' => intval($item['uid'])];
		} else {
			$a->profile = ['uid' => intval($update_uid)];
		}
		$item_parent = $item['parent'];
		$item_parent_uri = $item['parent-uri'];
	} else {
		$item_id = (($a->argc > 2) ? $a->argv[2] : 0);
		$item_parent = $item_id;

		if ($a->argc == 2) {
			$item_parent = 0;
			$fields = ['id', 'parent', 'parent-uri', 'uid'];

			if (local_user()) {
				$condition = ['guid' => $a->argv[1], 'uid' => local_user()];
				$item = Item::selectFirstForUser(local_user(), $fields, $condition);
				if (DBA::isResult($item)) {
					$item_id = $item['id'];
					$item_parent = $item['parent'];
					$item_parent_uri = $item['parent-uri'];
				}
			}

			if (($item_parent == 0) && remote_user()) {
				$item = Item::selectFirst($fields, ['guid' => $a->argv[1], 'private' => Item::PRIVATE, 'origin' => true]);
				if (DBA::isResult($item) && Contact::isFollower(remote_user(), $item['uid'])) {
					$item_id = $item['id'];
					$item_parent = $item['parent'];
					$item_parent_uri = $item['parent-uri'];
				}
			}

			if ($item_parent == 0) {
				$condition = ['private' => [Item::PUBLIC, Item::UNLISTED], 'guid' => $a->argv[1], 'uid' => 0];
				$item = Item::selectFirstForUser(local_user(), $fields, $condition);
				if (DBA::isResult($item)) {
					$item_id = $item['id'];
					$item_parent = $item['parent'];
					$item_parent_uri = $item['parent-uri'];
				}
			}
		}
	}

	if (empty($item)) {
		throw new HTTPException\NotFoundException(DI::l10n()->t('The requested item doesn\'t exist or has been deleted.'));
	}

	// We are displaying an "alternate" link if that post was public. See issue 2864
	$is_public = Item::exists(['id' => $item_id, 'private' => [Item::PUBLIC, Item::UNLISTED]]);
	if ($is_public) {
		// For the atom feed the nickname doesn't matter at all, we only need the item id.
		$alternate = DI::baseUrl().'/display/feed-item/'.$item_id.'.atom';
		$conversation = DI::baseUrl().'/display/feed-item/'.$item_parent.'/conversation.atom';
	} else {
		$alternate = '';
		$conversation = '';
	}

	DI::page()['htmlhead'] .= Renderer::replaceMacros(Renderer::getMarkupTemplate('display-head.tpl'),
				['$alternate' => $alternate,
					'$conversation' => $conversation]);

	$is_remote_contact = false;
	$item_uid = local_user();

	$parent = null;
	if (!empty($item_parent_uri)) {
		$parent = Item::selectFirst(['uid'], ['uri' => $item_parent_uri, 'wall' => true]);
	}

	if (DBA::isResult($parent)) {
		$a->profile['uid'] = ($a->profile['uid'] ?? 0) ?: $parent['uid'];
		$is_remote_contact = Session::getRemoteContactID($a->profile['uid']);
		if ($is_remote_contact) {
			$item_uid = $parent['uid'];
		}
	} else {
		$a->profile = ['uid' => intval($item['uid'])];
	}

	$page_contact = DBA::selectFirst('contact', [], ['self' => true, 'uid' => $a->profile['uid']]);
	if (DBA::isResult($page_contact)) {
		$a->page_contact = $page_contact;
	}

	$is_owner = (local_user() && (in_array($a->profile['uid'], [local_user(), 0])) ? true : false);

	if (!empty($a->profile['hidewall']) && !$is_owner && !$is_remote_contact) {
		throw new HTTPException\ForbiddenException(DI::l10n()->t('Access to this profile has been restricted.'));
	}

	// We need the editor here to be able to reshare an item.
	if ($is_owner && !$update) {
		$x = [
			'is_owner' => true,
			'allow_location' => $a->user['allow_location'],
			'default_location' => $a->user['default-location'],
			'nickname' => $a->user['nickname'],
			'lockstate' => (is_array($a->user) && (strlen($a->user['allow_cid']) || strlen($a->user['allow_gid']) || strlen($a->user['deny_cid']) || strlen($a->user['deny_gid'])) ? 'lock' : 'unlock'),
			'acl' => ACL::getFullSelectorHTML(DI::page(), $a->user, true),
			'bang' => '',
			'visitor' => 'block',
			'profile_uid' => local_user(),
		];
		$o .= status_editor($a, $x, 0, true);
	}
	$sql_extra = Item::getPermissionsSQLByUserId($a->profile['uid']);

	if (local_user() && (local_user() == $a->profile['uid'])) {
		$condition = ['parent-uri' => $item_parent_uri, 'uid' => local_user(), 'unseen' => true];
		$unseen = Item::exists($condition);
	} else {
		$unseen = false;
	}

	if ($update && !$unseen && !$force) {
		return '';
	}

	$condition = ["`id` = ? AND `item`.`uid` IN (0, ?) " . $sql_extra, $item_id, $item_uid];
	$fields = ['parent-uri', 'body', 'title', 'author-name', 'author-avatar', 'plink', 'author-id', 'owner-id', 'contact-id'];
	$item = Item::selectFirstForUser($a->profile['uid'], $fields, $condition);

	if (!DBA::isResult($item)) {
		throw new HTTPException\NotFoundException(DI::l10n()->t('The requested item doesn\'t exist or has been deleted.'));
	}

	$item['uri'] = $item['parent-uri'];

	if ($unseen) {
		$condition = ['parent-uri' => $item_parent_uri, 'uid' => local_user(), 'unseen' => true];
		Item::update(['unseen' => false], $condition);
	}

	if (!$update) {
		$o .= "<script> var netargs = '?item_id=" . $item_id . "'; </script>";
	}

	$o .= conversation($a, [$item], 'display', $update_uid, false, 'commented', $item_uid);

	// Preparing the meta header
	$description = trim(HTML::toPlaintext(BBCode::convert($item["body"], false), 0, true));
	$title = trim(HTML::toPlaintext(BBCode::convert($item["title"], false), 0, true));
	$author_name = $item["author-name"];

	$image = DI::baseUrl()->remove($item["author-avatar"]);

	if ($title == "") {
		$title = $author_name;
	}

	// Limit the description to 160 characters
	if (strlen($description) > 160) {
		$description = substr($description, 0, 157) . '...';
	}

	$description = htmlspecialchars($description, ENT_COMPAT, 'UTF-8', true); // allow double encoding here
	$title = htmlspecialchars($title, ENT_COMPAT, 'UTF-8', true); // allow double encoding here
	$author_name = htmlspecialchars($author_name, ENT_COMPAT, 'UTF-8', true); // allow double encoding here

	$page = DI::page();

	if (DBA::exists('contact', ['unsearchable' => true, 'id' => [$item['contact-id'], $item['author-id'], $item['owner-id']]])) {
		$page['htmlhead'] .= '<meta content="noindex, noarchive" name="robots" />' . "\n";
	}

	DI::page()['htmlhead'] .= '<meta name="author" content="'.$author_name.'" />'."\n";
	$page['htmlhead'] .= '<meta name="title" content="'.$title.'" />'."\n";
	$page['htmlhead'] .= '<meta name="fulltitle" content="'.$title.'" />'."\n";
	$page['htmlhead'] .= '<meta name="description" content="'.$description.'" />'."\n";

	// Schema.org microdata
	$page['htmlhead'] .= '<meta itemprop="name" content="'.$title.'" />'."\n";
	$page['htmlhead'] .= '<meta itemprop="description" content="'.$description.'" />'."\n";
	$page['htmlhead'] .= '<meta itemprop="image" content="'.$image.'" />'."\n";
	$page['htmlhead'] .= '<meta itemprop="author" content="'.$author_name.'" />'."\n";

	// Twitter cards
	$page['htmlhead'] .= '<meta name="twitter:card" content="summary" />'."\n";
	$page['htmlhead'] .= '<meta name="twitter:title" content="'.$title.'" />'."\n";
	$page['htmlhead'] .= '<meta name="twitter:description" content="'.$description.'" />'."\n";
	$page['htmlhead'] .= '<meta name="twitter:image" content="'.DI::baseUrl().'/'.$image.'" />'."\n";
	$page['htmlhead'] .= '<meta name="twitter:url" content="'.$item["plink"].'" />'."\n";

	// Dublin Core
	$page['htmlhead'] .= '<meta name="DC.title" content="'.$title.'" />'."\n";
	$page['htmlhead'] .= '<meta name="DC.description" content="'.$description.'" />'."\n";

	// Open Graph
	$page['htmlhead'] .= '<meta property="og:type" content="website" />'."\n";
	$page['htmlhead'] .= '<meta property="og:title" content="'.$title.'" />'."\n";
	$page['htmlhead'] .= '<meta property="og:image" content="'.DI::baseUrl().'/'.$image.'" />'."\n";
	$page['htmlhead'] .= '<meta property="og:url" content="'.$item["plink"].'" />'."\n";
	$page['htmlhead'] .= '<meta property="og:description" content="'.$description.'" />'."\n";
	$page['htmlhead'] .= '<meta name="og:article:author" content="'.$author_name.'" />'."\n";
	// article:tag

	return $o;
}

function displayShowFeed($item_id, $conversation)
{
	$xml = DFRN::itemFeed($item_id, $conversation);
	if ($xml == '') {
		throw new HTTPException\InternalServerErrorException(DI::l10n()->t('The feed for this item is unavailable.'));
	}
	header("Content-type: application/atom+xml");
	echo $xml;
	exit();
}
