<?php

namespace Code\Module;

use Code\Lib\Libzot;
use Code\Lib\Activity;
use Code\Lib\Libprofile;
use Code\Lib\ActivityStreams;
use Code\Lib\LDSignatures;
use Code\Lib\Crypto;
use Code\Lib\PConfig;
use Code\Lib as Zlib;
use Code\Web\HTTPSig;
use App;
use Code\Web\Controller;
use Code\Lib\PermissionDescription;
use Code\Widget\Pinned;
use Code\Lib\Navbar;
use Code\Lib\Libacl;
use Code\Lib\Head;
use Code\Extend\Hook;
use Code\Render\Theme;


require_once('include/items.php');
require_once('include/security.php');
require_once('include/conversation.php');


/**
 * @brief Channel Controller
 *
 */
class Channel extends Controller
{

    // State passed in from the Update module.

    public $profile_uid = 0;
    public $loading = 0;
    public $updating = 0;


    public function init()
    {

        if (isset($_GET['search']) && (in_array(substr($_GET['search'], 0, 1), ['@', '!', '?']) || str_starts_with($_GET['search'], 'https://'))) {
            goaway(z_root() . '/search' . '?f=&search=' . urlencode($_GET['search']));
        }

        $which = null;
        if (argc() > 1) {
            $which = argv(1);
        }
        if (!$which) {
            if (local_channel()) {
                $channel = App::get_channel();
                if ($channel && $channel['channel_address']) {
                    $which = $channel['channel_address'];
                }
            }
        }
        if (!$which) {
            notice(t('You must be logged in to see this page.') . EOL);
            return;
        }

        $profile = 0;
        $channel = App::get_channel();

        if ((local_channel()) && (argc() > 2) && (argv(2) === 'view')) {
            $which = $channel['channel_address'];
            $profile = argv(1);
        }

        $channel = Zlib\Channel::from_username($which, true);
        if (!$channel) {
            http_status_exit(404, 'Not found');
        }
        if ($channel['channel_removed']) {
            http_status_exit(410, 'Gone');
        }

        if (get_pconfig($channel['channel_id'], 'system', 'noindex')) {
            App::$meta->set('robots', 'noindex, noarchive');
        }

        Head::add_link([
            'rel' => 'alternate',
            'type' => 'application/atom+xml',
            'title' => t('Only posts'),
            'href' => z_root() . '/feed/' . $which
        ]);


        // An ActivityStreams actor record is more or less required for ActivityStreams compliance
        // unless the actor object is inlined into every activity/object. This implies that it
        // is more or less required for the Zot6 protocol, which uses ActivityStreams as a content
        // serialisation and which doesn't always include the full actor record with every
        // activity/object.

        // "more or less" means it isn't spelled out in the ActivityStreams spec, but a number of
        // things will break in subtle ways if it isn't provided.

        // The ActivityPub protocol requires an 'inbox', which will not be present in this record
        // if/when the ActivityPub protocol is disabled. This will be the case when using the Redmatrix
        // fork of Zap; which disables ActivityPub connectivity by default.

        if (ActivityStreams::is_as_request()) {
            // Somebody may attempt an ActivityStreams fetch on one of our message permalinks
            // Make it do the right thing.

            $mid = ((x($_REQUEST, 'mid')) ? $_REQUEST['mid'] : '');
            $mid = unpack_link_id($mid);

            if ($mid) {
                $obj = null;
                if (str_starts_with($mid, z_root() . '/item/')) {
                    App::$argc = 2;
                    App::$argv = ['item', basename($mid)];
                    $obj = new Item();
                }
                if (str_starts_with($mid, z_root() . '/activity/')) {
                    App::$argc = 2;
                    App::$argv = ['activity', basename($mid)];
                    $obj = new Activity();
                }
                $obj?->init();
            }
            if (intval($channel['channel_system'])) {
                goaway(z_root());
            }
            as_return_and_die(Activity::encode_person($channel, true, true), $channel);
        }

        // handle zot6 channel discovery

        if (Libzot::is_nomad_request()) {
            $sigdata = HTTPSig::verify(file_get_contents('php://input'), EMPTY_STR, 'zot6');

            if ($sigdata && $sigdata['signer'] && $sigdata['header_valid']) {

                $data = json_encode(Libzot::zotinfo(['guid_hash' => $channel['channel_hash'], 'target_url' => $sigdata['signer']]));
                $s = q(
                    "select site_crypto, hubloc_sitekey from site left join hubloc on hubloc_url = site_url where hubloc_id_url = '%s' and hubloc_network in ('nomad','zot6') and hubloc_deleted = 0 order by hubloc_id desc limit 1",
                    dbesc($sigdata['signer'])
                );

                if ($s && $s[0]['hubloc_sitekey'] && $s[0]['site_crypto']) {
                    $data = json_encode(Crypto::encapsulate($data, $s[0]['hubloc_sitekey'], Libzot::best_algorithm($s[0]['site_crypto'])));
                }
            } else {
                $data = json_encode(Libzot::zotinfo(['guid_hash' => $channel['channel_hash']]));
            }
    
            $headers = [
                'Content-Type' => 'application/x-nomad+json',
                'Digest' => HTTPSig::generate_digest_header($data),
                '(request-target)' => strtolower($_SERVER['REQUEST_METHOD']) . ' ' . $_SERVER['REQUEST_URI']
            ];
            $h = HTTPSig::create_sig($headers, $channel['channel_prvkey'], Zlib\Channel::url($channel));
            HTTPSig::set_headers($h);
            echo $data;
            killme();
        }


        // Run Libprofile::load() here to make sure the theme is set before
        // we start loading content

        Libprofile::load($which, $profile);

        if (!$_REQUEST['mid']) {
            App::$meta->set('og:title', $channel['channel_name']);
            App::$meta->set('og:image', $channel['xchan_photo_l']);
            App::$meta->set('og:type', 'webpage');
            App::$meta->set('og:url:secure_url', Zlib\Channel::url($channel));
            if (App::$profile['about'] && perm_is_allowed($channel['channel_id'], get_observer_hash(), 'view_profile')) {
                App::$meta->set('og:description', App::$profile['about']);
            } else {
                App::$meta->set('og:description', sprintf(t('This is the home page of %s.'), $channel['channel_name']));
            }
        }
    }

    public function get()
    {

        $noscript_content = get_config('system', 'noscript_content', '1');
        $sql_extra2  = '';

        $category = $datequery = $datequery2 = '';

        $mid = ((x($_REQUEST, 'mid')) ? $_REQUEST['mid'] : '');
        $mid = unpack_link_id($mid);

        $datequery = ((x($_GET, 'dend') && is_a_date_arg($_GET['dend'])) ? notags($_GET['dend']) : '');
        $datequery2 = ((x($_GET, 'dbegin') && is_a_date_arg($_GET['dbegin'])) ? notags($_GET['dbegin']) : '');

        $category = ((x($_REQUEST, 'cat')) ? $_REQUEST['cat'] : '');
        $hashtags = ((x($_REQUEST, 'tag')) ? $_REQUEST['tag'] : '');
        $order = ((x($_GET, 'order')) ? notags($_GET['order']) : 'post');
        $static = ((array_key_exists('static', $_REQUEST)) ? intval($_REQUEST['static']) : 0);
        $search = ((x($_GET, 'search')) ? $_GET['search'] : EMPTY_STR);
        $distance = 0;
        $distance_from = '';

        $groups = [];

        $o = '';

        if ($this->updating) {
            // Ensure we've got a profile owner if updating.
            App::$profile['profile_uid'] = App::$profile_uid = $this->profile_uid;
        }

        $is_owner = (((local_channel()) && (App::$profile['profile_uid'] == local_channel())) ? true : false);

        $channel = App::get_channel();
        $observer = App::get_observer();
        $ob_hash = (($observer) ? $observer['xchan_hash'] : '');

        $perms = get_all_perms(App::$profile['profile_uid'], $ob_hash);


        if ($this->loading && !$mid) {
            $_SESSION['loadtime_channel'] = datetime_convert();
            if ($is_owner) {
                PConfig::Set(local_channel(), 'system', 'loadtime_channel', $_SESSION['loadtime_channel']);
            }
        }


        if (!$perms['view_stream']) {
            // We may want to make the target of this redirect configurable
            if ($perms['view_profile']) {
                notice(t('Insufficient permissions.  Request redirected to profile page.') . EOL);
                goaway(z_root() . "/profile/" . App::$profile['channel_address']);
            }
            notice(t('Permission denied.') . EOL);
            return '';
        }


        if (!$this->updating) {
            Navbar::set_selected('Channel Home');

            $static = Zlib\Channel::manual_conv_update(App::$profile['profile_uid']);

            // search terms header
            if ($search) {
                $o .= replace_macros(Theme::get_template("section_title.tpl"), [
                    '$title' => t('Search Results For:') . ' ' . htmlspecialchars($search, ENT_COMPAT, 'UTF-8')
                ]);
            }

            $role = get_pconfig(App::$profile['profile_uid'], 'system', 'permissions_role');
            if ($role === 'social_restricted' && (!$ob_hash)) {
                // provide warning that content is probably hidden ?
            }

            if ($channel && $is_owner) {
                $channel_acl = [
                    'allow_cid' => $channel['channel_allow_cid'],
                    'allow_gid' => $channel['channel_allow_gid'],
                    'deny_cid' => $channel['channel_deny_cid'],
                    'deny_gid' => $channel['channel_deny_gid']
                ];
            } else {
                $channel_acl = ['allow_cid' => '', 'allow_gid' => '', 'deny_cid' => '', 'deny_gid' => ''];
            }


            if ($perms['post_wall']) {
                $x = [
                    'is_owner' => $is_owner,
                    'allow_location' => ((($is_owner || $observer) && (intval(get_pconfig(App::$profile['profile_uid'], 'system', 'use_browser_location')))) ? true : false),
                    'default_location' => (($is_owner) ? App::$profile['channel_location'] : ''),
                    'nickname' => App::$profile['channel_address'],
                    'lockstate' => (((strlen(App::$profile['channel_allow_cid'])) || (strlen(App::$profile['channel_allow_gid'])) || (strlen(App::$profile['channel_deny_cid'])) || (strlen(App::$profile['channel_deny_gid']))) ? 'lock' : 'unlock'),
                    'acl' => (($is_owner) ? Libacl::populate($channel_acl, true, PermissionDescription::fromGlobalPermission('view_stream'), Libacl::get_post_aclDialogDescription(), 'acl_dialog_post') : ''),
                    'permissions' => $channel_acl,
                    'showacl' => (($is_owner) ? 'yes' : ''),
                    'bang' => '',
                    'visitor' => (($is_owner || $observer) ? true : false),
                    'profile_uid' => App::$profile['profile_uid'],
                    'editor_autocomplete' => true,
                    'bbco_autocomplete' => 'bbcode',
                    'bbcode' => true,
                    'jotnets' => true,
                    'reset' => t('Reset form')
                ];

                $o .= status_editor($x);
            }

            if (!$mid && !$search) {
                $obj = new Pinned();
                $o .= $obj->widget([]);
            }
        }


        /**
         * Get permissions SQL
         */

        $item_normal = " and item.item_hidden = 0 and item.item_type = 0 and item.item_deleted = 0
		    and item.item_unpublished = 0 and item.item_pending_remove = 0
		    and item.item_blocked = 0 ";
        if (!$is_owner) {
            $item_normal .= "and item.item_delayed = 0 ";
        }
        $item_normal_update = item_normal_update();
        $sql_extra = item_permissions_sql(App::$profile['profile_uid']);

        if (get_pconfig(App::$profile['profile_uid'], 'system', 'channel_list_mode') && (!$mid)) {
            $page_mode = 'list';
        } else {
            $page_mode = 'client';
        }

        $abook_uids = " and abook.abook_channel = " . intval(App::$profile['profile_uid']) . " ";

        $simple_update = (($this->updating) ? " AND item_unseen = 1 " : '');

        if ($search) {
            $search = escape_tags($search);
            if (str_starts_with($search, '#')) {
                $sql_extra .= term_query('item', substr($search, 1), TERM_HASHTAG, TERM_COMMUNITYTAG);
            } else {
                $sql_extra .= sprintf(
                    " AND (item.body like '%s' OR item.title like '%s') ",
                    dbesc(protect_sprintf('%' . $search . '%')),
                    dbesc(protect_sprintf('%' . $search . '%'))
                );
            }
        }


        Head::add_link([
            'rel' => 'alternate',
            'type' => 'application/json+oembed',
            'href' => z_root() . '/oep?f=&url=' . urlencode(z_root() . '/' . App::$query_string),
            'title' => 'oembed'
        ]);

        if ($this->updating && isset($_SESSION['loadtime_channel'])) {
            $simple_update = " AND item.changed > '" . datetime_convert('UTC', 'UTC', $_SESSION['loadtime_channel']) . "' ";
        }
        if ($this->loading) {
            $simple_update = '';
        }

        if ($static && $simple_update) {
            $simple_update .= " and author_xchan = '" . protect_sprintf(get_observer_hash()) . "' ";
        }

        if (($this->updating) && (!$this->loading)) {
            if ($mid) {
                $r = q(
                    "SELECT parent AS item_id from item where mid like '%s' and uid = %d $item_normal_update
					AND item_wall = 1 $simple_update $sql_extra limit 1",
                    dbesc($mid . '%'),
                    intval(App::$profile['profile_uid'])
                );
            } else {
                $r = q(
                    "SELECT parent AS item_id from item
					left join abook on ( item.owner_xchan = abook.abook_xchan $abook_uids )
					WHERE uid = %d $item_normal_update
					AND item_wall = 1 $simple_update
					AND (abook.abook_blocked = 0 or abook.abook_flags is null)
					$sql_extra
					ORDER BY created DESC",
                    intval(App::$profile['profile_uid'])
                );
            }
        } else {
            if (x($category)) {
                $sql_extra2 .= protect_sprintf(term_item_parent_query(App::$profile['profile_uid'], 'item', $category, TERM_CATEGORY));
            }
            if (x($hashtags)) {
                $sql_extra2 .= protect_sprintf(term_item_parent_query(App::$profile['profile_uid'], 'item', $hashtags, TERM_HASHTAG, TERM_COMMUNITYTAG));
            }

            if ($datequery) {
                $sql_extra2 .= protect_sprintf(sprintf(" AND item.created <= '%s' ", dbesc(datetime_convert(date_default_timezone_get(), '', $datequery))));
                $order = 'post';
            }
            if ($datequery2) {
                $sql_extra2 .= protect_sprintf(sprintf(" AND item.created >= '%s' ", dbesc(datetime_convert(date_default_timezone_get(), '', $datequery2))));
            }

            if ($datequery || $datequery2) {
                $sql_extra2 .= " and item.item_thread_top != 0 ";
            }

            if ($order === 'post') {
                $ordering = "created";
            } else {
                $ordering = "commented";
            }

            $itemspage = get_pconfig(local_channel(), 'system', 'itemspage');
            App::set_pager_itemspage(((intval($itemspage)) ? $itemspage : 20));
            $pager_sql = sprintf(" LIMIT %d OFFSET %d ", intval(App::$pager['itemspage']), intval(App::$pager['start']));

            if ($noscript_content || $this->loading) {
                if ($mid) {
                    $r = q(
                        "SELECT parent AS item_id from item where mid like '%s' and uid = %d $item_normal
						AND item_wall = 1 $sql_extra limit 1",
                        dbesc($mid . '%'),
                        intval(App::$profile['profile_uid'])
                    );
                    if (!$r) {
                        notice(t('Permission denied.') . EOL);
                    }
                } else {
                    $r = q(
                        "SELECT DISTINCT item.parent AS item_id, $ordering FROM item 
						left join abook on ( item.author_xchan = abook.abook_xchan $abook_uids )
						WHERE true and item.uid = %d $item_normal
						AND (abook.abook_blocked = 0 or abook.abook_flags is null)
						AND item.item_wall = 1 AND item.item_thread_top = 1
						$sql_extra $sql_extra2 
						ORDER BY $ordering DESC $pager_sql ",
                        intval(App::$profile['profile_uid'])
                    );
                }
            } else {
                $r = [];
            }
        }
        if ($r) {
            $parents_str = ids_to_querystr($r, 'item_id');

            $items = q(
                "SELECT item.*, item.id AS item_id
				FROM item
				WHERE item.uid = %d $item_normal
				AND item.parent IN ( %s )
				$sql_extra ",
                intval(App::$profile['profile_uid']),
                dbesc($parents_str)
            );

            xchan_query($items);
            $items = fetch_post_tags($items);
            $items = conv_sort($items, $ordering);

            if ($this->loading && $mid && (!count($items))) {
                // This will happen if we don't have sufficient permissions
                // to view the parent item (or the item itself if it is toplevel)
                notice(t('Permission denied.') . EOL);
            }
        } else {
            $items = [];
        }

        if ((!$this->updating) && (!$this->loading)) {
            // This is ugly, but we can't pass the profile_uid through the session to the ajax updater,
            // because browser prefetching might change it on us. We have to deliver it with the page.

            $maxheight = get_pconfig(App::$profile['profile_uid'], 'system', 'channel_divmore_height');
            if (!$maxheight) {
                $maxheight = 400;
            }

            $o .= '<div id="live-channel"></div>' . "\r\n";
            $o .= "<script> var profile_uid = " . App::$profile['profile_uid']
                . "; var netargs = '?f='; var profile_page = " . App::$pager['page']
                . "; divmore_height = " . intval($maxheight) . "; </script>\r\n";

            App::$page['htmlhead'] .= replace_macros(Theme::get_template("build_query.tpl"), [
                '$baseurl' => z_root(),
                '$pgtype' => 'channel',
                '$uid' => ((App::$profile['profile_uid']) ? App::$profile['profile_uid'] : '0'),
                '$gid' => '0',
                '$cid' => '0',
                '$cmin' => '(-1)',
                '$cmax' => '(-1)',
                '$star' => '0',
                '$liked' => '0',
                '$conv' => '0',
                '$spam' => '0',
                '$nouveau' => '0',
                '$wall' => '1',
                '$draft' => '0',
                '$fh' => '0',
                '$dm' => '0',
                '$static' => $static,
                '$page' => ((App::$pager['page'] != 1) ? App::$pager['page'] : 1),
                '$search' => $search,
                '$xchan' => '',
                '$order' => (($order) ? urlencode($order) : ''),
                '$list' => ((x($_REQUEST, 'list')) ? intval($_REQUEST['list']) : 0),
                '$file' => '',
                '$cats' => (($category) ? urlencode($category) : ''),
                '$tags' => (($hashtags) ? urlencode($hashtags) : ''),
                '$mid' => (($mid) ? urlencode($mid) : ''),
                '$verb' => '',
                '$net' => '',
                '$dend' => $datequery,
                '$dbegin' => $datequery2,
                '$distance' => (($distance) ? intval($distance) : '0'),
                '$distance_from' => (($distance_from) ? urlencode($distance_from) : ''),
                '$maxtags' => '0',
                '$mintags' => '0',
            ]);
        }

        $update_unseen = '';

        if ($page_mode === 'list') {

            /**
             * in "list mode", only mark the parent item and any like activities as "seen".
             * We won't distinguish between comment likes and post likes. The important thing
             * is that the number of unseen comments will be accurate. The SQL to separate the
             * comment likes could also get somewhat hairy.
             */

            if (isset($parents_str) && $parents_str) {
                $update_unseen = " AND ( id IN ( " . dbesc($parents_str) . " )";
                $update_unseen .= " OR ( parent IN ( " . dbesc($parents_str) . " ) AND verb in ( '" . dbesc(ACTIVITY_LIKE) . "','" . dbesc(ACTIVITY_DISLIKE) . "' ))) ";
            }
        } else {
            if (isset($parents_str) && $parents_str) {
                $update_unseen = " AND parent IN ( " . dbesc($parents_str) . " )";
            }
        }

        if ($is_owner && $update_unseen && (!$_SESSION['sudo'])) {
            $x = ['channel_id' => local_channel(), 'update' => 'unset'];
            Hook::call('update_unseen', $x);
            if ($x['update'] === 'unset' || intval($x['update'])) {
                $r = q(
                    "UPDATE item SET item_unseen = 0 where item_unseen = 1 and item_wall = 1 AND uid = %d $update_unseen",
                    intval(local_channel())
                );
            }

            $ids = ids_to_array($items, 'item_id');
            $seen = $_SESSION['seen_items'];
            if (!$seen) {
                $seen = [];
            }
            $seen = array_values(array_unique(array_merge($ids, $seen)));
            $_SESSION['seen_items'] = $seen;
            PConfig::Set(local_channel(), 'system', 'seen_items', $seen);
        }

        $mode = (($search) ? 'search' : 'channel');

        if ($this->updating) {
            $o .= conversation($items, $mode, $this->updating, $page_mode);
        } else {
            $o .= '<noscript>';
            if ($noscript_content) {
                $o .= conversation($items, $mode, $this->updating, 'traditional');
                $o .= alt_pager(count($items));
            } else {
                $o .= '<div class="section-content-warning-wrapper">' . t('You must enable javascript for your browser to be able to view this content.') . '</div>';
            }
            $o .= '</noscript>';

            $o .= conversation($items, $mode, $this->updating, $page_mode);

            if ($mid && $items[0]['title']) {
                App::$page['title'] = $items[0]['title'] . " - " . App::$page['title'];
            }
        }

        // We reset $channel so that info can be obtained for unlogged visitors
        $channel = Zlib\Channel::from_id(App::$profile['profile_uid']);

        if (isset($_REQUEST['mid']) && $_REQUEST['mid']) {
            if (preg_match("/\[[zi]mg(.*?)]([^\[]+)/is", $items[0]['body'], $matches)) {
                $ogimage = $matches[2];
                //  Will we use og:image:type someday? We keep this just in case
                //  $ogimagetype = guess_image_type($ogimage);
            }

            // some work on post content to generate a description
            // almost fully based on work done on Hubzilla by Max Kostikov
            $ogdesc = $items[0]['body'];

            $ogdesc = str_replace("#^[", "[", $ogdesc);

            $ogdesc = bbcode($ogdesc, ['tryoembed' => false]);
            $ogdesc = trim(html2plain($ogdesc, 0, true));
            $ogdesc = html_entity_decode($ogdesc, ENT_QUOTES, 'UTF-8');

            // remove all URLs
            $ogdesc = preg_replace("/https?:\/\/[a-zA-Z0-9:\/\-?&;.=_~#%\$!+,@]+/", "", $ogdesc);

            // shorten description
            $ogdesc = substr($ogdesc, 0, 300);
            $ogdesc = str_replace("\n", " ", $ogdesc);
            while (str_contains($ogdesc, "  ")) {
                $ogdesc = str_replace("  ", " ", $ogdesc);
            }
            $ogdesc = (strlen($ogdesc) < 298 ? $ogdesc : rtrim(substr($ogdesc, 0, strrpos($ogdesc, " ")), "?.,:;!-") . "...");

            // we can now start loading content

            App::$meta->set('og:title', ($items[0]['title'] ? $items[0]['title'] : $channel['channel_name']));
            App::$meta->set('og:image', ($ogimage ? $ogimage : $channel['xchan_photo_l']));
            App::$meta->set('og:type', 'article');
            App::$meta->set('og:url:secure_url', Zlib\Channel::url($channel));
            App::$meta->set('og:description', ($ogdesc ? $ogdesc : sprintf(t('This post was published on the home page of %s.'), $channel['channel_name'])));
        }

        if ($mid) {
            $o .= '<div id="content-complete"></div>';
        }

        return $o;
    }
}