<?php

$debug = ($_GET['d'] ?? "0") == 1;


if ($debug) {
    ini_set('display_errors', 1);
    ini_set('display_startup_errors', 1);
    error_reporting(E_ALL);
}
function d() {
    echo "<pre>";
    call_user_func_array('var_dump', func_get_args());
}

function dd() {   
    call_user_func_array('d', func_get_args());
    die();
}


class HttpException extends Exception {}


function http_get($url, $accept='application/activity+json') {
    $options = [
        CURLOPT_RETURNTRANSFER => true,   // return web page
        CURLOPT_HEADER         => false,  // don't return headers
        CURLOPT_FOLLOWLOCATION => true,   // follow redirects
        CURLOPT_MAXREDIRS      => 10,     // stop after 10 redirects
        CURLOPT_ENCODING       => "",     // handle compressed
        CURLOPT_USERAGENT      => "apthread", // name of client
        CURLOPT_AUTOREFERER    => true,   // set referrer on redirect
        CURLOPT_CONNECTTIMEOUT => 120,    // time-out on connect
        CURLOPT_TIMEOUT        => 120,    // time-out on response
    ];

    $headers = [
        "Accept: $accept",
    ];

    $ch = curl_init($url);
    curl_setopt_array($ch, $options);
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    $server_output = curl_exec ($ch);
    $res = curl_getinfo($ch);
    curl_close ($ch);

    if ($res['http_code'] >= 400) {
        throw new HttpException("HTTP Error " . $res['http_code']);
    }
    return $server_output;
}

function as_obj($data) {
    if (is_array($data)) {
        return $data;
    }
    elseif (is_string($data)) {
        try {
            return json_decode(http_get($data), true);
        } catch (HttpException $e) {
            error($e->getMessage());
        }
    }
    return null;
}

function as_url($obj) {
    if (is_array($obj)) return $obj['id'];
    return $obj;
}

function get_first_reply($obj) {
    $replies = as_obj($obj['replies'] ?? null);
    if (is_null($replies)) return null;

    $page = as_obj($replies['first']);
    $items = $page['items'] ?? [];
    if (count($items) > 0) {
        return as_obj($items[0]);
    }

    return null;
}

function title($obj, $max=8) {
    // $t = preg_replace("|<[^>]*>|", "", $obj['content']);
    $t = $obj['summary'] ?? "";
    if ($t != "")
        return $t;
    $t = $obj['content'];
    $t = preg_replace("%(</p>|br\w*/?>)%", "\$1\n", $t);
    $t = explode("\n", trim($t))[0];
    $t = strip_tags($t);
    $t = html_entity_decode($t);
    $t = preg_split("|[.!?(\[{]|", $t)[0];
    $ta = preg_split("|\s+|", $t);
    $tb = array_slice($ta, 0, $max);
    $t = implode(" ", $tb);
    if (count($ta) > $max) $t = $t . "...";
    //$t = htmlentities($t);
    return $t;
}

$ogcache = [];
function get_opengraph($url) {
    // twitter to nitter
    $url = str_replace("https://twitter.com/", "https://nitter.net/", $url);

    if (isset($ogcache[$url])) {
        return $ogcache[$url];
    }

    try {
        $page = http_get($url, 'text/*');
    } catch (HttpException $e) {
        return null;
    }
    return parse_opengraph($page, $url);
}

function parse_opengraph($page, $url) {
    if (! strpos(trim($page), '<?xml') !== 0) {
        // force utf8. looks like load html doesn't read encoding from html tags
        $page = '<' .'?xml encoding="utf-8" ?' .'>'.$page;
    }

    $dom = new DomDocument();
    $dom->loadHTML($page, LIBXML_NONET|LIBXML_NOERROR|LIBXML_NOWARNING);
    $xpath = new DOMXpath($dom);

    // defaults from page
    $parsed = parse_url($url,  PHP_URL_HOST);
    $data = [
        'og:type' => 'article',
        'og:url' => $url,
        'og:title' => $url,
        'og:site_name' => parse_url($url,  PHP_URL_HOST),
    ];
    $items = $xpath->query('//title');
    if ($items->length > 0) {
        $data['og:title'] = $items->item(0)->nodeValue;
    }

    // look for opengraph meta tags
    $items = $xpath->query('//meta[starts-with(@property, "og:")]');
    if ($items->length > 0) {
        for ($i = 0; $i < $items->length; $i++) {
            $key = $items->item($i)->attributes->getNamedItem('property')->value;
            $value = $items->item($i)->attributes->getNamedItem('content')->value;
            $data[$key] = $value;
        }
    }
    $ogcache[$url] = $data;
    return $data;
}


function first_url_in_text($obj) {
    $t = preg_replace('|<br[ /]*>|', "\n", $obj['content']);
    $t = preg_replace("|</p>([^\n])|", "</p>\n\$1", $obj['content']);
    $t = strip_tags($t);
    $toks  = preg_split('|(https?://)|', $t, 2, PREG_SPLIT_DELIM_CAPTURE);
    if (isset($toks[2])){
        [$_, $prot, $res] = $toks;
        $toks = preg_split('|[^A-Za-z0-9._~:\/?#[\]@!$\'()*+,;=-]|', $res, 2);
        $url = $toks[0];
        return  $prot . $url;
    }
    return null;
}


function error($error) {
    global $body, $footer, $title;
    $title .= " - Error";
    $body .= "<p>$error</p>";
    include "page.tpl.php";
    die();
}