<?php
    function get_base_url($url)
    {
        $split_url = explode("/", $url);
        $base_url = $split_url[0] . "//" . $split_url[2] . "/";
        return $base_url;
    }

    function try_replace_with_frontend($url, $frontend, $original)
    {
        $config = require "config.php";

        if (isset($_COOKIE[$frontend]) || isset($_REQUEST[$frontend]) || !empty($config->$frontend))
        {
            if (isset($_COOKIE[$frontend]))
                $frontend = $_COOKIE[$frontend];
            else if (isset($_REQUEST[$frontend]))
                $frontend = $_REQUEST[$frontend];
            else if (!empty($config->$frontend))
                $frontend = $config->$frontend;

            if ($original == "instagram.com")
            {
                if (!strpos($url, "/p/"))
                    $frontend .= "/u";
            }

            if (empty(trim($frontend)))
                return $url;

            if (strpos($url, "wikipedia.org") !== false)
            {
                $wiki_split = explode(".", $url);
                if (count($wiki_split) > 1)
                {
                    $lang = explode("://", $wiki_split[0])[1];
                    $url =  $frontend . explode($original, $url)[1] . "?lang=" . $lang;
                }
            }
            else
            {
                $url =  $frontend . explode($original, $url)[1];
            }

            return $url;
        }

        return $url;
    }

    function check_for_privacy_frontend($url)
    {
        if (isset($_COOKIE["disable_frontends"]))
            return $url;

        $frontends = array(
            "youtube.com" => "invidious",
            "instagram.com" => "bibliogram",
            "twitter.com" => "nitter",
            "reddit.com" => "libreddit",
            "tiktok.com" => "proxitok",
            "wikipedia.org" => "wikiless",
            "quora.com" => "quetre",
            "imdb.com" => "libremdb"
        );

        foreach($frontends as $original => $frontend)
        {
            if (strpos($url, $original))
            {
                $url = try_replace_with_frontend($url, $frontend, $original);
                break;
            }
        }

        return $url;
    }

    function check_ddg_bang($query)
    {

        $bangs_json = file_get_contents("static/misc/ddg_bang.json");
        $bangs = json_decode($bangs_json, true);

        if (substr($query, 0, 1) == "!")
            $search_word = substr(explode(" ", $query)[0], 1);
        else
            $search_word = substr(end(explode(" ", $query)), 1);
        
        $bang_url = null;

        foreach($bangs as $bang)
        {
            if ($bang["t"] == $search_word)
            {
                $bang_url = $bang["u"];
                break;
            }
        }

        if ($bang_url)
        {
            $bang_query_array = explode("!" . $search_word, $query);
            $bang_query = trim(implode("", $bang_query_array));

            $request_url = str_replace("{{{s}}}", $bang_query, $bang_url);
            $request_url = check_for_privacy_frontend($request_url);

            header("Location: " . $request_url);
            die();
        }
    }

    function check_for_special_search($query)
    {
        if (isset($_COOKIE["disable_special"]) || isset($_REQUEST["disable_special"]))
            return 0;

         $query_lower = strtolower($query);
         $split_query = explode(" ", $query);

         if (strpos($query_lower, "to") && count($split_query) >= 4) // currency
         {
            $amount_to_convert = floatval($split_query[0]);
            if ($amount_to_convert != 0)
                return 1;
         }
         else if (strpos($query_lower, "mean") && count($split_query) >= 2) // definition
         {
             return 2;
         }
         else if (strpos($query_lower, "my") !== false)
         {
            if (strpos($query_lower, "ip"))
            {
                return 3;
            }
            else if (strpos($query_lower, "user agent") || strpos($query_lower, "ua"))
            {
                return 4;
            }
         }
         else if (strpos($query_lower, "weather") !== false)
         {
                return 5;
         }
         else if ($query_lower == "tor")
         {
                return 6;
         }
         else if (3 > count(explode(" ", $query))) // wikipedia
         {
             return 7;
         }

        return 0;
    }

    function get_xpath($response)
    {
        $htmlDom = new DOMDocument;
        @$htmlDom->loadHTML($response);
        $xpath = new DOMXPath($htmlDom);

        return $xpath;
    }

    function request($url)
    {
        global $config;

        $ch = curl_init($url);
        curl_setopt_array($ch, $config->curl_settings);
        $response = curl_exec($ch);

        return $response;
    }

    function human_filesize($bytes, $dec = 2)
    {
        $size   = array('B', 'kB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB');
        $factor = floor((strlen($bytes) - 1) / 3);

        return sprintf("%.{$dec}f ", $bytes / pow(1024, $factor)) . @$size[$factor];
    }

    function remove_special($string)
    {
        $string = preg_replace("/[\r\n]+/", "\n", $string);
        return trim(preg_replace("/\s+/", ' ', $string));
     }

    function print_elapsed_time($start_time)
        {
            $end_time = number_format(microtime(true) - $start_time, 2, '.', '');
            echo "<p id=\"time\">Fetched the results in $end_time seconds</p>";
        }

    function print_next_page_button($text, $page, $query, $type)
    {
        echo "<form class=\"page\" action=\"search.php\" target=\"_top\" method=\"get\" autocomplete=\"off\">";
        foreach($_REQUEST as $key=>$value)
        {
            if ($key != "q" && $key != "p" && $key != "t")
            {
                echo "<input type=\"hidden\" name=\"$key\" value=\"$value\"/>";
            }
        }
        echo "<input type=\"hidden\" name=\"p\" value=\"" . $page . "\" />";
        echo "<input type=\"hidden\" name=\"q\" value=\"$query\" />";
        echo "<input type=\"hidden\" name=\"t\" value=\"$type\" />";
        echo "<button type=\"submit\">$text</button>";
        echo "</form>";
    }
?>