<?php
define('SERIA_ROOT', __DIR__);
define('SERIA_STARTUP', microtime(true));
define('SERIA_DEBUG', is_file(SERIA_ROOT . '/.debug'));
define('SERIA_SRC', SERIA_ROOT . '/src');
define('SERIA_ERRORS', SERIA_ROOT . '/errors.log');
define('SERIA_VERSION', '1.0');

ini_set('display_errors', 'on');

if(SERIA_DEBUG) {
    set_error_handler(function($errno, $errstr, $errfile, $errline) {
        if(!is_file(SERIA_ERRORS))
            touch(SERIA_ERRORS);
        file_put_contents(SERIA_ERRORS, sprintf("(%s) [%s:%s] %s\r\n", date('Y-m-d H:i:s'), $errfile, $errline, $errstr), FILE_APPEND);
    }, -1);
} else error_reporting(0);

require_once SERIA_ROOT . '/config.php';

try {
    $pdo = new PDO(SERIA_PDO_DSN, SERIA_PDO_USER, SERIA_PDO_PASS, [
        PDO::ATTR_CASE => PDO::CASE_NATURAL,
        PDO::ATTR_ERRMODE => PDO::ERRMODE_WARNING,
        PDO::ATTR_ORACLE_NULLS => PDO::NULL_NATURAL,
        PDO::ATTR_STRINGIFY_FETCHES => false,
        PDO::ATTR_EMULATE_PREPARES => false,
        PDO::MYSQL_ATTR_INIT_COMMAND => 'SET SESSION time_zone = \'+00:00\''
            . ', sql_mode = \'STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION\'',
    ]);
} catch(PDOException $ex) {
    die($ex->getMessage());
}

require_once SERIA_SRC . '/user.php';
require_once SERIA_SRC . '/benben.php';
require_once SERIA_SRC . '/torrent.php';
require_once SERIA_SRC . '/announce.php';

header('X-Powered-By: Seria/' . SERIA_VERSION);

$sInAnnounce = $_SERVER['SCRIPT_NAME'] === '/announce.php';
$sIsIPv4 = strlen(inet_pton($_SERVER['REMOTE_ADDR'])) === 4;

if(!$sInAnnounce && !$sIsIPv4)
    die('The tracker is only supported over IPv4, please reset your DNS cache.');

$sUserInfo = SeriaUser::anonymous();
$sVerification = '';

if(!$sInAnnounce) {
    // replace this with id.flashii.net shit
    $mszAuth = (string)filter_input(INPUT_COOKIE, 'msz_auth');
    if(!empty($mszAuth)) {
        $loginMethod = 'Misuzu';
        $loginSignature = sprintf('verify#%s#%s#%s', $loginMethod, $mszAuth, $_SERVER['REMOTE_ADDR']);
        $loginSignature = hash_hmac('sha256', $loginSignature, SERIA_MSZ_SECRET);

        $login = curl_init(SERIA_CAUTH_ENDPOINT);
        curl_setopt_array($login, [
            CURLOPT_AUTOREFERER => false,
            CURLOPT_FAILONERROR => false,
            CURLOPT_FOLLOWLOCATION => true,
            CURLOPT_HEADER => false,
            CURLOPT_POST => true,
            CURLOPT_POSTFIELDS => http_build_query([
                'method' => $loginMethod,
                'token' => $mszAuth,
                'ipaddr' => $_SERVER['REMOTE_ADDR'],
            ], '', '&', PHP_QUERY_RFC3986),
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TCP_FASTOPEN => true,
            CURLOPT_CONNECTTIMEOUT => 2,
            CURLOPT_MAXREDIRS => 2,
            CURLOPT_PROTOCOLS => CURLPROTO_HTTPS,
            CURLOPT_TIMEOUT => 5,
            CURLOPT_USERAGENT => 'Seria/' . SERIA_VERSION,
            CURLOPT_HTTPHEADER => [
                'Content-Type: application/x-www-form-urlencoded',
                'X-SharpChat-Signature: ' . $loginSignature,
            ],
        ]);
        $loginResponse = json_decode(curl_exec($login));
        curl_close($login);

        if(!empty($loginResponse->success))
            $sUserInfo = SeriaUser::fromMisuzu($pdo, $loginResponse);

        unset($mszAuth, $loginMethod, $loginSignature, $loginMethod, $login, $loginResponse);
    }

    if(empty($_COOKIE['seria_random'])) {
        $sVerification = SeriaUser::generatePassKey(32);
        setcookie('seria_random', $sVerification, strtotime('1 day'), '/', $_SERVER['HTTP_HOST']);
    } else
        $sVerification = (string)filter_input(INPUT_COOKIE, 'seria_random');

    $sVerification = hash('sha256', $sVerification);
}

function byte_symbol(int $bytes, bool $decimal = true, array $symbols = ['', 'K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y']): string {
    if($bytes < 1)
        return '0 B';

    $divider = $decimal ? 1000 : 1024;
    $exp = floor(log($bytes) / log($divider));
    $bytes = $bytes / pow($divider, $exp);
    $symbol = $symbols[$exp];

    return sprintf("%.2f %s%sB", $bytes, $symbol, $symbol !== '' && !$decimal ? 'i' : '');
}

function seria_weighted_number(float $num1, float $num2, float $weight): int {
    $weight = min(1, max(0, $weight));
    return round(($num1 * $weight) + ($num2 * (1 - $weight)));
}

function seria_weighted_colour(int $colour1, int $colour2, float $weight): int {
    $colour1 = [ ($colour1 >> 16) & 0xFF, ($colour1 >> 8) & 0xFF, $colour1 & 0xFF ];
    $colour2 = [ ($colour2 >> 16) & 0xFF, ($colour2 >> 8) & 0xFF, $colour2 & 0xFF ];
    return (seria_weighted_number($colour1[0], $colour2[0], $weight) << 16)
         | (seria_weighted_number($colour1[1], $colour2[1], $weight) << 8)
         |  seria_weighted_number($colour1[2], $colour2[2], $weight);
}

function seria_weighted_colour_hex(int $colour1, int $colour2, float $weight): string {
    return sprintf('#%06x', seria_weighted_colour($colour1, $colour2, $weight));
}

function seria_easeInQuad(float $n): float {
    return $n * $n;
}

function seria_easeOutQuad(float $n): float {
    return 1 - (1 - $n) * (1 - $n);
}

function seria_ratio_colour(float $ratio): string {
    $ratio *= 2;
    if($ratio > 1)
        return seria_weighted_colour_hex(0x008000, 0xFFAA00, seria_easeInQuad($ratio - 1));
    return seria_weighted_colour_hex(0xFFAA00, 0xFF0000, seria_easeOutQuad($ratio));
}

function seria_size_colour(int $bytes): string {
    if($bytes >= 53687090000)
        return '#ec32a4';
    if($bytes >= 21474840000)
        return '#db5ff1';
    if($bytes >= 10737420000)
        return '#cca1f4';
    if($bytes >= 5368709000)
        return '#cdd';
    if($bytes >= 1073742000)
        return '#bae9c7';
    return '#a0f5b8';
}