<?php

declare(strict_types=1);

/**

* Response information module.

*

* This file is part of MadelineProto.

* MadelineProto 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.

* MadelineProto 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 General Public License along with MadelineProto.

* If not, see <http://www.gnu.org/licenses/>.

*

* @author Daniil Gentili <daniil@daniil.it>

* @copyright 2016-2025 Daniil Gentili <daniil@daniil.it>

* @license https://opensource.org/licenses/AGPL-3.0 AGPLv3

* @link https://docs.madelineproto.xyz MadelineProto documentation

*/

namespace danog\MadelineProto\MTProtoTools;

use Amp\Http\HttpStatus;

use danog\MadelineProto\Lang;

/**

* Obtain response information for file to server.

*

* @internal

*/

final class ResponseInfo

{

private const NO_CACHE = [

'Cache-Control' => ['no-store, no-cache, must-revalidate, max-age=0', 'post-check=0, pre-check=0'],

'Pragma' => 'no-cache',

];

/**

* Whether to serve file.

*/

private bool $serve = false;

/**

* Serving range.

*/

private array $serveRange = [];

/**

* HTTP response code.

*/

private int $code = HttpStatus::OK;

/**

* Header array.

*

* @var array<non-empty-string, string|list<string>>

*/

private array $headers = [];

/**

* Parse headers.

*

* @param string $method HTTP method

* @param array $headers HTTP headers

* @param array|int $messageMedia Media info

*/

private function __construct(string $method, array $headers, array|int $messageMedia)

{

if (\is_int($messageMedia)) {

$this->code = $messageMedia;

$this->serve = false;

$this->headers = self::NO_CACHE;

return;

}

if (isset($headers['range'])) {

$range = explode('=', $headers['range'], 2);

if (\count($range) == 1) {

$range[1] = '';

}

[$size_unit, $range_orig] = $range;

if ($size_unit == 'bytes') {

//multiple ranges could be specified at the same time, but for simplicity only serve the first range

//http://tools.ietf.org/id/draft-ietf-http-range-retrieval-00.txt

$list = explode(',', $range_orig, 2);

if (\count($list) == 1) {

$list[1] = '';

}

[$range, $extra_ranges] = $list;

} else {

$this->serve = false;

$this->code = HttpStatus::RANGE_NOT_SATISFIABLE;

$this->headers = self::NO_CACHE;

return;

}

} else {

$range = '';

}

$listseek = explode('-', $range, 2);

if (\count($listseek) == 1) {

$listseek[1] = '';

}

[$seek_start, $seek_end] = $listseek;

$size = $messageMedia['size'] ?? 0;

$seek_end = empty($seek_end) ? ($size - 1) : min(abs(\intval($seek_end)), $size - 1);

if (!empty($seek_start) && $seek_end < abs(\intval($seek_start))) {

$this->serve = false;

$this->code = HttpStatus::RANGE_NOT_SATISFIABLE;

$this->headers = self::NO_CACHE;

return;

}

$seek_start = empty($seek_start) ? 0 : abs(\intval($seek_start));

$isSafari = !empty($headers['user-agent']) && preg_match('/^((?!chrome|android).)*safari/i', $headers['user-agent']);

if ($range !== '' && $isSafari) {

//Safari video streaming fix

$length = ($seek_end - $seek_start + 1);

$maxChunkSize = 10 * 1024 ** 2;

if ($length > $maxChunkSize) {

$seek_end = $seek_start + $maxChunkSize - 1;

}

}

$this->serve = $method !== 'HEAD';

if ($seek_start > 0 || $seek_end < $size - 1) {

$this->code = HttpStatus::PARTIAL_CONTENT;

$this->headers['Content-Range'] = "bytes $seek_start-$seek_end/$size";

$this->headers['Content-Length'] = (string) ($seek_end - $seek_start + 1);

} elseif ($size > 0) {

$this->headers['Content-Length'] = (string) $size;

}

$this->headers['Content-Type'] = (string) $messageMedia['mime'];

$this->headers['Cache-Control'] = 'max-age=31556926';

$this->headers['Content-Transfer-Encoding'] = 'Binary';

$this->headers['Accept-Ranges'] = 'bytes';

if ($this->serve) {

if ($seek_start === 0 && $seek_end === -1) {

$this->serveRange = [0, -1];

} else {

$this->serveRange = [$seek_start, $seek_end + 1];

}

if (!empty($messageMedia['name']) && !empty($messageMedia['ext'])) {

$this->headers["Content-Disposition"] = "inline; filename=\"{$messageMedia['name']}{$messageMedia['ext']}\"";

}

}

}

/**

* Parse headers.

*

* @param string $method HTTP method

* @param array $headers HTTP headers

* @param array $messageMedia Media info

*/

public static function parseHeaders(string $method, array $headers, array $messageMedia): self

{

return new self($method, $headers, $messageMedia);

}

public static function error(int $code): self

{

return new self('', [], $code);

}

/**

* Get explanation for HTTP code.

*/

public function getCodeExplanation(): string

{

$reason = HttpStatus::getReason($this->code);

$body = "<html lang='en'><body><h1>{$this->code} $reason</h1>";

if ($this->code === HttpStatus::RANGE_NOT_SATISFIABLE) {

$body .= '<p>Could not use selected range.</p>';

}

if ($this->code === HttpStatus::BAD_GATEWAY) {

$body .= "<h2 style='color:red;'>".Lang::$current_lang["dl.php_check_logs_make_sure_session_running"].'</h2>';

}

$body .= '<small>'.Lang::$current_lang["dl.php_powered_by_madelineproto"].'</small>';

$body .= '</body></html>';

return $body;

}

/**

* Whether to serve file.

*

* @return bool Whether to serve file

*/

public function shouldServe(): bool

{

return $this->serve;

}

/**

* Get serving range.

*

* @return array HTTP serving range

*/

public function getServeRange(): array

{

return $this->serveRange;

}

/**

* Get HTTP response code.

*

* @return int HTTP response code

*/

public function getCode(): int

{

return $this->code;

}

/**

* Get header array.

*

* @return array<non-empty-string, string|list<string>> Header array

*/

public function getHeaders(): array

{

return $this->headers;

}

/**

* Write headers.

*/

public function writeHeaders(): void

{

http_response_code($this->getCode());

foreach ($this->getHeaders() as $key => $value) {

if (\is_array($value)) {

foreach ($value as $subValue) {

header("$key: $subValue", false);

}

} else {

header("$key: $value");

}

}

}

}