<?php
/**
 * HttpProxy 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 2016-2018 Daniil Gentili <daniil@daniil.it>
 * @license   https://opensource.org/licenses/AGPL-3.0 AGPLv3
 *
 * @link      https://docs.madelineproto.xyz MadelineProto documentation
 */
class HttpProxy implements \danog\MadelineProto\Proxy
{
    private $domain;
    private $type;
    private $protocol;
    private $extra;
    private $sock;

    public function __construct(int $domain, int $type, int $protocol)
    {
        if (!in_array($domain, [AF_INET, AF_INET6])) {
            throw new \danog\MadelineProto\Exception('Wrong protocol family provided');
        }
        if (!in_array($type, [SOCK_STREAM])) {
            throw new \danog\MadelineProto\Exception('Wrong connection type provided');
        }
        if (!in_array($protocol, [getprotobyname('tcp'), PHP_INT_MAX])) {
            throw new \danog\MadelineProto\Exception('Wrong protocol provided');
        }
        $this->domain = $domain;
        $this->type = $type;
        $this->protocol = $protocol;
    }

    public function setExtra(array $extra = [])
    {
        $this->extra = $extra;
        $name = $this->protocol === PHP_INT_MAX ? '\\FSocket' : '\\Socket';
        $this->sock = new $name(strlen(@inet_pton($this->extra['address'])) !== 4 ? \AF_INET6 : \AF_INET, \SOCK_STREAM, $this->protocol);
    }

    public function setOption(int $level, int $name, $value)
    {
        return $this->sock->setOption($level, $name, $value);
    }

    public function getOption(int $level, int $name)
    {
        return $this->sock->getOption($level, $name);
    }

    public function setBlocking(bool $blocking)
    {
        return $this->sock->setBlocking($blocking);
    }

    public function bind(string $address, int $port = 0)
    {
        throw new \danog\MadelineProto\Exception('Not Implemented');
    }

    public function listen(int $backlog = 0)
    {
        throw new \danog\MadelineProto\Exception('Not Implemented');
    }

    public function accept()
    {
        throw new \danog\MadelineProto\Exception('Not Implemented');
    }

    public function select(array &$read, array &$write, array &$except, int $tv_sec, int $tv_usec = 0)
    {
        return $this->sock->select($read, $write, $except, $tv_sec, $tv_usec);
    }

    public function connect(string $address, int $port = 0)
    {
        $this->sock->connect($this->extra['address'], $this->extra['port']);

        try {
            if (strlen(inet_pton($address)) !== 4) {
                $address = '['.$address.']';
            }
        } catch (\danog\MadelineProto\Exception $e) {
        }
        $this->sock->write("CONNECT $address:$port HTTP/1.1\r\nHost: $address:$port\r\nAccept: */*\r\n".$this->getProxyAuthHeader()."Connection: keep-Alive\r\n\r\n");
        $response = $this->read_http_payload();
        if ($response['code'] !== 200) {
            \danog\MadelineProto\Logger::log(trim($response['body']));

            throw new \danog\MadelineProto\Exception($response['description'], $response['code']);
        }
        \danog\MadelineProto\Logger::log('Connected to '.$address.':'.$port.' via http');

        return true;
    }

    public function read_http_line()
    {
        $line = $lastchar = $curchar = '';
        while ($lastchar.$curchar !== "\r\n") {
            $line .= $lastchar;
            $lastchar = $curchar;
            $curchar = $this->sock->read(1);
        }

        return $line;
    }

    public function read_http_payload()
    {
        list($protocol, $code, $description) = explode(' ', $this->read_http_line(), 3);
        list($protocol, $protocol_version) = explode('/', $protocol);
        if ($protocol !== 'HTTP') {
            throw new \danog\MadelineProto\Exception('Wrong protocol');
        }
        $code = (int) $code;
        $headers = [];
        while (strlen($current_header = $this->read_http_line())) {
            $current_header = explode(':', $current_header, 2);
            $headers[strtolower($current_header[0])] = trim($current_header[1]);
        }

        $read = '';
        if (isset($headers['content-length'])) {
            $read = $this->sock->read((int) $headers['content-length']);
        }/* elseif (isset($headers['transfer-encoding']) && $headers['transfer-encoding'] === 'chunked') {
            do {
                $length = hexdec($this->read_http_line());
                $read .= $this->sock->read($length);
                $this->read_http_line();
            } while ($length);
        }*/

        return ['protocol' => $protocol, 'protocol_version' => $protocol_version, 'code' => $code, 'description' => $description, 'body' => $read, 'headers' => $headers];
    }

    public function read(int $length, int $flags = 0)
    {
        return $this->sock->read($length, $flags);
    }

    public function write(string $buffer, int $length = -1)
    {
        return $this->sock->write($buffer, $length);
    }

    public function send(string $data, int $length, int $flags)
    {
        throw new \danog\MadelineProto\Exception('Not Implemented');
    }

    public function close()
    {
        $this->sock->close();
    }

    public function getPeerName(bool $port = true)
    {
        throw new \danog\MadelineProto\Exception('Not Implemented');
    }

    public function getSockName(bool $port = true)
    {
        throw new \danog\MadelineProto\Exception('Not Implemented');
    }

    private function getProxyAuthHeader()
    {
        if (!isset($this->extra['username']) || !isset($this->extra['password'])) {
            return '';
        }

        return 'Proxy-Authorization: Basic '.base64_encode($this->extra['username'].':'.$this->extra['password'])."\r\n";
    }

    public function getProxyHeaders()
    {
        return '';
    }

    public function getResource()
    {
        return $this->sock->getResource();
    }
}