<?php

/**

 * HTTP Proxy connection interface

 *

 * @package Requests\Proxy

 * @since   1.6

 */

namespace WpOrg\Requests\Proxy;

use WpOrg\Requests\Exception\ArgumentCount;

use WpOrg\Requests\Exception\InvalidArgument;

use WpOrg\Requests\Hooks;

use WpOrg\Requests\Proxy;

/**

 * HTTP Proxy connection interface

 *

 * Provides a handler for connection via an HTTP proxy

 *

 * @package Requests\Proxy

 * @since   1.6

 */

final class Http implements Proxy {

	/**

	 * Proxy host and port

	 *

	 * Notation: "host:port" (eg 127.0.0.1:8080 or someproxy.com:3128)

	 *

	 * @var string

	 */

	public $proxy;

	/**

	 * Username

	 *

	 * @var string

	 */

	public $user;

	/**

	 * Password

	 *

	 * @var string

	 */

	public $pass;

	/**

	 * Do we need to authenticate? (ie username & password have been provided)

	 *

	 * @var boolean

	 */

	public $use_authentication;

	/**

	 * Constructor

	 *

	 * @since 1.6

	 *

	 * @param array|string|null $args Proxy as a string or an array of proxy, user and password.

	 *                                When passed as an array, must have exactly one (proxy)

	 *                                or three elements (proxy, user, password).

	 *

	 * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed argument is not an array, a string or null.

	 * @throws \WpOrg\Requests\Exception\ArgumentCount On incorrect number of arguments (`proxyhttpbadargs`)

	 */

	public function __construct($args = null) {

		if (is_string($args)) {

			$this->proxy = $args;

		} elseif (is_array($args)) {

			if (count($args) === 1) {

				list($this->proxy) = $args;

			} elseif (count($args) === 3) {

				list($this->proxy, $this->user, $this->pass) = $args;

				$this->use_authentication                    = true;

			} else {

				throw ArgumentCount::create(

					'an array with exactly one element or exactly three elements',

					count($args),

					'proxyhttpbadargs'

				);

			}

		} elseif ($args !== null) {

			throw InvalidArgument::create(1, '$args', 'array|string|null', gettype($args));

		}

	}

	/**

	 * Register the necessary callbacks

	 *

	 * @since 1.6

	 * @see \WpOrg\Requests\Proxy\Http::curl_before_send()

	 * @see \WpOrg\Requests\Proxy\Http::fsockopen_remote_socket()

	 * @see \WpOrg\Requests\Proxy\Http::fsockopen_remote_host_path()

	 * @see \WpOrg\Requests\Proxy\Http::fsockopen_header()

	 * @param \WpOrg\Requests\Hooks $hooks Hook system

	 */

	public function register(Hooks $hooks) {

		$hooks->register('curl.before_send', [$this, 'curl_before_send']);

		$hooks->register('fsockopen.remote_socket', [$this, 'fsockopen_remote_socket']);

		$hooks->register('fsockopen.remote_host_path', [$this, 'fsockopen_remote_host_path']);

		if ($this->use_authentication) {

			$hooks->register('fsockopen.after_headers', [$this, 'fsockopen_header']);

		}

	}

	/**

	 * Set cURL parameters before the data is sent

	 *

	 * @since 1.6

	 * @param resource|\CurlHandle $handle cURL handle

	 */

	public function curl_before_send(&$handle) {

		curl_setopt($handle, CURLOPT_PROXYTYPE, CURLPROXY_HTTP);

		curl_setopt($handle, CURLOPT_PROXY, $this->proxy);

		if ($this->use_authentication) {

			curl_setopt($handle, CURLOPT_PROXYAUTH, CURLAUTH_ANY);

			curl_setopt($handle, CURLOPT_PROXYUSERPWD, $this->get_auth_string());

		}

	}

	/**

	 * Alter remote socket information before opening socket connection

	 *

	 * @since 1.6

	 * @param string $remote_socket Socket connection string

	 */

	public function fsockopen_remote_socket(&$remote_socket) {

		$remote_socket = $this->proxy;

	}

	/**

	 * Alter remote path before getting stream data

	 *

	 * @since 1.6

	 * @param string $path Path to send in HTTP request string ("GET ...")

	 * @param string $url Full URL we're requesting

	 */

	public function fsockopen_remote_host_path(&$path, $url) {

		$path = $url;

	}

	/**

	 * Add extra headers to the request before sending

	 *

	 * @since 1.6

	 * @param string $out HTTP header string

	 */

	public function fsockopen_header(&$out) {

		$out .= sprintf("Proxy-Authorization: Basic %s\r\n", base64_encode($this->get_auth_string()));

	}

	/**

	 * Get the authentication string (user:pass)

	 *

	 * @since 1.6

	 * @return string

	 */

	public function get_auth_string() {

		return $this->user . ':' . $this->pass;

	}

}