<?php

/**

 * cURL HTTP transport

 *

 * @package Requests\Transport

 */

namespace WpOrg\Requests\Transport;

use RecursiveArrayIterator;

use RecursiveIteratorIterator;

use WpOrg\Requests\Capability;

use WpOrg\Requests\Exception;

use WpOrg\Requests\Exception\InvalidArgument;

use WpOrg\Requests\Exception\Transport\Curl as CurlException;

use WpOrg\Requests\Requests;

use WpOrg\Requests\Transport;

use WpOrg\Requests\Utility\InputValidator;

/**

 * cURL HTTP transport

 *

 * @package Requests\Transport

 */

final class Curl implements Transport {

	const CURL_7_10_5 = 0x070A05;

	const CURL_7_16_2 = 0x071002;

	/**

	 * Raw HTTP data

	 *

	 * @var string

	 */

	public $headers = '';

	/**

	 * Raw body data

	 *

	 * @var string

	 */

	public $response_data = '';

	/**

	 * Information on the current request

	 *

	 * @var array cURL information array, see {@link https://www.php.net/curl_getinfo}

	 */

	public $info;

	/**

	 * cURL version number

	 *

	 * @var int

	 */

	public $version;

	/**

	 * cURL handle

	 *

	 * @var resource|\CurlHandle Resource in PHP < 8.0, Instance of CurlHandle in PHP >= 8.0.

	 */

	private $handle;

	/**

	 * Hook dispatcher instance

	 *

	 * @var \WpOrg\Requests\Hooks

	 */

	private $hooks;

	/**

	 * Have we finished the headers yet?

	 *

	 * @var boolean

	 */

	private $done_headers = false;

	/**

	 * If streaming to a file, keep the file pointer

	 *

	 * @var resource

	 */

	private $stream_handle;

	/**

	 * How many bytes are in the response body?

	 *

	 * @var int

	 */

	private $response_bytes;

	/**

	 * What's the maximum number of bytes we should keep?

	 *

	 * @var int|bool Byte count, or false if no limit.

	 */

	private $response_byte_limit;

	/**

	 * Constructor

	 */

	public function __construct() {

		$curl          = curl_version();

		$this->version = $curl['version_number'];

		$this->handle  = curl_init();

		curl_setopt($this->handle, CURLOPT_HEADER, false);

		curl_setopt($this->handle, CURLOPT_RETURNTRANSFER, 1);

		if ($this->version >= self::CURL_7_10_5) {

			curl_setopt($this->handle, CURLOPT_ENCODING, '');

		}

		if (defined('CURLOPT_PROTOCOLS')) {

			// phpcs:ignore PHPCompatibility.Constants.NewConstants.curlopt_protocolsFound

			curl_setopt($this->handle, CURLOPT_PROTOCOLS, CURLPROTO_HTTP | CURLPROTO_HTTPS);

		}

		if (defined('CURLOPT_REDIR_PROTOCOLS')) {

			// phpcs:ignore PHPCompatibility.Constants.NewConstants.curlopt_redir_protocolsFound

			curl_setopt($this->handle, CURLOPT_REDIR_PROTOCOLS, CURLPROTO_HTTP | CURLPROTO_HTTPS);

		}

	}

	/**

	 * Destructor

	 */

	public function __destruct() {

		if (is_resource($this->handle)) {

			curl_close($this->handle);

		}

	}

	/**

	 * Perform a request

	 *

	 * @param string|Stringable $url URL to request

	 * @param array $headers Associative array of request headers

	 * @param string|array $data Data to send either as the POST body, or as parameters in the URL for a GET/HEAD

	 * @param array $options Request options, see {@see \WpOrg\Requests\Requests::response()} for documentation

	 * @return string Raw HTTP result

	 *

	 * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed $url argument is not a string or Stringable.

	 * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed $headers argument is not an array.

	 * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed $data parameter is not an array or string.

	 * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed $options argument is not an array.

	 * @throws \WpOrg\Requests\Exception       On a cURL error (`curlerror`)

	 */

	public function request($url, $headers = [], $data = [], $options = []) {

		if (InputValidator::is_string_or_stringable($url) === false) {

			throw InvalidArgument::create(1, '$url', 'string|Stringable', gettype($url));

		}

		if (is_array($headers) === false) {

			throw InvalidArgument::create(2, '$headers', 'array', gettype($headers));

		}

		if (!is_array($data) && !is_string($data)) {

			if ($data === null) {

				$data = '';

			} else {

				throw InvalidArgument::create(3, '$data', 'array|string', gettype($data));

			}

		}

		if (is_array($options) === false) {

			throw InvalidArgument::create(4, '$options', 'array', gettype($options));

		}

		$this->hooks = $options['hooks'];

		$this->setup_handle($url, $headers, $data, $options);

		$options['hooks']->dispatch('curl.before_send', [&$this->handle]);

		if ($options['filename'] !== false) {

			// phpcs:ignore WordPress.PHP.NoSilencedErrors -- Silenced the PHP native warning in favour of throwing an exception.

			$this->stream_handle = @fopen($options['filename'], 'wb');

			if ($this->stream_handle === false) {

				$error = error_get_last();

				throw new Exception($error['message'], 'fopen');

			}

		}

		$this->response_data       = '';

		$this->response_bytes      = 0;

		$this->response_byte_limit = false;

		if ($options['max_bytes'] !== false) {

			$this->response_byte_limit = $options['max_bytes'];

		}

		if (isset($options['verify'])) {

			if ($options['verify'] === false) {

				curl_setopt($this->handle, CURLOPT_SSL_VERIFYHOST, 0);

				curl_setopt($this->handle, CURLOPT_SSL_VERIFYPEER, 0);

			} elseif (is_string($options['verify'])) {

				curl_setopt($this->handle, CURLOPT_CAINFO, $options['verify']);

			}

		}

		if (isset($options['verifyname']) && $options['verifyname'] === false) {

			curl_setopt($this->handle, CURLOPT_SSL_VERIFYHOST, 0);

		}

		curl_exec($this->handle);

		$response = $this->response_data;

		$options['hooks']->dispatch('curl.after_send', []);

		if (curl_errno($this->handle) === CURLE_WRITE_ERROR || curl_errno($this->handle) === CURLE_BAD_CONTENT_ENCODING) {

			// Reset encoding and try again

			curl_setopt($this->handle, CURLOPT_ENCODING, 'none');

			$this->response_data  = '';

			$this->response_bytes = 0;

			curl_exec($this->handle);

			$response = $this->response_data;

		}

		$this->process_response($response, $options);

		// Need to remove the $this reference from the curl handle.

		// Otherwise \WpOrg\Requests\Transport\Curl won't be garbage collected and the curl_close() will never be called.

		curl_setopt($this->handle, CURLOPT_HEADERFUNCTION, null);

		curl_setopt($this->handle, CURLOPT_WRITEFUNCTION, null);

		return $this->headers;

	}

	/**

	 * Send multiple requests simultaneously

	 *

	 * @param array $requests Request data

	 * @param array $options Global options

	 * @return array Array of \WpOrg\Requests\Response objects (may contain \WpOrg\Requests\Exception or string responses as well)

	 *

	 * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed $requests argument is not an array or iterable object with array access.

	 * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed $options argument is not an array.

	 */

	public function request_multiple($requests, $options) {

		// If you're not requesting, we can't get any responses ¯\_(ツ)_/¯

		if (empty($requests)) {

			return [];

		}

		if (InputValidator::has_array_access($requests) === false || InputValidator::is_iterable($requests) === false) {

			throw InvalidArgument::create(1, '$requests', 'array|ArrayAccess&Traversable', gettype($requests));

		}

		if (is_array($options) === false) {

			throw InvalidArgument::create(2, '$options', 'array', gettype($options));

		}

		$multihandle = curl_multi_init();

		$subrequests = [];

		$subhandles  = [];

		$class = get_class($this);

		foreach ($requests as $id => $request) {

			$subrequests[$id] = new $class();

			$subhandles[$id]  = $subrequests[$id]->get_subrequest_handle($request['url'], $request['headers'], $request['data'], $request['options']);

			$request['options']['hooks']->dispatch('curl.before_multi_add', [&$subhandles[$id]]);

			curl_multi_add_handle($multihandle, $subhandles[$id]);

		}

		$completed       = 0;

		$responses       = [];

		$subrequestcount = count($subrequests);

		$request['options']['hooks']->dispatch('curl.before_multi_exec', [&$multihandle]);

		do {

			$active = 0;

			do {

				$status = curl_multi_exec($multihandle, $active);

			} while ($status === CURLM_CALL_MULTI_PERFORM);

			$to_process = [];

			// Read the information as needed

			while ($done = curl_multi_info_read($multihandle)) {

				$key = array_search($done['handle'], $subhandles, true);

				if (!isset($to_process[$key])) {

					$to_process[$key] = $done;

				}

			}

			// Parse the finished requests before we start getting the new ones

			foreach ($to_process as $key => $done) {

				$options = $requests[$key]['options'];

				if ($done['result'] !== CURLE_OK) {

					//get error string for handle.

					$reason          = curl_error($done['handle']);

					$exception       = new CurlException(

						$reason,

						CurlException::EASY,

						$done['handle'],

						$done['result']

					);

					$responses[$key] = $exception;

					$options['hooks']->dispatch('transport.internal.parse_error', [&$responses[$key], $requests[$key]]);

				} else {

					$responses[$key] = $subrequests[$key]->process_response($subrequests[$key]->response_data, $options);

					$options['hooks']->dispatch('transport.internal.parse_response', [&$responses[$key], $requests[$key]]);

				}

				curl_multi_remove_handle($multihandle, $done['handle']);

				curl_close($done['handle']);

				if (!is_string($responses[$key])) {

					$options['hooks']->dispatch('multiple.request.complete', [&$responses[$key], $key]);

				}

				$completed++;

			}

		} while ($active || $completed < $subrequestcount);

		$request['options']['hooks']->dispatch('curl.after_multi_exec', [&$multihandle]);

		curl_multi_close($multihandle);

		return $responses;

	}

	/**

	 * Get the cURL handle for use in a multi-request

	 *

	 * @param string $url URL to request

	 * @param array $headers Associative array of request headers

	 * @param string|array $data Data to send either as the POST body, or as parameters in the URL for a GET/HEAD

	 * @param array $options Request options, see {@see \WpOrg\Requests\Requests::response()} for documentation

	 * @return resource|\CurlHandle Subrequest's cURL handle

	 */

	public function &get_subrequest_handle($url, $headers, $data, $options) {

		$this->setup_handle($url, $headers, $data, $options);

		if ($options['filename'] !== false) {

			$this->stream_handle = fopen($options['filename'], 'wb');

		}

		$this->response_data       = '';

		$this->response_bytes      = 0;

		$this->response_byte_limit = false;

		if ($options['max_bytes'] !== false) {

			$this->response_byte_limit = $options['max_bytes'];

		}

		$this->hooks = $options['hooks'];

		return $this->handle;

	}

	/**

	 * Setup the cURL handle for the given data

	 *

	 * @param string $url URL to request

	 * @param array $headers Associative array of request headers

	 * @param string|array $data Data to send either as the POST body, or as parameters in the URL for a GET/HEAD

	 * @param array $options Request options, see {@see \WpOrg\Requests\Requests::response()} for documentation

	 */

	private function setup_handle($url, $headers, $data, $options) {

		$options['hooks']->dispatch('curl.before_request', [&$this->handle]);

		// Force closing the connection for old versions of cURL (<7.22).

		if (!isset($headers['Connection'])) {

			$headers['Connection'] = 'close';

		}

		/**

		 * Add "Expect" header.

		 *

		 * By default, cURL adds a "Expect: 100-Continue" to most requests. This header can

		 * add as much as a second to the time it takes for cURL to perform a request. To

		 * prevent this, we need to set an empty "Expect" header. To match the behaviour of

		 * Guzzle, we'll add the empty header to requests that are smaller than 1 MB and use

		 * HTTP/1.1.

		 *

		 * https://curl.se/mail/lib-2017-07/0013.html

		 */

		if (!isset($headers['Expect']) && $options['protocol_version'] === 1.1) {

			$headers['Expect'] = $this->get_expect_header($data);

		}

		$headers = Requests::flatten($headers);

		if (!empty($data)) {

			$data_format = $options['data_format'];

			if ($data_format === 'query') {

				$url  = self::format_get($url, $data);

				$data = '';

			} elseif (!is_string($data)) {

				$data = http_build_query($data, '', '&');

			}

		}

		switch ($options['type']) {

			case Requests::POST:

				curl_setopt($this->handle, CURLOPT_POST, true);

				curl_setopt($this->handle, CURLOPT_POSTFIELDS, $data);

				break;

			case Requests::HEAD:

				curl_setopt($this->handle, CURLOPT_CUSTOMREQUEST, $options['type']);

				curl_setopt($this->handle, CURLOPT_NOBODY, true);

				break;

			case Requests::TRACE:

				curl_setopt($this->handle, CURLOPT_CUSTOMREQUEST, $options['type']);

				break;

			case Requests::PATCH:

			case Requests::PUT:

			case Requests::DELETE:

			case Requests::OPTIONS:

			default:

				curl_setopt($this->handle, CURLOPT_CUSTOMREQUEST, $options['type']);

				if (!empty($data)) {

					curl_setopt($this->handle, CURLOPT_POSTFIELDS, $data);

				}

		}