<?php

/**
 * Joomla! Content Management System
 *
 * @copyright  (C) 2011 Open Source Matters, Inc. <https://www.joomla.org>
 * @license    GNU General Public License version 2 or later; see LICENSE.txt
 */

namespace Joomla\CMS\Http\Transport;

use Composer\CaBundle\CaBundle;
use Joomla\CMS\Factory;
use Joomla\CMS\Http\Response;
use Joomla\CMS\Http\TransportInterface;
use Joomla\CMS\Uri\Uri;
use Joomla\Http\AbstractTransport;
use Joomla\Http\Exception\InvalidResponseCodeException;
use Joomla\Uri\UriInterface;
use Laminas\Diactoros\Stream as StreamResponse;

// phpcs:disable PSR1.Files.SideEffects
\defined('JPATH_PLATFORM') or die;
// phpcs:enable PSR1.Files.SideEffects

/**
 * HTTP transport class for using cURL.
 *
 * @since  1.7.3
 */
class CurlTransport extends AbstractTransport implements TransportInterface
{
    /**
     * Send a request to the server and return a Response object with the response.
     *
     * @param   string        $method     The HTTP method for sending the request.
     * @param   UriInterface  $uri        The URI to the resource to request.
     * @param   mixed         $data       Either an associative array or a string to be sent with the request.
     * @param   array         $headers    An array of request headers to send with the request.
     * @param   integer       $timeout    Read timeout in seconds.
     * @param   string        $userAgent  The optional user agent string to send with the request.
     *
     * @return  Response
     *
     * @since   1.7.3
     * @throws  \RuntimeException
     */
    public function request($method, UriInterface $uri, $data = null, array $headers = [], $timeout = null, $userAgent = null)
    {
        // Setup the cURL handle.
        $ch = curl_init();

        $options = [];

        // Set the request method.
        switch (strtoupper($method)) {
            case 'GET':
                $options[CURLOPT_HTTPGET] = true;
                break;

            case 'POST':
                $options[CURLOPT_POST] = true;
                break;

            case 'PUT':
            default:
                $options[CURLOPT_CUSTOMREQUEST] = strtoupper($method);
                break;
        }

        // Don't wait for body when $method is HEAD
        $options[CURLOPT_NOBODY] = ($method === 'HEAD');

        // Initialize the certificate store
        $options[CURLOPT_CAINFO] = $this->getOption('curl.certpath', CaBundle::getBundledCaBundlePath());

        // If data exists let's encode it and make sure our Content-type header is set.
        if (isset($data)) {
            // If the data is a scalar value simply add it to the cURL post fields.
            if (is_scalar($data) || (isset($headers['Content-Type']) && strpos($headers['Content-Type'], 'multipart/form-data') === 0)) {
                $options[CURLOPT_POSTFIELDS] = $data;
            } else {
                // Otherwise we need to encode the value first.
                $options[CURLOPT_POSTFIELDS] = http_build_query($data);
            }

            if (!isset($headers['Content-Type'])) {
                $headers['Content-Type'] = 'application/x-www-form-urlencoded; charset=utf-8';
            }

            // Add the relevant headers.
            if (is_scalar($options[CURLOPT_POSTFIELDS])) {
                $headers['Content-Length'] = \strlen($options[CURLOPT_POSTFIELDS]);
            }
        }

        // Build the headers string for the request.
        $headerArray = [];

        if (isset($headers)) {
            foreach ($headers as $key => $value) {
                $headerArray[] = $key . ': ' . $value;
            }

            // Add the headers string into the stream context options array.
            $options[CURLOPT_HTTPHEADER] = $headerArray;
        }

        // Curl needs the accepted encoding header as option
        if (isset($headers['Accept-Encoding'])) {
            $options[CURLOPT_ENCODING] = $headers['Accept-Encoding'];
        }

        // If an explicit timeout is given user it.
        if (isset($timeout)) {
            $options[CURLOPT_TIMEOUT]        = (int) $timeout;
            $options[CURLOPT_CONNECTTIMEOUT] = (int) $timeout;
        }

        // If an explicit user agent is given use it.
        if (isset($userAgent)) {
            $options[CURLOPT_USERAGENT] = $userAgent;
        }

        // Set the request URL.
        $options[CURLOPT_URL] = (string) $uri;

        // We want our headers. :-)
        $options[CURLOPT_HEADER] = true;

        // Return it... echoing it would be tacky.
        $options[CURLOPT_RETURNTRANSFER] = true;

        // Override the Expect header to prevent cURL from confusing itself in its own stupidity.
        // Link: http://the-stickman.com/web-development/php-and-curl-disabling-100-continue-header/
        $options[CURLOPT_HTTPHEADER][] = 'Expect:';

        // Follow redirects if server config allows
        if ($this->redirectsAllowed()) {
            $options[CURLOPT_FOLLOWLOCATION] = (bool) $this->getOption('follow_location', true);
        }

        // Proxy configuration
        $app = Factory::getApplication();

        if ($app->get('proxy_enable')) {
            $options[CURLOPT_PROXY] = $app->get('proxy_host') . ':' . $app->get('proxy_port');

            if ($user = $app->get('proxy_user')) {
                $options[CURLOPT_PROXYUSERPWD] = $user . ':' . $app->get('proxy_pass');
            }
        }

        // Set any custom transport options
        foreach ($this->getOption('transport.curl', []) as $key => $value) {
            $options[$key] = $value;
        }

        // Authentication, if needed
        if ($this->getOption('userauth') && $this->getOption('passwordauth')) {
            $options[CURLOPT_USERPWD]  = $this->getOption('userauth') . ':' . $this->getOption('passwordauth');
            $options[CURLOPT_HTTPAUTH] = CURLAUTH_BASIC;
        }

        // Set the cURL options.
        curl_setopt_array($ch, $options);

        // Execute the request and close the connection.
        $content = curl_exec($ch);

        // Check if the content is a string. If it is not, it must be an error.
        if (!\is_string($content)) {
            $message = curl_error($ch);

            if (empty($message)) {
                // Error but nothing from cURL? Create our own
                $message = 'No HTTP response received';
            }

            throw new \RuntimeException($message);
        }

        // Get the request information.
        $info = curl_getinfo($ch);

        // Close the connection.
        curl_close($ch);

        $response = $this->getResponse($content, $info);

        // Manually follow redirects if server doesn't allow to follow location using curl
        if ($response->code >= 301 && $response->code < 400 && isset($response->headers['Location']) && (bool) $this->getOption('follow_location', true)) {
            $redirect_uri = new Uri($response->headers['Location']);

            if (\in_array($redirect_uri->getScheme(), ['file', 'scp'])) {
                throw new \RuntimeException('Curl redirect cannot be used in file or scp requests.');
            }

            $response = $this->request($method, $redirect_uri, $data, $headers, $timeout, $userAgent);
        }

        return $response;
    }

    /**
     * Method to get a response object from a server response.
     *
     * @param   string  $content  The complete server response, including headers
     *                            as a string if the response has no errors.
     * @param   array   $info     The cURL request information.
     *
     * @return  Response
     *
     * @since   1.7.3
     * @throws  InvalidResponseCodeException
     */
    protected function getResponse($content, $info)
    {
        // Try to get header size
        if (isset($info['header_size'])) {
            $headerString = trim(substr($content, 0, $info['header_size']));
            $headerArray  = explode("\r\n\r\n", $headerString);

            // Get the last set of response headers as an array.
            $headers = explode("\r\n", array_pop($headerArray));

            // Set the body for the response.
            $body = substr($content, $info['header_size']);
        } else {
            // Fallback and try to guess header count by redirect count
            // Get the number of redirects that occurred.
            $redirects = $info['redirect_count'] ?? 0;

            /*
             * Split the response into headers and body. If cURL encountered redirects, the headers for the redirected requests will
             * also be included. So we split the response into header + body + the number of redirects and only use the last two
             * sections which should be the last set of headers and the actual body.
             */
            $response = explode("\r\n\r\n", $content, 2 + $redirects);

            // Set the body for the response.
            $body = array_pop($response);

            // Get the last set of response headers as an array.
            $headers = explode("\r\n", array_pop($response));
        }

        // Get the response code from the first offset of the response headers.
        preg_match('/[0-9]{3}/', array_shift($headers), $matches);

        $code = \count($matches) ? $matches[0] : null;

        if (!is_numeric($code)) {
            // No valid response code was detected.
            throw new InvalidResponseCodeException('No HTTP response code found.');
        }

        $statusCode      = (int) $code;
        $verifiedHeaders = $this->processHeaders($headers);

        $streamInterface = new StreamResponse('php://memory', 'rw');
        $streamInterface->write($body);

        return new Response($streamInterface, $statusCode, $verifiedHeaders);
    }

    /**
     * Method to check if HTTP transport cURL is available for use
     *
     * @return boolean true if available, else false
     *
     * @since   3.0.0
     */
    public static function isSupported()
    {
        return \function_exists('curl_version') && curl_version();
    }

    /**
     * Check if redirects are allowed
     *
     * @return  boolean
     *
     * @since   3.0.0
     */
    private function redirectsAllowed()
    {
        $curlVersion = curl_version();

        // If open_basedir is enabled we also need to check if libcurl version is 7.19.4 or higher
        if (!ini_get('open_basedir') || version_compare($curlVersion['version'], '7.19.4', '>=')) {
            return true;
        }

        return false;
    }
}
