<?php
/**
 * PrivateBin
 *
 * a zero-knowledge paste bin
 *
 * @link      https://github.com/PrivateBin/PrivateBin
 * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
 * @license   https://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
 * @version   1.4.0
 */

namespace PrivateBin;

use Exception;
use PrivateBin\Configuration;
use PrivateBin\Json;

/**
 * YourlsProxy
 *
 * Forwards a URL for shortening to YOURLS (your own URL shortener) and stores
 * the result.
 */
class YourlsProxy
{
    /**
     * error message
     *
     * @access private
     * @var    string
     */
    private $_error = '';

    /**
     * shortened URL
     *
     * @access private
     * @var    string
     */
    private $_url = '';

    /**
     * constructor
     *
     * initializes and runs PrivateBin
     *
     * @access public
     * @param string $link
     */
    public function __construct(Configuration $conf, $link)
    {
        if (strpos($link, $conf->getKey('basepath') . '/?') === false) {
            $this->_error = 'Trying to shorten a URL not pointing to our PrivateBin instance.';
            return;
        }

        // Init the CURL session
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $conf->getKey("apiurl", "yourls"));
        curl_setopt($ch, CURLOPT_HEADER, 0);            // No header in the result
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); // Return, do not echo result
        curl_setopt($ch, CURLOPT_POST, 1);              // This is a POST request
        curl_setopt($ch, CURLOPT_POSTFIELDS, array(     // Data to POST
                            'signature' => $conf->getKey("signature", "yourls"),
                            'format'   => 'json',
                            'action'   => 'shorturl',
                            'url' =>  $link
        ));
        // Fetch and return content
        $data = curl_exec($ch);
        curl_close($ch);

        if ($data === false || !is_string($data)) {
            $this->_error = 'Error calling YOURLS. Probably a configuration issue, like wrong or missing "apiurl" or "signature".';
            return;
        }

        try {
            $data = Json::decode($data);
        } catch (Exception $e) {
            $this->_error = $e->getMessage();
            return;
        }

        if (
            !is_null($data) &&
            array_key_exists('statusCode', $data) &&
            array_key_exists('shorturl', $data) &&
            $data['statusCode'] == 200
        ) {
            $this->_url = $data['shorturl'];
        } else {
            $this->_error = 'Error parsing YOURLS response.';
        }
    }

    /**
     * Returns the (untranslated) error message
     *
     * @access public
     * @return string
     */
    public function getError()
    {
        return $this->_error;
    }

    /**
     * Returns the shortened URL
     *
     * @access public
     * @return string
     */
    public function getUrl()
    {
        return $this->_url;
    }

    /**
     * Returns true if any error has occurred
     *
     * @access public
     * @return bool
     */
    public function isError()
    {
        return !empty($this->_error);
    }
}