/Wikimate.php

<?php

/**
 * Wikimate is a wrapper for the MediaWiki API that aims to be very easy to use.
 *
 * @package    Wikimate
 * @version    1.0.0
 * @copyright  SPDX-License-Identifier: MIT
 */

/**
 * Provides an interface over wiki API objects such as pages and files.
 *
 * All requests to the API can throw WikimateException if the server is lagged
 * and a finite number of retries is exhausted.  By default requests are
 * retried indefinitely.  See {@see Wikimate::request()} for more information.
 *
 * @author  Robert McLeod & Frans P. de Vries
 * @since   0.2  December 2010
 */
class Wikimate
{
    /**
     * The current version number (conforms to Semantic Versioning)
     *
     * @var string
     * @link https://semver.org/
     */
    const VERSION = '1.0.0';

    /**
     * Identifier for CSRF token
     *
     * @var string
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Tokens
     */
    const TOKEN_DEFAULT = 'csrf';

    /**
     * Identifier for Login token
     *
     * @var string
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Tokens
     */
    const TOKEN_LOGIN = 'login';

    /**
     * Default lag value in seconds
     *
     * @var integer
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/Manual:Maxlag_parameter
     */
    const MAXLAG_DEFAULT = 5;

    /**
     * Base URL for API requests
     *
     * @var string
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Main_page#Endpoint
     */
    protected $api;

    /**
     * Default headers for Requests_Session
     *
     * @var array
     */
    protected $headers;

    /**
     * Default data for Requests_Session
     *
     * @var array
     */
    protected $data;

    /**
     * Default options for Requests_Session
     *
     * @var array
     */
    protected $options;

    /**
     * Username for API requests
     *
     * @var string
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Login#Method_1._login
     */
    protected $username;

    /**
     * Password for API requests
     *
     * @var string
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Login#Method_1._login
     */
    protected $password;

    /**
     * Session object for HTTP requests
     *
     * @var Requests_Session
     * @link https://requests.ryanmccue.info/
     */
    protected $session;

    /**
     * User agent string for Requests_Session
     *
     * @var string
     * @link https://requests.ryanmccue.info/docs/usage-advanced.html#session-handling
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Etiquette#The_User-Agent_header
     */
    protected $useragent;

    /**
     * Error array with API and Wikimate errors
     *
     * @var array|null
     */
    protected $error = null;

    /**
     * Whether to output debug logging
     *
     * @var boolean
     */
    protected $debugMode = false;

    /**
     * Maximum lag in seconds to accept in requests
     *
     * @var integer
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/Manual:Maxlag_parameter
     */
    protected $maxlag = self::MAXLAG_DEFAULT;

    /**
     * Maximum number of retries for lagged requests (-1 = retry indefinitely)
     *
     * @var integer
     */
    protected $maxretries = -1;

    /**
     * Stored CSRF token for API requests
     *
     * @var string|null
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Tokens
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Edit#Additional_notes
     */
    private $csrfToken = null;

    /**
     * Creates a new Wikimate object.
     *
     * @param   string    $api      Base URL for the API
     * @param   array     $headers  Default headers for API requests
     * @param   array     $data     Default data for API requests
     * @param   array     $options  Default options for API requests
     * @return  Wikimate
     */
    public function __construct($api, $headers = array(), $data = array(), $options = array())
    {
        $this->api     = $api;
        $this->headers = $headers;
        $this->data    = $data;
        $this->options = $options;

        $this->initRequests();
    }

    /**
     * Sets up a Requests_Session with appropriate user agent.
     *
     * @return  void
     * @link https://requests.ryanmccue.info/docs/usage-advanced.html#session-handling
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Etiquette#The_User-Agent_header
     */
    protected function initRequests()
    {
        $this->useragent = 'Wikimate/' . self::VERSION . ' (https://github.com/hamstar/Wikimate)';

        $this->session = new Requests_Session($this->api, $this->headers, $this->data, $this->options);
        $this->session->useragent = $this->useragent;
    }

    /**
     * Sends a GET or POST request in JSON format to the API.
     *
     * This method handles maxlag errors as advised at:
     * {@see https://www.mediawiki.org/wiki/Special:MyLanguage/Manual:Maxlag_parameter}
     * The request is sent with the current maxlag value
     * (default: 5 seconds, per MAXLAG_DEFAULT).
     * If a lag error is received, the method waits (sleeps) for the
     * recommended time (per the Retry-After header), then tries again.
     * It will do this indefinitely unless the number of retries is limited,
     * in which case WikimateException is thrown once the limit is reached.
     *
     * The string type for $data is used only for upload POST requests,
     * and must contain the complete multipart body, including maxlag.
     *
     * @param  array|string  $data     Data for the request
     * @param  array         $headers  Optional extra headers to send with the request
     * @param  boolean       $post     True to send a POST request, otherwise GET
     * @return array                   The API response
     * @throw  WikimateException       If lagged and ran out of retries,
     *                                 or got an unexpected API response
     */
    private function request($data, $headers = array(), $post = false)
    {
        $retries = 0;

        // Add format & maxlag parameter to request
        if (is_array($data)) {
            $data['format'] = 'json';
            $data['maxlag'] = $this->getMaxlag();
            $action = $data['action'];
        } else {
            $action = 'upload';
        }
        // Define type of HTTP request for messages
        $httptype = $post ? 'POST' : 'GET';

        // Send appropriate type of request, once or multiple times
        do {
            if ($post) {
                // Debug logging of POST requests, except for upload string
                if ($this->debugMode && is_array($data)) {
                    echo "$action $httptype parameters:\n";
                    print_r($data);
                }
                $response = $this->session->post($this->api, $headers, $data);
            } else {
                // Debug logging of GET requests as a query string
                if ($this->debugMode) {
                    echo "$action $httptype parameters:\n";
                    echo http_build_query($data) . "\n";
                }
                $response = $this->session->get($this->api . '?' . http_build_query($data), $headers);
            }

            // Check for replication lag error
            $serverLagged = ($response->headers->offsetGet('X-Database-Lag') !== null);
            if ($serverLagged) {
                // Determine recommended or default delay
                if ($response->headers->offsetGet('Retry-After') !== null) {
                    $sleep = (int)$response->headers->offsetGet('Retry-After');
                } else {
                    $sleep = $this->getMaxlag();
                }

                if ($this->debugMode) {
                    preg_match('/Waiting for [^ ]*: ([0-9.-]+) seconds? lagged/', $response->body, $match);
                    echo "Server lagged for {$match[1]} seconds; will retry in {$sleep} seconds\n";
                }
                sleep($sleep);

                // Check retries limit
                if ($this->getMaxretries() >= 0) {
                    $retries++;
                } else {
                    $retries = -1; // continue indefinitely
                }
            }
        } while ($serverLagged && $retries <= $this->getMaxretries());

        // Throw exception if we ran out of retries
        if ($serverLagged) {
            throw new WikimateException("Server lagged ($retries consecutive maxlag responses)");
        }

        // Check if we got the API doc page (invalid request)
        if (strpos($response->body, "This is an auto-generated MediaWiki API documentation page") !== false) {
            throw new WikimateException("The API could not understand the $action $httptype request");
        }

        // Check if we got a JSON result
        $result = json_decode($response->body, true);
        if ($result === null) {
            throw new WikimateException("The API did not return the $action JSON response");
        }

        if ($this->debugMode) {
            echo "$action $httptype response:\n";
            print_r($result);
        }

        return $result;
    }

    /**
     * Obtains a wiki token for logging in or data-modifying actions.
     *
     * If a CSRF (default) token is requested, it is stored and returned
     * upon further such requests, instead of making another API call.
     * The stored token is discarded via {@see Wikimate::logout()}.
     *
     * For now this method, in Wikimate tradition, is kept simple and supports
     * only the two token types needed elsewhere in the library.  It also
     * doesn't support the option to request multiple tokens at once.
     * See {@see https://www.mediawiki.org/wiki/Special:MyLanguage/API:Tokens}
     * for more information.
     *
     * @param   string  $type  The token type
     * @return  mixed          The requested token (string), or null if error
     */
    protected function token($type = self::TOKEN_DEFAULT)
    {
        // Check for supported token types
        if ($type != self::TOKEN_DEFAULT && $type != self::TOKEN_LOGIN) {
            $this->error = array();
            $this->error['token'] = 'The API does not support the token type';
            return null;
        }

        // Check for existing CSRF token for this login session
        if ($type == self::TOKEN_DEFAULT && $this->csrfToken !== null) {
            return $this->csrfToken;
        }

        $details = array(
            'action' => 'query',
            'meta' => 'tokens',
            'type' => $type,
        );

        // Send the token request
        $tokenResult = $this->request($details, array(), true);

        // Check for errors
        if (isset($tokenResult['error'])) {
            $this->error = $tokenResult['error']; // Set the error if there was one
            return null;
        } else {
            $this->error = null; // Reset the error status
        }

        if ($type == self::TOKEN_LOGIN) {
            return $tokenResult['query']['tokens']['logintoken'];
        } else {
            // Store CSRF token for this login session
            $this->csrfToken = $tokenResult['query']['tokens']['csrftoken'];
            return $this->csrfToken;
        }
    }

    /**
     * Logs in to the wiki.
     *
     * @param   string   $username  The user name
     * @param   string   $password  The user password
     * @param   string   $domain    The domain (optional)
     * @return  boolean             True if logged in
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Login#Method_1._login
     */
    public function login($username, $password, $domain = null)
    {
        // Obtain login token first
        if (($logintoken = $this->token(self::TOKEN_LOGIN)) === null) {
            return false;
        }

        $details = array(
            'action' => 'login',
            'lgname' => $username,
            'lgpassword' => $password,
            'lgtoken' => $logintoken,
        );

        // If $domain is provided, set the corresponding detail in the request information array
        if (is_string($domain)) {
            $details['lgdomain'] = $domain;
        }

        // Send the login request
        $loginResult = $this->request($details, array(), true);

        // Check for errors
        if (isset($loginResult['error'])) {
            $this->error = $loginResult['error']; // Set the error if there was one
            return false;
        } else {
            $this->error = null; // Reset the error status
        }

        if (isset($loginResult['login']['result']) && $loginResult['login']['result'] != 'Success') {
            // Some more comprehensive error checking
            $this->error = array();
            switch ($loginResult['login']['result']) {
                case 'Failed':
                    $this->error['auth'] = 'Incorrect username or password';
                    break;
                default:
                    $this->error['auth'] = 'The API result was: ' . $loginResult['login']['result'];
                    break;
            }
            return false;
        }

        return true;
    }

    /**
     * Logs out of the wiki and discard CSRF token.
     *
     * @return  boolean  True if logged out
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Logout
     */
    public function logout()
    {
        // Obtain logout token first
        if (($logouttoken = $this->token()) === null) {
            return false;
        }

        // Token is needed in MediaWiki v1.34+, older versions produce an
        // 'Unrecognized parameter' warning which can be ignored
        $details = array(
            'action' => 'logout',
            'token' => $logouttoken,
        );

        // Send the logout request
        $logoutResult = $this->request($details, array(), true);

        // Check for errors
        if (isset($logoutResult['error'])) {
            $this->error = $logoutResult['error']; // Set the error if there was one
            return false;
        } else {
            $this->error = null; // Reset the error status
        }

        // Discard CSRF token for this login session
        $this->csrfToken = null;
        return true;
    }

    /**
     * Gets the current value of the maxlag parameter.
     *
     * @return  integer  The maxlag value in seconds
     */
    public function getMaxlag()
    {
        return $this->maxlag;
    }

    /**
     * Sets the new value of the maxlag parameter.
     *
     * @param   integer   $ml  The new maxlag value in seconds
     * @return  Wikimate       This object
     */
    public function setMaxlag($ml)
    {
        $this->maxlag = (int)$ml;
        return $this;
    }

    /**
     * Gets the current value of the max retries limit.
     *
     * @return  integer  The max retries limit
     */
    public function getMaxretries()
    {
        return $this->maxretries;
    }

    /**
     * Sets the new value of the max retries limit.
     *
     * @param   integer   $mr  The new max retries limit
     * @return  Wikimate       This object
     */
    public function setMaxretries($mr)
    {
        $this->maxretries = (int)$mr;
        return $this;
    }

    /**
     * Gets the user agent for API requests.
     *
     * @return  string  The default user agent, or the current one defined
     *                  by {@see Wikimate::setUserAgent()}
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Etiquette#The_User-Agent_header
     */
    public function getUserAgent()
    {
        return $this->useragent;
    }

    /**
     * Sets the user agent for API requests.
     *
     * In order to use a custom user agent for all requests in the session,
     * call this method before invoking {@see Wikimate::login()}.
     *
     * @param   string   $ua  The new user agent
     * @return  Wikimate      This object
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Etiquette#The_User-Agent_header
     */
    public function setUserAgent($ua)
    {
        $this->useragent = (string)$ua;
        // Update the session
        $this->session->useragent = $this->useragent;
        return $this;
    }

    /**
     * Sets the debug mode.
     *
     * @param   boolean   $b  True to turn debugging on
     * @return  Wikimate      This object
     */
    public function setDebugMode($b)
    {
        $this->debugMode = $b;
        return $this;
    }

    /**
     * Gets or prints the Requests configuration.
     *
     * @param   boolean  $echo  Whether to echo the session options and headers
     * @return  mixed           Options array if $echo is false, or
     *                          True if options/headers have been echoed to STDOUT
     */
    public function debugRequestsConfig($echo = false)
    {
        if ($echo) {
            echo "<pre>Requests options:\n";
            print_r($this->session->options);
            echo "Requests headers:\n";
            print_r($this->session->headers);
            echo "</pre>";
            return true;
        }
        return $this->session->options;
    }

    /**
     * Returns a WikiPage object populated with the page data.
     *
     * @param   string    $title  The name of the wiki article
     * @return  WikiPage          The page object
     */
    public function getPage($title)
    {
        return new WikiPage($title, $this);
    }

    /**
     * Returns a WikiFile object populated with the file data.
     *
     * @param   string    $filename  The name of the wiki file
     * @return  WikiFile             The file object
     */
    public function getFile($filename)
    {
        return new WikiFile($filename, $this);
    }

    /**
     * Performs a query to the wiki API with the given details.
     *
     * @param   array  $array  Array of details to be passed in the query
     * @return  array          Decoded JSON output from the wiki API
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Query
     */
    public function query($array)
    {
        $array['action'] = 'query';

        return $this->request($array);
    }

    /**
     * Performs a parse query to the wiki API.
     *
     * @param   array  $array  Array of details to be passed in the query
     * @return  array          Decoded JSON output from the wiki API
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Parsing_wikitext
     */
    public function parse($array)
    {
        $array['action'] = 'parse';

        return $this->request($array);
    }

    /**
     * Perfoms an edit query to the wiki API.
     *
     * @param   array         $array  Array of details to be passed in the query
     * @return  array|boolean         Decoded JSON output from the wiki API
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Edit
     */
    public function edit($array)
    {
        // Obtain default token first
        if (($edittoken = $this->token()) === null) {
            return false;
        }

        $headers = array(
            'Content-Type' => "application/x-www-form-urlencoded"
        );

        $array['action'] = 'edit';
        $array['token'] = $edittoken;

        return $this->request($array, $headers, true);
    }

    /**
     * Perfoms a delete query to the wiki API.
     *
     * @param   array          $array  Array of details to be passed in the query
     * @return  array|boolean          Decoded JSON output from the wiki API
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Delete
     */
    public function delete($array)
    {
        // Obtain default token first
        if (($deletetoken = $this->token()) === null) {
            return false;
        }

        $headers = array(
            'Content-Type' => "application/x-www-form-urlencoded"
        );

        $array['action'] = 'delete';
        $array['token'] = $deletetoken;

        return $this->request($array, $headers, true);
    }

    /**
     * Downloads data from the given URL.
     *
     * @param   string  $url  The URL to download from
     * @return  mixed         The downloaded data (string), or null if error
     */
    public function download($url)
    {
        $getResult = $this->session->get($url);

        if (!$getResult->success) {
            // Debug logging of Requests_Response only on failed download
            if ($this->debugMode) {
                echo "download GET response:\n";
                print_r($getResult);
            }
            $this->error = array();
            $this->error['file'] = 'Download error (HTTP status: ' . $getResult->status_code . ')';
            $this->error['http'] = $getResult->status_code;
            return null;
        }
        return $getResult->body;
    }

    /**
     * Uploads a file to the wiki API.
     *
     * @param   array            $array  Array of details to be used in the upload
     * @return  array|boolean            Decoded JSON output from the wiki API
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Upload
     */
    public function upload($array)
    {
        // Obtain default token first
        if (($uploadtoken = $this->token()) === null) {
            return false;
        }

        $array['action'] = 'upload';
        $array['format'] = 'json';
        $array['maxlag'] = $this->getMaxlag();
        $array['token'] = $uploadtoken;

        // Construct multipart body:
        // https://www.mediawiki.org/w/index.php?title=API:Upload&oldid=2293685#Sample_Raw_Upload
        // https://www.mediawiki.org/w/index.php?title=API:Upload&oldid=2339771#Sample_Raw_POST_of_a_single_chunk
        $boundary = '---Wikimate-' . md5(microtime());
        $body = '';
        foreach ($array as $fieldName => $fieldData) {
            $body .= "--{$boundary}\r\n";
            $body .= 'Content-Disposition: form-data; name="' . $fieldName . '"';
            // Process the (binary) file
            if ($fieldName == 'file') {
                $body .= '; filename="' . $array['filename'] . '"' . "\r\n";
                $body .= "Content-Type: application/octet-stream; charset=UTF-8\r\n";
                $body .= "Content-Transfer-Encoding: binary\r\n";
            // Process text parameters
            } else {
                $body .= "\r\n";
                $body .= "Content-Type: text/plain; charset=UTF-8\r\n";
                $body .= "Content-Transfer-Encoding: 8bit\r\n";
            }
            $body .= "\r\n{$fieldData}\r\n";
        }
        $body .= "--{$boundary}--\r\n";

        // Construct multipart headers
        $headers = array(
            'Content-Type' => "multipart/form-data; boundary={$boundary}",
            'Content-Length' => strlen($body),
        );

        return $this->request($body, $headers, true);
    }

    /**
     * Performs a file revert query to the wiki API.
     *
     * @param   array          $array  Array of details to be passed in the query
     * @return  array|boolean          Decoded JSON output from the wiki API
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Filerevert
     */
    public function filerevert($array)
    {
        // Obtain default token first
        if (($reverttoken = $this->token()) === null) {
            return false;
        }

        $array['action'] = 'filerevert';
        $array['token'] = $reverttoken;

        $headers = array(
            'Content-Type' => "application/x-www-form-urlencoded"
        );

        return $this->request($array, $headers, true);
    }

    /**
     * Returns the latest error if there is one.
     *
     * @return  mixed  The error array, or null if no error
     */
    public function getError()
    {
        return $this->error;
    }
}


/**
 * Defines Wikimate's exception for unexpected run-time errors
 * while communicating with the API.
 * WikimateException can be thrown only from Wikimate::request(),
 * and is propagated to callers of this library.
 *
 * @author  Frans P. de Vries
 * @since   1.0.0  August 2021
 * @link    https://www.php.net/manual/en/class.runtimeexception.php
 */
class WikimateException extends RuntimeException
{
}


/**
 * Models a wiki article page that can have its text altered and retrieved.
 *
 * @author  Robert McLeod & Frans P. de Vries
 * @since   0.2  December 2010
 */
class WikiPage
{
    /**
     * Use section indexes as keys in return array of {@see WikiPage::getAllSections()}
     *
     * @var integer
     */
    const SECTIONLIST_BY_INDEX = 1;

    /**
     * Use section names as keys in return array of {@see WikiPage::getAllSections()}
     *
     * @var integer
     */
    const SECTIONLIST_BY_NAME = 2;

    /**
     * The title of the page
     *
     * @var string|null
     */
    protected $title = null;

    /**
     * Wikimate object for API requests
     *
     * @var Wikimate|null
     */
    protected $wikimate = null;

    /**
     * Whether the page exists
     *
     * @var boolean
     */
    protected $exists = false;

    /**
     * Whether the page is invalid
     *
     * @var boolean
     */
    protected $invalid = false;

    /**
     * Error array with API and WikiPage errors
     *
     * @var array|null
     */
    protected $error = null;

    /**
     * Stores the timestamp for detection of edit conflicts
     *
     * @var integer|null
     */
    protected $starttimestamp = null;

    /**
     * The complete text of the page
     *
     * @var string|null
     */
    protected $text = null;

    /**
     * The sections object for the page
     *
     * @var stdClass|null
     */
    protected $sections = null;

    /*
     *
     * Magic methods
     *
     */

    /**
     * Constructs a WikiPage object from the title given
     * and associate with the passed Wikimate object.
     *
     * @param  string    $title     Name of the wiki article
     * @param  Wikimate  $wikimate  Wikimate object
     */
    public function __construct($title, $wikimate)
    {
        $this->wikimate = $wikimate;
        $this->title    = $title;
        $this->sections = new \stdClass();
        $this->text     = $this->getText(true);

        if ($this->invalid) {
            $this->error['page'] = 'Invalid page title - cannot create WikiPage';
        }
    }

    /**
     * Forgets all object properties.
     */
    public function __destruct()
    {
        $this->title          = null;
        $this->wikimate       = null;
        $this->exists         = false;
        $this->invalid        = false;
        $this->error          = null;
        $this->starttimestamp = null;
        $this->text           = null;
        $this->sections       = null;
    }

    /**
     * Returns the wikicode of the page.
     *
     * @return  string  String of wikicode
     */
    public function __toString()
    {
        return $this->text;
    }

    /**
     * Returns an array sections with the section name as the key
     * and the text as the element, e.g.
     *
     * array(
     *   'intro' => 'this text is the introduction',
     *   'History' => 'this is text under the history section'
     *)
     *
     * @return  array  Array of sections
     */
    public function __invoke()
    {
        return $this->getAllSections(false, self::SECTIONLIST_BY_NAME);
    }

    /**
     * Returns the page existence status.
     *
     * @return  boolean  True if page exists
     */
    public function exists()
    {
        return $this->exists;
    }

    /**
     * Alias of self::__destruct().
     *
     * @return void
     */
    public function destroy()
    {
        $this->__destruct();
    }

    /*
     *
     * Page meta methods
     *
     */

    /**
     * Returns the latest error if there is one.
     *
     * @return  mixed  The error array, or null if no error
     */
    public function getError()
    {
        return $this->error;
    }

    /**
     * Returns the title of this page.
     *
     * @return  string  The title of this page
     */
    public function getTitle()
    {
        return $this->title;
    }

    /**
     * Returns the number of sections in this page.
     *
     * @return  integer  The number of sections in this page
     */
    public function getNumSections()
    {
        return count($this->sections->byIndex);
    }

    /**
     * Returns the sections offsets and lengths.
     *
     * @return  stdClass  Section class
     */
    public function getSectionOffsets()
    {
        return $this->sections;
    }

    /*
     *
     * Getter methods
     *
     */

    /**
     * Gets the text of the page. If refresh is true,
     * then this method will query the wiki API again for the page details.
     *
     * @param   boolean  $refresh  True to query the wiki API again
     * @return  mixed              The text of the page (string), or null if error
     */
    public function getText($refresh = false)
    {
        if ($refresh) { // We want to query the API
            // Specify relevant page properties to retrieve
            $data = array(
                'titles' => $this->title,
                'prop' => 'info|revisions',
                'rvprop' => 'content', // Need to get page text
                'curtimestamp' => 1,
            );

            $r = $this->wikimate->query($data); // Run the query

            // Check for errors
            if (isset($r['error'])) {
                $this->error = $r['error']; // Set the error if there was one
                return null;
            } else {
                $this->error = null; // Reset the error status
            }

            // Get the page (there should only be one)
            $page = array_pop($r['query']['pages']);

            // Abort if invalid page title
            if (isset($page['invalid'])) {
                $this->invalid = true;
                return null;
            }

            $this->starttimestamp = $r['curtimestamp'];
            unset($r, $data);

            if (!isset($page['missing'])) {
                // Update the existence if the page is there
                $this->exists = true;
                // Put the content into text
                $this->text   = $page['revisions'][0]['*'];
            }
            unset($page);

            // Now we need to get the section headers, if any
            preg_match_all('/(={1,6}).*?\1 *(?:\n|$)/', $this->text, $matches);

            // Set the intro section (between title and first section)
            $this->sections->byIndex[0]['offset']      = 0;
            $this->sections->byName['intro']['offset'] = 0;

            // Check for section header matches
            if (empty($matches[0])) {
                // Define lengths for page consisting only of intro section
                $this->sections->byIndex[0]['length']      = strlen($this->text);
                $this->sections->byName['intro']['length'] = strlen($this->text);
            } else {
                // Array of section header matches
                $sections = $matches[0];

                // Set up the current section
                $currIndex = 0;
                $currName  = 'intro';

                // Collect offsets and lengths from section header matches
                foreach ($sections as $section) {
                    // Get the current offset
                    $currOffset = strpos($this->text, $section, $this->sections->byIndex[$currIndex]['offset']);

                    // Are we still on the first section?
                    if ($currIndex == 0) {
                        $this->sections->byIndex[$currIndex]['length'] = $currOffset;
                        $this->sections->byIndex[$currIndex]['depth']  = 0;
                        $this->sections->byName[$currName]['length']   = $currOffset;
                        $this->sections->byName[$currName]['depth']    = 0;
                    }

                    // Get the current name and index
                    $currName = trim(str_replace('=', '', $section));
                    $currIndex++;

                    // Search for existing name and create unique one
                    $cName = $currName;
                    for ($seq = 2; array_key_exists($cName, $this->sections->byName); $seq++) {
                        $cName = $currName . '_' . $seq;
                    }
                    if ($seq > 2) {
                        $currName = $cName;
                    }

                    // Set the offset and depth (from the matched ='s) for the current section
                    $this->sections->byIndex[$currIndex]['offset'] = $currOffset;
                    $this->sections->byIndex[$currIndex]['depth']  = strlen($matches[1][$currIndex - 1]);
                    $this->sections->byName[$currName]['offset']   = $currOffset;
                    $this->sections->byName[$currName]['depth']    = strlen($matches[1][$currIndex - 1]);

                    // If there is a section after this, set the length of this one
                    if (isset($sections[$currIndex])) {
                        // Get the offset of the next section
                        $nextOffset = strpos($this->text, $sections[$currIndex], $currOffset);
                        // Calculate the length of this one
                        $length     = $nextOffset - $currOffset;

                        // Set the length of this section
                        $this->sections->byIndex[$currIndex]['length'] = $length;
                        $this->sections->byName[$currName]['length']   = $length;
                    } else {
                        // Set the length of last section
                        $this->sections->byIndex[$currIndex]['length'] = strlen($this->text) - $currOffset;
                        $this->sections->byName[$currName]['length']   = strlen($this->text) - $currOffset;
                    }
                }
            }
        }

        return $this->text; // Return the text in any case
    }

    /**
     * Returns the requested section, with its subsections, if any.
     *
     * Section can be the following:
     * - section name (string, e.g. "History")
     * - section index (int, e.g. 3)
     *
     * @param   mixed    $section             The section to get
     * @param   boolean  $includeHeading      False to get section text only,
     *                                        true to include heading too
     * @param   boolean  $includeSubsections  False to get section text only,
     *                                        true to include subsections too
     * @return  mixed                         Wikitext of the section on the page,
     *                                        or null if section is undefined
     */
    public function getSection($section, $includeHeading = false, $includeSubsections = true)
    {
        // Check if we have a section name or index
        if (is_int($section)) {
            if (!isset($this->sections->byIndex[$section])) {
                return null;
            }
            $coords = $this->sections->byIndex[$section];
        } elseif (is_string($section)) {
            if (!isset($this->sections->byName[$section])) {
                return null;
            }
            $coords = $this->sections->byName[$section];
        } else {
            $coords = array();
        }

        // Extract the offset, depth and (initial) length
        @extract($coords);
        // Find subsections if requested, and not the intro
        if ($includeSubsections && $offset > 0) {
            $found = false;
            foreach ($this->sections->byName as $section) {
                if ($found) {
                    // Include length of this subsection
                    if ($depth < $section['depth']) {
                        $length += $section['length'];
                    // Done if not a subsection
                    } else {
                        break;
                    }
                } else {
                    // Found our section if same offset
                    if ($offset == $section['offset']) {
                        $found = true;
                    }
                }
            }
        }
        // Extract text of section, and its subsections if requested
        $text = substr($this->text, $offset, $length);

        // Whack off the heading if requested, and not the intro
        if (!$includeHeading && $offset > 0) {
            // Chop off the first line
            $text = substr($text, strpos($text, "\n"));
        }

        return $text;
    }

    /**
     * Returns all the sections of the page in an array - the key names can be
     * set to name or index by using the following for the second param:
     * - self::SECTIONLIST_BY_NAME
     * - self::SECTIONLIST_BY_INDEX
     *
     * @param   boolean  $includeHeading  False to get section text only
     * @param   integer  $keyNames        Modifier for the array key names
     * @return  array                     Array of sections
     * @throw   UnexpectedValueException  If $keyNames is not a supported constant
     */
    public function getAllSections($includeHeading = false, $keyNames = self::SECTIONLIST_BY_INDEX)
    {
        $sections = array();

        switch ($keyNames) {
            case self::SECTIONLIST_BY_INDEX:
                $array = array_keys($this->sections->byIndex);
                break;
            case self::SECTIONLIST_BY_NAME:
                $array = array_keys($this->sections->byName);
                break;
            default:
                throw new \UnexpectedValueException("Unexpected keyNames parameter " .
                    "($keyNames) passed to WikiPage::getAllSections()");
        }

        foreach ($array as $key) {
            $sections[$key] = $this->getSection($key, $includeHeading);
        }

        return $sections;
    }

    /*
     *
     * Setter methods
     *
     */

    /**
     * Sets the text in the page.  Updates the starttimestamp to the timestamp
     * after the page edit (if the edit is successful).
     *
     * Section can be the following:
     * - section name (string, e.g. "History")
     * - section index (int, e.g. 3)
     * - a new section (the string "new")
     * - the whole page (null)
     *
     * @param   string   $text     The article text
     * @param   string   $section  The section to edit (whole page by default)
     * @param   boolean  $minor    True for minor edit
     * @param   string   $summary  Summary text, and section header in case
     *                             of new section
     * @return  boolean            True if page was edited successfully
     */
    public function setText($text, $section = null, $minor = false, $summary = null)
    {
        $data = array(
            'title' => $this->title,
            'text' => $text,
            'md5' => md5($text),
            'bot' => "true",
            'starttimestamp' => $this->starttimestamp,
        );

        // Set options from arguments
        if (!is_null($section)) {
            // Obtain section index in case it is a name
            $data['section'] = $this->findSection($section);
            if ($data['section'] == -1) {
                return false;
            }
        }
        if ($minor) {
            $data['minor'] = $minor;
        }
        if (!is_null($summary)) {
            $data['summary'] = $summary;
        }

        // Make sure we don't create a page by accident or overwrite another one
        if (!$this->exists) {
            $data['createonly'] = "true"; // createonly if not exists
        } else {
            $data['nocreate'] = "true"; // Don't create, it should exist
        }

        $r = $this->wikimate->edit($data); // The edit query

        // Check if it worked
        if (isset($r['edit']['result']) && $r['edit']['result'] == 'Success') {
            $this->exists = true;

            if (is_null($section)) {
                $this->text = $text;
            }

            // Get the new starttimestamp
            $data = array(
                'titles' => $this->title,
                'prop' => 'info',
                'curtimestamp' => 1,
            );

            $r = $this->wikimate->query($data);

            // Check for errors
            if (isset($r['error'])) {
                $this->error = $r['error']; // Set the error if there was one
                return false;
            } else {
                $this->error = null; // Reset the error status
            }

            $this->starttimestamp = $r['curtimestamp']; // Update the starttimestamp
            return true;
        }

        // Return error response
        if (isset($r['error'])) {
            $this->error = $r['error'];
        } else {
            $this->error = array();
            $this->error['page'] = 'Unexpected edit response: ' . $r['edit']['result'];
        }
        return false;
    }

    /**
     * Sets the text of the given section.
     * Essentially an alias of WikiPage:setText()
     * with the summary and minor parameters switched.
     *
     * Section can be the following:
     * - section name (string, e.g. "History")
     * - section index (int, e.g. 3)
     * - a new section (the string "new")
     * - the whole page (null)
     *
     * @param   string   $text     The text of the section
     * @param   mixed    $section  The section to edit (intro by default)
     * @param   string   $summary  Summary text, and section header in case
     *                             of new section
     * @param   boolean  $minor    True for minor edit
     * @return  boolean            True if the section was saved
     */
    public function setSection($text, $section = 0, $summary = null, $minor = false)
    {
        return $this->setText($text, $section, $minor, $summary);
    }

    /**
     * Alias of WikiPage::setSection() specifically for creating new sections.
     *
     * @param   string   $name  The heading name for the new section
     * @param   string   $text  The text of the new section
     * @return  boolean         True if the section was saved
     */
    public function newSection($name, $text)
    {
        return $this->setSection($text, 'new', $name, false);
    }

    /**
     * Deletes the page.
     *
     * @param   string   $reason  Reason for the deletion
     * @return  boolean           True if page was deleted successfully
     */
    public function delete($reason = null)
    {
        $data = array(
            'title' => $this->title,
        );

        // Set options from arguments
        if (!is_null($reason)) {
            $data['reason'] = $reason;
        }

        $r = $this->wikimate->delete($data); // The delete query

        // Check if it worked
        if (isset($r['delete'])) {
            $this->exists = false; // The page was deleted

            $this->error = null; // Reset the error status
            return true;
        }

        $this->error = $r['error']; // Return error response
        return false;
    }

    /*
     *
     * Private methods
     *
     */

    /**
     * Finds a section's index by name.
     * If a section index or 'new' is passed, it is returned directly.
     *
     * @param   mixed  $section  The section name or index to find
     * @return  mixed            The section index, or -1 if not found
     */
    private function findSection($section)
    {
        // Check section type
        if (is_int($section) || $section === 'new') {
            return $section;
        } elseif (is_string($section)) {
            // Search section names for related index
            $sections = array_keys($this->sections->byName);
            $index = array_search($section, $sections);

            // Return index if found
            if ($index !== false) {
                return $index;
            }
        }

        // Return error message and value
        $this->error = array();
        $this->error['page'] = "Section '$section' was not found on this page";
        return -1;
    }
}


/**
 * Models a wiki file that can have its properties retrieved and
 * its contents downloaded and uploaded.
 * All properties pertain to the current revision of the file.
 *
 * @author  Robert McLeod & Frans P. de Vries
 * @since   0.12.0  October 2016
 */
class WikiFile
{
    /**
     * The name of the file
     *
     * @var string|null
     */
    protected $filename = null;

    /**
     * Wikimate object for API requests
     *
     * @var Wikimate|null
     */
    protected $wikimate = null;

    /**
     * Whether the file exists
     *
     * @var boolean
     */
    protected $exists = false;

    /**
     * Whether the file is invalid
     *
     * @var boolean
     */
    protected $invalid = false;

    /**
     * Error array with API and WikiFile errors
     *
     * @var array|null
     */
    protected $error = null;

    /**
     * Image info for the current file revision
     *
     * @var array|null
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Imageinfo
     */
    protected $info = null;

    /**
     * Image info for all file revisions
     *
     * @var array|null
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Imageinfo
     */
    protected $history = null;

    /*
     *
     * Magic methods
     *
     */

    /**
     * Constructs a WikiFile object from the filename given
     * and associate with the passed Wikimate object.
     *
     * @param  string    $filename  Name of the wiki file
     * @param  Wikimate  $wikimate  Wikimate object
     */
    public function __construct($filename, $wikimate)
    {
        $this->wikimate = $wikimate;
        $this->filename = $filename;
        $this->info     = $this->getInfo(true);

        if ($this->invalid) {
            $this->error['file'] = 'Invalid filename - cannot create WikiFile';
        }
    }

    /**
     * Forgets all object properties.
     */
    public function __destruct()
    {
        $this->filename = null;
        $this->wikimate = null;
        $this->exists   = false;
        $this->invalid  = false;
        $this->error    = null;
        $this->info     = null;
        $this->history  = null;
    }

    /**
     * Returns the file existence status.
     *
     * @return  boolean  True if file exists
     */
    public function exists()
    {
        return $this->exists;
    }

    /**
     * Alias of self::__destruct().
     *
     * @return void
     */
    public function destroy()
    {
        $this->__destruct();
    }

    /*
     *
     * File meta methods
     *
     */

    /**
     * Returns the latest error if there is one.
     *
     * @return  mixed  The error array, or null if no error
     */
    public function getError()
    {
        return $this->error;
    }

    /**
     * Returns the name of this file.
     *
     * @return  string  The name of this file
     */
    public function getFilename()
    {
        return $this->filename;
    }

    /*
     *
     * Getter methods
     *
     */

    /**
     * Gets the information of the file. If refresh is true,
     * then this method will query the wiki API again for the file details.
     *
     * @param   boolean  $refresh  True to query the wiki API again
     * @param   array    $history  An optional array of revision history parameters
     * @return  mixed              The info of the file (array), or null if error
     */
    public function getInfo($refresh = false, $history = null)
    {
        if ($refresh) { // We want to query the API
            // Specify relevant file properties to retrieve
            $data = array(
                'titles' => 'File:' . $this->filename,
                'prop' => 'info|imageinfo',
                'iiprop' => 'bitdepth|canonicaltitle|comment|parsedcomment|'
                          . 'commonmetadata|metadata|extmetadata|mediatype|'
                          . 'mime|thumbmime|sha1|size|timestamp|url|user|userid',
            );
            // Add optional history parameters
            if (is_array($history)) {
                foreach ($history as $key => $val) {
                    $data[$key] = $val;
                }
                // Retrieve archive name property as well
                $data['iiprop'] .= '|archivename';
            }

            $r = $this->wikimate->query($data); // Run the query

            // Check for errors
            if (isset($r['error'])) {
                $this->error = $r['error']; // Set the error if there was one
                return null;
            } else {
                $this->error = null; // Reset the error status
            }

            // Get the page (there should only be one)
            $page = array_pop($r['query']['pages']);
            unset($r, $data);

            // Abort if invalid file title
            if (isset($page['invalid'])) {
                $this->invalid = true;
                return null;
            }

            // Check that file is present and has info
            if (!isset($page['missing']) && isset($page['imageinfo'])) {
                // Update the existence if the file is there
                $this->exists = true;
                // Put the content into info & history
                $this->info    = $page['imageinfo'][0];
                $this->history = $page['imageinfo'];
            }
            unset($page);
        }

        return $this->info; // Return the info in any case
    }

    /**
     * Returns the anonymous flag of this file,
     * or of its specified revision.
     * If true, then getUser()'s value represents an anonymous IP address.
     *
     * @param   mixed  $revision  The index or timestamp of the revision (optional)
     * @return  mixed             The anonymous flag of this file (boolean),
     *                            or null if revision not found
     */
    public function getAnon($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            // Check for anon flag
            return isset($this->info['anon']) ? true : false;
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return null;
        }

        // Check for anon flag
        return isset($info['anon']) ? true : false;
    }

    /**
     * Returns the aspect ratio of this image,
     * or of its specified revision.
     * Returns 0 if file is not an image (and thus has no dimensions).
     *
     * @param   mixed  $revision  The index or timestamp of the revision (optional)
     * @return  float             The aspect ratio of this image, or 0 if no dimensions,
     *                            or -1 if revision not found
     */
    public function getAspectRatio($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            // Check for dimensions
            if ($this->info['height'] > 0) {
                return $this->info['width'] / $this->info['height'];
            } else {
                return 0;
            }
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return -1;
        }

        // Check for dimensions
        if (isset($info['height'])) {
            return $info['width'] / $info['height'];
        } else {
            return 0;
        }
    }

    /**
     * Returns the bit depth of this file,
     * or of its specified revision.
     *
     * @param   mixed    $revision  The index or timestamp of the revision (optional)
     * @return  integer             The bit depth of this file,
     *                              or -1 if revision not found
     */
    public function getBitDepth($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return (int)$this->info['bitdepth'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return -1;
        }

        return (int)$info['bitdepth'];
    }

    /**
     * Returns the canonical title of this file,
     * or of its specified revision.
     *
     * @param   mixed  $revision  The index or timestamp of the revision (optional)
     * @return  mixed             The canonical title of this file (string),
     *                            or null if revision not found
     */
    public function getCanonicalTitle($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return $this->info['canonicaltitle'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return null;
        }

        return $info['canonicaltitle'];
    }

    /**
     * Returns the edit comment of this file,
     * or of its specified revision.
     *
     * @param   mixed  $revision  The index or timestamp of the revision (optional)
     * @return  mixed             The edit comment of this file (string),
     *                            or null if revision not found
     */
    public function getComment($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return $this->info['comment'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return null;
        }

        return $info['comment'];
    }

    /**
     * Returns the common metadata of this file,
     * or of its specified revision.
     *
     * @param   mixed  $revision  The index or timestamp of the revision (optional)
     * @return  mixed             The common metadata of this file (array),
     *                            or null if revision not found
     */
    public function getCommonMetadata($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return $this->info['commonmetadata'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return null;
        }

        return $info['commonmetadata'];
    }

    /**
     * Returns the description URL of this file,
     * or of its specified revision.
     *
     * @param   mixed  $revision  The index or timestamp of the revision (optional)
     * @return  mixed             The description URL of this file (string),
     *                            or null if revision not found
     */
    public function getDescriptionUrl($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return $this->info['descriptionurl'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return null;
        }

        return $info['descriptionurl'];
    }

    /**
     * Returns the extended metadata of this file,
     * or of its specified revision.
     *
     * @param   mixed  $revision  The index or timestamp of the revision (optional)
     * @return  mixed             The extended metadata of this file (array),
     *                            or null if revision not found
     */
    public function getExtendedMetadata($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return $this->info['extmetadata'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return null;
        }

        return $info['extmetadata'];
    }

    /**
     * Returns the height of this file,
     * or of its specified revision.
     *
     * @param   mixed    $revision  The index or timestamp of the revision (optional)
     * @return  integer             The height of this file, or -1 if revision not found
     */
    public function getHeight($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return (int)$this->info['height'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return -1;
        }

        return (int)$info['height'];
    }

    /**
     * Returns the media type of this file,
     * or of its specified revision.
     *
     * @param   mixed  $revision  The index or timestamp of the revision (optional)
     * @return  mixed             The media type of this file (string),
     *                            or null if revision not found
     */
    public function getMediaType($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return $this->info['mediatype'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return null;
        }

        return $info['mediatype'];
    }

    /**
     * Returns the Exif metadata of this file,
     * or of its specified revision.
     *
     * @param   mixed  $revision  The index or timestamp of the revision (optional)
     * @return  mixed             The metadata of this file (array),
     *                            or null if revision not found
     */
    public function getMetadata($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return $this->info['metadata'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return null;
        }

        return $info['metadata'];
    }

    /**
     * Returns the MIME type of this file,
     * or of its specified revision.
     *
     * @param   mixed  $revision  The index or timestamp of the revision (optional)
     * @return  mixed             The MIME type of this file (string),
     *                            or null if revision not found
     */
    public function getMime($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return $this->info['mime'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return null;
        }

        return $info['mime'];
    }

    /**
     * Returns the parsed edit comment of this file,
     * or of its specified revision.
     *
     * @param   mixed  $revision  The index or timestamp of the revision (optional)
     * @return  mixed             The parsed edit comment of this file (string),
     *                            or null if revision not found
     */
    public function getParsedComment($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return $this->info['parsedcomment'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return null;
        }

        return $info['parsedcomment'];
    }

    /**
     * Returns the SHA-1 hash of this file,
     * or of its specified revision.
     *
     * @param   mixed  $revision  The index or timestamp of the revision (optional)
     * @return  mixed             The SHA-1 hash of this file (string),
     *                            or null if revision not found
     */
    public function getSha1($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return $this->info['sha1'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return null;
        }

        return $info['sha1'];
    }

    /**
     * Returns the size of this file,
     * or of its specified revision.
     *
     * @param   mixed    $revision  The index or timestamp of the revision (optional)
     * @return  integer             The size of this file, or -1 if revision not found
     */
    public function getSize($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return (int)$this->info['size'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return -1;
        }

        return (int)$info['size'];
    }

    /**
     * Returns the MIME type of this file's thumbnail,
     * or of its specified revision.
     * Returns empty string if property not available for this file type.
     *
     * @param   mixed  $revision  The index or timestamp of the revision (optional)
     * @return  mixed             The MIME type of this file's thumbnail (string),
     *                            or '' if unavailable, or null if revision not found
     */
    public function getThumbMime($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return (isset($this->info['thumbmime']) ? $this->info['thumbmime'] : '');
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return null;
        }

        // Check for thumbnail MIME type
        return (isset($info['thumbmime']) ? $info['thumbmime'] : '');
    }

    /**
     * Returns the timestamp of this file,
     * or of its specified revision.
     *
     * @param   mixed  $revision  The index or timestamp of the revision (optional)
     * @return  mixed             The timestamp of this file (string),
     *                            or null if revision not found
     */
    public function getTimestamp($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return $this->info['timestamp'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return null;
        }

        return $info['timestamp'];
    }

    /**
     * Returns the URL of this file,
     * or of its specified revision.
     *
     * @param   mixed  $revision  The index or timestamp of the revision (optional)
     * @return  mixed             The URL of this file (string),
     *                            or null if revision not found
     */
    public function getUrl($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return $this->info['url'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return null;
        }

        return $info['url'];
    }

    /**
     * Returns the user who uploaded this file,
     * or of its specified revision.
     *
     * @param   mixed  $revision  The index or timestamp of the revision (optional)
     * @return  mixed             The user of this file (string),
     *                            or null if revision not found
     */
    public function getUser($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return $this->info['user'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return null;
        }

        return $info['user'];
    }

    /**
     * Returns the ID of the user who uploaded this file,
     * or of its specified revision.
     *
     * @param   mixed    $revision  The index or timestamp of the revision (optional)
     * @return  integer             The user ID of this file,
     *                              or -1 if revision not found
     */
    public function getUserId($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return (int)$this->info['userid'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return -1;
        }

        return (int)$info['userid'];
    }

    /**
     * Returns the width of this file,
     * or of its specified revision.
     *
     * @param   mixed    $revision  The index or timestamp of the revision (optional)
     * @return  integer             The width of this file, or -1 if revision not found
     */
    public function getWidth($revision = null)
    {
        // Without revision, use current info
        if (!isset($revision)) {
            return (int)$this->info['width'];
        }

        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return -1;
        }

        return (int)$info['width'];
    }

    /*
     *
     * File history & deletion methods
     *
     */

    /**
     * Returns the revision history of this file with all properties.
     * The initial history at object creation contains only the
     * current revision of the file. To obtain more revisions,
     * set $refresh to true and also optionally set $limit and
     * the timestamps.
     *
     * The maximum limit is 500 for user accounts and 5000 for bot accounts.
     *
     * Timestamps can be in several formats as described here:
     * {@see https://www.mediawiki.org/w/api.php?action=help&modules=main#main.2Fdatatypes}
     *
     * @param   boolean  $refresh  True to query the wiki API again
     * @param   integer  $limit    The number of file revisions to return
     *                             (the maximum number by default)
     * @param   string   $startts  The start timestamp of the listing (optional)
     * @param   string   $endts    The end timestamp of the listing (optional)
     * @return  mixed              The array of selected file revisions, or null if error
     */
    public function getHistory($refresh = false, $limit = null, $startts = null, $endts = null)
    {
        if ($refresh) { // We want to query the API
            // Collect optional history parameters
            $history = array();
            if (!is_null($limit)) {
                $history['iilimit'] = $limit;
            } else {
                $history['iilimit'] = 'max';
            }
            if (!is_null($startts)) {
                $history['iistart'] = $startts;
            }
            if (!is_null($endts)) {
                $history['iiend'] = $endts;
            }

            // Get file revision history
            if ($this->getInfo($refresh, $history) === null) {
                return null;
            }
        }

        return $this->history;
    }

    /**
     * Returns the properties of the specified file revision.
     *
     * Revision can be the following:
     * - revision timestamp (string, e.g. "2001-01-15T14:56:00Z")
     * - revision index (int, e.g. 3)
     * The most recent revision has index 0,
     * and it increments towards older revisions.
     * A timestamp must be in ISO 8601 format.
     *
     * @param   mixed  $revision  The index or timestamp of the revision
     * @return  mixed             The properties (array), or null if not found
     */
    public function getRevision($revision)
    {
        // Select revision by index
        if (is_int($revision)) {
            if (isset($this->history[$revision])) {
                return $this->history[$revision];
            }
        // Search revision by timestamp
        } else {
            foreach ($this->history as $history) {
                if ($history['timestamp'] == $revision) {
                    return $history;
                }
            }
        }

        // Return error message
        $this->error = array();
        $this->error['file'] = "Revision '$revision' was not found for this file";
        return null;
    }

    /**
     * Returns the archive name of the specified file revision.
     *
     * Revision can be the following:
     * - revision timestamp (string, e.g. "2001-01-15T14:56:00Z")
     * - revision index (int, e.g. 3)
     * The most recent revision has index 0,
     * and it increments towards older revisions.
     * A timestamp must be in ISO 8601 format.
     *
     * @param   mixed  $revision  The index or timestamp of the revision
     * @return  mixed             The archive name (string), or null if not found
     */
    public function getArchivename($revision)
    {
        // Obtain the properties of the revision
        if (($info = $this->getRevision($revision)) === null) {
            return null;
        }

        // Check for archive name
        if (!isset($info['archivename'])) {
            // Return error message
            $this->error = array();
            $this->error['file'] = 'This revision contains no archive name';
            return null;
        }

        return $info['archivename'];
    }

    /**
     * Deletes the file, or only an older revision of it.
     *
     * @param   string   $reason       Reason for the deletion
     * @param   string   $archivename  The archive name of the older revision
     * @return  boolean                True if file (revision) was deleted successfully
     */
    public function delete($reason = null, $archivename = null)
    {
        $data = array(
            'title' => 'File:' . $this->filename,
        );

        // Set options from arguments
        if (!is_null($reason)) {
            $data['reason'] = $reason;
        }
        if (!is_null($archivename)) {
            $data['oldimage'] = $archivename;
        }

        $r = $this->wikimate->delete($data); // The delete query

        // Check if it worked
        if (isset($r['delete'])) {
            if (is_null($archivename)) {
                $this->exists = false; // The file was deleted altogether
            }

            $this->error = null; // Reset the error status
            return true;
        }

        $this->error = $r['error']; // Return error response
        return false;
    }

    /**
     * Reverts file to an older revision.
     *
     * @param   string   $archivename  The archive name of the older revision
     * @param   string   $reason       Reason for the revert
     * @return  boolean                True if reverting was successful
     * @link https://www.mediawiki.org/wiki/Special:MyLanguage/API:Filerevert
     */
    public function revert($archivename, $reason = null)
    {
        // Set options from arguments
        $data = array(
            'filename' => $this->filename,
            'archivename' => $archivename,
        );
        if (!is_null($reason)) {
            $data['comment'] = $reason;
        }

        $r = $this->wikimate->filerevert($data); // The revert query

        // Check if it worked
        if (isset($r['filerevert']['result']) && $r['filerevert']['result'] == 'Success') {
            $this->error = null; // Reset the error status
            return true;
        }

        $this->error = $r['error']; // Return error response
        return false;
    }

    /*
     *
     * File contents methods
     *
     */

    /**
     * Downloads and returns the current file's contents,
     * or null if an error occurs.
     *
     * @return  mixed  Contents (string), or null if error
     */
    public function downloadData()
    {
        // Download file, or handle error
        $data = $this->wikimate->download($this->getUrl());
        if ($data === null) {
            $this->error = $this->wikimate->getError(); // Copy error if there was one
        } else {
            $this->error = null; // Reset the error status
        }

        return $data;
    }

    /**
     * Downloads the current file's contents and writes it to the given path.
     *
     * @param   string   $path  The file path to write to
     * @return  boolean         True if path was written successfully
     */
    public function downloadFile($path)
    {
        // Download contents of current file
        if (($data = $this->downloadData()) === null) {
            return false;
        }

        // Write contents to specified path
        if (@file_put_contents($path, $data) === false) {
            $this->error = array();
            $this->error['file'] = "Unable to write file '$path'";
            return false;
        }

        return true;
    }

    /**
     * Uploads to the current file using the given parameters.
     * $text is only used for the page contents of a new file,
     * not an existing one (update that via WikiPage::setText()).
     * If no $text is specified, $comment will be used as new page text.
     *
     * @param   array    $params     The upload parameters
     * @param   string   $comment    Upload comment for the file
     * @param   string   $text       The article text for the file page
     * @param   boolean  $overwrite  True to overwrite existing file
     * @return  boolean              True if uploading was successful
     */
    private function uploadCommon(array $params, $comment, $text = null, $overwrite = false)
    {
        // Check whether to overwrite existing file
        if ($this->exists && !$overwrite) {
            $this->error = array();
            $this->error['file'] = 'Cannot overwrite existing file';
            return false;
        }

        // Collect upload parameters
        $params['filename']       = $this->filename;
        $params['comment']        = $comment;
        $params['ignorewarnings'] = $overwrite;
        if (!is_null($text)) {
            $params['text']   = $text;
        }

        // Upload file, or handle error
        $r = $this->wikimate->upload($params);

        if (isset($r['upload']['result']) && $r['upload']['result'] == 'Success') {
            // Update the file's properties
            $this->info = $r['upload']['imageinfo'];

            $this->error = null; // Reset the error status
            return true;
        }

        // Return error response
        if (isset($r['error'])) {
            $this->error = $r['error'];
        } else {
            $this->error = array();
            $this->error['file'] = 'Unexpected upload response: ' . $r['upload']['result'];
        }
        return false;
    }

    /**
     * Uploads the given contents to the current file.
     * $text is only used for the page contents of a new file,
     * not an existing one (update that via WikiPage::setText()).
     * If no $text is specified, $comment will be used as new page text.
     *
     * @param   string   $data       The data to upload
     * @param   string   $comment    Upload comment for the file
     * @param   string   $text       The article text for the file page
     * @param   boolean  $overwrite  True to overwrite existing file
     * @return  boolean              True if uploading was successful
     */
    public function uploadData($data, $comment, $text = null, $overwrite = false)
    {
        // Collect upload parameter
        $params = array(
            'file' => $data,
        );

        // Upload contents to current file
        return $this->uploadCommon($params, $comment, $text, $overwrite);
    }

    /**
     * Reads contents from the given path and uploads it to the current file.
     * $text is only used for the page contents of a new file,
     * not an existing one (update that via WikiPage::setText()).
     * If no $text is specified, $comment will be used as new page text.
     *
     * @param   string   $path       The file path to upload
     * @param   string   $comment    Upload comment for the file
     * @param   string   $text       The article text for the file page
     * @param   boolean  $overwrite  True to overwrite existing file
     * @return  boolean              True if uploading was successful
     */
    public function uploadFile($path, $comment, $text = null, $overwrite = false)
    {
        // Read contents from specified path
        if (($data = @file_get_contents($path)) === false) {
            $this->error = array();
            $this->error['file'] = "Unable to read file '$path'";
            return false;
        }

        // Upload contents to current file
        return $this->uploadData($data, $comment, $text, $overwrite);
    }

    /**
     * Uploads file contents from the given URL to the current file.
     * $text is only used for the page contents of a new file,
     * not an existing one (update that via WikiPage::setText()).
     * If no $text is specified, $comment will be used as new page text.
     *
     * @param   string   $url        The URL from which to upload
     * @param   string   $comment    Upload comment for the file
     * @param   string   $text       The article text for the file page
     * @param   boolean  $overwrite  True to overwrite existing file
     * @return  boolean              True if uploading was successful
     */
    public function uploadFromUrl($url, $comment, $text = null, $overwrite = false)
    {
        // Collect upload parameter
        $params = array(
            'url' => $url,
        );

        // Upload URL to current file
        return $this->uploadCommon($params, $comment, $text, $overwrite);
    }
}