<?php

/**
 * A simple wrapper for the Twitter API
 *
 * @package codebird
 * @author J.M. <me@mynetx.net>
 * @copyright 2010-2012 J.M. <me@mynetx.net>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * Define constants
 */
$constants = explode(' ', 'OBJECT ARRAY');
foreach ($constants as $i => $id) {
    $id = 'CODEBIRD_RETURNFORMAT_' . $id;
    defined($id) or define($id, $i);
}
unset($constants);
unset($id);

/**
 * A simple wrapper for the Twitter API
 *
 * @package codebird
 * @subpackage codebird-php
 */
class Codebird
{
    /**
     * The current singleton instance
     */
    private static $_instance = null;

    /**
     * The OAuth consumer key of your registered app
     */
    private static $_oauth_consumer_key = null;

    /**
     * The corresponding consumer secret
     */
    private static $_oauth_consumer_secret = null;

    /**
     * The API endpoint to use
     */
    private $_endpoint = 'https://api.twitter.com/1.1/';

    /**
     * The API endpoint to use for OAuth requests
     */
    private $_endpoint_oauth = 'https://api.twitter.com/';

    /**
     * The API endpoint to use for untransitioned methods
     */
    private $_endpoint_old = 'https://api.twitter.com/1/';

    /**
     * The Request or access token. Used to sign requests
     */
    private $_oauth_token = null;

    /**
     * The corresponding request or access token secret
     */
    private $_oauth_token_secret = null;

    /**
     * The format of data to return from API calls
     */
    private $_return_format = CODEBIRD_RETURNFORMAT_OBJECT;

    /**
     * The cache to use for the public timeline
     */
    private $_statuses_public_timeline_cache = array('timestamp' => false, 'data' => false);

    /**
     * The file formats that Twitter accepts as image uploads
     */
    private $_supported_media_files = array(IMAGETYPE_GIF, IMAGETYPE_JPEG, IMAGETYPE_PNG);

    /**
     * The current Codebird version
     */
    private $_version = '2.2.3';

    /**
     * Returns singleton class instance
     * Always use this method unless you're working with multiple authenticated users at once
     *
     * @return Codebird The instance
     */
    public static function getInstance()
    {
        if (self::$_instance == null) {
            self::$_instance = new self;
        }
        return self::$_instance;
    }

    /**
     * Sets the OAuth consumer key and secret (App key)
     *
     * @param string $key    OAuth consumer key
     * @param string $secret OAuth consumer secret
     *
     * @return void
     */
    public static function setConsumerKey($key, $secret)
    {
        self::$_oauth_consumer_key    = $key;
        self::$_oauth_consumer_secret = $secret;
    }

    /**
     * Gets the current Codebird version
     *
     * @return string The version number
     */
    public function getVersion()
    {
        return $this->_version;
    }

    /**
     * Sets the OAuth request or access token and secret (User key)
     *
     * @param string $token  OAuth request or access token
     * @param string $secret OAuth request or access token secret
     *
     * @return void
     */
    public function setToken($token, $secret)
    {
        $this->_oauth_token        = $token;
        $this->_oauth_token_secret = $secret;
    }

    /**
     * Sets the format for API replies
     *
     * @param int $return_format One of these:
     *                           CODEBIRD_RETURNFORMAT_OBJECT (default)
     *                           CODEBIRD_RETURNFORMAT_ARRAY
     *
     * @return void
     */
    public function setReturnFormat($return_format)
    {
        $this->_return_format = $return_format;
    }

    /**
     * Main API handler working on any requests you issue
     *
     * @param string $fn    The member function you called
     * @param array $params The parameters you sent along
     *
     * @return mixed The API reply encoded in the set return_format
     */

    public function __call($fn, $params)
    {
        // parse parameters
        $apiparams = array();
        if (count($params) > 0) {
            if (is_array($params[0])) {
                $apiparams = $params[0];
            } else {
                parse_str($params[0], $apiparams);
            }
        }

        // map function name to API method
        $method = '';

        // replace _ by /
        $path = explode('_', $fn);
        for ($i = 0; $i < count($path); $i++) {
            if ($i > 0) {
                $method .= '/';
            }
            $method .= $path[$i];
        }
        // undo replacement for URL parameters
        $url_parameters_with_underscore = array('screen_name');
        foreach ($url_parameters_with_underscore as $param) {
            $param = strtoupper($param);
            $replacement_was = str_replace('_', '/', $param);
            $method = str_replace($replacement_was, $param, $method);
        }

        // replace AA by URL parameters
        $method_template = $method;
        $match   = array();
        if (preg_match('/[A-Z_]{2,}/', $method, $match)) {
            foreach ($match as $param) {
                $param_l = strtolower($param);
                $method_template = str_replace($param, ':' . $param_l, $method_template);
                if (!isset($apiparams[$param_l])) {
                    for ($i = 0; $i < 26; $i++) {
                        $method_template = str_replace(chr(65 + $i), '_' . chr(97 + $i), $method_template);
                    }
                    throw new Exception(
                        'To call the templated method "' . $method_template
                        . '", specify the parameter value for "' . $param_l . '".'
                    );
                }
                $method  = str_replace($param, $apiparams[$param_l], $method);
                unset($apiparams[$param_l]);
            }
        }

        // replace A-Z by _a-z
        for ($i = 0; $i < 26; $i++) {
            $method  = str_replace(chr(65 + $i), '_' . chr(97 + $i), $method);
            $method_template = str_replace(chr(65 + $i), '_' . chr(97 + $i), $method_template);
        }

        $httpmethod = $this->_detectMethod($method_template, $apiparams);
        $multipart  = $this->_detectMultipart($method_template);

        // geek-geek: Now allowing to specify filenames as params
        $this->_detectFilenames($method_template, $apiparams);

        return $this->_callApi($httpmethod, $method, $method_template, $apiparams, $multipart);
    }

    /**
     * Uncommon API methods
     */

    /**
     * The public timeline is cached for 1 minute
     * API method wrapper
     *
     * @param mixed Any parameters are sent to __call, untouched
     *
     * @return mixed The API reply
     */
    public function statuses_publicTimeline($mixed = null)
    {
        if ($this->_statuses_public_timeline_cache['timestamp'] && $this->_statuses_public_timeline_cache['timestamp'] + 60 > time()) {
            return $this->_statuses_public_timeline_cache['data'];
        }
        $reply = $this->__call(__FUNCTION__, func_get_args());
        if ($reply->httpstatus == 200) {
            $this->_statuses_public_timeline_cache = array(
                'timestamp' => time(),
                'data' => $reply
            );
        }
        return $reply;
    }

    /**
     * Gets the OAuth authenticate URL for the current request token
     *
     * @return string The OAuth authenticate URL
     */
    public function oauth_authenticate()
    {
        if ($this->_oauth_token == null) {
            throw new Exception('To get the authenticate URL, the OAuth token must be set.');
        }
        return $this->_endpoint_oauth . 'oauth/authenticate?oauth_token=' . $this->_url($this->_oauth_token);
    }

    /**
     * Gets the OAuth authorize URL for the current request token
     *
     * @return string The OAuth authorize URL
     */
    public function oauth_authorize()
    {
        if ($this->_oauth_token == null) {
            throw new Exception('To get the authorize URL, the OAuth token must be set.');
        }
        return $this->_endpoint_oauth . 'oauth/authorize?oauth_token=' . $this->_url($this->_oauth_token);
    }

    /**
     * Signing helpers
     */

    /**
     * URL-encodes the given data
     *
     * @param mixed $data
     *
     * @return mixed The encoded data
     */
    private function _url($data)
    {
        if (is_array($data)) {
            return array_map(array(
                $this,
                '_url'
            ), $data);
        } elseif (is_scalar($data)) {
            return str_replace(array(
                '+',
                '!',
                '*',
                "'",
                '(',
                ')'
            ), array(
                ' ',
                '%21',
                '%2A',
                '%27',
                '%28',
                '%29'
            ), rawurlencode($data));
        } else {
            return '';
        }
    }

    /**
     * Gets the base64-encoded SHA1 hash for the given data
     *
     * @param string $data The data to calculate the hash from
     *
     * @return string The hash
     */
    private function _sha1($data)
    {
        if (self::$_oauth_consumer_secret == null) {
            throw new Exception('To generate a hash, the consumer secret must be set.');
        }
        if (!function_exists('hash_hmac')) {
            throw new Exception('To generate a hash, the PHP hash extension must be available.');
        }
        return base64_encode(hash_hmac('sha1', $data, self::$_oauth_consumer_secret . '&'
            . ($this->_oauth_token_secret != null ? $this->_oauth_token_secret : ''), true));
    }

    /**
     * Generates a (hopefully) unique random string
     *
     * @param int optional $length The length of the string to generate
     *
     * @return string The random string
     */
    private function _nonce($length = 8)
    {
        if ($length < 1) {
            throw new Exception('Invalid nonce length.');
        }
        return substr(md5(microtime(true)), 0, $length);
    }

    /**
     * Generates an OAuth signature
     *
     * @param string          $httpmethod Usually either 'GET' or 'POST' or 'DELETE'
     * @param string          $method     The API method to call
     * @param array  optional $params     The API call parameters, associative
     * @param bool   optional $multipart  Whether the request is going to be multipart/form-data
     *
     * @return string The API call parameters including the signature
     *                If multipart, the Authorization HTTP header is returned
     */
    private function _sign($httpmethod, $method, $params = array(), $multipart = false)
    {
        if (self::$_oauth_consumer_key == null) {
            throw new Exception('To generate a signature, the consumer key must be set.');
        }
        $sign_params      = array(
            'consumer_key' => self::$_oauth_consumer_key,
            'version' => '1.0',
            'timestamp' => time(),
            'nonce' => $this->_nonce(),
            'signature_method' => 'HMAC-SHA1'
        );
        $sign_base_params = array();
        foreach ($sign_params as $key => $value) {
            $sign_base_params['oauth_' . $key] = $this->_url($value);
        }
        if ($this->_oauth_token != null) {
            $sign_base_params['oauth_token'] = $this->_url($this->_oauth_token);
        }
        foreach ($params as $key => $value) {
            $sign_base_params[$key] = $this->_url($value);
        }
        ksort($sign_base_params);
        $sign_base_string = '';
        foreach ($sign_base_params as $key => $value) {
            $sign_base_string .= $key . '=' . $value . '&';
        }
        $sign_base_string = substr($sign_base_string, 0, -1);
        $signature        = $this->_sha1($httpmethod . '&' . $this->_url($method) . '&' . $this->_url($sign_base_string));
        if ($multipart) {
            $params = array_merge($sign_base_params, array(
                'oauth_signature' => $signature
            ));
            ksort($params);
            $authorization = 'Authorization: OAuth ';
            foreach ($params as $key => $value) {
                $authorization .= $key . '="' . $this->_url($value) . '", ';
            }
            return substr($authorization, 0, -2);
        }
        return ($httpmethod == 'GET' ? $method . '?' : '') . $sign_base_string . '&oauth_signature=' . $this->_url($signature);
    }

    /**
     * Detects HTTP method to use for API call
     *
     * @param string $method The API method to call
     * @param array  $params The parameters to send along
     *
     * @return string The HTTP method that should be used
     */
    private function _detectMethod($method, $params)
    {
        // multi-HTTP method endpoints
        switch($method) {
            case 'account/settings':
                $method = count($params) > 0 ? $method . '__post' : $method;
                break;
        }

        $httpmethods         = array();
        $httpmethods['GET']  = array(
            // Timelines
            'statuses/mentions_timeline',
            'statuses/user_timeline',
            'statuses/home_timeline',
            'statuses/retweets_of_me',

            // Tweets
            'statuses/retweets/:id',
            'statuses/show/:id',
            'statuses/oembed',

            // Search
            'search/tweets',

            // Direct Messages
            'direct_messages',
            'direct_messages/sent',
            'direct_messages/show',

            // Friends & Followers
            'friends/ids',
            'followers/ids',
            'friendships/lookup',
            'friendships/incoming',
            'friendships/outgoing',
            'friendships/show',
            'friends/list',
            'followers/list',

            // Users
            'account/settings',
            'account/verify_credentials',
            'blocks/list',
            'blocks/ids',
            'users/lookup',
            'users/show',
            'users/search',
            'users/contributees',
            'users/contributors',
            'users/profile_banner',

            // Suggested Users
            'users/suggestions/:slug',
            'users/suggestions',
            'users/suggestions/:slug/members',

            // Favorites
            'favorites/list',

            // Lists
            'lists/list',
            'lists/statuses',
            'lists/memberships',
            'lists/subscribers',
            'lists/subscribers/show',
            'lists/members/show',
            'lists/members',
            'lists/show',
            'lists/subscriptions',

            // Saved searches
            'saved_searches/list',
            'saved_searches/show/:id',

            // Places & Geo
            'geo/id/:place_id',
            'geo/reverse_geocode',
            'geo/search',
            'geo/similar_places',

            // Trends
            'trends/place',
            'trends/available',
            'trends/closest',

            // OAuth
            'oauth/authenticate',
            'oauth/authorize',

            // Help
            'help/configuration',
            'help/languages',
            'help/privacy',
            'help/tos',
            'application/rate_limit_status',

            // Old
            'users/recommendations'
        );
        $httpmethods['POST'] = array(
            // Tweets
            'statuses/destroy/:id',
            'statuses/update',
            'statuses/retweet/:id',
            'statuses/update_with_media',

            // Direct Messages
            'direct_messages/destroy',
            'direct_messages/new',

            // Friends & Followers
            'friendships/create',
            'friendships/destroy',
            'friendships/update',

            // Users
            'account/settings__post',
            'account/update_delivery_device',
            'account/update_profile',
            'account/update_profile_background_image',
            'account/update_profile_colors',
            'account/update_profile_image',
            'blocks/create',
            'blocks/destroy',
            'account/update_profile_banner',
            'account/remove_profile_banner',

            // Favorites
            'favorites/destroy',
            'favorites/create',

            // Lists
            'lists/members/destroy',
            'lists/subscribers/create',
            'lists/subscribers/destroy',
            'lists/members/create_all',
            'lists/members/create',
            'lists/destroy',
            'lists/update',
            'lists/create',
            'lists/members/destroy_all',

            // Saved Searches
            'saved_searches/create',
            'saved_searches/destroy/:id',

            // Places & Geo
            'geo/place',

            // Spam Reporting
            'users/report_spam',

            // OAuth
            'oauth/access_token',
            'oauth/request_token'
        );
        foreach ($httpmethods as $httpmethod => $methods) {
            if (in_array($method, $methods)) {
                return $httpmethod;
            }
        }
        throw new Exception('Can\'t find HTTP method to use for "' . $method . '".');
    }

    /**
     * Detects if API call should use multipart/form-data
     *
     * @param string $method The API method to call
     *
     * @return bool Whether the method should be sent as multipart
     */
    private function _detectMultipart($method)
    {
        $multiparts = array(
            // Tweets
            'statuses/update_with_media',

            // Users
            'account/update_profile_background_image',
            'account/update_profile_image',
            'account/update_profile_banner'
        );
        return in_array($method, $multiparts);
    }

    /**
     * Detects if API call should use the old endpoint
     *
     * @param string $method The API method to call
     *
     * @return bool Whether the method is defined in old API
     */
    private function _detectOld($method)
    {
        $olds = array(
            // Users
            'users/recommendations'
        );
        return in_array($method, $olds);
    }

    /**
     * Detects filenames in upload parameters
     *
     * @param       string $method  The API method to call
     * @param byref array  $params  The parameters to send along
     *
     * @return void
     */
    private function _detectFilenames($method, &$params)
    {
        // well, files will only work in multipart methods
        if (! $this->_detectMultipart($method)) {
            return;
        }

        // only check specific parameters
        $possible_files = array(
            // Tweets
            'statuses/update_with_media' => 'media[]',
            // Accounts
            'account/update_profile_background_image' => 'image',
            'account/update_profile_image' => 'image',
            'account/update_profile_banner' => 'banner'
        );
        // method might have files?
        if (! in_array($method, array_keys($possible_files))) {
            return;
        }

        // check for filenames
        $possible_files = explode(' ', $possible_files[$method]);
        foreach ($possible_files as $possible_file) {
            // is this parameter set currently?
            if (! isset($params[$possible_file])) {
                continue;
            }
            // is it an array?
            if (is_array($params[$possible_file])) {
                throw new Exception('Using URL-encoded parameters is not supported for uploading media.');
                continue;
            }
            // is it a file, a readable one?
            if (! @file_exists($params[$possible_file])
                || ! @is_readable($params[$possible_file])
            ) {
                continue;
            }
            // is it a valid image?
            if (! $data = @getimagesize($params[$possible_file])) {
                continue;
            }
            // is it a supported image format?
            if (! in_array($data[2], $this->_supported_media_files)) {
                continue;
            }
            // try to read the file
            ob_start();
            readfile($params[$possible_file]);
            $data = ob_get_contents();
            ob_end_clean();
            if (strlen($data) == 0) {
                continue;
            }
            $params[$possible_file] = $data;
        }
    }


    /**
     * Builds the complete API endpoint url
     *
     * @param string $method           The API method to call
     * @param string $method_template  The API method template to call
     *
     * @return string The URL to send the request to
     */
    private function _getEndpoint($method, $method_template)
    {
        if (substr($method, 0, 6) == 'oauth/') {
            $url = $this->_endpoint_oauth . $method;
        } elseif ($this->_detectOld($method_template)) {
            $url = $this->_endpoint_old . $method . '.json';
        } else {
            $url = $this->_endpoint . $method . '.json';
        }
        return $url;
    }

    /**
     * Calls the API using cURL
     *
     * @param string          $httpmethod      The HTTP method to use for making the request
     * @param string          $method          The API method to call
     * @param string          $method_template The templated API method to call
     * @param array  optional $params          The parameters to send along
     * @param bool   optional $multipart       Whether to use multipart/form-data
     *
     * @return mixed The API reply, encoded in the set return_format
     */

    private function _callApi($httpmethod, $method, $method_template, $params = array(), $multipart = false)
    {
        if (! function_exists('curl_init')) {
            throw new Exception('To make API requests, the PHP curl extension must be available.');
        }
        $url = $this->_getEndpoint($method, $method_template);
        $ch  = false;
        if ($httpmethod == 'GET') {
            $ch = curl_init($this->_sign($httpmethod, $url, $params));
        } else {
            if ($multipart) {
                $authorization = $this->_sign('POST', $url, array(), true);
                $post_fields   = $params;
            } else {
                $post_fields = $this->_sign('POST', $url, $params);
            }
            $ch = curl_init($url);
            curl_setopt($ch, CURLOPT_POST, 1);
            curl_setopt($ch, CURLOPT_POSTFIELDS, $post_fields);
        }
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 0);
        curl_setopt($ch, CURLOPT_HEADER, 1);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
        if (isset($authorization)) {
            curl_setopt($ch, CURLOPT_HTTPHEADER, array(
                $authorization,
                'Expect:'
            ));
        }
        $reply      = curl_exec($ch);
        $httpstatus = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $reply = $this->_parseApiReply($method_template, $reply);
        if ($this->_return_format == CODEBIRD_RETURNFORMAT_OBJECT) {
            $reply->httpstatus = $httpstatus;
        } else {
            $reply['httpstatus'] = $httpstatus;
        }
        return $reply;
    }

    /**
     * Parses the API reply to encode it in the set return_format
     *
     * @param string $method The method that has been called
     * @param string $reply  The actual reply, JSON-encoded or URL-encoded
     *
     * @return array|object The parsed reply
     */
    private function _parseApiReply($method, $reply)
    {
        // split headers and body
        $headers = array();
        $reply = explode("\r\n\r\n", $reply, 2);
        $headers_array = explode("\r\n", $reply[0]);
        foreach ($headers_array as $header) {
            $header_array = explode(': ', $header, 2);
            $key = $header_array[0];
            $value = '';
            if (count($header_array) > 1) {
                $value = $header_array[1];
            }
            $headers[$key] = $value;
        }
        if (count($reply) > 1) {
            $reply = $reply[1];
        } else {
            $reply = '';
        }

        $need_array = $this->_return_format == CODEBIRD_RETURNFORMAT_ARRAY;
        if ($reply == '[]') {
            return $need_array ? array() : new stdClass;
        }
        $parsed = array();
        if ($method == 'users/profile_image/:screen_name') {
            // this method returns a 302 redirect, we need to extract the URL
            if (isset($headers['Location'])) {
                $parsed = array('profile_image_url_https' => $headers['Location']);
            }
        } elseif (!$parsed = json_decode($reply, $need_array)) {
            if ($reply) {
                $reply = explode('&', $reply);
                foreach ($reply as $element) {
                    if (stristr($element, '=')) {
                        list($key, $value) = explode('=', $element);
                        $parsed[$key] = $value;
                    } else {
                        $parsed['message'] = $element;
                    }
                }
            }
        }
        if (!$need_array) {
            $parsed = (object) $parsed;
        }
        return $parsed;
    }
}

?>