<?php
/*

Stan Scates
blr | further

stan@sc8s.com
blrfurther.com

Basic OAuth and caching layer for Seaofclouds' tweet.js, designed
to introduce compatibility with Twitter's v1.1 API.

Version: 1.3.1
Created: 2013.02.20

https://github.com/seaofclouds/tweet
https://github.com/themattharris/tmhOAuth

 */

if(empty($_POST)) { die(); }

class ezTweet {
    /*************************************** config ***************************************/

    // Your Twitter App Consumer Key
    private $consumer_key    = 'YOUR_CONSUMER_KEY';

    // Your Twitter App Consumer Secret
    private $consumer_secret = 'YOUR_CONSUMER_SECRET';

    // Your Twitter App Access Token
    private $user_token      = 'YOUR_ACCESS_TOKEN';

    // Your Twitter App Access Token Secret
    private $user_secret     = 'YOUR_ACCESS_TOKEN_SECRET';

    // Path to tmhOAuth libraries
    private $lib             = './lib/';

    // Enable caching
    private $cache_enabled   = false;

    // Cache interval (minutes)
    private $cache_interval  = 1;

    // Path to writable cache directory
    private $cache_dir       = './';

    // Enable debugging
    private $debug           = false;

    /**************************************************************************************/

    public function __construct() {
        // Initialize paths and etc.
        $this->pathify($this->cache_dir);
        $this->pathify($this->lib);
        $this->message = '';

        // Set server-side debug params
        if($this->debug === true) {
            error_reporting(-1);
        } else {
            error_reporting(0);
        }
    }

    public function fetch() {
        echo json_encode(
            array(
                'response' => json_decode($this->getJSON(), true),
                'message' => ($this->debug) ? $this->message : false
            )
        );
    }

    private function getJSON() {
        if($this->cache_enabled === true) {
            $CFID = $this->generateCFID();
            $cache_file = $this->cache_dir.$CFID;

            if(file_exists($cache_file) && (filemtime($cache_file) > (time() - 60 * intval($this->cache_interval)))) {
                return file_get_contents($cache_file, FILE_USE_INCLUDE_PATH);
            } else {

                $JSONraw = $this->getTwitterJSON();
                $JSON = $JSONraw['response'];

                // Don't write a bad cache file if there was a CURL error
                if($JSONraw['errno'] != 0) {
                    $this->consoleDebug($JSONraw['error']);
                    return $JSON;
                }

                if($this->debug === true) {
                    // Check for twitter-side errors
                    $pj = json_decode($JSON, true);
                    if(isset($pj['errors'])) {
                        foreach($pj['errors'] as $error) {
                            $message = 'Twitter Error: "'.$error['message'].'", Error Code #'.$error['code'];
                            $this->consoleDebug($message);
                        }
                        return false;
                    }
                }

                if(is_writable($this->cache_dir) && $JSONraw) {
                    if(file_put_contents($cache_file, $JSON, LOCK_EX) === false) {
                        $this->consoleDebug("Error writing cache file");
                    }
                } else {
                    $this->consoleDebug("Cache directory is not writable");
                }
                return $JSON;
            }
        } else {
            $JSONraw = $this->getTwitterJSON();

            if($this->debug === true) {
                // Check for CURL errors
                if($JSONraw['errno'] != 0) {
                    $this->consoleDebug($JSONraw['error']);
                }

                // Check for twitter-side errors
                $pj = json_decode($JSONraw['response'], true);
                if(isset($pj['errors'])) {
                    foreach($pj['errors'] as $error) {
                        $message = 'Twitter Error: "'.$error['message'].'", Error Code #'.$error['code'];
                        $this->consoleDebug($message);
                    }
                    return false;
                }
            }
            return $JSONraw['response'];
        }
    }

    private function getTwitterJSON() {
        require $this->lib.'tmhOAuth.php';
        require $this->lib.'tmhUtilities.php';

        $tmhOAuth = new tmhOAuth(array(
            'consumer_key'          => $this->consumer_key,
            'consumer_secret'       => $this->consumer_secret,
            'user_token'            => $this->user_token,
            'user_secret'           => $this->user_secret,
            'curl_ssl_verifypeer'   => false
        ));

        $url = $_POST['request']['url'];
        $params = $_POST['request']['parameters'];

        $tmhOAuth->request('GET', $tmhOAuth->url($url), $params);
        return $tmhOAuth->response;
    }

    private function generateCFID() {
        // The unique cached filename ID
        return md5(serialize($_POST)).'.json';
    }

    private function pathify(&$path) {
        // Ensures our user-specified paths are up to snuff
        $path = realpath($path).'/';
    }

    private function consoleDebug($message) {
        if($this->debug === true) {
            $this->message .= 'tweet.js: '.$message."\n";
        }
    }
}

$ezTweet = new ezTweet;
$ezTweet->fetch();

?>
