PHP: Twitter Auto Reply

twitter.php

<?php
	
	class TwitterAutoReply
	{
	        // Constants
	        const SEARCH_URL = 'http://search.twitter.com/search.json?q=%s&since_id=%s';
	        const UPDATE_URL = 'https://twitter.com/statuses/update.json';
	        const VERIFY_URL = 'http://api.twitter.com/1/account/verify_credentials.json';
	        const REQUEST_TOKEN_URL = 'https://twitter.com/oauth/request_token';
	        const ACCESS_TOKEN_URL = 'https://twitter.com/oauth/access_token';
	        const AUTH_URL = 'http://twitter.com/oauth/authorize';
	        
	        // Variables
	        private $_replies = array();
	        private $_oauth;
	        
	        // Methods
	        public function __construct($consumer_key, $consumer_secret)
	        {
	                $this->_oauth = new OAuth($consumer_key, $consumer_secret, OAUTH_SIG_METHOD_HMACSHA1, OAUTH_AUTH_TYPE_URI);
	                $this->_oauth->disableSSLChecks();
	        }
	        
	        public function setToken($token, $secret)
	        {
	                $this->_oauth->setToken($token, $secret);
	        }
	        
	        public function addReplies($term, $replyarray)
	        {
	                // Find the total number of rows in the array
	                $replycount = count($replyarray);
	                // Offset for array's zero val
	                $replycount--;
	                
	                // Generate a random number as key for the array
	                $rand = rand(0,$replycount);
	                
	                // Plug in the key & add that reply!
	                $this->_replies[$term] = $replyarray[$rand];            
	        }
	        
	        public function run()
	        {
	                // Get the last ID we replied to
	                $since_id = @file_get_contents('since_id');
	                if ($since_id == null)
	                        $since_id = 0;
	                        
	                // This will store the ID of the last tweet we get
	                $max_id = $since_id;
	                
	                // Verify their Twitter account is valid
	                if (!$this->verifyAccountWorks())
	                {
	                        // Get a request token and show instructions
	                        $this->doAuth();
	                        die();
	                }
	                
	                // Go through each reply
	                foreach ($this->_replies as $term => $reply)
	                {
	                        
	                        $search = json_decode(file_get_contents(sprintf(self::SEARCH_URL, urlencode($term), $since_id)));
	                        
	                        // Store the max ID
	                        if ($search->max_id_str > $max_id)
	                                $max_id = $search->max_id_str;
	                        
	                        // Now let's go through the results
	                        foreach ($search->results as $tweet)
	                        {
	                                $this->sendReply($tweet, $reply);
	                        }
	                }
	                
	                file_put_contents('since_id', $max_id);
	        }
	        
	        private function sendReply($tweet, $reply)
	        {
	                $this->_oauth->fetch(self::UPDATE_URL, array(
	                        'status' => '@' . $tweet->from_user . ' ' . $reply,
	                        'in_reply_to_status_id' => $tweet->id_str,
	                ), OAUTH_HTTP_METHOD_POST);
	        }
	        
	        private function verifyAccountWorks()
	        {
	                try
	                {
	                        $response = $this->_oauth->fetch(self::VERIFY_URL, array(), OAUTH_HTTP_METHOD_GET);
	                        return true;
	                }
	                catch (Exception $ex)
	                {
	                        return false;
	                }
	        }
	        
	        private function doAuth()
	        {
	                // First get a request token, and prompt them to go to the URL
	                $request_token_info = $this->_oauth->getRequestToken(self::REQUEST_TOKEN_URL);
	                fread(STDIN, 10);
	                
	                $pin = trim(fread(STDIN, 10));
	                
	                // Now let's swap that for an access token
	                $this->_oauth->setToken($request_token_info['oauth_token'], $request_token_info['oauth_token_secret']);
	                $access_token_info = $this->_oauth->getAccessToken(self::ACCESS_TOKEN_URL, null, $pin);
	                
	
	                die();
	        }
	        
	        public function testTweet()
	        {
	                $this->_oauth->fetch(self::UPDATE_URL, array(
	                        'status' => 'Test from TwitterAutoReply',
	                ), OAUTH_HTTP_METHOD_POST);
	        }
	}
	
	/****************************************
	  EXAMPLE USAGE
	*****************************************/
	
	date_default_timezone_set('America/New_York');
	
	// Consumer key and consumer secret
	$twitter = new TwitterAutoReply('*', '*');
	// Token and secret
	$twitter->setToken('*', '*');
	
	// queue up the potential responses in $replyarray
	$replyarray = array('reply1','reply2','reply3');
	
	// add the replies
	$twitter->addReplies($searchkey, $replyarray);
	
	// execute against twitter api
	$twitter->run();
	///Requires the pecl oauth extension. Best when run from the command-line (cron job is a nice way to go about it).