Sub Reddit auto mod bot

<?php
require_once('inc/httpful.phar');

class reddit_api
{
    static $url = 'https://www.reddit.com/';
    private $modhash=null;
    private $cookie=null;

    function doCommand($url,$data=null)
    {
        if (substr($url,0,4)=='api/')
            $request = \Httpful\Request::post(reddit_api::$url.$url);
        else
            $request = \Httpful\Request::get(reddit_api::$url.$url);
        $request -> addHeader('User-Agent','atpeace_bot 0.1');
        if ($this->modhash!==null)
            $request -> addHeader('X-Modhash',$this->modhash);
        if ($this->cookie!==null)
            $request -> addHeader('Cookie','reddit_session='.$this->cookie);
        if ($data!==null)
        {
            $data['api_type'] = 'json';
            $request -> body(http_build_query($data));
        }
        $request -> expectsJson();
        $response = null;
        try
        {
            $response = $request -> send();
        }  catch (Exception $e) {
            echo 'Error '.$e;
            die();
        }

        if (isset($response->body->json->data->modhash))
            $this->modhash = $response->body->json->data->modhash;
        if (isset($response->body->json->data->cookie))
            $this->cookie = $response->body->json->data->cookie;

        //echo $this->modhash;
        if (isset($response->body->json->data))
            return $response->body->json->data;
        else
            return $response->body;
    }
}

class reddit_bot
{
    private $api;

    private $username;
    private $password;
    public $rules = array();

    public $removed = 0;
    public $checked = 0;

    private $auth=false;

    function __construct($username,$password)
    {
        $this->username = $username;
        $this->password = $password;
        $this->api = new reddit_api();
    }

    function login()
    {
        $reply = $this->api->doCommand('api/login',array('user'=>$this->username,'passwd'=>$this->password));
        $this->auth=true;
    }

    function logout()
    {
        $reply = $this->api->doCommand('logout');
    }

    function process_rules()
    {
        $page=null;
        foreach ($this->rules as $rule)
        {
            if ($rule['page']=='reports')
                $page=$this->api->doCommand('r/'.$rule['sub'].'/about/reports.json');
            else
                $page=$this->api->doCommand('r/'.$rule['sub'].'.json');
            $rule_eval = new rule($rule['remove']);
            foreach ($page->data->children as $post)
            {
                $fail = $rule_eval->match($post);
                if ($fail)
                {
                    $this->api->doCommand('api/remove',array('id'=>$post->data->name,'spam'=>0));
                    $this->removed++;
                }
                $this->checked++;
            }
        }
    }

}

class rule
{
    private $rule_string;
    private $eval = '';

    function __construct($rule)
    {
        $this->rule_string=$rule;
        $this->eval='return '.$rule.';';
        $this->eval=str_replace('num_reports','$post->data->num_reports',$this->eval);
        $this->eval=str_replace('score','$post->data->score',$this->eval);
    }

    function match($post)
    {
        return eval($this->eval);
    }

}

$my_bot = new reddit_bot('XXXaccountnameXXX','XXXpasswordXXXX');
$my_bot->rules[]=array('sub'=>'XXXsubredditnameXXX','page'=>'reports','remove'=>'num_reports>5&&score<1');
$my_bot->login();
$my_bot->process_rules();
$my_bot->logout();
echo 'Removed ('.$my_bot->removed.'/'.$my_bot->checked.')';
?>