<?php if (!defined('BASEPATH')) exit('No direct script access allowed');
/**
 * Code Igniter
 *
 * An open source application development framework for PHP 4.3.2 or newer
 *
 * @package     CodeIgniter
 * @author      Rick Ellis
 * @copyright   Copyright (c) 2006, pMachine, Inc.
 * @license     http://www.codeignitor.com/user_guide/license.html
 * @link        http://www.codeigniter.com
 * @since       Version 1.0
 * @filesource
 */

// ------------------------------------------------------------------------ 

/**
 * PayPal_Lib Controller Class (Paypal IPN Class)
 *
 * This CI library is based on the Paypal PHP class by Micah Carrick
 * See www.micahcarrick.com for the most recent version of this class
 * along with any applicable sample files and other documentaion.
 *
 * This file provides a neat and simple method to interface with paypal and
 * The paypal Instant Payment Notification (IPN) interface.  This file is
 * NOT intended to make the paypal integration "plug 'n' play". It still
 * requires the developer (that should be you) to understand the paypal
 * process and know the variables you want/need to pass to paypal to
 * achieve what you want.
 *
 * This class handles the submission of an order to paypal as well as the
 * processing an Instant Payment Notification.
 * This class enables you to mark points and calculate the time difference
 * between them.  Memory consumption can also be displayed.
 *
 * The class requires the use of the PayPal_Lib config file.
 *
 * @package     CodeIgniter
 * @subpackage  Libraries
 * @category    Commerce
 * @author      Ran Aroussi <ran@aroussi.com>
 * @copyright   Copyright (c) 2006, http://aroussi.com/ci/
 *
 */

// ------------------------------------------------------------------------ 

class Paypal_Lib {

    var $last_error;            // holds the last error encountered 
    var $ipn_log;               // bool: log IPN results to text file? 

    var $ipn_log_file;          // filename of the IPN log 
    var $ipn_response;          // holds the IPN response from paypal    
    var $ipn_data = array();    // array contains the POST values for IPN 
    var $fields = array();      // array holds the fields to submit to paypal 

    var $submit_btn = '';       // Image/Form button 
    var $button_path = '';      // The path of the buttons 

    var $CI;

    function __construct()
    {
        $this->CI =& get_instance();
        $this->CI->load->helper('url');
        $this->CI->load->helper('form');
        $this->CI->load->config('paypallib_config');

        $this->paypal_url = 'https://www.paypal.com/cgi-bin/webscr';
        if ( $this->CI->config->item('paypal_lib_sandbox_mode') )
            $this->paypal_url = 'https://www.sandbox.paypal.com/cgi-bin/webscr';

        $this->last_error = '';
        $this->ipn_response = '';

        $this->ipn_log_file = $this->CI->config->item('paypal_lib_ipn_log_file');
        $this->ipn_log = $this->CI->config->item('paypal_lib_ipn_log');

        $this->button_path = $this->CI->config->item('paypal_lib_button_path');

        // populate $fields array with a few default values.  See the paypal 
        // documentation for a list of fields and their data types. These defaul 
        // values can be overwritten by the calling script. 
        $this->add_field('rm','2');            // Return method = POST 
        $this->add_field('cmd','_xclick');

        $this->add_field('currency_code', $this->CI->config->item('paypal_lib_currency_code'));
        $this->add_field('quantity', '1');
        $this->button('Pay Now!');
    }

    function button($value)
    {
        // changes the default caption of the submit button 
        $this->submit_btn = form_submit('pp_submit', $value);
    }

    function image($file)
    {
        $this->submit_btn = '<input type="image" name="add" src="' . base_url() . $this->button_path .'/'. $file . '" border="0" />';
    }


    function add_field($field, $value)
    {
        // adds a key=>value pair to the fields array, which is what will be  
        // sent to paypal as POST variables.  If the value is already in the  
        // array, it will be overwritten. 
        $this->fields[$field] = $value;
    }

    function paypal_get_request_link() {
        $url = $this->paypal_url . '?';

        foreach ( $this->fields as $name => $value )
            $url .= $name . '=' . $value . "&";

        return $url;
    }

    function paypal_auto_form()
    {
        // this function actually generates an entire HTML page consisting of 
        // a form with hidden elements which is submitted to paypal via the  
        // BODY element's onLoad attribute.  We do this so that you can validate 
        // any POST vars from you custom form before submitting to paypal.  So  
        // basically, you'll have your own form which is submitted to your script 
        // to validate the data, which in turn calls this function to create 
        // another hidden form and submit to paypal. 

        $this->button('Click here if you\'re not automatically redirected...');

        echo '<html>' . "\n";
        echo '<head><title>Processing Payment...</title></head>' . "\n";
        echo '<body onLoad="document.forms[\'paypal_auto_form\'].submit();">' . "\n";
        echo '<p>Please wait, your order is being processed and you will be redirected to the paypal website.</p>' . "\n";
        echo $this->paypal_form('paypal_auto_form');
        echo '</body></html>';
    }

    function paypal_form($form_name='paypal_form')
    {
        $str = '';
        $str .= '<form method="post" action="'.$this->paypal_url.'" name="'.$form_name.'"/>' . "\n";
        foreach ($this->fields as $name => $value)
            $str .= form_hidden($name, $value) . "\n";
        $str .= '<p>'. $this->submit_btn . '</p>';
        $str .= form_close() . "\n";

        return $str;
    }

    function validate_ipn()
    {
        // parse the paypal URL 
        $url_parsed = parse_url($this->paypal_url);

        // generate the post string from the _POST vars aswell as load the 
        // _POST vars into an arry so we can play with them from the calling 
        // script. 
        $post_string = '';

        if (isset($_POST))
        {
            foreach ($_POST as $field=>$value)
            {       
                // str_replace("\n", "\r\n", $value) 
                // put line feeds back to CR+LF as that's how PayPal sends them out
                // otherwise multi-line data will be rejected as INVALID
                $value = str_replace("\n", "\r\n", $value);
                $this->ipn_data[$field] = $value;
                $post_string .= $field.'='.urlencode(stripslashes($value)).'&';
            }
        }

        $post_string.="cmd=_notify-validate"; // append ipn command 

        // open the connection to paypal 
        $fp = fsockopen($url_parsed['host'],"80",$err_num,$err_str,30);

        if(!$fp)
        {
            // could not open the connection.  If loggin is on, the error message 
            // will be in the log. 
            $this->last_error = "fsockopen error no. $errnum: $errstr";
            $this->log_ipn_results(false);
            return false;
        }
        else
        {
            // Post the data back to paypal 
            fputs($fp, "POST $url_parsed[path] HTTP/1.1\r\n");
            fputs($fp, "Host: $url_parsed[host]\r\n");
            fputs($fp, "Content-type: application/x-www-form-urlencoded\r\n");
            fputs($fp, "Content-length: ".strlen($post_string)."\r\n");
            fputs($fp, "Connection: close\r\n\r\n");
            fputs($fp, $post_string . "\r\n\r\n");

            // loop through the response from the server and append to variable 
            while(!feof($fp))
                $this->ipn_response .= fgets($fp, 1024);

            fclose($fp); // close connection 
        }

        if (@eregi("VERIFIED",$this->ipn_response))
        {
            // Valid IPN transaction. 
            $this->log_ipn_results(true);
            return true;
        }
        else
        {
            // Invalid IPN transaction.  Check the log for details. 
            $this->last_error = 'IPN Validation Failed.';
            $this->log_ipn_results(false);
            return false;
        }
    }

    function log_ipn_results($success)
    {
        if (!$this->ipn_log) return;  // is logging turned off? 

        // Timestamp 
        $text = '['.date('m/d/Y g:i A').'] - ';

        // Success or failure being logged? 
        if ($success) $text .= "SUCCESS!\n";
        else $text .= 'FAIL: '.$this->last_error."\n";

        // Log the POST variables 
        $text .= "IPN POST Vars from Paypal:\n";
        foreach ($this->ipn_data as $key=>$value)
            $text .= "$key=$value, ";

        // Log the response from the paypal server 
        $text .= "\nIPN Response from Paypal Server:\n ".$this->ipn_response;

        // Write to log 
        $fp=fopen($this->ipn_log_file,'a');
        fwrite($fp, $text . "\n\n");

        fclose($fp);  // close file 
    }


    function dump()
    {
        // Used for debugging, this function will output all the field/value pairs 
        // that are currently defined in the instance of the class using the 
        // add_field() function. 

        ksort($this->fields);
        echo '<h2>ppal->dump() Output:</h2>' . "\n";
        echo '<code style="font: 12px Monaco, \'Courier New\', Verdana, Sans-serif;  background: #f9f9f9; border: 1px solid #D0D0D0; color: #002166; display: block; margin: 14px 0; padding: 12px 10px;">' . "\n";
        foreach ($this->fields as $key => $value) echo '<strong>'. $key .'</strong>:  '. urldecode($value) .'<br/>';
        echo "</code>\n";
    }

}