<?php

define('SIMPLE_PAYPAL_URL_LIVE', 0);
define('SIMPLE_PAYPAL_URL_TEST', 1);

define('SIMPLE_PAYPAL_URL',      'simple_paypal_url');
define('SIMPLE_PAYPAL_DEFAULT_CURRENCY', 'simple_paypal_default_currency');

function simple_paypal_get_urls() {
  return array(
    SIMPLE_PAYPAL_URL_LIVE => 'https://www.paypal.com/cgi-bin/webscr',
    SIMPLE_PAYPAL_URL_TEST => 'https://www.sandbox.paypal.com/cgi-bin/webscr',
  );
}

/**
 * Implementation of hook_menu().
 */
function simple_paypal_menu() {
    $items = array();
  
    $items['admin/settings/paypal'] = array(
      'title' => 'Paypal',
      'page callback' => 'drupal_get_form',
      'page arguments' => array('simple_paypal_admin'),
      'description' => 'Administer Paypal',
      'access arguments' => array('access administration pages'),
      'type' => MENU_NORMAL_ITEM,
      );
  
    return $items;
  }

/**
 * Implementation of hook_admin().
 */
function simple_paypal_admin() {
  $form[SIMPLE_PAYPAL_URL] = array(
    '#type'           => 'select',
    '#title'          => t('Payment URL for Paypal'),
    '#default_value'  => variable_get(SIMPLE_PAYPAL_URL, SIMPLE_PAYPAL_URL_LIVE),
    '#options'        => simple_paypal_get_urls(),
    '#description' => t('Select whether you want to use a live URL, or a test one.'),
  );
  $form[SIMPLE_PAYPAL_DEFAULT_CURRENCY] = array(
      '#type'          => 'select',
      '#title'         => t('Default Currency'),
      '#default_value' => variable_get(SIMPLE_PAYPAL_DEFAULT_CURRENCY, 'USD'),
      '#options'       => simple_paypal_get_currencies(),
      );
  return system_settings_form($form);
}

function simple_paypal_get_url() {
  $urls = simple_paypal_get_urls();
  return $urls[variable_get(SIMPLE_PAYPAL_URL, SIMPLE_PAYPAL_URL_LIVE)];
}

function simple_paypal_get_currencies() {
  $default_currency = variable_get(SIMPLE_PAYPAL_DEFAULT_CURRENCY, 'USD');
  $country_currencies = array(
    'AUD' => t('Australian Dollar'),
    'GBP' => t('British Pound'),
    'CAD' => t('Canadian Dollar'),
    'CZK' => t('Czech Koruna'),
    'DKK' => t('Danish Kroner'),
    'EUR' => t('Euro'),
    'HKD' => t('Hong Kong Dollar'),
    'HUF' => t('Hungarian Forint'),
    'ILS' => t('Israeli New Shekel'),
    'JPY' => t('Japanese Yen'),
    'MXN' => t('Mexican Peso'),
    'NZD' => t('New Zealand Dollar'),
    'NOK' => t('Norwegian Kroner'),
    'PLN' => t('Polish Zlotych'),
    'SGD' => t('Singapore Dollar'),
    'SEK' => t('Swedish Kronor'),
    'CHF' => t('Swiss Franc'),
    'USD' => t('U.S. Dollar'),
  );
  
  if (variable_get(SIMPLE_PAYPAL_DEFAULT_CURRENCY, 'USD')) {
    $ordered_currencies[$default_currency] = $country_currencies[$default_currency];
    foreach ($country_currencies as $key => $value) {
      if($key != $default_currency) {
        $ordered_currencies[$key] = $value;
      }
    }
    return $ordered_currencies;
  }
  return $country_currencies;
}

function simple_paypal_format_amount($amount, $currency) {
  $amount = number_format($amount, 2);
  switch ($currency) {
    case 'EUR':
      return "€ $amount";
    case 'GBP':
      return "£ $amount";
    case 'USD':
      return "$ $amount";
    default:
      return check_plain($currency). " $amount";
  }
}

function simple_paypal_ipn_verify($vars = array()) {
  // If we are in test mode, log the variables.
  if (SIMPLE_PAYPAL_URL_TEST == variable_get(SIMPLE_PAYPAL_URL, SIMPLE_PAYPAL_URL_TEST)) {
    watchdog('simple_paypal', 'Post variables from Paypal IPN <pre>@vars</pre>', array(
      '@vars' => print_r($vars, TRUE)), WATCHDOG_DEBUG);
  }

  $url = simple_paypal_get_url();
  $ch = curl_init();

  curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
  curl_setopt($ch, CURLOPT_URL, $url);
  curl_setopt($ch, CURLOPT_POST, 1);
  curl_setopt($ch, CURLOPT_POSTFIELDS, simple_paypal_post($vars));

  ob_start();

  if (curl_exec($ch)) {
    $info = ob_get_contents();
    curl_close($ch);
    ob_end_clean();

    if (eregi('VERIFIED', $info)) {
      return TRUE;
    }
    else {
      return FALSE;
    }
  }
  else {
    watchdog('simple_paypal', 'Call to curl_exec() failed. url=@url vars=@vars', array(
      '@vars' => print_r($vars, TRUE),
      '@url'  => $url,
      ), WATCHDOG_ERROR);
    return FALSE;
  }
}

function simple_paypal_post($data = array()) {
  $post = '';
  foreach ($data as $key => $value) {
    $post .= $key. '='. urlencode($value). '&';
  }
  $post .= 'cmd=_notify-validate';

  return $post;
}