<?php
// $Id$

/**
 * @file
 * Discounts framework for Ubercart.
 */

require_once(dirname(__FILE__) .'/uc_discount.ca.inc');

/******************************************************************************
 * Drupal Hooks                                                               *
 ******************************************************************************/

/**
 * Implementation of hook_menu().
 */
function uc_discount_menu() {
  $items = array();

  $items['discounts/calculate'] = array(
    'title' => 'Calculate discounts',
    'page callback' => 'uc_discount_javascript',
    'access arguments' => array('access content'),
    'type' => MENU_CALLBACK,
  );
  $items['discounts/autocomplete'] = array(
    'title' => 'Node autocomplete for discounts',
    'page callback' => 'uc_discount_autocomplete',
    'access arguments' => array('access content'),
    'type' => MENU_CALLBACK
  );

  return $items;
}

/**
 * Implementation of hook_form_alter().
 *
 * Add JavaScript functions and settings on the checkout and order-edit pages.
 */
function uc_discount_form_alter(&$form, &$form_state, $form_id) {
  if ($form_id == 'uc_cart_checkout_form') {
    if (isset($form['panes']['payment'])) {
      drupal_add_js(drupal_get_path('module', 'uc_discount') .'/uc_discount.js');
    }
  }
  elseif ($form_id == 'uc_order_edit_form') {
    if (isset($form['quotes'])) {
      drupal_add_js(drupal_get_path('module', 'uc_discount') .'/uc_discount.js');
    }
  }
  else {
    $triggers = array_keys(uc_discount_ca_trigger());

    if ($form_id == 'ca_predicate_meta_form') {
      if ($predicate = ca_load_predicate($form['predicate_pid']['#value']) && in_array($predicate['#trigger'], $triggers)) {
        $form['#submit'][] = 'uc_discount_clear_price_cache';
      }
    }
    elseif ($form_id == 'ca_conditions_form' || $form_id == 'ca_actions_form') {
      if ($predicate = ca_load_predicate($form['pid']['#value']) && in_array($predicate['#trigger'], $triggers)) {
        if ($form_id == 'ca_conditions_form') {
          $form['save']['#submit'][] = 'uc_discount_clear_price_cache';
        }
        else {
          $form['submit']['#submit'][] = 'uc_discount_clear_price_cache';
        }
      }
    }
  }
}

/******************************************************************************
 * Ubercart hooks                                                             *
 ******************************************************************************/

/**
 * Implementation of hook_uc_price_handler().
 */
function uc_discount_uc_price_handler() {
  return array(
    'alter' => array(
      'title' => t('Discount price handler'),
      'description' => t('Adds discounts to product prices.'),
      'callback' => 'uc_discount_price_handler_alter',
    ),
  );
}

function uc_discount_price_handler_alter(&$price_info, &$context, &$options) {
  global $user;
  static $prices = array();

  switch ($context['type']) {
    case 'product':
      if (isset($context['field']) && $context['field'] != 'sell_price') {
        // Don't discount list_price or cost.
        return;
      }
      $node = clone $context['subject']['node'];
      $cache = 'node:'. $node->nid .':'. $price_info['price'];
      break;
    case 'cart_item':
      $node = clone $context['subject']['node'];
      $item = $context['subject']['cart_item'];
      $cache = 'cart_item:'. $node->nid .':'. $price_info['price'] .':'. serialize($item->data);
      break;
    case 'order_product':
      if (isset($context['subject']['node']) && is_object($context['subject']['node'])){
        $node = clone $context['subject']['node'];
        $item = $context['subject']['product'];
        $cache = 'order_product:'. $node->nid .':'. $price_info['price'] .':'. serialize($item->data);
      }
      else if (isset($context['subject']['order_product'])){
        $order_product = clone $context['subject']['order_product'];
        $cache = 'order_product:'. $order_product->nid .':'. $price_info['price'] .':'. serialize($order_product->data);
      }
      break;
    default:
      // Nothing to do.
      return;
  }

  if (!isset($prices[$cache])) {
    // The discount action modifies the node's sell_price field.
    $node->sell_price = $price_info['price'];
    ca_pull_trigger('calculate_product_discounts', $node, $user);
    $prices[$cache] = $node->sell_price;
  }
  else {
    $node->sell_price = $prices[$cache];
  }

  // Alter the price given in place.
  $price_info['price'] = $node->sell_price;
}

/**
 * Update and save discount line items to the order.
 */
function uc_discount_order($op, &$arg1, $arg2) {
  switch ($op) {
    case 'save':
      $changes = array();
      $discounts = uc_line_item_discount('load', $arg1);

      // Compare newly calculated discounts to those already present.
      // Delete line items that weren't calculated, update those that have
      // the same titles with the new amounts, and add any that were not there
      // before.
      $context = array(
        'revision' => 'formatted',
        'type' => 'line_item',
        'subject' => array(
          'order' => $arg1,
        ),
      );
      if (is_array($arg1->line_items)) {
        foreach ($arg1->line_items as $i => $line) {
          if ($line['type'] == 'discount') {
            $delete = TRUE;
            foreach ($discounts as $id => $new_line) {
              // Only change line items if the titles are the same, but the
              // amounts are not.
              if ($new_line['title'] == $line['title']) {
                if ($new_line['amount'] != $line['amount']) {
                  $context['subject']['line_item'] = $new_line;
                  uc_order_update_line_item($line['line_item_id'], $new_line['title'], $new_line['amount']);
                  $arg1->line_items[$i]['amount'] = $new_line['amount'];
                  $changes[] = t('Changed %title to %amount.', array('%amount' => uc_price($new_line['amount'], $context), '%title' => $new_line['title']));
                }

                // Hide this discount so we don't add or delete it later.
                unset($discounts[$id]);
                $delete = FALSE;

                // Shortcut to the next line item.
                break;
              }
            }

            // This line item did not have a discount calculated again.
            // It is obsolete, so delete it.
            if ($delete) {
              uc_order_delete_line_item($line['line_item_id']);
              unset($arg1->line_items[$i]);
              $changes[] = t('Removed %title.', array('%title' => $line['title']));
            }
          }
        }
      }

      // Add new discounts.
      if (is_array($discounts)) {
        foreach ($discounts as $line) {
          uc_order_line_item_add($arg1->order_id, $line['id'], $line['title'], $line['amount'], $line['weight']);
          $line['type'] = 'discount';
          $arg1->line_items[] = $line;
          $context['subject']['line_item'] = $line;
          $changes[] = t('Added %amount for %title.', array('%amount' => uc_price($line['amount'], $context), '%title' => $line['title']));
        }
      }

      // Log any changes.
      if (count($changes)) {
        uc_order_log_changes($arg1->order_id, $changes);
      }
    break;
  }
}

/**
 * Implementation of hook_line_item().
 */
function uc_discount_line_item() {
  $items = array();

  $items[] = array(
    'id' => 'discount',
    'title' => t('Discount'),
    'callback' => 'uc_line_item_discount',
    'weight' => 5,
    'stored' => TRUE,
    'default' => FALSE,
    'calculated' => TRUE,
    'display_only' => FALSE,
  );

  return $items;
}

/**
 * Callback function for the discount line item.
 */
function uc_line_item_discount($op, $order) {
  switch ($op) {
    case 'load':
      $discounts = uc_discount_calculate_discounts($order);
      $lines = array();
      foreach ($discounts as $discount) {
        $lines[] = array(
          'id' => 'discount',
          'title' => $discount['title'],
          'amount' => $discount['amount'],
          'weight' => variable_get('uc_li_discount_weight', 5),
        );
      }
      return $lines;
  }
}

/**
 * Implementation of hook_line_item_alter().
 */
function uc_discount_line_item_alter(&$line_item, $order) {
  $account = user_load($order->uid);
  ca_pull_trigger('calculate_line_item_discounts', $line_item, $account);
}

function uc_discount_checkout_pane() {
  $panes[] = array(
    'id' => 'coupon_discount',
    'callback' => 'uc_checkout_pane_coupon_discount',
    'title' => t('Coupon Discount'),
    'desc' => t('Allows shoppers to use a coupon during checkout for order discounts.'),
    'weight' => 5,
    'process' => TRUE,
  );

  return $panes;
}

function uc_checkout_pane_coupon_discount($op, &$arg1, $arg2) {
  switch ($op) {
    case 'view':
      $description = t('Enter a coupon code for this order.');
      $contents['coupon_code'] = array(
        '#type' => 'textfield',
        '#title' => t('Coupon code'),
        '#default_value' => $arg1->data['coupon_code'],
        '#size' => 25,
      );
      return array('description' => $description, 'contents' => $contents);
    case 'process':
      if ($arg2['coupon_code']) {
        $arg1->data['coupon_code'] = $arg2['coupon_code'];

        if (uc_discount_validate_coupon($arg1)) {
          $changes = array(t('Coupon code %code redeemed.', array('%code' => $arg1->data['coupon_code'])));
          uc_order_log_changes($arg1->order_id, $changes);
        }
        else {
          unset($arg1->data['coupon_code']);
          drupal_set_message(t('Invalid coupon code.'), 'error');
        }
      }

      // Continue processing even if the coupon doesn't apply.
      return TRUE;
  }
}

/**
 * Implementation of hook_order_pane
 */
function uc_discount_order_pane() {
  $panes[] = array(
    'id' => 'coupon_code',
    'callback' => 'uc_order_pane_coupon_discount',
    'title' => t('Coupon Codes'),
    'desc' => t('Coupon codes.'),
    'class' => 'pos-left',
    'weight' => 7,
    'show' => array('edit'),
  );

  return $panes;
}

/**
 * Callback from hook_order_pane
 */
function uc_order_pane_coupon_discount($op, $arg1) {
  switch ($op) {
    case 'edit-form':
      $pane = uc_checkout_pane_coupon_discount('view', $arg1, NULL);
      $form['coupons'] = $pane['contents'];
      unset($form['coupons']['coupon_code']['#title']);

      $form['coupons']['add_coupon'] = array(
        '#type' => 'submit',
        '#value' => t('Apply coupon'),
      );

      return $form;
    case 'edit-theme':
      return drupal_render($arg1['coupons']);
    case 'edit-ops':
      return array(t('Apply coupon'));
    case t('Apply coupon'):
      if ($order = uc_order_load($arg1['order_id'])) {
        $changes = array();
        $order->data['coupon_code'] = $arg1['coupon_code'];

        if (uc_discount_validate_coupon($order)) {
          $changes[] = t('Coupon code %code redeemed.', array('%code' => $order->data['coupon_code']));
        }
        else {
          unset($order->data['coupon_code']);
          drupal_set_message(t('Invalid coupon code.'), 'error');
        }

        uc_order_save($order);

        // Log any changes.
        if (count($changes)) {
          uc_order_log_changes($order->order_id, $changes);
        }
      }
      break;
  }
}

/**
 * Implementation of hook_discount_registry().
 */
function uc_discount_discount_registry() {
  $discounts = array();

  $discounts['order'] = array(
    'title' => t('Order total'),
    'callback' => 'uc_discount_order_total_discount',
    'context' => 'order',
  );
  $discounts['order_products'] = array(
    'title' => t('Order products'),
    'callback' => 'uc_discount_order_product_discount',
    'form' => 'uc_discount_order_product_discount_form',
    'context' => 'order',
  );
  $discounts['line_items'] = array(
    'title' => t('Line items'),
    'callback' => 'uc_discount_line_items_discount',
    'form' => 'uc_discount_line_items_discount_form',
    'context' => 'order',
  );
  $discounts['nodes'] = array(
    'title' => t('Products'),
    'callback' => 'uc_discount_node_discount',
    'context' => 'product',
  );

  return $discounts;
}

/**
 * Allows discounts based on the order total.
 *
 * This discount does not have any settings, so it does not provide a form.
 *
 * @param $order
 *   The order object for which the discount is calculated.
 * @param $settings
 *   The settings array from the conditional action form.
 * @return The $order->total.
 */
function uc_discount_order_total_discount($order, $settings) {
  $total = uc_order_get_total($order, TRUE);

  return $total;
}

function uc_discount_order_product_discount($order, $settings) {
  $multiplier = 0;

  $context = array(
    'revision' => 'altered',
    'type' => 'order_product',
    'subject' => array(
      'order' => $order,
    ),
  );

  foreach ($order->products as $product) {
    if ($product->nid == $settings['product']) {
      $context['subject']['product'] = $product;
      $context['subject']['node'] = node_load($product->nid);
      $price_info = array(
        'price' => $product->price,
        'qty' => min($settings['qty'], $product->qty),
      );

      $multiplier += uc_price($price_info, $context);
    }
  }

  return $multiplier;
}

function uc_discount_order_product_discount_form($form_state, $settings = array()) {
  $form = array();

  $form['qty'] = array(
    '#type' => 'textfield',
    '#title' => t('Max. quantity'),
    '#default_value' => $settings['qty'],
    '#description' => t('The discount will apply to each matching product in the order up to this number.'),
  );

  $form['product'] = array(
    '#type' => 'textfield',
    '#title' => t('Products'),
    '#autocomplete_path' => 'discounts/autocomplete',
    '#element_validate' => array('uc_discount_autocomplete_validate'),
    '#default_value' => isset($settings['product']) ? ('[nid:'. $settings['product'] .']') : '',
  );

  return $form;
}

/**
 * Validate an autocomplete element.
 *
 * Remove the wrapper layer and set the right element's value.
 * This will move the nested value at 'field-name-0-nid-nid'
 * back to its original location, 'field-name-0-nid'.
 */
function uc_discount_autocomplete_validate($element, &$form_state) {
  $value = $element['#value'];
  $nid = NULL;
  if (!empty($value)) {
    preg_match('/^(?:\s*|(.*) )?\[\s*nid\s*:\s*(\d+)\s*\]$/', $value, $matches);
    if (!empty($matches)) {
      // Explicit [nid:n].
      list(, $title, $nid) = $matches;
      if (!empty($title) && ($n = node_load($nid)) && $title != $n->title) {
        form_error($element, t('Products: title mismatch. Please check your selection.'));
      }
    }
    else {
      // No explicit nid.
      $reference = uc_discount_potential_references($value, 'equals', NULL, 1);
      if (empty($reference)) {
        form_error($element, t('Products: found no valid post with that title.'));
      }
      else {
        // TODO:
        // the best thing would be to present the user with an additional form,
        // allowing the user to choose between valid candidates with the same title
        // ATM, we pick the first matching candidate...
        $nid = key($reference);
      }
    }
  }
  form_set_value($element, $nid, $form_state);
}

/**
 * Fetch an array of all candidate referenced nodes.
 */
function uc_discount_potential_references($string = '', $match = 'contains', $ids = array()) {
  static $results = array();

  // Create unique id for static cache.
  $cid = $match .':'. ($string !== '' ? $string : implode('-', $ids)) .':'. $limit;

  if (!isset($results[$cid])) {
    $related_types = array();
    $where = array();
    $args = array();

    foreach (array_keys(uc_product_type_names()) as $related_type) {
      $related_types[] = "n.type = '%s'";
      $args[] = $related_type;
    }

    $where[] = implode(' OR ', $related_types);

    if (!count($related_types)) {
      return array();
    }

    if ($string !== '') {
      $match_operators = array(
        'contains' => "LIKE '%%%s%%'",
        'equals' => "= '%s'",
        'starts_with' => "LIKE '%s%%'",
      );
      $where[] = 'n.title '. (isset($match_operators[$match]) ? $match_operators[$match] : $match_operators['contains']);
      $args[] = $string;
    }
    elseif ($ids) {
      $where[] = 'n.nid IN ('. db_placeholders($ids) . ')';
      $args = array_merge($args, $ids);
    }

    $where_clause = $where ? 'WHERE ('. implode(') AND (', $where) .')' : '';
    $sql = db_rewrite_sql("SELECT n.nid, n.title AS node_title, n.type AS node_type FROM {node} n $where_clause ORDER BY n.title, n.type");
    $result = $limit ? db_query_range($sql, $args, 0, $limit) : db_query($sql, $args);
    $references = array();
    while ($node = db_fetch_object($result)) {
      $references[$node->nid] = array(
        'title' => $node->node_title,
        'rendered' => $node->node_title,
      );
    }

    $results[$cid] = $references;
  }

  return $results[$cid];
}

/**
 * Menu callback; Retrieve a pipe delimited string of autocomplete suggestions for existing users
 */
function uc_discount_autocomplete($string = '') {
  $references = uc_discount_potential_references($string, 'contains', array(), 10);
  foreach ($references as $id => $row) {
    // Add a class wrapper for a few required CSS overrides.
    $matches[$row['title'] ." [nid:$id]"] = '<div class="reference-autocomplete">'. $row['rendered'] .'</div>';
  }
  drupal_json($matches);
}

/**
 * Allows discounts based on the line items.
 *
 * @param $order
 *   The order object for which the discount is calculated.
 * @param $settings
 *   The settings array from the conditional action form.
 * @return The value of the selected line items at the time discounts were
 *   calculated.
 */
function uc_discount_line_items_discount($order, $settings) {
  $total = 0;

  if (is_array($order->line_items)) {
    foreach ($order->line_items as $i => $item) {
      if (in_array($item['type'], $settings['line_items'])) {
        $total += $item['amount'];
      }
    }
  }
  if (in_array('discount', $settings['line_items'])) {
    foreach ($order->discounts as $other_discount) {
      $amount += $other_discount['amount'];
    }
  }

  return $total;
}

function uc_discount_line_items_discount_form($form_state, $settings = array()) {
  $form = array();

  $line_items = _line_item_list();
  $options = array();
  foreach ($line_items as $i => $item) {
    // Remove lines like Subtotal and Total. These are merely conveniently
    // displayed values, not real line items.
    if ($item['calculated']) {
      $options[$i] = $item['title'];
    }
  }

  $form['line_items'] = array(
    '#type' => 'checkboxes',
    '#title' => t('Line items'),
    '#options' => $options,
    '#default_value' => (array)$settings['line_items'],
    '#description' => t('Select the line items which should be discounted.'),
  );

  return $form;
}

/**
 * Allows discounts based on the products' price.
 *
 * @param $order
 *   The order object for which the discount is calculated.
 * @param $settings
 *   The settings array from the conditional action form.
 * @return The total price of the products selected from the action's settings..
 */
function uc_discount_node_discount($product, $settings) {
  return $product->sell_price;
}

/******************************************************************************
 * Module and Helper Functions                                                *
 ******************************************************************************/

/**
 * Retrieves information about defined discount types.
 *
 * @param $key
 *   The discount ID. Only information about the corresponding discount is
 *   returned, if set.
 * @return
 *   The discount definition. This array contains the callback information as
 *   well as the ID and title.
 */
function uc_discount_get_discounts($op = NULL, $key = NULL) {
  static $discounts;

  if (!isset($discounts)) {
    $discounts = module_invoke_all('discount_registry');
  }

  if (isset($key)) {
    if (isset($discounts[$key])) {
      return $discounts[$key];
    }
    else {
      return FALSE;
    }
  }

  return $discounts;
}

/**
 * Formats the defined discounts as an option list.
 *
 * @return
 *   An array of options for a select element whose keys are the discount IDs
 *   and whose values are the discount names.
 */
function uc_discount_get_discount_options($context) {
  static $discounts;

  if (!isset($discounts)) {
    $discounts = module_invoke_all('discount_registry');
  }

  $options = array();
  foreach ($discounts as $id => $discount) {
    if (!isset($discount['context']) || $discount['context'] == $context) {
      $options[$id] = $discount['title'];
    }
  }

  return $options;
}

/**
 * Collects the settings forms of the defined discounts
 *
 * @param $form_state
 *   The $form_state of the parent form.
 * @param $settings
 *   The array of values for the discounts.
 * @param $key
 *   If set, returns only the specified discount's form.
 * @return
 *   The settings form arrays for the specified discount.
 */
function uc_discount_get_discount_forms($form_state, $settings, $key = NULL) {
  $discounts = module_invoke_all('discount_registry');

  $forms = array();
  foreach ($discounts as $id => $discount) {
    if ((!isset($discount['context']) || $discount['context'] == $settings['context']) && function_exists($discount['form'])) {
      if (isset($settings['discount'][$id])) {
        $discount_settings = $settings['discount'][$id];
      }
      else {
        $discount_settings = array();
      }
      $form = call_user_func($discount['form'], $form_state, $discount_settings);
      if (is_array($form)) {
        $forms[$id] = $form;
      }
    }
    else {
      $forms[$id] = array();
    }
  }
  if (isset($key)) {
    if (isset($forms[$key])) {
      return $forms[$key];
    }
    else {
      return FALSE;
    }
  }
  else {
    return $forms;
  }
}

/**
 * Calculates the discount line items from the configured conditional actions.
 *
 * @param $order
 *   The order object.
 * @return
 *   The array of line items, each containing an id, a title, and an amount.
 */
function uc_discount_calculate_discounts($order) {
  global $user;

  if ($order->uid > 0) {
    $account = user_load($order->uid);
  }
  else {
    $account = $user;
  }

  if (is_array($order->line_items)) {
    foreach ($order->line_items as $i => $line) {
      if (drupal_substr($line['type'], 0, 9) == 'discount_') {
        unset($order->line_items[$i]);
      }
    }
  }

  $arguments = array(
    'order' => array(
      '#entity' => 'uc_order',
      '#title' => t('Order'),
      '#data' => $order,
    ),
    'account' => array(
      '#entity' => 'user',
      '#title' => t('User'),
      '#data' => $account,
    ),
  );

  $id = 0;
  $order->discounts = array();

  //Calculate overall order discounts
  // Pull the "calculate_discounts" trigger in such a way to get the results.
  $predicates = ca_load_trigger_predicates('calculate_order_discounts');
  foreach ($predicates as $predicate) {
    if (ca_evaluate_conditions($predicate, $arguments)) {
      $discounts = ca_perform_actions($predicate, $arguments);
      foreach ((array) $discounts as $i => $discount) {
        if ($predicate['#actions'][$i]['#name'] == 'uc_discount_action_get_order_discount' && $discount) {
          // Allow successive discounts to inspect this discount by putting
          // it in the order object.
          $order->discounts[$id] = array(
            'id' => $id,
            'title' => check_plain($predicate['#actions'][$i]['#title']),
            'amount' => $discount,
            'weight' => variable_get('uc_li_discount_weight', 5) + $predicate['#actions'][$i]['#settings']['line_item_weight'] / 10,
          );
          $id++;
        }
      }
    }
  }

  $product_predicates = ca_load_trigger_predicates('calculate_order_product_discounts');

  foreach ($order->products as $product) {

    //define the arguments that should be passed to the condition/action
    $product_arguments = array(
      'order' => array(
        '#entity' => 'uc_order',
        '#title' => t('Order'),
        '#data' => $order,
      ),
      'node' => array(
        '#entity' => 'user',
        '#title' => t('User'),
        '#data' => $product,
      ),
    );

    foreach ($product_predicates as $predicate) {

      if (ca_evaluate_conditions($predicate, $product_arguments)) {
        $discounts = ca_perform_actions($predicate, $product_arguments);
        foreach ((array) $discounts as $i => $discount) {
          if ($predicate['#actions'][$i]['#name'] == 'uc_discount_action_get_order_discount' && $discount) {
            // Allow successive discounts to inspect this discount by putting
            // it in the order object.
            $order->discounts[$id] = array(
              'id' => $id,
              'title' => check_plain($predicate['#actions'][$i]['#title']),
              'amount' => $discount,
              'weight' => $predicate['#actions'][$i]['#settings']['line_item_weight'],
            );
            $id++;
          }
        }
      }
    }
  }

  return $order->discounts;
}

/**
 * AJAX callback for order preview.
 *
 * Calculate tax amounts for an order in the payment checkout pane.
 */
function uc_discount_javascript() {
  drupal_set_header("Content-Type: text/javascript; charset=utf-8");
  $order = $_POST['order'];
  if ($order = unserialize(rawurldecode($order))) {
    $discounts = uc_discount_calculate_discounts($order);
    if (count($discounts)) {
      print drupal_to_js((array)$discounts);
    }
    else {
      print '{}';
    }
  }
  else {
    print '{}';
  }
  exit();
}

/**
 * Form submit callback for discount CA predicates.
 *
 * Changes to discount conditions or actions invalidate cached prices.
 */
function uc_discount_clear_price_cache() {
  cache_clear_all(NULL, 'cache_uc_price');
}

/**
 * Indicate that the coupon entered causes a discount to be applied.
 */
function uc_discount_validate_coupon($order) {
  $valid = FALSE;

  // Log the entered coupon code if it granted a discount.
  if ($order->data['coupon_code']) {
    $account = user_load($order->uid);
    $arguments = array(
      'order' => array(
        '#entity' => 'uc_order',
        '#title' => t('Order'),
        '#data' => $order,
      ),
      'account' => array(
        '#entity' => 'user',
        '#title' => t('User'),
        '#data' => $account,
      ),
    );

    $predicates = ca_load_trigger_predicates('calculate_order_discounts');
    foreach ($predicates as $predicate) {
      if (ca_evaluate_conditions($predicate, $arguments)) {
        // serialize() and strpos() is faster than writing a recursive
        // funciton to actually find the right condition. Don't know about
        // actual performance.
        $conditions = serialize($predicate['#conditions']);
        if (strpos($conditions, 'uc_discount_condition_coupon_code') !== FALSE) {
          $valid = TRUE;
          break;
        }
      }
    }
  }

  return $valid;
}