<?php

/**
 * @file
 * Custom code for this website.
 */

/**
 * Implements hook_form_FORM_ID_alter().
 * @see http://api.drupal.org/api/drupal/modules--system--system.api.php/function/hook_form_FORM_ID_alter/7
 *
 * This hook alters the add-to-cart forms on product display pages by adding
 * javascript to a set of radio buttons that define the possible colors on a
 * product display. On the client side this can be used to alter the display
 * of the set of radio buttons.
 */
function pbcosmetics_form_commerce_cart_add_to_cart_form_alter(&$form, &$form_state, $form_id) {
  static $count = 0;
  $field_name = 'field_product_color';
  if (isset($form['attributes'][$field_name])) {
    $element = &$form['attributes'][$field_name];

    // Retrieve the product-id's
    $line_item = $form_state['line_item'];
    $entity_data = $line_item->data['context']['entity'];
    $entity = entity_load_single($entity_data['entity_type'], $entity_data['entity_id']);
    $product_ids = entity_metadata_wrapper($entity_data['entity_type'], $entity)->{$entity_data['product_reference_field_name']}->raw();

    // Load all the active products intended for sale on this form.
    $products = commerce_product_load_multiple($product_ids, array('status' => 1));

    // Load all the terms
    $tids = array_keys($element['#options']);
    $terms = taxonomy_term_load_multiple($tids);

    // The radio buttons are displayed based on the term-id's, so we have to
    // couple the images (in the product) to the term-id's.
    $color_radio_settings = array();
    foreach ($products as $product) {
      $image_field = field_get_items('commerce_product', $product, 'field_image_color');
      $image = !empty($image_field[0]['uri']) ? file_create_url($image_field[0]['uri']) : null;
      $color_term_field = field_get_items('commerce_product', $product, 'field_product_color');
      $tid = !empty($color_term_field[0]['tid']) ? $color_term_field[0]['tid'] : $product->product_id;
      $title = module_exists('i18n_taxonomy') ? i18n_taxonomy_term_name($terms[$tid]) : $terms[$tid]->name;
      $color_radio_settings[$tid] = array('title' => $title, 'image' => $image);
    }

    // Add class and javascript to radios
    $count++;
    $element['#attributes']['class'][] = "pb-color-radios pb-color-radios-$count";
    $element['#attached']['js'][] = drupal_get_path('module', 'pbcosmetics') . '/pbcosmetics.js';
    $element['#attached']['js'][] = array(
      'data' => array('pbCosmetics' => array(
        "pb-color-radios-$count" => $color_radio_settings,
       )),
      'type' => 'setting',
    );
  }
}