<?php

/**
 * Implements hook_form_FORM_ID_alter().
 * Alters the Field UI field edit form to add per-instance settings for fields
 */
function commerce_product_field_product_attribute_form_field_ui_field_edit_form_alter(&$form, &$form_state) {
  // Extract the instance info from the form.
  $instance = $form['#instance'];

  // If the current field instance is not locked, is attached to a product type,
  // and of a field type that defines an options list...
  if (empty($form['locked']) && $instance['entity_type'] == 'commerce_product' &&
    function_exists($form['#field']['module'] . '_options_list')) {
    // Get the current instance's attribute settings for use as default values.
    $commerce_cart_settings = commerce_cart_field_instance_attribute_settings($instance);

    // Get all the allowed vocabulary for this field
    $bundle = $instance['bundle'];

    // Create the form element
    $form['instance']['commerce_cart_settings'] += array('replace_product_field' =>
        array(
        '#type' => 'select',
        '#title' => t('Replace radio options displayed by product field'),
        '#description' => t('Select which product field to use for replacement'),
        '#options' => _commerce_product_field_product_attribute_taxonomy_field_options($bundle),
        '#default_value' => (isset($commerce_cart_settings['replace_product_field']) ? $commerce_cart_settings['replace_product_field'] : 'commerce_default'),
        '#required' => false,
        '#states' => array(
          'visible' => array(
            ':input[name="instance[commerce_cart_settings][attribute_widget]"]' => array('value' => 'radios'),
          ),
        ),
      ),
    );
  }
}

/**
 * Create an option list of available product fields to replace the taxonomy terms within the selected vocabulary
 * @param  $bundle
 *  The product fields
 * @return array
 */
function _commerce_product_field_product_attribute_taxonomy_field_options($bundle) {
  $fields_list = field_info_instances('commerce_product', $bundle);
  $options = array();
  $options['commerce_default'] = 'Use Commerce default behavior';
  foreach($fields_list as $option)
    $options[$option['field_name']] = $option['label'];
  return $options;
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function commerce_product_field_product_attribute_form_commerce_cart_add_to_cart_form_alter(&$form, &$form_state, $form_id) {
  //If there isn't enabled product to be displayed, we leave the function now
  if(!isset($form_state['default_product'])) {
    return;
  }
  
  //First, get all cart enabled fields of the current product entity being displayed.
  //Get the current product type.
  $current_product = $form_state['default_product'];

  //Get all the current product type extra fields.
  $fields_info = field_info_instances('commerce_product', $current_product->type);

  //Create an array of attribute options to replace with taxonomy values
  $options = array();
  foreach ($fields_info as $field_info) {
    if (isset($field_info['commerce_cart_settings']) &&
        isset($field_info['commerce_cart_settings']['attribute_widget']) &&
        isset($field_info['commerce_cart_settings']['attribute_field']) &&
        isset($field_info['commerce_cart_settings']['replace_product_field'])) {
      //If the replace_product_field attribute is "commerce_default" we don't do anything for this field
      if($field_info['commerce_cart_settings']['attribute_widget'] == 'radios' &&
         $field_info['commerce_cart_settings']['replace_product_field'] != 'commerce_default') {
        $options[] = array(
          "product_field" => $field_info['field_name'],
          "replacement_field" => $field_info['commerce_cart_settings']['replace_product_field'],
        );
      }
    }
  }

  //Alter the display of taxonomy term reference fields.
  foreach($options as $current_altered_field) {
    //Check if the field is to be displayed in the current display
    if(!isset($form['attributes'][$current_altered_field['product_field']]['#options']))
      continue;
    
	//Get all of the product ids for the current form
	$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));

    // The radio buttons are displayed based on the term id's, so we have to couple the selected product field to the term id's.
    foreach ($products as $product) {
	  // determine product term id
      $replace_term_field = field_get_items('commerce_product', $product, $current_altered_field['product_field']);
      $tid = !empty($replace_term_field[0]['tid']) ? $replace_term_field[0]['tid'] : $product->product_id;
	  // get the renderable version of the replacement field
	  $product_renderable = commerce_product_build_content($product);
	  if(!empty($product_renderable['commerce_product'][$product->product_id][$current_altered_field['replacement_field']][0])) {
	  	$form['attributes'][$current_altered_field['product_field']]['#options'][$tid] = render($product_renderable['commerce_product'][$product->product_id][$current_altered_field['replacement_field']][0]);
	  }
	}
  }
}