Index: modules/order/src/Element/ProfileSelect.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- modules/order/src/Element/ProfileSelect.php	(revision )
+++ modules/order/src/Element/ProfileSelect.php	(revision )
@@ -92,6 +92,83 @@
       }
     }
 
+    if (\Drupal::currentUser()->isAuthenticated()) {
+
+      /**
+       * @var \Drupal\profile\ProfileStorage $profileStorage
+       */
+      $profileStorage = \Drupal::service('entity_type.manager')->getStorage('profile');
+
+      /**
+       * @var \Drupal\profile\Entity\Profile[] $profiles
+       */
+      $profiles = $profileStorage->loadMultipleByUser(\Drupal::currentUser()->getAccount(), $element['#default_value']->get('type')->getString());
+      $optionsList = array();
+
+      foreach ($profiles as $profile) {
+        $profileArray = $profile->toArray();
+        if (!empty($profileArray['address'])) {
+          $optionsList[$profile->id()] = ''
+            .$profileArray['address'][0]['given_name'].' '
+            .$profileArray['address'][0]['family_name'].', '
+            .$profileArray['address'][0]['address_line1'].', '
+            .$profileArray['address'][0]['locality'].' '
+            .$profileArray['address'][0]['postal_code'].' ';
+        }
+      }
+
+      // Pass on the parents tree for ajax processing in order to reach the correct form element
+      if (!empty($optionsList)) {
+        $form_state->setTemporary(array('parent_forms' => $element['#parents']));
+      }
+
+      $optionsList['new'] = 'Add new';
+
+      $defaultSelectValue = $element['#default_value']->id();
+
+      // Check if a value has been selected
+      $tmpValues = $form_state->getValues();
+
+      foreach ($element['#parents'] as $parent) {
+        if(!empty($tmpValues[$parent])) {
+          $tmpValues = $tmpValues[$parent];
+        }
+      }
+
+      if (!empty($tmpValues['profile_select'])) {
+        // Assign selected value as the default select value
+        $defaultSelectValue = $tmpValues['profile_select'];
+
+        if ($tmpValues['profile_select'] != 'new') {
+          // Set the default profile to the selected one
+          $element['#default_value'] = $profileStorage->load($tmpValues['profile_select']);
+        } else {
+          // Create a new default for empty values
+          $element['#default_value'] = $profileStorage->create();
+        }
+      }
+      // end check
+
+
+      $element['profile_select'] = [
+        '#type' => 'select',
+        '#title' => 'Select profile to reuse',
+        '#options' => $optionsList,
+        '#default_value' => $defaultSelectValue,
+        '#ajax' => [
+          'callback' => '\Drupal\commerce_order\Element\ProfileSelect::setPreselectedProfileAjax',
+          'event' => 'change',
+          'wrapper' => $element['#id'],
+          'progress' => array(
+            'type' => 'throbber',
+            'message' => 'Selecting profile'
+          ),
+        ],
+      ];
+    }
+
+    // TODO: Prepopulate the form fields with values from $element['#default_value']
+
     $element['#profile'] = $element['#default_value'];
     $form_display = EntityFormDisplay::collectRenderDisplay($element['#profile'], 'default');
     $form_display->buildForm($element['#profile'], $element, $form_state);
@@ -144,4 +221,17 @@
     $element['#profile']->save();
   }
 
+  public function setPreselectedProfileAjax(array $element, FormStateInterface $form_state){
+    // Set default return element
+    $returnElement = $element;
+    $parentForms = $form_state->getTemporaryValue('parent_forms');
+    // If there are parents, go down the tree until the payment select element reached
+    if (!empty($parentForms)) {
+      foreach ($parentForms as $parentForm) {
+        $returnElement = $returnElement[$parentForm];
+      }
+    }
+    return $returnElement;
+  }
+
 }