<?php

/**
 * Creates an order for the given user containing the product with the given id.
 * This example may be extended easily to create an order containing several
 * products, a shipping and so far.
 *
 * Returns a commerce order that's now saved in the database with the status
 * "processing and can be finished by an administrator in the UI.
 * Throws an exception, if something is wrong.
 *
 * @param integer $uid The numeric user id, e.g. "1"
 * @param integer $product_id The numeric product id (NOT SKU! ;))
 * @return CommerceORder
 * @throws Exception
 */
function my_module_api_create_order($uid, $product_id) {
  if (empty($uid) || !is_numeric($uid)) {
    throw new Exception('User ID may not be empty and must be numeric!');
  }
  $user = user_load($uid);

  if (empty($product_id) || !is_numeric($product_id)) {
    throw new Exception('Product ID may not be empty and must be numeric!');
  }

  // Use a transaction to ensure that no broken order is created!
  $transaction = db_transaction();
  try {
    // Create the new order in checkout; you might also check first to
    // see if your user already has an order to use instead of a new one.
    $order = commerce_order_new($user->uid, 'checkout_checkout');

    // Save the order to get its ID.
    commerce_order_save($order);
    // Get the order wrapper which provides helper functionality
    $order_wrapper = entity_metadata_wrapper('commerce_order', $order);

    // Add address profiles.
    // IMPORTANT! The address MUST be set before the line item to
    // correctly determine the country of supply.
    // IMPORTANT2: This address setup is made based on single fields in the user
    // account. If you already use an address field in the user account
    // this is much simpler and you should have a look at the
    // commerce_extra module for address fields ;)
    // Billing
    // Check that we have at least all REQUIRED fields!
    if (empty($user->field_firstname[LANGUAGE_NONE][0]['value'])) {
      throw new Exception('field_firstname may not be empty!');
    }
    if (empty($user->field_lastname[LANGUAGE_NONE][0]['value'])) {
      throw new Exception('field_lastname may not be empty!');
    }
    if (empty($user->field_city[LANGUAGE_NONE][0]['value'])) {
      throw new Exception('field_city may not be empty!');
    }
    if (empty($user->field_zip[LANGUAGE_NONE][0]['value'])) {
      throw new Exception('field_zip may not be empty!');
    }
    if (empty($user->field_street[LANGUAGE_NONE][0]['value'])) {
      throw new Exception('field_street may not be empty!');
    }
    if (empty($user->field_country[LANGUAGE_NONE][0]['value'])) {
      throw new Exception('field_country may not be empty!');
    }
    // We have to get or create the first order profile of the users to set the values into.
    // We use a helper function for that!
    $billing = _my_module_api_create_order_get_first_customer_profile('billing', $user);
    $customer_profile_billing_array = array(
      'country' => isset($user->field_country[LANGUAGE_NONE][0]['value']) ? $user->field_country[LANGUAGE_NONE][0]['value'] : NULL, // DE
      'name_line' => NULL, // Testperson
      'first_name' => isset($user->field_firstname[LANGUAGE_NONE][0]['value']) ? $user->field_firstname[LANGUAGE_NONE][0]['value'] : NULL, // Max
      'last_name' => isset($user->field_lastname[LANGUAGE_NONE][0]['value']) ? $user->field_lastname[LANGUAGE_NONE][0]['value'] : NULL, // Mustermann
      'organisation_name' => isset($user->field_firma[LANGUAGE_NONE][0]['value']) ? $user->field_firma[LANGUAGE_NONE][0]['value'] : NULL, // Muster AG
      'administrative_area' => NULL,
      'sub_administrative_area' => NULL,
      'locality' => isset($user->field_wohnort[LANGUAGE_NONE][0]['value']) ? $user->field_wohnort[LANGUAGE_NONE][0]['value'] : NULL, // Musterstadt
      'dependent_locality' => NULL,
      'postal_code' => isset($user->field_zip[LANGUAGE_NONE][0]['value']) ? $user->field_zip[LANGUAGE_NONE][0]['value'] : NULL, // 32457
      'thoroughfare' => isset($user->field_street[LANGUAGE_NONE][0]['value']) ? $user->field_street[LANGUAGE_NONE][0]['value'] : NULL, // Musterstraße 10
      'premise' => NULL,
      'sub_premise' => NULL,
      'data' => NULL,
    );
    // Set the values in the profile entity and attache it to the order
    $billing->commerce_customer_address[LANGUAGE_NONE][0] = $customer_profile_billing_array;
    commerce_customer_profile_save($billing);
    $order->commerce_customer_billing[LANGUAGE_NONE][0]['profile_id'] = $billing->profile_id;

    // This is only required if you use the commerce_vat module and you want to
    // set the vat id programmatically with implications on the price calculation!
    if (!empty($user->field_vat_number[LANGUAGE_NONE][0]['value'])) {
      $eu_vat_rc = _my_module_api_create_order_get_first_customer_profile('eu_vat_rc', $user);
      $customer_profile_vat_array = array(
        'value' => !empty($user->field_vat_number[LANGUAGE_NONE][0]['value']) ? $user->field_vat_number[LANGUAGE_NONE][0]['value'] : NULL,
      );
      $eu_vat_rc->commerce_vat_number[LANGUAGE_NONE][0] = $customer_profile_vat_array;
      commerce_customer_profile_save($eu_vat_rc);
      $order->commerce_customer_eu_vat_rc[LANGUAGE_NONE][0]['profile_id'] = $eu_vat_rc->profile_id;
    }

    // IMPORTANT: If we also use shipping address, this would be the
    // place to set it here like we already did in "billing"!
    // Save the order again to save the address attached.
    $order_wrapper->save();

    // Load whatever product represents the item the customer will be
    // paying for and create a line item for it.
    $product = commerce_product_load($product_id);

    // Create a new line item with multiplicity = 1
    $line_item = commerce_product_line_item_new($product, 1, $order->order_id);
    // You may set line item properties here.
    // Calculate the sell price!
    rules_invoke_event('commerce_product_calculate_sell_price', $line_item);
    // Save the line item
    commerce_line_item_save($line_item);

    // Attach the line item to the order using the order wrapper.
    $order_wrapper->commerce_line_items[] = $line_item;
    $order_wrapper->save();

    // Now calculate the total price and save the order again.
    commerce_order_calculate_total($order);
    $order_wrapper->save();

    // To create the payment we need some information from the order:
    $total = $order_wrapper->commerce_order_total->amount->value();
    $currency_code = $order_wrapper->commerce_order_total->currency_code->value();
    $charge = array(
      'amount' => $total,
      'currency_code' => $currency_code,
    );

    // The following is an example for payment methods commerce_directdebit and bank_transfer.
    // You may use this as example for other payment types!
    // SEPA if we have the required users direct debit fields, otherwise bank transfer!
    if (!empty($user->field_accountholder[LANGUAGE_NONE][0]['value']) && !empty($user->field_bic[LANGUAGE_NONE][0]['value']) && !empty($user->field_iban[LANGUAGE_NONE][0]['value'])) {
      // SEPA
      $payment_method = array(
        'instance_id' => 'commerce_directdebit|commerce_payment_commerce_directdebit',
      );
      commerce_directdebit_transaction($payment_method, $order, $charge, $user->field_accountholder[LANGUAGE_NONE][0]['value'], '', '', 1, $user->field_bic[LANGUAGE_NONE][0]['value'], $user->field_iban[LANGUAGE_NONE][0]['value']);
    }
    else {
      // BANK TRANSFER
      $payment_method = array(
        'instance_id' => 'bank_transfer|commerce_payment_bank_transfer',
      );
      commerce_bank_transfer_transaction($payment_method, $order, $charge);
    }
    // Set the payment id in the order array to make it available for invoicing
    // (no idea why we have to do that manually here. Perhaps there's a better way?)
    $order->data['payment_method'] = $payment_method['instance_id'];
    $order_wrapper->save();

    // Update the status to processing to allow manual finishing later on.
    commerce_order_status_update($order, 'processing');

    // No explicit transaction commit wanted by drupal...
  } catch (Exception $e) {
    // Something went wrong! We don't want to save a broken order to the database
    // at all. So let's roll back the transaction:
    $transaction->rollback();
    // Add some information to the exception for easier debugging in an outer try / catch!
    $e->user_id = $uid;
    $e->product_id = $product_id;
    // We've done what we could. Re-throw the exception and let an outer
    // try/catch handle it for error logging.
    throw $e;
  }

  // Yeah, the order was created successfully. Provide it to the outer call! :)
  return $order;
}

/**
 * Helper function to get the users already existing (as implemented: first)
 * commerce customer profile and return it.
 * If the user has no customer profile yet, create a new one and return that.
 *
 * @param string $type The type of the customer profile e.g. "billing".
 * @param stdClass $user The user object.
 * @return stdClass The CommerceCustomerProfile object.
 */
function _my_module_api_create_order_get_first_customer_profile($type, stdClass $user) {
  $query = new EntityFieldQuery();
  $query->entityCondition('entity_type', 'commerce_customer_profile')
      ->propertyCondition('uid', $user->uid)
      ->propertyCondition('type', $type);

  $results = $query->execute();
  if (!empty($results['commerce_customer_profile'])) {
    // Profile already exists. Load!
    $profile_info = reset($results['commerce_customer_profile']);
    return commerce_customer_profile_load($profile_info->profile_id);
  }
  else {
    // No profile yet. Create one!
    return commerce_customer_profile_new($type, $user->uid);
  }
}