Mostly implement order refunds and cancellations

Summary:
Ref T2787. This has some rough edges but basically works.

  - Users can cancel orders that are in incomplete states (or in complete states, if the application allows them to -- for example, some future application might allow cancellation of billed-but-not-shipped orders).
  - Merchant controllers can partially or fully refund orders from any state after payment.

Test Plan: This is still rough around the edges, but issued Stripe and WePay refunds.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: chad, epriestley

Maniphest Tasks: T2787

Differential Revision: https://secure.phabricator.com/D10664

resources/sql/autopatches/20141008.phortunerefund.sql

@@ -0,0 +1,11 @@
+ALTER TABLE {$NAMESPACE}_phortune.phortune_charge
+  ADD amountRefundedAsCurrency VARCHAR(64) NOT NULL COLLATE utf8_bin;
+
+UPDATE {$NAMESPACE}_phortune.phortune_charge
+  SET amountRefundedAsCurrency = '0.00 USD';
+
+ALTER TABLE {$NAMESPACE}_phortune.phortune_charge
+  ADD refundingPHID VARBINARY(64);
+
+ALTER TABLE {$NAMESPACE}_phortune.phortune_charge
+  ADD refundedChargePHID VARBINARY(64);

src/__phutil_library_map__.php

@@ -2554,6 +2554,7 @@ phutil_register_library_map(array(
     'PhortuneAccountViewController' => 'applications/phortune/controller/PhortuneAccountViewController.php',
     'PhortuneBalancedPaymentProvider' => 'applications/phortune/provider/PhortuneBalancedPaymentProvider.php',
     'PhortuneCart' => 'applications/phortune/storage/PhortuneCart.php',
+    'PhortuneCartCancelController' => 'applications/phortune/controller/PhortuneCartCancelController.php',
     'PhortuneCartCheckoutController' => 'applications/phortune/controller/PhortuneCartCheckoutController.php',
     'PhortuneCartController' => 'applications/phortune/controller/PhortuneCartController.php',
     'PhortuneCartImplementation' => 'applications/phortune/cart/PhortuneCartImplementation.php',
@@ -5608,6 +5609,7 @@ phutil_register_library_map(array(
       'PhortuneDAO',
       'PhabricatorPolicyInterface',
     ),
+    'PhortuneCartCancelController' => 'PhortuneCartController',
     'PhortuneCartCheckoutController' => 'PhortuneCartController',
     'PhortuneCartController' => 'PhortuneController',
     'PhortuneCartListController' => 'PhortuneController',

src/applications/fund/phortune/FundBackerProduct.php

@@ -115,4 +115,11 @@ final class FundBackerProduct extends PhortuneProductImplementation {
     return;
   }
 
+  public function didRefundProduct(
+    PhortuneProduct $product,
+    PhortunePurchase $purchase) {
+    $viewer = $this->getViewer();
+    // TODO: Undonate.
+  }
+
 }

src/applications/phortune/application/PhabricatorPhortuneApplication.php

@@ -48,6 +48,7 @@ final class PhabricatorPhortuneApplication extends PhabricatorApplication {
         'cart/(?P<id>\d+)/' => array(
           '' => 'PhortuneCartViewController',
           'checkout/' => 'PhortuneCartCheckoutController',
+          '(?P<action>cancel|refund)/' => 'PhortuneCartCancelController',
         ),
         'account/' => array(
           '' => 'PhortuneAccountListController',

src/applications/phortune/cart/PhortuneCartImplementation.php

@@ -16,6 +16,21 @@ abstract class PhortuneCartImplementation {
   abstract public function getCancelURI(PhortuneCart $cart);
   abstract public function getDoneURI(PhortuneCart $cart);
 
+  public function assertCanCancelOrder(PhortuneCart $cart) {
+    switch ($cart->getStatus()) {
+      case PhortuneCart::STATUS_PURCHASED:
+        throw new Exception(
+          pht(
+            'This order can not be cancelled because it has already been '.
+            'completed.'));
+        break;
+    }
+  }
+
+  public function assertCanRefundOrder(PhortuneCart $cart) {
+    return;
+  }
+
   abstract public function willCreateCart(
     PhabricatorUser $viewer,
     PhortuneCart $cart);

src/applications/phortune/controller/PhortuneAccountViewController.php

@@ -12,9 +12,20 @@ final class PhortuneAccountViewController extends PhortuneController {
     $request = $this->getRequest();
     $user = $request->getUser();
 
+    // TODO: Currently, you must be able to edit an account to view the detail
+    // page, because the account must be broadly visible so merchants can
+    // process orders but merchants should not be able to see all the details
+    // of an account. Ideally this page should be visible to merchants, too,
+    // just with less information.
+
     $account = id(new PhortuneAccountQuery())
       ->setViewer($user)
       ->withIDs(array($this->accountID))
+      ->requireCapabilities(
+        array(
+          PhabricatorPolicyCapability::CAN_VIEW,
+          PhabricatorPolicyCapability::CAN_EDIT,
+        ))
       ->executeOne();
 
     if (!$account) {

src/applications/phortune/controller/PhortuneCartCancelController.php

@@ -0,0 +1,195 @@
+<?php
+
+final class PhortuneCartCancelController
+  extends PhortuneCartController {
+
+  private $id;
+  private $action;
+
+  public function willProcessRequest(array $data) {
+    $this->id = $data['id'];
+    $this->action = $data['action'];
+  }
+
+  public function processRequest() {
+    $request = $this->getRequest();
+    $viewer = $request->getUser();
+
+    $cart = id(new PhortuneCartQuery())
+      ->setViewer($viewer)
+      ->withIDs(array($this->id))
+      ->needPurchases(true)
+      ->executeOne();
+    if (!$cart) {
+      return new Aphront404Response();
+    }
+
+    switch ($this->action) {
+      case 'cancel':
+        // You must be able to edit the account to cancel an order.
+        PhabricatorPolicyFilter::requireCapability(
+          $viewer,
+          $cart->getAccount(),
+          PhabricatorPolicyCapability::CAN_EDIT);
+        $is_refund = false;
+        break;
+      case 'refund':
+        // You must be able to control the merchant to refund an order.
+        PhabricatorPolicyFilter::requireCapability(
+          $viewer,
+          $cart->getMerchant(),
+          PhabricatorPolicyCapability::CAN_EDIT);
+        $is_refund = true;
+        break;
+      default:
+        return new Aphront404Response();
+    }
+
+    $cancel_uri = $cart->getDetailURI();
+    $merchant = $cart->getMerchant();
+
+    try {
+      if ($is_refund) {
+        $title = pht('Unable to Refund Order');
+        $cart->assertCanRefundOrder();
+      } else {
+        $title = pht('Unable to Cancel Order');
+        $cart->assertCanCancelOrder();
+      }
+    } catch (Exception $ex) {
+      return $this->newDialog()
+        ->setTitle($title)
+        ->appendChild($ex->getMessage())
+        ->addCancelButton($cancel_uri);
+    }
+
+    $charges = id(new PhortuneChargeQuery())
+      ->setViewer($viewer)
+      ->withCartPHIDs(array($cart->getPHID()))
+      ->withStatuses(
+        array(
+          PhortuneCharge::STATUS_CHARGED,
+        ))
+      ->execute();
+
+    $amounts = mpull($charges, 'getAmountAsCurrency');
+    $maximum = PhortuneCurrency::newFromList($amounts);
+    $v_refund = $maximum->formatForDisplay();
+
+    $errors = array();
+    $e_refund = true;
+    if ($request->isFormPost()) {
+      if ($is_refund) {
+        try {
+          $refund = PhortuneCurrency::newFromUserInput(
+            $viewer,
+            $request->getStr('refund'));
+          $refund->assertInRange('0.00 USD', $maximum->formatForDisplay());
+        } catch (Exception $ex) {
+          $errors[] = $ex;
+          $e_refund = pht('Invalid');
+        }
+      } else {
+        $refund = $maximum;
+      }
+
+      if (!$errors) {
+        $charges = msort($charges, 'getID');
+        $charges = array_reverse($charges);
+
+        if ($charges) {
+          $providers = id(new PhortunePaymentProviderConfigQuery())
+            ->setViewer($viewer)
+            ->withPHIDs(mpull($charges, 'getProviderPHID'))
+            ->execute();
+          $providers = mpull($providers, null, 'getPHID');
+        } else {
+          $providers = array();
+        }
+
+        foreach ($charges as $charge) {
+          $refundable = $charge->getAmountRefundableAsCurrency();
+          if (!$refundable->isPositive()) {
+            // This charge is a refund, or has already been fully refunded.
+            continue;
+          }
+
+          if ($refund->isGreaterThan($refundable)) {
+            $refund_amount = $refundable;
+          } else {
+            $refund_amount = $refund;
+          }
+
+          $provider_config = idx($providers, $charge->getProviderPHID());
+          if (!$provider_config) {
+            throw new Exception(pht('Unable to load provider for charge!'));
+          }
+
+          $provider = $provider_config->buildProvider();
+
+          $refund_charge = $cart->willRefundCharge(
+            $viewer,
+            $provider,
+            $charge,
+            $refund_amount);
+
+          $refunded = false;
+          try {
+            $provider->refundCharge($charge, $refund_charge);
+            $refunded = true;
+          } catch (Exception $ex) {
+            phlog($ex);
+            $cart->didFailRefund($charge, $refund_charge);
+          }
+
+          if ($refunded) {
+            $cart->didRefundCharge($charge, $refund_charge);
+            $refund = $refund->subtract($refund_amount);
+          }
+
+          if (!$refund->isPositive()) {
+            break;
+          }
+        }
+
+        if ($refund->isPositive()) {
+          throw new Exception(pht('Unable to refund some charges!'));
+        }
+
+        return id(new AphrontRedirectResponse())->setURI($cancel_uri);
+      }
+    }
+
+    if ($is_refund) {
+      $title = pht('Refund Order?');
+      $body = pht(
+        'Really refund this order?');
+      $button = pht('Refund Order');
+
+      $form = id(new AphrontFormView())
+        ->setUser($viewer)
+        ->appendChild(
+          id(new AphrontFormTextControl())
+            ->setName('refund')
+            ->setLabel(pht('Amount'))
+            ->setError($e_refund)
+            ->setValue($v_refund));
+
+      $form = $form->buildLayoutView();
+    } else {
+      $title = pht('Cancel Order?');
+      $body = pht(
+        'Really cancel this order? Any payment will be refunded.');
+      $button = pht('Cancel Order');
+
+      $form = null;
+    }
+
+    return $this->newDialog()
+      ->setTitle($title)
+      ->appendChild($body)
+      ->appendChild($form)
+      ->addSubmitButton($button)
+      ->addCancelButton($cancel_uri);
+  }
+}

src/applications/phortune/controller/PhortuneCartCheckoutController.php

@@ -119,8 +119,12 @@ final class PhortuneCartCheckoutController
       }
     }
 
-    $cart_box = $this->buildCartContents($cart);
-    $cart_box->setFormErrors($errors);
+    $cart_table = $this->buildCartContentTable($cart);
+
+    $cart_box = id(new PHUIObjectBoxView())
+      ->setFormErrors($errors)
+      ->setHeaderText(pht('Cart Contents'))
+      ->appendChild($cart_table);
 
     $title = pht('Buy Stuff');
 

src/applications/phortune/controller/PhortuneCartController.php

@@ -3,7 +3,7 @@
 abstract class PhortuneCartController
   extends PhortuneController {
 
-  protected function buildCartContents(PhortuneCart $cart) {
+  protected function buildCartContentTable(PhortuneCart $cart) {
 
     $rows = array();
     foreach ($cart->getPurchases() as $purchase) {
@@ -39,9 +39,7 @@ abstract class PhortuneCartController
         'right',
       ));
 
-    return id(new PHUIObjectBoxView())
-      ->setHeaderText(pht('Cart Contents'))
-      ->appendChild($table);
+    return $table;
   }
 
 }

src/applications/phortune/controller/PhortuneCartViewController.php

@@ -22,7 +22,26 @@ final class PhortuneCartViewController
       return new Aphront404Response();
     }
 
-    $cart_box = $this->buildCartContents($cart);
+    $can_admin = PhabricatorPolicyFilter::hasCapability(
+      $viewer,
+      $cart->getMerchant(),
+      PhabricatorPolicyCapability::CAN_EDIT);
+
+    $cart_table = $this->buildCartContentTable($cart);
+
+    $properties = $this->buildPropertyListView($cart);
+    $actions = $this->buildActionListView($cart, $can_admin);
+    $properties->setActionList($actions);
+
+    $header = id(new PHUIHeaderView())
+      ->setUser($viewer)
+      ->setHeader(pht('Order Detail'))
+      ->setPolicyObject($cart);
+
+    $cart_box = id(new PHUIObjectBoxView())
+      ->setHeader($header)
+      ->appendChild($properties)
+      ->appendChild($cart_table);
 
     $charges = id(new PhortuneChargeQuery())
       ->setViewer($viewer)
@@ -49,4 +68,80 @@ final class PhortuneCartViewController
       ));
 
   }
+
+  private function buildPropertyListView(PhortuneCart $cart) {
+
+    $viewer = $this->getRequest()->getUser();
+
+    $view = id(new PHUIPropertyListView())
+      ->setUser($viewer)
+      ->setObject($cart);
+
+    $handles = $this->loadViewerHandles(
+      array(
+        $cart->getAccountPHID(),
+        $cart->getAuthorPHID(),
+        $cart->getMerchantPHID(),
+      ));
+
+    $view->addProperty(
+      pht('Order Name'),
+      $cart->getName());
+    $view->addProperty(
+      pht('Account'),
+      $handles[$cart->getAccountPHID()]->renderLink());
+    $view->addProperty(
+      pht('Authorized By'),
+      $handles[$cart->getAuthorPHID()]->renderLink());
+    $view->addProperty(
+      pht('Merchant'),
+      $handles[$cart->getMerchantPHID()]->renderLink());
+    $view->addProperty(
+      pht('Status'),
+      PhortuneCart::getNameForStatus($cart->getStatus()));
+    $view->addProperty(
+      pht('Updated'),
+      phabricator_datetime($cart->getDateModified(), $viewer));
+
+    return $view;
+  }
+
+  private function buildActionListView(PhortuneCart $cart, $can_admin) {
+    $viewer = $this->getRequest()->getUser();
+    $id = $cart->getID();
+
+    $can_edit = PhabricatorPolicyFilter::hasCapability(
+      $viewer,
+      $cart,
+      PhabricatorPolicyCapability::CAN_EDIT);
+
+    $view = id(new PhabricatorActionListView())
+      ->setUser($viewer)
+      ->setObject($cart);
+
+    $can_cancel = ($can_edit && $cart->canCancelOrder());
+
+    $cancel_uri = $this->getApplicationURI("cart/{$id}/cancel/");
+    $refund_uri = $this->getApplicationURI("cart/{$id}/refund/");
+
+    $view->addAction(
+      id(new PhabricatorActionView())
+        ->setName(pht('Cancel Order'))
+        ->setIcon('fa-times')
+        ->setDisabled(!$can_cancel)
+        ->setWorkflow(true)
+        ->setHref($cancel_uri));
+
+    if ($can_admin) {
+      $view->addAction(
+        id(new PhabricatorActionView())
+          ->setName(pht('Refund Order'))
+          ->setIcon('fa-reply')
+          ->setWorkflow(true)
+          ->setHref($refund_uri));
+    }
+
+    return $view;
+  }
+
 }

src/applications/phortune/controller/PhortuneController.php

@@ -28,10 +28,12 @@ abstract class PhortuneController extends PhabricatorController {
         $charge->getID(),
         $handles[$charge->getCartPHID()]->renderLink(),
         $handles[$charge->getProviderPHID()]->renderLink(),
-        $handles[$charge->getPaymentMethodPHID()]->renderLink(),
+        $charge->getPaymentMethodPHID()
+          ? $handles[$charge->getPaymentMethodPHID()]->renderLink()
+          : null,
         $handles[$charge->getMerchantPHID()]->renderLink(),
         $charge->getAmountAsCurrency()->formatForDisplay(),
-        PhortuneCharge::getNameForStatus($charge->getStatus()),
+        $charge->getStatusForDisplay(),
         phabricator_datetime($charge->getDateCreated(), $viewer),
       );
     }

src/applications/phortune/currency/PhortuneCurrency.php

@@ -48,13 +48,11 @@ final class PhortuneCurrency extends Phobject {
     $value = (int)round(100 * $value);
 
     $currency = idx($matches, 2, $default);
-    if ($currency) {
-      switch ($currency) {
-        case 'USD':
-          break;
-        default:
-          throw new Exception("Unsupported currency '{$currency}'!");
-      }
+    switch ($currency) {
+      case 'USD':
+        break;
+      default:
+        throw new Exception("Unsupported currency '{$currency}'!");
     }
 
     return self::newFromValueAndCurrency($value, $currency);
@@ -126,9 +124,17 @@ final class PhortuneCurrency extends Phobject {
     throw new Exception("Invalid currency format ('{$string}').");
   }
 
+  private function throwUnlikeCurrenciesException(PhortuneCurrency $other) {
+    throw new Exception(
+      pht(
+        'Trying to operate on unlike currencies ("%s" and "%s")!',
+        $this->currency,
+        $other->currency));
+  }
+
   public function add(PhortuneCurrency $other) {
     if ($this->currency !== $other->currency) {
-      throw new Exception(pht('Trying to add unlike currencies!'));
+      $this->throwUnlikeCurrenciesException($other);
     }
 
     $currency = new PhortuneCurrency();
@@ -140,6 +146,46 @@ final class PhortuneCurrency extends Phobject {
     return $currency;
   }
 
+  public function subtract(PhortuneCurrency $other) {
+    if ($this->currency !== $other->currency) {
+      $this->throwUnlikeCurrenciesException($other);
+    }
+
+    $currency = new PhortuneCurrency();
+
+    // TODO: This should check for integer overflows, etc.
+    $currency->value = $this->value - $other->value;
+    $currency->currency = $this->currency;
+
+    return $currency;
+  }
+
+  public function isEqualTo(PhortuneCurrency $other) {
+    if ($this->currency !== $other->currency) {
+      $this->throwUnlikeCurrenciesException($other);
+    }
+
+    return ($this->value === $other->value);
+  }
+
+  public function negate() {
+    $currency = new PhortuneCurrency();
+    $currency->value = -$this->value;
+    $currency->currency = $this->currency;
+    return $currency;
+  }
+
+  public function isPositive() {
+    return ($this->value > 0);
+  }
+
+  public function isGreaterThan(PhortuneCurrency $other) {
+    if ($this->currency !== $other->currency) {
+      $this->throwUnlikeCurrenciesException($other);
+    }
+    return $this->value > $other->value;
+  }
+
   /**
    * Assert that a currency value lies within a range.
    *

src/applications/phortune/product/PhortuneProductImplementation.php

@@ -28,4 +28,10 @@ abstract class PhortuneProductImplementation {
     return;
   }
 
+  public function didRefundProduct(
+    PhortuneProduct $product,
+    PhortunePurchase $purchase) {
+    return;
+  }
+
 }

src/applications/phortune/provider/PhortuneBalancedPaymentProvider.php

@@ -179,6 +179,13 @@ final class PhortuneBalancedPaymentProvider extends PhortunePaymentProvider {
     $charge->save();
   }
 
+  protected function executeRefund(
+    PhortuneCharge $charge,
+    PhortuneCharge $refund) {
+    // TODO: Implement.
+    throw new PhortuneNotImplementedException($this);
+  }
+
   private function getMarketplaceID() {
     return $this
       ->getProviderConfig()
@@ -192,7 +199,7 @@ final class PhortuneBalancedPaymentProvider extends PhortunePaymentProvider {
   }
 
   private function getMarketplaceURI() {
-    return '/v1/marketplace/'.$this->getMarketplaceID();
+    return '/v1/marketplaces/'.$this->getMarketplaceID();
   }
 
 

src/applications/phortune/provider/PhortunePayPalPaymentProvider.php

@@ -167,6 +167,13 @@ final class PhortunePayPalPaymentProvider extends PhortunePaymentProvider {
     throw new Exception('!');
   }
 
+  protected function executeRefund(
+    PhortuneCharge $charge,
+    PhortuneCharge $refund) {
+    // TODO: Implement.
+    throw new PhortuneNotImplementedException($this);
+  }
+
   private function getPaypalAPIUsername() {
     return $this
       ->getProviderConfig()

src/applications/phortune/provider/PhortunePaymentProvider.php

@@ -137,10 +137,20 @@ abstract class PhortunePaymentProvider {
     $this->executeCharge($payment_method, $charge);
   }
 
+  final public function refundCharge(
+    PhortuneCharge $charge,
+    PhortuneCharge $refund) {
+    $this->executeRefund($charge, $refund);
+  }
+
   abstract protected function executeCharge(
     PhortunePaymentMethod $payment_method,
     PhortuneCharge $charge);
 
+  abstract protected function executeRefund(
+    PhortuneCharge $charge,
+    PhortuneCharge $charge);
+
 
 /* -(  Adding Payment Methods  )--------------------------------------------- */
 

src/applications/phortune/provider/PhortuneStripePaymentProvider.php

@@ -146,12 +146,7 @@ final class PhortuneStripePaymentProvider extends PhortunePaymentProvider {
       'capture'     => true,
     );
 
-    try {
-      $stripe_charge = Stripe_Charge::create($params, $secret_key);
-    } catch (Stripe_CardError $ex) {
-      // TODO: Fail charge explicitly.
-      throw $ex;
-    }
+    $stripe_charge = Stripe_Charge::create($params, $secret_key);
 
     $id = $stripe_charge->id;
     if (!$id) {
@@ -162,6 +157,41 @@ final class PhortuneStripePaymentProvider extends PhortunePaymentProvider {
     $charge->save();
   }
 
+  protected function executeRefund(
+    PhortuneCharge $charge,
+    PhortuneCharge $refund) {
+
+    $charge_id = $charge->getMetadataValue('stripe.chargeID');
+    if (!$charge_id) {
+      throw new Exception(
+        pht('Unable to refund charge; no Stripe chargeID!'));
+    }
+
+    $root = dirname(phutil_get_library_root('phabricator'));
+    require_once $root.'/externals/stripe-php/lib/Stripe.php';
+
+    $refund_cents = $refund
+      ->getAmountAsCurrency()
+      ->negate()
+      ->getValueInUSDCents();
+
+    $secret_key = $this->getSecretKey();
+    $params = array(
+      'amount' => $refund_cents,
+    );
+
+    $stripe_charge = Stripe_Charge::retrieve($charge_id, $secret_key);
+    $stripe_refund = $stripe_charge->refunds->create($params);
+
+    $id = $stripe_refund->id;
+    if (!$id) {
+      throw new Exception(pht('Stripe refund call did not return an ID!'));
+    }
+
+    $charge->setMetadataValue('stripe.refundID', $id);
+    $charge->save();
+  }
+
   private function getPublishableKey() {
     return $this
       ->getProviderConfig()

src/applications/phortune/provider/PhortuneTestPaymentProvider.php

@@ -56,6 +56,12 @@ final class PhortuneTestPaymentProvider extends PhortunePaymentProvider {
     return;
   }
 
+  protected function executeRefund(
+    PhortuneCharge $charge,
+    PhortuneCharge $refund) {
+    return;
+  }
+
   public function getAllConfigurableProperties() {
     return array();
   }

src/applications/phortune/provider/PhortuneWePayPaymentProvider.php

@@ -186,6 +186,29 @@ final class PhortuneWePayPaymentProvider extends PhortunePaymentProvider {
       ->getMetadataValue(self::WEPAY_ACCOUNT_ID);
   }
 
+  protected function executeRefund(
+    PhortuneCharge $charge,
+    PhortuneCharge $refund) {
+
+    $root = dirname(phutil_get_library_root('phabricator'));
+    require_once $root.'/externals/wepay/wepay.php';
+
+    WePay::useStaging(
+      $this->getWePayClientID(),
+      $this->getWePayClientSecret());
+
+    $wepay = new WePay($this->getWePayAccessToken());
+
+    $charge_id = $charge->getMetadataValue('wepay.checkoutID');
+
+    $params = array(
+      'checkout_id' => $charge_id,
+      'refund_reason' => pht('Refund'),
+      'amount' => $refund->getAmountAsCurrency()->negate()->formatBareValue(),
+    );
+
+    $wepay->request('checkout/refund', $params);
+  }
 
 /* -(  One-Time Payments  )-------------------------------------------------- */
 

src/applications/phortune/storage/PhortuneAccount.php

@@ -106,11 +106,19 @@ final class PhortuneAccount extends PhortuneDAO
   }
 
   public function getPolicy($capability) {
-    if ($this->getPHID() === null) {
-      // Allow a user to create an account for themselves.
-      return PhabricatorPolicies::POLICY_USER;
-    } else {
-      return PhabricatorPolicies::POLICY_NOONE;
+    switch ($capability) {
+      case PhabricatorPolicyCapability::CAN_VIEW:
+        // Accounts are technically visible to all users, because merchant
+        // controllers need to be able to see accounts in order to process
+        // orders. We lock things down more tightly at the application level.
+        return PhabricatorPolicies::POLICY_USER;
+      case PhabricatorPolicyCapability::CAN_EDIT:
+        if ($this->getPHID() === null) {
+          // Allow a user to create an account for themselves.
+          return PhabricatorPolicies::POLICY_USER;
+        } else {
+          return PhabricatorPolicies::POLICY_NOONE;
+        }
     }
   }
 

src/applications/phortune/storage/PhortuneCart.php

@@ -92,20 +92,22 @@ final class PhortuneCart extends PhortuneDAO
     $this->openTransaction();
       $this->beginReadLocking();
 
-      $copy = clone $this;
-      $copy->reload();
+        $copy = clone $this;
+        $copy->reload();
 
-      if ($copy->getStatus() !== self::STATUS_READY) {
-        throw new Exception(
-          pht(
-            'Cart has wrong status ("%s") to call willApplyCharge(), expected '.
-            '"%s".',
-            $copy->getStatus(),
-            self::STATUS_READY));
-      }
+        if ($copy->getStatus() !== self::STATUS_READY) {
+          throw new Exception(
+            pht(
+              'Cart has wrong status ("%s") to call willApplyCharge(), '.
+              'expected "%s".',
+              $copy->getStatus(),
+              self::STATUS_READY));
+        }
 
-      $charge->save();
-      $this->setStatus(PhortuneCart::STATUS_PURCHASING)->save();
+        $charge->save();
+        $this->setStatus(PhortuneCart::STATUS_PURCHASING)->save();
+
+      $this->endReadLocking();
     $this->saveTransaction();
 
     return $charge;
@@ -117,20 +119,22 @@ final class PhortuneCart extends PhortuneDAO
     $this->openTransaction();
       $this->beginReadLocking();
 
-      $copy = clone $this;
-      $copy->reload();
+        $copy = clone $this;
+        $copy->reload();
 
-      if ($copy->getStatus() !== self::STATUS_PURCHASING) {
-        throw new Exception(
-          pht(
-            'Cart has wrong status ("%s") to call didApplyCharge(), expected '.
-            '"%s".',
-            $copy->getStatus(),
-            self::STATUS_PURCHASING));
-      }
+        if ($copy->getStatus() !== self::STATUS_PURCHASING) {
+          throw new Exception(
+            pht(
+              'Cart has wrong status ("%s") to call didApplyCharge(), '.
+              'expected "%s".',
+              $copy->getStatus(),
+              self::STATUS_PURCHASING));
+        }
 
-      $charge->save();
-      $this->setStatus(self::STATUS_CHARGED)->save();
+        $charge->save();
+        $this->setStatus(self::STATUS_CHARGED)->save();
+
+      $this->endReadLocking();
     $this->saveTransaction();
 
     foreach ($this->purchases as $purchase) {
@@ -142,6 +146,127 @@ final class PhortuneCart extends PhortuneDAO
     return $this;
   }
 
+  public function willRefundCharge(
+    PhabricatorUser $actor,
+    PhortunePaymentProvider $provider,
+    PhortuneCharge $charge,
+    PhortuneCurrency $amount) {
+
+    if (!$amount->isPositive()) {
+      throw new Exception(
+        pht('Trying to refund nonpositive amount of money!'));
+    }
+
+    if ($amount->isGreaterThan($charge->getAmountRefundableAsCurrency())) {
+      throw new Exception(
+        pht('Trying to refund more money than remaining on charge!'));
+    }
+
+    if ($charge->getRefundedChargePHID()) {
+      throw new Exception(
+        pht('Trying to refund a refund!'));
+    }
+
+    if ($charge->getStatus() !== PhortuneCharge::STATUS_CHARGED) {
+      throw new Exception(
+        pht('Trying to refund an uncharged charge!'));
+    }
+
+    $refund_charge = PhortuneCharge::initializeNewCharge()
+      ->setAccountPHID($this->getAccount()->getPHID())
+      ->setCartPHID($this->getPHID())
+      ->setAuthorPHID($actor->getPHID())
+      ->setMerchantPHID($this->getMerchant()->getPHID())
+      ->setProviderPHID($provider->getProviderConfig()->getPHID())
+      ->setPaymentMethodPHID($charge->getPaymentMethodPHID())
+      ->setRefundedChargePHID($charge->getPHID())
+      ->setAmountAsCurrency($amount->negate());
+
+    $charge->openTransaction();
+      $charge->beginReadLocking();
+
+        $copy = clone $charge;
+        $copy->reload();
+
+        if ($copy->getRefundingPHID() !== null) {
+          throw new Exception(
+            pht('Trying to refund a charge which is already refunding!'));
+        }
+
+        $refund_charge->save();
+        $charge->setRefundingPHID($refund_charge->getPHID());
+        $charge->save();
+
+      $charge->endReadLocking();
+    $charge->saveTransaction();
+
+    return $refund_charge;
+  }
+
+  public function didRefundCharge(
+    PhortuneCharge $charge,
+    PhortuneCharge $refund) {
+
+    $refund->setStatus(PhortuneCharge::STATUS_CHARGED);
+
+    $this->openTransaction();
+      $this->beginReadLocking();
+
+        $copy = clone $charge;
+        $copy->reload();
+
+        if ($charge->getRefundingPHID() !== $refund->getPHID()) {
+          throw new Exception(
+            pht('Charge is in the wrong refunding state!'));
+        }
+
+        $charge->setRefundingPHID(null);
+
+        // NOTE: There's some trickiness here to get the signs right. Both
+        // these values are positive but the refund has a negative value.
+        $total_refunded = $charge
+          ->getAmountRefundedAsCurrency()
+          ->add($refund->getAmountAsCurrency()->negate());
+
+        $charge->setAmountRefundedAsCurrency($total_refunded);
+        $charge->save();
+        $refund->save();
+
+      $this->endReadLocking();
+    $this->saveTransaction();
+
+    foreach ($this->purchases as $purchase) {
+      $purchase->getProduct()->didRefundProduct($purchase);
+    }
+
+    return $this;
+  }
+
+  public function didFailRefund(
+    PhortuneCharge $charge,
+    PhortuneCharge $refund) {
+
+    $refund->setStatus(PhortuneCharge::STATUS_FAILED);
+
+    $this->openTransaction();
+      $this->beginReadLocking();
+
+        $copy = clone $charge;
+        $copy->reload();
+
+        if ($charge->getRefundingPHID() !== $refund->getPHID()) {
+          throw new Exception(
+            pht('Charge is in the wrong refunding state!'));
+        }
+
+        $charge->setRefundingPHID(null);
+        $charge->save();
+        $refund->save();
+
+      $this->endReadLocking();
+    $this->saveTransaction();
+  }
+
   public function getName() {
     return $this->getImplementation()->getName($this);
   }
@@ -162,6 +287,56 @@ final class PhortuneCart extends PhortuneDAO
     return '/phortune/cart/'.$this->getID().'/checkout/';
   }
 
+  public function canCancelOrder() {
+    try {
+      $this->assertCanCancelOrder();
+      return true;
+    } catch (Exception $ex) {
+      return false;
+    }
+  }
+
+  public function canRefundOrder() {
+    try {
+      $this->assertCanRefundOrder();
+      return true;
+    } catch (Exception $ex) {
+      return false;
+    }
+  }
+
+  public function assertCanCancelOrder() {
+    switch ($this->getStatus()) {
+      case self::STATUS_BUILDING:
+        throw new Exception(
+          pht(
+            'This order can not be cancelled because the application has not '.
+            'finished building it yet.'));
+      case self::STATUS_READY:
+        throw new Exception(
+          pht(
+            'This order can not be cancelled because it has not been placed.'));
+    }
+
+    return $this->getImplementation()->assertCanCancelOrder($this);
+  }
+
+  public function assertCanRefundOrder() {
+    switch ($this->getStatus()) {
+      case self::STATUS_BUILDING:
+        throw new Exception(
+          pht(
+            'This order can not be refunded because the application has not '.
+            'finished building it yet.'));
+      case self::STATUS_READY:
+        throw new Exception(
+          pht(
+            'This order can not be refunded because it has not been placed.'));
+    }
+
+    return $this->getImplementation()->assertCanRefundOrder($this);
+  }
+
   public function getConfiguration() {
     return array(
       self::CONFIG_AUX_PHID => true,
@@ -260,11 +435,30 @@ final class PhortuneCart extends PhortuneDAO
   }
 
   public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
-    return $this->getAccount()->hasAutomaticCapability($capability, $viewer);
+    if ($this->getAccount()->hasAutomaticCapability($capability, $viewer)) {
+      return true;
+    }
+
+    // If the viewer controls the merchant this order was placed with, they
+    // can view the order.
+    if ($capability == PhabricatorPolicyCapability::CAN_VIEW) {
+      $can_admin = PhabricatorPolicyFilter::hasCapability(
+        $viewer,
+        $this->getMerchant(),
+        PhabricatorPolicyCapability::CAN_EDIT);
+      if ($can_admin) {
+        return true;
+      }
+    }
+
+    return false;
   }
 
   public function describeAutomaticCapability($capability) {
-    return pht('Carts inherit the policies of the associated account.');
+    return array(
+      pht('Orders inherit the policies of the associated account.'),
+      pht('The merchant you placed an order with can review and manage it.'),
+    );
   }
 
 }

src/applications/phortune/storage/PhortuneCharge.php

@@ -20,6 +20,9 @@ final class PhortuneCharge extends PhortuneDAO
   protected $merchantPHID;
   protected $paymentMethodPHID;
   protected $amountAsCurrency;
+  protected $amountRefundedAsCurrency;
+  protected $refundedChargePHID;
+  protected $refundingPHID;
   protected $status;
   protected $metadata = array();
 
@@ -28,7 +31,8 @@ final class PhortuneCharge extends PhortuneDAO
 
   public static function initializeNewCharge() {
     return id(new PhortuneCharge())
-      ->setStatus(self::STATUS_CHARGING);
+      ->setStatus(self::STATUS_CHARGING)
+      ->setAmountRefundedAsCurrency(PhortuneCurrency::newEmptyCurrency());
   }
 
   public function getConfiguration() {
@@ -39,11 +43,14 @@ final class PhortuneCharge extends PhortuneDAO
       ),
       self::CONFIG_APPLICATION_SERIALIZERS => array(
         'amountAsCurrency' => new PhortuneCurrencySerializer(),
+        'amountRefundedAsCurrency' => new PhortuneCurrencySerializer(),
       ),
       self::CONFIG_COLUMN_SCHEMA => array(
-        'paymentProviderKey' => 'text128',
         'paymentMethodPHID' => 'phid?',
+        'refundedChargePHID' => 'phid?',
+        'refundingPHID' => 'phid?',
         'amountAsCurrency' => 'text64',
+        'amountRefundedAsCurrency' => 'text64',
         'status' => 'text32',
       ),
       self::CONFIG_KEY_SCHEMA => array(
@@ -75,6 +82,26 @@ final class PhortuneCharge extends PhortuneDAO
     return idx(self::getStatusNameMap(), $status, pht('Unknown'));
   }
 
+  public function getStatusForDisplay() {
+    if ($this->getStatus() == self::STATUS_CHARGED) {
+      if ($this->getRefundedChargePHID()) {
+        return pht('Refund');
+      }
+
+      $refunded = $this->getAmountRefundedAsCurrency();
+
+      if ($refunded->isPositive()) {
+        if ($refunded->isEqualTo($this->getAmountAsCurrency())) {
+          return pht('Fully Refunded');
+        } else {
+          return pht('%s Refunded', $refunded->formatForDisplay());
+        }
+      }
+    }
+
+    return self::getNameForStatus($this->getStatus());
+  }
+
   public function generatePHID() {
     return PhabricatorPHID::generateNewPHID(
       PhortuneChargePHIDType::TYPECONST);
@@ -107,6 +134,21 @@ final class PhortuneCharge extends PhortuneDAO
     return $this;
   }
 
+  public function getAmountRefundableAsCurrency() {
+    $amount = $this->getAmountAsCurrency();
+    $refunded = $this->getAmountRefundedAsCurrency();
+
+    // We can't refund negative amounts of money, since it does not make
+    // sense and is not possible in the various payment APIs.
+
+    $refundable = $amount->subtract($refunded);
+    if ($refundable->isPositive()) {
+      return $refundable;
+    } else {
+      return PhortuneCurrency::newEmptyCurrency();
+    }
+  }
+
 
 /* -(  PhabricatorPolicyInterface  )----------------------------------------- */
 

src/applications/phortune/storage/PhortuneProduct.php

@@ -78,6 +78,10 @@ final class PhortuneProduct extends PhortuneDAO
     return $this->getImplementation()->didPurchaseProduct($this, $purchase);
   }
 
+  public function didRefundProduct(PhortunePurchase $purchase) {
+    return $this->getImplementation()->didRefundProduct($this, $purchase);
+  }
+
 
 /* -(  PhabricatorPolicyInterface  )----------------------------------------- */