Allow configuration of a "staging area" for each repository

Summary:
Ref T8238. This allows configuration of a "staging area" for Git repositories, which is the URI to some Git repository (possibly the same repository).

If a staging area is configured, `arc` will push a copy of anything it creates a diff for there (see next revision). This primarily makes handoff to build systems easier.

This is a bit leaky and I intend for it to eventually be positioned as a less-preferred solution, but from the perspective of build systems it's the same as the real (virtual ref) solution that I want to build.

Test Plan: Ran `arc diff` with various flags, saw appropriate changes copied into the staging area. See also discussion in T8238.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: cburroughs, epriestley

Maniphest Tasks: T8238

Differential Revision: https://secure.phabricator.com/D13019

src/applications/diffusion/controller/DiffusionRepositoryEditMainController.php

@@ -30,6 +30,7 @@ final class DiffusionRepositoryEditMainController
 
     $has_branches = ($is_git || $is_hg);
     $has_local = $repository->usesLocalWorkingCopy();
+    $supports_staging = $repository->supportsStaging();
 
     $crumbs = $this->buildApplicationCrumbs($is_main = true);
 
@@ -92,6 +93,13 @@ final class DiffusionRepositoryEditMainController
         $this->buildStorageActions($repository));
     }
 
+    $staging_properties = null;
+    if ($supports_staging) {
+      $staging_properties = $this->buildStagingProperties(
+        $repository,
+        $this->buildStagingActions($repository));
+    }
+
     $actions_properties = $this->buildActionsProperties(
       $repository,
       $this->buildActionsActions($repository));
@@ -157,6 +165,12 @@ final class DiffusionRepositoryEditMainController
         ->addPropertyList($storage_properties);
     }
 
+    if ($staging_properties) {
+      $boxes[] = id(new PHUIObjectBoxView())
+        ->setHeaderText(pht('Staging'))
+        ->addPropertyList($staging_properties);
+    }
+
     $boxes[] = id(new PHUIObjectBoxView())
       ->setHeaderText(pht('Text Encoding'))
       ->addPropertyList($encoding_properties);
@@ -609,6 +623,45 @@ final class DiffusionRepositoryEditMainController
     return $view;
   }
 
+
+  private function buildStagingActions(PhabricatorRepository $repository) {
+    $viewer = $this->getViewer();
+
+    $view = id(new PhabricatorActionListView())
+      ->setObjectURI($this->getRequest()->getRequestURI())
+      ->setUser($viewer);
+
+    $edit = id(new PhabricatorActionView())
+      ->setIcon('fa-pencil')
+      ->setName(pht('Edit Staging'))
+      ->setHref(
+        $this->getRepositoryControllerURI($repository, 'edit/staging/'));
+    $view->addAction($edit);
+
+    return $view;
+  }
+
+  private function buildStagingProperties(
+    PhabricatorRepository $repository,
+    PhabricatorActionListView $actions) {
+    $viewer = $this->getViewer();
+
+    $view = id(new PHUIPropertyListView())
+      ->setUser($viewer)
+      ->setActionList($actions);
+
+    $staging_uri = $repository->getStagingURI();
+    if (!$staging_uri) {
+      $staging_uri = phutil_tag('em', array(), pht('No Staging Area'));
+    }
+
+    $view->addProperty(
+      pht('Staging Area'),
+      $staging_uri);
+
+    return $view;
+  }
+
   private function buildHostingActions(PhabricatorRepository $repository) {
     $user = $this->getRequest()->getUser();