Add a "refs" table to Diffusion

Summary:
Ref T7100. When a user navigates to a branch like "default" which is ambiguous:

  - don't fatal;
  - choose one alternative to resolve it to (currently more or less at random);
  - sometimes show what we did in the UI.

Also, add a new table to show the alternatives.

This will get refined in followup changes.

Test Plan:
{F384335}

{F384336}

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T7100

Differential Revision: https://secure.phabricator.com/D12547

src/__phutil_library_map__.php

@@ -577,6 +577,7 @@ phutil_register_library_map(array(
     'DiffusionRawDiffQueryConduitAPIMethod' => 'applications/diffusion/conduit/DiffusionRawDiffQueryConduitAPIMethod.php',
     'DiffusionReadmeView' => 'applications/diffusion/view/DiffusionReadmeView.php',
     'DiffusionRefNotFoundException' => 'applications/diffusion/exception/DiffusionRefNotFoundException.php',
+    'DiffusionRefTableController' => 'applications/diffusion/controller/DiffusionRefTableController.php',
     'DiffusionRefsQueryConduitAPIMethod' => 'applications/diffusion/conduit/DiffusionRefsQueryConduitAPIMethod.php',
     'DiffusionRenameHistoryQuery' => 'applications/diffusion/query/DiffusionRenameHistoryQuery.php',
     'DiffusionRepositoryByIDRemarkupRule' => 'applications/diffusion/remarkup/DiffusionRepositoryByIDRemarkupRule.php',
@@ -3789,6 +3790,7 @@ phutil_register_library_map(array(
     'DiffusionRawDiffQueryConduitAPIMethod' => 'DiffusionQueryConduitAPIMethod',
     'DiffusionReadmeView' => 'DiffusionView',
     'DiffusionRefNotFoundException' => 'Exception',
+    'DiffusionRefTableController' => 'DiffusionController',
     'DiffusionRefsQueryConduitAPIMethod' => 'DiffusionQueryConduitAPIMethod',
     'DiffusionRepositoryByIDRemarkupRule' => 'PhabricatorObjectRemarkupRule',
     'DiffusionRepositoryController' => 'DiffusionController',

src/applications/diffusion/application/PhabricatorDiffusionApplication.php

@@ -76,6 +76,7 @@ final class PhabricatorDiffusionApplication extends PhabricatorApplication {
           'diff/'                       => 'DiffusionDiffController',
           'tags/(?P<dblob>.*)'          => 'DiffusionTagListController',
           'branches/(?P<dblob>.*)'      => 'DiffusionBranchTableController',
+          'refs/(?P<dblob>.*)'          => 'DiffusionRefTableController',
           'lint/(?P<dblob>.*)'          => 'DiffusionLintController',
           'commit/(?P<commit>[a-z0-9]+)/branches/'
             => 'DiffusionCommitBranchesController',

src/applications/diffusion/controller/DiffusionRefTableController.php

@@ -0,0 +1,131 @@
+<?php
+
+final class DiffusionRefTableController extends DiffusionController {
+
+  public function shouldAllowPublic() {
+    return true;
+  }
+
+  protected function processDiffusionRequest(AphrontRequest $request) {
+    $viewer = $this->getViewer();
+
+    $drequest = $this->getDiffusionRequest();
+    $repository = $drequest->getRepository();
+
+    if (!$drequest->supportsBranches()) {
+      return $this->newDialog()
+        ->setTitle(pht('No Ref Support'))
+        ->appendParagraph(
+          pht(
+            'The version control system this repository uses does not '.
+            'support named references, so you can not resolve or list '.
+            'repository refs in this repository.'))
+        ->addCancelButton($repository->getURI());
+    }
+
+    $ref_name = $drequest->getBranch();
+
+    $cache_query = id(new DiffusionCachedResolveRefsQuery())
+      ->setRepository($repository);
+    if ($ref_name !== null) {
+      $cache_query->withRefs(array($ref_name));
+    }
+    $cache_refs = $cache_query->execute();
+
+    $vcs_refs = DiffusionQuery::callConduitWithDiffusionRequest(
+      $viewer,
+      $drequest,
+      'diffusion.resolverefs',
+      array(
+        'refs' => array($ref_name),
+      ));
+
+    $all = array();
+    foreach ($cache_refs as $ref => $results) {
+      foreach ($results as $result) {
+        $id = $result['type'].'/'.$result['identifier'];
+        $all[$ref][$id]['cache'] = $result;
+      }
+    }
+
+    foreach ($vcs_refs as $ref => $results) {
+      foreach ($results as $result) {
+        $id = $result['type'].'/'.$result['identifier'];
+        $all[$ref][$id]['vcs'] = $result;
+      }
+    }
+
+    $rows = array();
+    foreach ($all as $ref => $results) {
+      foreach ($results as $info) {
+        $cache = idx($info, 'cache', array());
+        $vcs = idx($info, 'vcs', array());
+
+        $type = idx($vcs, 'type');
+        if (!$type) {
+          $type = idx($cache, 'type');
+        }
+
+        $identifier = idx($vcs, 'identifier');
+        if ($identifier !== null) {
+          $identifier = DiffusionView::linkCommit(
+            $repository,
+            $identifier);
+        }
+
+        $cache_identifier = idx($cache, 'identifier');
+        if ($cache_identifier !== null) {
+          $cache_identifier = DiffusionView::linkCommit(
+            $repository,
+            $cache_identifier);
+        }
+
+        $alternate = idx($vcs, 'alternate');
+        if ($alternate !== null) {
+          $alternate = DiffusionView::linkCommit(
+            $repository,
+            $alternate);
+        }
+
+        $rows[] = array(
+          $ref,
+          $type,
+          $identifier,
+          $cache_identifier,
+          $alternate,
+        );
+      }
+    }
+
+    $table = id(new AphrontTableView($rows))
+      ->setHeaders(
+        array(
+          pht('Ref'),
+          pht('Type'),
+          pht('Identifier'),
+          pht('Cached'),
+          pht('Alternate'),
+        ));
+
+    $content = id(new PHUIObjectBoxView())
+      ->setHeaderText(pht('Ref "%s"', $ref_name))
+      ->appendChild($table);
+
+    $crumbs = $this->buildCrumbs(array());
+    $crumbs->addTextCrumb(pht('Refs'));
+
+    return $this->buildApplicationPage(
+      array(
+        $crumbs,
+        $content,
+      ),
+      array(
+        'title' => array(
+          pht('Refs'),
+          $repository->getMonogram(),
+          $ref_name,
+        ),
+      ));
+  }
+
+}

src/applications/diffusion/controller/DiffusionRepositoryController.php

@@ -303,10 +303,40 @@ final class DiffusionRepositoryController extends DiffusionController {
 
     $view->setActionList($actions);
 
-    return id(new PHUIObjectBoxView())
+    $box = id(new PHUIObjectBoxView())
       ->setHeader($header)
       ->addPropertyList($view);
 
+    $info = null;
+    $drequest = $this->getDiffusionRequest();
+    if ($drequest->getRefAlternatives()) {
+      $message = array(
+        pht(
+          'The ref "%s" is ambiguous in this repository.',
+          $drequest->getBranch()),
+        ' ',
+        phutil_tag(
+          'a',
+          array(
+            'href' => $drequest->generateURI(
+              array(
+                'action' => 'refs',
+              )),
+          ),
+          pht('View Alternatives')),
+      );
+
+      $messages = array($message);
+
+      $info = id(new PHUIInfoView())
+        ->setSeverity(PHUIInfoView::SEVERITY_WARNING)
+        ->setErrors(array($message));
+
+      $box->setInfoView($info);
+    }
+
+
+    return $box;
   }
 
   private function buildBranchListTable(DiffusionRequest $drequest) {

src/applications/diffusion/query/lowlevel/DiffusionLowLevelResolveRefsQuery.php

@@ -45,6 +45,8 @@ final class DiffusionLowLevelResolveRefsQuery
   private function resolveGitRefs() {
     $repository = $this->getRepository();
 
+    // TODO: When refs are ambiguous (for example, tags and branches with
+    // the same name) this will only resolve one of them.
     $future = $repository->getLocalCommandFuture('cat-file --batch-check');
     $future->write(implode("\n", $this->refs));
     list($stdout) = $future->resolvex();

src/applications/diffusion/request/DiffusionRequest.php

@@ -28,6 +28,7 @@ abstract class DiffusionRequest {
   private $initFromConduit = true;
   private $user;
   private $branchObject = false;
+  private $refAlternatives;
 
   abstract public function supportsBranches();
   abstract protected function isStableCommit($symbol);
@@ -528,6 +529,7 @@ abstract class DiffusionRequest {
       case 'tags':
       case 'branches':
       case 'lint':
+      case 'refs':
         $req_callsign = true;
         break;
       case 'branch':
@@ -559,6 +561,7 @@ abstract class DiffusionRequest {
       case 'branches':
       case 'lint':
       case 'pathtree':
+      case 'refs':
         $uri = "/diffusion/{$callsign}{$action}/{$path}{$commit}{$line}";
         break;
       case 'branch':
@@ -728,18 +731,41 @@ abstract class DiffusionRequest {
     $results = $this->resolveRefs(array($ref));
 
     $matches = idx($results, $ref, array());
-    if (count($matches) !== 1) {
-      $message = pht('Ref "%s" is ambiguous or does not exist.', $ref);
+    if (!$matches) {
+      $message = pht(
+        'Ref "%s" does not exist in this repository.',
+        $ref);
       throw id(new DiffusionRefNotFoundException($message))
         ->setRef($ref);
     }
 
-    $match = head($matches);
+    if (count($matches) > 1) {
+      $match = $this->chooseBestRefMatch($ref, $matches);
+    } else {
+      $match = head($matches);
+    }
 
     $this->stableCommit = $match['identifier'];
     $this->symbolicType = $match['type'];
   }
 
+  public function getRefAlternatives() {
+    // Make sure we've resolved the reference into a stable commit first.
+    $this->getStableCommit();
+    return $this->refAlternatives;
+  }
+
+  private function chooseBestRefMatch($ref, array $results) {
+    // TODO: Do a better job of selecting the best match.
+    $match = head($results);
+
+    // After choosing the best alternative, save all the alternatives so the
+    // UI can show them to the user.
+    $this->refAlternatives = $results;
+
+    return $match;
+  }
+
   protected function getResolvableBranchName($branch) {
     return $branch;
   }