Implement viewing versions and downloading patches in Phragment

Summary:
This adds support for viewing individual versions on a fragment as well as comparing versions and downloading diff_match_patch-based patches.

It does not use the side-by-side diff format as while it works for small changes, it quickly becomes impossible to distingush what changes have been made due to the diff_match_patch format.

Test Plan: Clicked on versions and downloaded patches.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Maniphest Tasks: T4205

Differential Revision: https://secure.phabricator.com/D7734

src/__phutil_library_map__.php

@@ -2186,8 +2186,10 @@ phutil_register_library_map(array(
     'PhragmentHistoryController' => 'applications/phragment/controller/PhragmentHistoryController.php',
     'PhragmentPHIDTypeFragment' => 'applications/phragment/phid/PhragmentPHIDTypeFragment.php',
     'PhragmentPHIDTypeFragmentVersion' => 'applications/phragment/phid/PhragmentPHIDTypeFragmentVersion.php',
+    'PhragmentPatchController' => 'applications/phragment/controller/PhragmentPatchController.php',
     'PhragmentPatchUtil' => 'applications/phragment/util/PhragmentPatchUtil.php',
     'PhragmentUpdateController' => 'applications/phragment/controller/PhragmentUpdateController.php',
+    'PhragmentVersionController' => 'applications/phragment/controller/PhragmentVersionController.php',
     'PhragmentZIPController' => 'applications/phragment/controller/PhragmentZIPController.php',
     'PhrequentController' => 'applications/phrequent/controller/PhrequentController.php',
     'PhrequentDAO' => 'applications/phrequent/storage/PhrequentDAO.php',
@@ -4786,8 +4788,10 @@ phutil_register_library_map(array(
     'PhragmentHistoryController' => 'PhragmentController',
     'PhragmentPHIDTypeFragment' => 'PhabricatorPHIDType',
     'PhragmentPHIDTypeFragmentVersion' => 'PhabricatorPHIDType',
+    'PhragmentPatchController' => 'PhragmentController',
     'PhragmentPatchUtil' => 'Phobject',
     'PhragmentUpdateController' => 'PhragmentController',
+    'PhragmentVersionController' => 'PhragmentController',
     'PhragmentZIPController' => 'PhragmentController',
     'PhrequentController' => 'PhabricatorController',
     'PhrequentDAO' => 'PhabricatorLiskDAO',

src/applications/phragment/application/PhabricatorApplicationPhragment.php

@@ -39,6 +39,8 @@ final class PhabricatorApplicationPhragment extends PhabricatorApplication {
         'update/(?P<dblob>.*)' => 'PhragmentUpdateController',
         'history/(?P<dblob>.*)' => 'PhragmentHistoryController',
         'zip/(?P<dblob>.*)' => 'PhragmentZIPController',
+        'version/(?P<id>[0-9]*)/' => 'PhragmentVersionController',
+        'patch/(?P<aid>[0-9x]*)/(?P<bid>[0-9]*)/' => 'PhragmentPatchController',
       ),
     );
   }

src/applications/phragment/controller/PhragmentHistoryController.php

@@ -47,6 +47,7 @@ final class PhragmentHistoryController extends PhragmentController {
     foreach ($versions as $version) {
       $item = id(new PHUIObjectItemView());
       $item->setHeader('Version '.$version->getSequence());
+      $item->setHref($version->getURI());
       $item->addAttribute(phabricator_datetime(
         $version->getDateCreated(),
         $viewer));

src/applications/phragment/controller/PhragmentPatchController.php

@@ -0,0 +1,88 @@
+<?php
+
+final class PhragmentPatchController extends PhragmentController {
+
+  private $aid;
+  private $bid;
+
+  public function willProcessRequest(array $data) {
+    $this->aid = idx($data, "aid", 0);
+    $this->bid = idx($data, "bid", 0);
+  }
+
+  public function processRequest() {
+    $request = $this->getRequest();
+    $viewer = $request->getUser();
+
+    // If "aid" is "x", then it means the user wants to generate
+    // a patch of an empty file to the version specified by "bid".
+
+    $ids = array($this->aid, $this->bid);
+    if ($this->aid === "x") {
+      $ids = array($this->bid);
+    }
+
+    $versions = id(new PhragmentFragmentVersionQuery())
+      ->setViewer($viewer)
+      ->withIDs($ids)
+      ->execute();
+
+    $version_a = null;
+    if ($this->aid !== "x") {
+      $version_a = idx($versions, $this->aid, null);
+      if ($version_a === null) {
+        return new Aphront404Response();
+      }
+    }
+
+    $version_b = idx($versions, $this->bid, null);
+    if ($version_b === null) {
+      return new Aphront404Response();
+    }
+
+    $file_phids = array();
+    if ($version_a !== null) {
+      $file_phids[] = $version_a->getFilePHID();
+    }
+    $file_phids[] = $version_b->getFilePHID();
+
+    $files = id(new PhabricatorFileQuery())
+      ->setViewer($viewer)
+      ->withPHIDs($file_phids)
+      ->execute();
+    $files = mpull($files, null, 'getPHID');
+
+    $file_a = null;
+    if ($version_a != null) {
+      $file_a = idx($files, $version_a->getFilePHID(), null);
+    }
+    $file_b = idx($files, $version_b->getFilePHID(), null);
+
+    $patch = PhragmentPatchUtil::calculatePatch($file_a, $file_b);
+
+    if ($patch === null) {
+      throw new Exception("Unable to compute patch!");
+    }
+
+    $a_sequence = 'x';
+    if ($version_a !== null) {
+      $a_sequence = $version_a->getSequence();
+    }
+
+    $name =
+      $version_b->getFragment()->getName().'.'.
+      $a_sequence.'.'.
+      $version_b->getSequence().'.patch';
+
+    $result = PhabricatorFile::buildFromFileDataOrHash(
+      $patch,
+      array(
+        'name' => $name,
+        'mime-type' => 'text/plain',
+        'ttl' => time() + 60 * 60 * 24,
+      ));
+    return id(new AphrontRedirectResponse())
+      ->setURI($result->getBestURI());
+  }
+
+}

src/applications/phragment/controller/PhragmentVersionController.php

@@ -0,0 +1,179 @@
+<?php
+
+final class PhragmentVersionController extends PhragmentController {
+
+  private $id;
+
+  public function willProcessRequest(array $data) {
+    $this->id = idx($data, "id", 0);
+  }
+
+  public function processRequest() {
+    $request = $this->getRequest();
+    $viewer = $request->getUser();
+
+    $version = id(new PhragmentFragmentVersionQuery())
+      ->setViewer($viewer)
+      ->withIDs(array($this->id))
+      ->executeOne();
+    if ($version === null) {
+      return new Aphront404Response();
+    }
+
+    $parents = $this->loadParentFragments($version->getFragment()->getPath());
+    if ($parents === null) {
+      return new Aphront404Response();
+    }
+    $current = idx($parents, count($parents) - 1, null);
+
+    $crumbs = $this->buildApplicationCrumbsWithPath($parents);
+    $crumbs->addCrumb(
+      id(new PhabricatorCrumbView())
+        ->setName(pht('View Version %d', $version->getSequence())));
+
+    $phids = array();
+    $phids[] = $version->getFilePHID();
+
+    $this->loadHandles($phids);
+
+    $file = id(new PhabricatorFileQuery())
+      ->setViewer($viewer)
+      ->withPHIDs(array($version->getFilePHID()))
+      ->executeOne();
+    if ($file !== null) {
+      $file_uri = $file->getBestURI();
+    }
+
+    $header = id(new PHUIHeaderView())
+      ->setHeader(pht(
+        "%s at version %d",
+        $version->getFragment()->getName(),
+        $version->getSequence()))
+      ->setPolicyObject($version)
+      ->setUser($viewer);
+
+    $actions = id(new PhabricatorActionListView())
+      ->setUser($viewer)
+      ->setObject($version)
+      ->setObjectURI($version->getURI());
+    $actions->addAction(
+      id(new PhabricatorActionView())
+        ->setName(pht('Download Version'))
+        ->setHref($file_uri)
+        ->setDisabled($file === null)
+        ->setIcon('download'));
+
+    $properties = id(new PHUIPropertyListView())
+      ->setUser($viewer)
+      ->setObject($version)
+      ->setActionList($actions);
+    $properties->addProperty(
+      pht('File'),
+      $this->renderHandlesForPHIDs(array($version->getFilePHID())));
+
+    $box = id(new PHUIObjectBoxView())
+      ->setHeader($header)
+      ->addPropertyList($properties);
+
+    return $this->buildApplicationPage(
+      array(
+        $crumbs,
+        $box,
+        $this->renderPatchFromPreviousVersion($version, $file),
+        $this->renderPreviousVersionList($version)),
+      array(
+        'title' => pht('View Version'),
+        'device' => true));
+  }
+
+  private function renderPatchFromPreviousVersion(
+    PhragmentFragmentVersion $version,
+    PhabricatorFile $file) {
+
+    $request = $this->getRequest();
+    $viewer = $request->getUser();
+
+    $previous_file = null;
+    $previous = id(new PhragmentFragmentVersionQuery())
+      ->setViewer($viewer)
+      ->withFragmentPHIDs(array($version->getFragmentPHID()))
+      ->withSequences(array($version->getSequence() - 1))
+      ->executeOne();
+    if ($previous !== null) {
+      $previous_file = id(new PhabricatorFileQuery())
+        ->setViewer($viewer)
+        ->withPHIDs(array($previous->getFilePHID()))
+        ->executeOne();
+    }
+
+    $patch = PhragmentPatchUtil::calculatePatch($previous_file, $file);
+
+    if ($patch === null) {
+      return id(new AphrontErrorView())
+        ->setSeverity(AphrontErrorView::SEVERITY_NOTICE)
+        ->setTitle(pht("Identical Version"))
+        ->appendChild(phutil_tag(
+          'p',
+          array(),
+          pht("This version is identical to the previous version.")));
+    }
+
+    if (strlen($patch) > 20480) {
+      // Patch is longer than 20480 characters.  Trim it and let the user know.
+      $patch = substr($patch, 0, 20480)."\n...\n";
+      $patch .= pht(
+        "This patch is longer than 20480 characters.  Use the link ".
+        "in the action list to download the full patch.");
+    }
+
+    return id(new PHUIObjectBoxView())
+      ->setHeader(id(new PHUIHeaderView())
+        ->setHeader(pht('Differences since previous version')))
+      ->appendChild(id(new PhabricatorSourceCodeView())
+        ->setLines(phutil_split_lines($patch)));
+  }
+
+  private function renderPreviousVersionList(
+    PhragmentFragmentVersion $version) {
+
+    $request = $this->getRequest();
+    $viewer = $request->getUser();
+
+    $previous_versions = id(new PhragmentFragmentVersionQuery())
+      ->setViewer($viewer)
+      ->withFragmentPHIDs(array($version->getFragmentPHID()))
+      ->withSequenceBefore($version->getSequence())
+      ->execute();
+
+    $list = id(new PHUIObjectItemListView())
+      ->setUser($viewer);
+
+    foreach ($previous_versions as $previous_version) {
+      $item = id(new PHUIObjectItemView());
+      $item->setHeader('Version '.$previous_version->getSequence());
+      $item->setHref($previous_version->getURI());
+      $item->addAttribute(phabricator_datetime(
+        $previous_version->getDateCreated(),
+        $viewer));
+      $item->addAction(id(new PHUIListItemView())
+        ->setIcon('patch')
+        ->setName(pht("Get Patch"))
+        ->setHref($this->getApplicationURI(
+          'patch/'.$previous_version->getID().'/'.$version->getID())));
+      $list->addItem($item);
+    }
+
+    $item = id(new PHUIObjectItemView());
+    $item->setHeader('Prior to Version 0');
+    $item->addAttribute('Prior to any content (empty file)');
+    $item->addAction(id(new PHUIListItemView())
+      ->setIcon('patch')
+      ->setName(pht("Get Patch"))
+      ->setHref($this->getApplicationURI(
+        'patch/x/'.$version->getID())));
+    $list->addItem($item);
+
+    return $list;
+  }
+
+}

src/applications/phragment/query/PhragmentFragmentVersionQuery.php

@@ -6,6 +6,8 @@ final class PhragmentFragmentVersionQuery
   private $ids;
   private $phids;
   private $fragmentPHIDs;
+  private $sequences;
+  private $sequenceBefore;
 
   public function withIDs(array $ids) {
     $this->ids = $ids;
@@ -22,6 +24,16 @@ final class PhragmentFragmentVersionQuery
     return $this;
   }
 
+  public function withSequences(array $sequences) {
+    $this->sequences = $sequences;
+    return $this;
+  }
+
+  public function withSequenceBefore($current) {
+    $this->sequenceBefore = $current;
+    return $this;
+  }
+
   public function loadPage() {
     $table = new PhragmentFragmentVersion();
     $conn_r = $table->establishConnection('r');
@@ -61,6 +73,20 @@ final class PhragmentFragmentVersionQuery
         $this->fragmentPHIDs);
     }
 
+    if ($this->sequences) {
+      $where[] = qsprintf(
+        $conn_r,
+        'sequence IN (%Ld)',
+        $this->sequences);
+    }
+
+    if ($this->sequenceBefore !== null) {
+      $where[] = qsprintf(
+        $conn_r,
+        'sequence < %d',
+        $this->sequenceBefore);
+    }
+
     $where[] = $this->buildPagingClause($conn_r);
 
     return $this->formatWhereClause($where);

src/applications/phragment/storage/PhragmentFragmentVersion.php

@@ -22,7 +22,7 @@ final class PhragmentFragmentVersion extends PhragmentDAO
   }
 
   public function getURI() {
-    return '/phragment/patch/'.$this->getID().'/';
+    return '/phragment/version/'.$this->getID().'/';
   }
 
   public function getFragment() {

src/applications/phragment/util/PhragmentPatchUtil.php

@@ -9,7 +9,7 @@ final class PhragmentPatchUtil extends Phobject {
    *
    * @phutil-external-symbol class diff_match_patch
    */
-  public function calculatePatch(
+  public static function calculatePatch(
     PhabricatorFile $old = null,
     PhabricatorFile $new = null) {