Delete tombstone if it exists (#97)

* Delete tombstone if it exists

* Coding standards

src/Flysystem/Adapter/FedoraAdapter.php

@@ -283,8 +283,14 @@ class FedoraAdapter implements AdapterInterface {
    */
   public function delete($path) {
     $response = $this->fedora->deleteResource($path);
-
     $code = $response->getStatusCode();
+    if ($code == 204) {
+      // Deleted so check for a tombstone as well.
+      $tomb_code = $this->deleteTombstone($path);
+      if (!is_null($tomb_code)) {
+        return $tomb_code;
+      }
+    }
     return in_array($code, [204, 404]);
   }
 
@@ -321,4 +327,36 @@ class FedoraAdapter implements AdapterInterface {
     return $this->getMetadata($dirname);
   }
 
+  /**
+   * Delete a tombstone for a path if it exists.
+   *
+   * @param string $path
+   *   The original deleted resource path.
+   *
+   * @return bool|null
+   *   NULL if no tombstone, TRUE if tombstone deleted, FALSE otherwise.
+   */
+  private function deleteTombstone($path) {
+    $response = $this->fedora->getResourceHeaders($path);
+    $return = NULL;
+    if ($response->getStatusCode() == 410) {
+      $return = FALSE;
+      $link_headers = Psr7\parse_header($response->getHeader('Link'));
+      if ($link_headers) {
+        $tombstones = array_filter($link_headers, function ($o) {
+          return (isset($o['rel']) && $o['rel'] == 'hasTombstone');
+        });
+        foreach ($tombstones as $tombstone) {
+          // Trim <> from URL.
+          $url = rtrim(ltrim($tombstone[0], '<'), '>');
+          $response = $this->fedora->deleteResource($url);
+          if ($response->getStatusCode() == 204) {
+            $return = TRUE;
+          }
+        }
+      }
+    }
+    return $return;
+  }
+
 }

tests/src/Kernel/FedoraAdapterTest.php

@@ -185,6 +185,60 @@ class FedoraAdapterTest extends IslandoraKernelTestBase {
     return new FedoraAdapter($api, $mime_guesser);
   }
 
+  /**
+   * Mocks up an adapter for Delete requests with a tombstone.
+   */
+  protected function createAdapterForDeleteWithTombstone() {
+    $fedora_prophecy = $this->prophesize(IFedoraApi::class);
+
+    $prophecy = $this->prophesize(Response::class);
+    $prophecy->getStatusCode()->willReturn(204);
+
+    $head_prophecy = $this->prophesize(Response::class);
+    $head_prophecy->getStatusCode()->willReturn(410);
+    $head_prophecy->getHeader('Link')->willReturn('<some-path-to-a-tombstone>; rel="hasTombstone"');
+
+    $tombstone_prophecy = $this->prophesize(Response::class);
+    $tombstone_prophecy->getStatusCode()->willReturn(204);
+
+    $fedora_prophecy->deleteResource('')->willReturn($prophecy->reveal());
+    $fedora_prophecy->getResourceHeaders('')->willReturn($head_prophecy->reveal());
+    $fedora_prophecy->deleteResource('some-path-to-a-tombstone')->willReturn($tombstone_prophecy->reveal());
+
+    $api = $fedora_prophecy->reveal();
+
+    $mime_guesser = $this->prophesize(MimeTypeGuesserInterface::class)->reveal();
+
+    return new FedoraAdapter($api, $mime_guesser);
+  }
+
+  /**
+   * Mocks up an adapter for Delete requests with a tombstone which fail.
+   */
+  protected function createAdapterForDeleteWithTombstoneFail() {
+    $fedora_prophecy = $this->prophesize(IFedoraApi::class);
+
+    $prophecy = $this->prophesize(Response::class);
+    $prophecy->getStatusCode()->willReturn(204);
+
+    $head_prophecy = $this->prophesize(Response::class);
+    $head_prophecy->getStatusCode()->willReturn(410);
+    $head_prophecy->getHeader('Link')->willReturn('<some-path-to-a-tombstone>; rel="hasTombstone"');
+
+    $tombstone_prophecy = $this->prophesize(Response::class);
+    $tombstone_prophecy->getStatusCode()->willReturn(500);
+
+    $fedora_prophecy->deleteResource('')->willReturn($prophecy->reveal());
+    $fedora_prophecy->getResourceHeaders('')->willReturn($head_prophecy->reveal());
+    $fedora_prophecy->deleteResource('some-path-to-a-tombstone')->willReturn($tombstone_prophecy->reveal());
+
+    $api = $fedora_prophecy->reveal();
+
+    $mime_guesser = $this->prophesize(MimeTypeGuesserInterface::class)->reveal();
+
+    return new FedoraAdapter($api, $mime_guesser);
+  }
+
   /**
    * Asserts the stucture/contents of a metadata response for a file.
    */
@@ -459,6 +513,24 @@ class FedoraAdapterTest extends IslandoraKernelTestBase {
     $this->assertTrue($adapter->deleteDir('') == TRUE, "deleteDir() must return TRUE on 204 or 404");
   }
 
+  /**
+   * @covers \Drupal\islandora\Flysystem\Adapter\FedoraAdapter::delete
+   */
+  public function testDeleteWithTombstone() {
+    $adapter = $this->createAdapterForDeleteWithTombstone();
+
+    $this->assertTrue($adapter->delete(''), 'delete() must return TRUE on 204 or 404 reponse after deleting the tombstone.');
+  }
+
+  /**
+   * @covers \Drupal\islandora\Flysystem\Adapter\FedoraAdapter::delete
+   */
+  public function testDeleteWithTombstoneFail() {
+    $adapter = $this->createAdapterForDeleteWithTombstoneFail();
+
+    $this->assertFalse($adapter->delete(''), 'delete() must return FALSE on non-(204 or 404) response after deleting the tombstone.');
+  }
+
   /**
    * @covers \Drupal\islandora\Flysystem\Adapter\FedoraAdapter::rename
    * @covers \Drupal\islandora\Flysystem\Adapter\FedoraAdapter::copy