Allow to do a principal property search based on metadata keys

Signed-off-by: Georg Ehrke <developer@georgehrke.com>

apps/dav/lib/CalDAV/ResourceBooking/AbstractPrincipalBackend.php

@@ -184,6 +184,37 @@ abstract class AbstractPrincipalBackend implements BackendInterface {
 		return $this->rowToPrincipal($row, $metadata);
 	}
 
+	/**
+	 * @param int $id
+	 * @return array|null
+	 */
+	public function getPrincipalById($id):?array {
+		$query = $this->db->getQueryBuilder();
+		$query->select(['id', 'backend_id', 'resource_id', 'email', 'displayname'])
+			->from($this->dbTableName)
+			->where($query->expr()->eq('id', $query->createNamedParameter($id)));
+		$stmt = $query->execute();
+		$row = $stmt->fetch(\PDO::FETCH_ASSOC);
+
+		if(!$row) {
+			return null;
+		}
+
+		$metaDataQuery = $this->db->getQueryBuilder();
+		$metaDataQuery->select(['key', 'value'])
+			->from($this->dbMetaDataTableName)
+			->where($metaDataQuery->expr()->eq($this->dbForeignKeyName, $metaDataQuery->createNamedParameter($row['id'])));
+		$metaDataStmt = $metaDataQuery->execute();
+		$metaDataRows = $metaDataStmt->fetchAll(\PDO::FETCH_ASSOC);
+		$metadata = [];
+
+		foreach($metaDataRows as $metaDataRow) {
+			$metadata[$metaDataRow['key']] = $metaDataRow['value'];
+		}
+
+		return $this->rowToPrincipal($row, $metadata);
+	}
+
 	/**
 	 * Returns the list of members for a group-principal
 	 *
@@ -296,7 +327,15 @@ abstract class AbstractPrincipalBackend implements BackendInterface {
 					break;
 
 				default:
-					$results[] = [];
+					$rowsByMetadata = $this->searchPrincipalsByMetadataKey($prop, $value);
+					$filteredRows = array_filter($rowsByMetadata, function($row) use ($usersGroups) {
+						return $this->isAllowedToAccessResource($row, $usersGroups);
+					});
+
+					$results[] = array_map(function($row) {
+						return $row['uri'];
+					}, $filteredRows);
+
 					break;
 			}
 		}
@@ -317,6 +356,39 @@ abstract class AbstractPrincipalBackend implements BackendInterface {
 		}
 	}
 
+	/**
+	 * Searches principals based on their metadata keys.
+	 * This allows to search for all principals with a specific key.
+	 * e.g.:
+	 * '{http://nextcloud.com/ns}room-building-address' => 'ABC Street 123, ...'
+	 *
+	 * @param $key
+	 * @param $value
+	 * @return array
+	 */
+	private function searchPrincipalsByMetadataKey($key, $value):array {
+		$query = $this->db->getQueryBuilder();
+		$query->select([$this->dbForeignKeyName])
+			->from($this->dbMetaDataTableName)
+			->where($query->expr()->eq('key', $query->createNamedParameter($key)))
+			->andWhere($query->expr()->iLike('value', $query->createNamedParameter('%' . $this->db->escapeLikeParameter($value) . '%')));
+		$stmt = $query->execute();
+
+		$rows = [];
+		while($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {
+			$id = $row[$this->dbForeignKeyName];
+
+			$principalRow = $this->getPrincipalById($id);
+			if (!$principalRow) {
+				continue;
+			}
+
+			$rows[] = $principalRow;
+		}
+
+		return $rows;
+	}
+
 	/**
 	 * @param string $uri
 	 * @param string $principalPrefix

apps/dav/tests/unit/CalDAV/ResourceBooking/AbstractPrincipalBackendTest.php

@@ -219,6 +219,26 @@ abstract class AbstractPrincipalBackendTest extends TestCase {
 		];
 	}
 
+	public function testSearchPrincipalsByMetadataKey() {
+		$user = $this->createMock(IUser::class);
+		$this->userSession->expects($this->once())
+			->method('getUser')
+			->with()
+			->will($this->returnValue($user));
+		$this->groupManager->expects($this->once())
+			->method('getUserGroupIds')
+			->with($user)
+			->will($this->returnValue(['group1', 'group2']));
+
+		$actual = $this->principalBackend->searchPrincipals($this->principalPrefix, [
+			'{http://nextcloud.com/ns}meta3' => 'value',
+		]);
+
+		$this->assertEquals([
+			$this->principalPrefix . '/backend2-res4',
+		], $actual);
+	}
+
 	public function testSearchPrincipalsByCalendarUserAddressSet() {
 		$user = $this->createMock(IUser::class);
 		$this->userSession->method('getUser')