Only enumerate materialised items in working set

Sources/NextcloudFileProviderKit/Database/FilesDatabaseManager.swift

@@ -240,7 +240,12 @@ public final class FilesDatabaseManager: Sendable {
             deletedMetadatas.append(metadataToDelete)
 
             Self.logger.debug(
-                "Deleting item metadata during update. ocID: \(existingMetadata.ocId, privacy: .public), etag: \(existingMetadata.etag, privacy: .public), fileName: \(existingMetadata.fileName, privacy: .public)"
+                """
+                Deleting item metadata during update.
+                    ocID: \(existingMetadata.ocId, privacy: .public)
+                    etag: \(existingMetadata.etag, privacy: .public)
+                    fileName: \(existingMetadata.fileName, privacy: .public)"
+                """
             )
         }
 
@@ -336,24 +341,48 @@ public final class FilesDatabaseManager: Sendable {
             //
             // - the ones that do exist remotely still are either the same or have been updated
             // - the ones that don't have been deleted
+            var cleanServerUrl = serverUrl
+            if cleanServerUrl.last == "/" {
+                cleanServerUrl.removeLast()
+            }
             let existingMetadatas = database
                 .objects(RealmItemMetadata.self)
-                .where { $0.account == account && $0.serverUrl == serverUrl && $0.uploaded }
+                .where {
+                    // Don't worry — root will be updated at the end of this method if is the target
+                    $0.ocId != NSFileProviderItemIdentifier.rootContainer.rawValue &&
+                    $0.account == account &&
+                    $0.serverUrl == cleanServerUrl &&
+                    $0.uploaded
+                }
+
+            var updatedChildMetadatas = updatedMetadatas
+
+            let readTargetMetadata: SendableItemMetadata?
+            if let targetMetadata = updatedMetadatas.first {
+                if targetMetadata.directory {
+                    readTargetMetadata = updatedChildMetadatas.removeFirst()
+                } else {
+                    readTargetMetadata = targetMetadata
+                }
+            } else {
+                readTargetMetadata = nil
+            }
 
             // NOTE: These metadatas are managed -- be careful!
             let metadatasToDelete = processItemMetadatasToDelete(
                 existingMetadatas: existingMetadatas,
-                updatedMetadatas: updatedMetadatas)
+                updatedMetadatas: updatedChildMetadatas
+            )
             let metadatasToDeleteCopy = metadatasToDelete.map { SendableItemMetadata(value: $0) }
 
             let metadatasToChange = processItemMetadatasToUpdate(
                 existingMetadatas: existingMetadatas,
-                updatedMetadatas: updatedMetadatas,
+                updatedMetadatas: updatedChildMetadatas,
                 keepExistingDownloadState: keepExistingDownloadState
             )
 
             var metadatasToUpdate = metadatasToChange.updatedMetadatas
-            let metadatasToCreate = metadatasToChange.newMetadatas
+            var metadatasToCreate = metadatasToChange.newMetadatas
             let directoriesNeedingRename = metadatasToChange.directoriesNeedingRename
 
             for metadata in directoriesNeedingRename {
@@ -366,6 +395,26 @@ public final class FilesDatabaseManager: Sendable {
                 }
             }
 
+            if var readTargetMetadata {
+                if let existing = itemMetadata(ocId: readTargetMetadata.ocId) {
+                    if existing.status == Status.normal.rawValue,
+                       !existing.isInSameDatabaseStoreableRemoteState(readTargetMetadata)
+                    {
+                        Self.logger.info("Depth 1 read target changed: \(readTargetMetadata.ocId)")
+                        if keepExistingDownloadState {
+                            readTargetMetadata.downloaded = existing.downloaded
+                        }
+                        if readTargetMetadata.directory {
+                            readTargetMetadata.visitedDirectory = true
+                        }
+                        metadatasToUpdate.insert(readTargetMetadata, at: 0)
+                    }
+                } else {
+                    Self.logger.info("Depth 1 read target is new: \(readTargetMetadata.ocId)")
+                    metadatasToCreate.insert(readTargetMetadata, at: 0)
+                }
+            }
+
             try database.write {
                 database.delete(metadatasToDelete)
                 database.add(metadatasToUpdate.map { RealmItemMetadata(value: $0) }, update: .modified)
@@ -463,6 +512,7 @@ public final class FilesDatabaseManager: Sendable {
                         trashbinFileName: \(metadata.trashbinFileName, privacy: .public)
                         downloaded: \(metadata.downloaded, privacy: .public)
                         uploaded: \(metadata.uploaded, privacy: .public)
+                        visitedDirectory: \(metadata.visitedDirectory, privacy: .public)
                     """
                 )
             }
@@ -601,4 +651,13 @@ public final class FilesDatabaseManager: Sendable {
         }
         return NSFileProviderItemIdentifier(parentMetadata.ocId)
     }
+
+    public func materialisedItemMetadatas(account: String) -> [SendableItemMetadata] {
+        itemMetadatas
+            .where {
+                $0.account == account &&
+                (($0.directory && $0.visitedDirectory) || (!$0.directory && $0.downloaded))
+            }
+            .toUnmanagedResults()
+    }
 }