FileWrapper Snapshot

Sources/TranslationCatalogFilesystem/DirectoryCatalog.swift

@@ -7,37 +7,16 @@ public typealias FilesystemCatalog = DirectoryCatalog
 /// Implementation of `Catalog` the reads/writes data from/to a filesystem directory.
 public class DirectoryCatalog: FilesystemContainer {
 
-    let url: URL
+    let medium: URL
+    let translationContainer: URL
+    let expressionContainer: URL
+    let projectContainer: URL
     var translationDocuments: [TranslationDocument] = []
     var expressionDocuments: [ExpressionDocument] = []
     var projectDocuments: [ProjectDocument] = []
 
-    @available(*, deprecated, renamed: "url")
-    var medium: URL { url }
-
-    var translationContainer: URL {
-        guard let url = try? directory(forPath: Self.translationsPath) else {
-            preconditionFailure("Invalid Translation Directory")
-        }
-
-        return url
-    }
-
-    var expressionContainer: URL {
-        guard let url = try? directory(forPath: Self.expressionsPath) else {
-            preconditionFailure("Invalid Expression Directory")
-        }
-
-        return url
-    }
-
-    var projectContainer: URL {
-        guard let url = try? directory(forPath: Self.projectsPath) else {
-            preconditionFailure("")
-        }
-
-        return url
-    }
+    @available(*, deprecated, message: "Match 'FilesystemContainer' protocol requirements.", renamed: "medium")
+    var url: URL { medium }
 
     private let fileManager = FileManager.default
 
@@ -46,7 +25,10 @@ public class DirectoryCatalog: FilesystemContainer {
             throw URLError(.unsupportedURL)
         }
 
-        self.url = url
+        medium = url
+        translationContainer = try FileManager.default.directory(forPath: Self.translationsPath, of: url)
+        expressionContainer = try FileManager.default.directory(forPath: Self.expressionsPath, of: url)
+        projectContainer = try FileManager.default.directory(forPath: Self.projectsPath, of: url)
         if let schemaVersion = getSchemaVersion() {
             try migrateSchema(from: schemaVersion, to: .current)
             try loadAllDocuments()
@@ -56,14 +38,6 @@ public class DirectoryCatalog: FilesystemContainer {
         }
     }
 
-    private func directory(forPath path: String) throws -> URL {
-        let url = url.appending(path: path, directoryHint: .isDirectory)
-        if !fileManager.fileExists(atPath: url.path()) {
-            try fileManager.createDirectory(at: url, withIntermediateDirectories: true)
-        }
-        return url
-    }
-
     func loadDocuments<T: Document>(from container: URL, using decoder: JSONDecoder) throws -> [T] {
         try fileManager
             .contentsOfDirectory(at: container, includingPropertiesForKeys: nil)
@@ -105,7 +79,7 @@ public class DirectoryCatalog: FilesystemContainer {
     }
 
     func getSchemaVersion(using decoder: JSONDecoder) -> DocumentSchemaVersion? {
-        let url = url.appending(path: Self.versionPath, directoryHint: .notDirectory)
+        let url = medium.appending(path: Self.versionPath, directoryHint: .notDirectory)
 
         do {
             let data = try Data(contentsOf: url)
@@ -117,7 +91,7 @@ public class DirectoryCatalog: FilesystemContainer {
     }
 
     func setSchemaVersion(_ version: DocumentSchemaVersion, using encoder: JSONEncoder) throws {
-        let url = url.appending(path: Self.versionPath, directoryHint: .notDirectory)
+        let url = medium.appending(path: Self.versionPath, directoryHint: .notDirectory)
         let data = try encoder.encode(version.rawValue)
         try data.write(to: url)
     }

Sources/TranslationCatalogFilesystem/Extensions/FileManager+TranslationCatalogFilesystem.swift

@@ -0,0 +1,11 @@
+import Foundation
+
+extension FileManager {
+    func directory(forPath path: String, of url: URL) throws -> URL {
+        let url = url.appending(path: path, directoryHint: .isDirectory)
+        if !fileExists(atPath: url.path()) {
+            try createDirectory(at: url, withIntermediateDirectories: true)
+        }
+        return url
+    }
+}

Sources/TranslationCatalogFilesystem/Extensions/FileWrapper+TranslationCatalogFilesystem.swift

@@ -0,0 +1,16 @@
+#if os(macOS) || os(iOS) || os(watchOS) || os(tvOS) || os(visionOS)
+import Foundation
+
+extension FileWrapper {
+    func directory(forPath path: String) -> FileWrapper {
+        guard let wrapper = fileWrappers?[path] else {
+            let directoryWrapper = FileWrapper(directoryWithFileWrappers: [:])
+            directoryWrapper.preferredFilename = path
+            addFileWrapper(directoryWrapper)
+            return directoryWrapper
+        }
+
+        return wrapper
+    }
+}
+#endif

Sources/TranslationCatalogFilesystem/FileWrapperCatalog.swift

@@ -6,28 +6,23 @@ import TranslationCatalog
 public class FileWrapperCatalog: FilesystemContainer {
 
     let medium: FileWrapper
+    let translationContainer: FileWrapper
+    let expressionContainer: FileWrapper
+    let projectContainer: FileWrapper
     var translationDocuments: [TranslationDocument] = []
     var expressionDocuments: [ExpressionDocument] = []
     var projectDocuments: [ProjectDocument] = []
 
-    var translationContainer: FileWrapper {
-        directory(forPath: Self.translationsPath)
-    }
-
-    var expressionContainer: FileWrapper {
-        directory(forPath: Self.expressionsPath)
-    }
-
-    var projectContainer: FileWrapper {
-        directory(forPath: Self.projectsPath)
-    }
-
     public init(fileWrapper: FileWrapper) throws {
         guard fileWrapper.isDirectory else {
             throw CocoaError(.fileReadUnsupportedScheme)
         }
 
         medium = fileWrapper
+        translationContainer = fileWrapper.directory(forPath: Self.translationsPath)
+        expressionContainer = fileWrapper.directory(forPath: Self.expressionsPath)
+        projectContainer = fileWrapper.directory(forPath: Self.projectsPath)
+
         if let schemaVersion = getSchemaVersion() {
             try migrateSchema(from: schemaVersion, to: .current)
             try loadAllDocuments()
@@ -37,15 +32,76 @@ public class FileWrapperCatalog: FilesystemContainer {
         }
     }
 
-    private func directory(forPath path: String) -> FileWrapper {
-        guard let wrapper = medium.fileWrappers?[path] else {
-            let directoryWrapper = FileWrapper(directoryWithFileWrappers: [:])
-            directoryWrapper.preferredFilename = path
-            medium.addFileWrapper(directoryWrapper)
-            return directoryWrapper
+    /// Add all catalog content to the provided `FileWrapper`
+    public func snapshot(to fileWrapper: FileWrapper, using encoder: JSONEncoder) throws {
+        let translationsWrapper = fileWrapper.directory(forPath: Self.translationsPath)
+        let expressionsWrapper = fileWrapper.directory(forPath: Self.expressionsPath)
+        let projectsWrapper = fileWrapper.directory(forPath: Self.projectsPath)
+
+        let existingTranslations = Set((translationsWrapper.fileWrappers ?? [:]).keys)
+        let existingExpressions = Set((expressionsWrapper.fileWrappers ?? [:]).keys)
+        let existingProjects = Set((projectsWrapper.fileWrappers ?? [:]).keys)
+
+        let nextTranslations = Set(translationDocuments.map(\.filename))
+        let nextExpressions = Set(expressionDocuments.map(\.filename))
+        let nextProjects = Set(projectDocuments.map(\.filename))
+
+        // Translations
+        let addedTranslations = nextTranslations.subtracting(existingTranslations)
+        let removedTranslations = existingTranslations.subtracting(nextTranslations)
+        for filename in removedTranslations {
+            if let wrapper = translationsWrapper.fileWrappers?[filename] {
+                translationsWrapper.removeFileWrapper(wrapper)
+            }
+        }
+
+        for document in translationDocuments {
+            let data = try encoder.encode(document)
+            if !addedTranslations.contains(document.filename) {
+                if let wrapper = translationsWrapper.fileWrappers?[document.filename] {
+                    translationsWrapper.removeFileWrapper(wrapper)
+                }
+            }
+            translationsWrapper.addRegularFile(withContents: data, preferredFilename: document.filename)
+        }
+
+        // Expressions
+        let addedExpressions = nextExpressions.subtracting(existingExpressions)
+        let removedExpressions = existingExpressions.subtracting(nextExpressions)
+        for filename in removedExpressions {
+            if let wrapper = expressionsWrapper.fileWrappers?[filename] {
+                expressionsWrapper.removeFileWrapper(wrapper)
+            }
+        }
+
+        for document in expressionDocuments {
+            let data = try encoder.encode(document)
+            if !addedExpressions.contains(document.filename) {
+                if let wrapper = expressionsWrapper.fileWrappers?[document.filename] {
+                    expressionsWrapper.removeFileWrapper(wrapper)
+                }
+            }
+            expressionsWrapper.addRegularFile(withContents: data, preferredFilename: document.filename)
+        }
+
+        // Projects
+        let addedProjects = nextProjects.subtracting(existingProjects)
+        let removedProjects = existingProjects.subtracting(nextProjects)
+        for filename in removedProjects {
+            if let wrapper = projectsWrapper.fileWrappers?[filename] {
+                projectsWrapper.removeFileWrapper(wrapper)
+            }
         }
 
-        return wrapper
+        for document in projectDocuments {
+            let data = try encoder.encode(document)
+            if !addedProjects.contains(document.filename) {
+                if let wrapper = expressionsWrapper.fileWrappers?[document.filename] {
+                    expressionsWrapper.removeFileWrapper(wrapper)
+                }
+            }
+            projectsWrapper.addRegularFile(withContents: data, preferredFilename: document.filename)
+        }
     }
 
     func loadDocuments<T: Document>(from container: FileWrapper, using decoder: JSONDecoder) throws -> [T] {