Make FTP server a separate module

.github/prompts/plan-modularizeFtpServer.prompt.md

@@ -0,0 +1,252 @@
+## Plan: Modularize FTP Server Functionality for Pluggable Server Implementations
+
+The goal is to extract FTP server functionality from the `app` module into a dedicated module, enabling future pluggable implementations (SSH server, WebDAV server, etc.). Currently, FTP-related code is tightly coupled with the app module, including UI (`FtpServerFragment`), services (`FtpService`, `FtpReceiver`, `FtpTileService`), notifications (`FtpNotification`), filesystem factories, and resources.
+
+### Implementation Progress
+
+#### ✅ Completed Steps
+
+1. **Define a server abstraction layer in a new core module** — Created `server-core` module with:
+   - `FileServer.kt` - Base interface for server implementations
+   - `ServerPreferences.kt` - Interface for server preferences management
+   - `ServerNotification.kt` - Interface for notification handling
+   - `ServerEvent.kt` - Sealed class for server state events
+   - `ServerRegistry.kt` - Registry for discovering and managing server providers
+
+2. **Restructure the existing `ftpserver` module** — Updated module to depend on `server-core` instead of `app`. Created:
+   - `service/FtpServerEngine.kt` - Core FTP server lifecycle management
+   - `service/FtpServerService.kt` - Abstract Android Service for FTP
+   - `service/FtpReceiver.kt` - Abstract BroadcastReceiver for FTP start/stop
+   - `service/FtpEventBus.kt` - Event bus using Kotlin Flow
+   - `service/FtpPreferences.kt` - FTP-specific preferences
+   - `service/FtpCipherSuites.kt` - SSL cipher configuration
+   - `service/FtpCommandFactoryFactory.kt` - Custom command factory
+
+3. **Move FTP filesystem factories to the ftpserver module** — Created in `ftpserver/filesystem/`:
+   - `AndroidFileSystemFactory.kt`
+   - `AndroidFtpFileSystemView.kt`
+   - `AndroidFtpFile.kt`
+   - `RootFileSystemFactory.kt`
+   - `RootFileSystemView.kt`
+   - `RootFtpFile.kt`
+   - `commands/AVBL.kt`, `FEAT.kt`, `PWD.kt`
+
+4. **Created FtpServerProvider** — Implementation of `ServerProvider` interface in `FtpServerProvider.kt`
+
+5. **Extract FTP UI components to the ftpserver module** — ✅ Completed:
+   - `ui/BaseFtpServerFragment.kt` - Abstract base fragment for FTP UI
+   - `ui/FtpServerNotification.kt` - Notification handler implementation
+   - `res/layout/fragment_ftp.xml` - FTP fragment layout
+   - `res/menu/ftp_server_menu.xml` - Menu resources
+   - `res/values/strings.xml` - FTP strings (with `ftpmod_` prefix to avoid collisions)
+   - `res/values/colors.xml` - Color resources
+   - `res/drawable/` - Icon drawables
+
+6. **Update AndroidManifest and app module integration** — ✅ Partially completed:
+   - Added abstract FtpServerService and FtpReceiver to ftpserver manifest
+   - App module still uses its own FtpService, FtpReceiver implementations (coexisting during transition)
+
+#### 🔄 Remaining Steps
+
+7. **Migration of app module FTP code** — ✅ Completed:
+   - Created `AppFtpService.kt` - Concrete implementation extending `FtpServerService`
+   - Created `AppFtpReceiver.kt` - Concrete implementation extending `FtpReceiver`
+   - Updated `FtpServerFragment.kt` to use ftpserver module classes (`FtpPreferences`, `FtpServerEngine`, `FtpServerEvent`, `FtpEventBus`)
+   - Updated `FtpTileService.kt` to use ftpserver module classes
+   - Updated `FtpNotification.java` to use ftpserver module classes
+   - Updated `AndroidManifest.xml` to register `AppFtpService` and `AppFtpReceiver`
+   - Added `@JvmStatic` annotations to `FtpPreferences` for Java interop
+   - Old `FtpService.kt` and `FtpReceiver.kt` are now deprecated (can be removed in future)
+
+8. **Move FTP tests to the ftpserver module** — ✅ Completed:
+   - Created `commands/LogMessageFilter.kt` - Test utility for capturing FTP responses
+   - Created `commands/AbstractFtpserverCommandTest.kt` - Base test class (plain JUnit)
+   - Created `commands/AVBLCommandTest.kt` - 8 tests for AVBL command
+   - Created `commands/PWDCommandTest.kt` - 3 tests for PWD command  
+   - Created `commands/FEATCommandTest.kt` - 1 test for FEAT command
+   - Total: 12 tests, all passing
+   - Uses mixed mocking approach: MockK for most mocks, Mockito for `java.io.File` (better final class support)
+
+### Module Structure Created
+
+```
+server-core/
+├── build.gradle
+├── src/main/
+│   ├── AndroidManifest.xml
+│   └── java/com/amaze/filemanager/server/
+│       ├── FileServer.kt
+│       ├── ServerEvent.kt
+│       ├── ServerNotification.kt
+│       ├── ServerPreferences.kt
+│       └── ServerRegistry.kt
+
+ftpserver/
+├── build.gradle
+├── src/main/
+│   ├── AndroidManifest.xml
+│   ├── java/com/amaze/filemanager/ftpserver/
+│   │   ├── FtpServerProvider.kt
+│   │   ├── commands/
+│   │   │   ├── AVBL.kt
+│   │   │   ├── FEAT.kt
+│   │   │   └── PWD.kt
+│   │   ├── filesystem/
+│   │   │   ├── AndroidFileSystemFactory.kt
+│   │   │   ├── AndroidFtpFile.kt
+│   │   │   ├── AndroidFtpFileSystemView.kt
+│   │   │   ├── RootFileSystemFactory.kt
+│   │   │   ├── RootFileSystemView.kt
+│   │   │   └── RootFtpFile.kt
+│   │   ├── service/
+│   │   │   ├── FtpCipherSuites.kt
+│   │   │   ├── FtpCommandFactoryFactory.kt
+│   │   │   ├── FtpEventBus.kt
+│   │   │   ├── FtpPreferences.kt
+│   │   │   ├── FtpReceiver.kt
+│   │   │   ├── FtpServerEngine.kt
+│   │   │   └── FtpServerService.kt
+│   │   └── ui/
+│   │       ├── BaseFtpServerFragment.kt
+│   │       └── FtpServerNotification.kt
+│   └── res/
+│       ├── drawable/
+│       │   ├── ic_clear_all.xml
+│       │   ├── ic_eye_grey600_24dp.xml
+│       │   ├── ic_ftp_dark.xml
+│       │   └── ic_ftp_light.xml
+│       ├── layout/
+│       │   └── fragment_ftp.xml
+│       ├── menu/
+│       │   └── ftp_server_menu.xml
+│       └── values/
+│           ├── colors.xml
+│           └── strings.xml
+├── src/test/
+│   ├── java/com/amaze/filemanager/ftpserver/commands/
+│   │   ├── AbstractFtpserverCommandTest.kt
+│   │   ├── AVBLCommandTest.kt
+│   │   ├── FEATCommandTest.kt
+│   │   ├── LogMessageFilter.kt
+│   │   └── PWDCommandTest.kt
+│   └── resources/mockito-extensions/
+│       └── org.mockito.plugins.MockMaker
+```
+
+### FTP Server Class Diagram
+
+```mermaid
+classDiagram
+direction LR
+
+namespace server_core {
+   class FileServer {
+      <<interface>>
+   }
+   class ServerPreferences {
+      <<interface>>
+   }
+   class ServerNotification {
+      <<interface>>
+   }
+   class ServerEvent {
+      <<sealed>>
+   }
+   class ServerRegistry
+   class ServerProvider {
+      <<interface>>
+   }
+}
+
+namespace ftpserver_service {
+   class FtpServerProvider
+   class FtpServerEngine
+   class FtpServerService {
+      <<abstract>>
+   }
+   class FtpReceiver {
+      <<abstract>>
+   }
+   class FtpEventBus
+   class FtpPreferences
+   class FtpCommandFactoryFactory
+   class FtpCipherSuites
+}
+
+namespace ftpserver_ui {
+   class BaseFtpServerFragment {
+      <<abstract>>
+   }
+   class FtpServerNotification
+}
+
+namespace ftpserver_filesystem {
+   class AndroidFileSystemFactory
+   class AndroidFtpFileSystemView
+   class AndroidFtpFile
+   class RootFileSystemFactory
+   class RootFileSystemView
+   class RootFtpFile
+}
+
+namespace ftpserver_commands {
+   class AVBL
+   class FEAT
+   class PWD
+}
+
+namespace app_integration {
+   class AppFtpService
+   class AppFtpReceiver
+   class FtpServerFragment
+   class FtpTileService
+   class FtpNotification
+}
+
+FtpServerProvider ..|> ServerProvider
+FtpServerProvider ..> ServerPreferences
+FtpServerProvider ..> FileServer
+ServerRegistry --> ServerProvider : registers
+
+FtpServerService --> FtpServerEngine : owns
+FtpServerService --> FtpEventBus : publishes
+FtpReceiver --> FtpServerEngine : start/stop
+FtpServerEngine ..> FtpPreferences : reads config
+FtpServerEngine ..> FtpCommandFactoryFactory : command factory
+FtpCommandFactoryFactory ..> AVBL
+FtpCommandFactoryFactory ..> FEAT
+FtpCommandFactoryFactory ..> PWD
+FtpServerEngine ..> FtpCipherSuites
+
+FtpServerEngine ..> AndroidFileSystemFactory
+FtpServerEngine ..> RootFileSystemFactory
+AndroidFileSystemFactory --> AndroidFtpFileSystemView
+AndroidFtpFileSystemView --> AndroidFtpFile
+RootFileSystemFactory --> RootFileSystemView
+RootFileSystemView --> RootFtpFile
+
+FtpServerNotification ..|> ServerNotification
+BaseFtpServerFragment --> FtpServerNotification
+BaseFtpServerFragment ..> FtpEventBus : observes
+BaseFtpServerFragment ..> FtpPreferences
+BaseFtpServerFragment ..> FtpServerEngine
+BaseFtpServerFragment ..> ServerEvent
+
+AppFtpService --|> FtpServerService
+AppFtpReceiver --|> FtpReceiver
+FtpServerFragment --|> BaseFtpServerFragment
+FtpTileService ..> FtpServerEngine
+FtpTileService ..> FtpEventBus
+FtpNotification ..> FtpServerNotification
+```
+
+### Further Considerations
+
+1. **Dependency inversion** — ✅ Done: `ftpserver` now depends on `server-core`, and `app` depends on both.
+
+2. **Feature module vs library module** — Implemented as library module (simpler approach).
+
+3. **Preference storage** — ✅ Done: `ServerPreferences` interface created in server-core, implemented in `FtpServerProvider`.
+
+4. **String resources** — Used `ftpmod_` prefix for all ftpserver module strings to avoid collision with app module's existing strings during transition period.
+

app/build.gradle

@@ -248,6 +248,8 @@ dependencies {
     implementation project(':commons_compress_7z')
     implementation project(':file_operations')
     implementation project(':portscanner')
+    implementation project(':server-core')
+    implementation project(':ftpserver')
 
     implementation libs.kotlin.stdlib.jdk8
     implementation libs.acra.core