* Implemented PDF reflow mode by introducing a mechanism to convert PDF content to Markdown/HTML for viewing in the EPUB reader.
Specific changes include:
- Added `PdfReflowGenerator` and `PdfToMarkdownGenerator` to handle PDF text extraction and conversion to reflowable formats.
- Updated `MainViewModel` with `toggleReflowMode` logic to switch between original PDF and reflowed views.
- Modified `RecentFileEntity` and `RecentFileDao` to persist user reflow preferences, including a Room database migration (v12 to v13).
- Updated `PdfViewerScreen` and `EpubReaderControls` to include UI options for toggling reflow mode.
- Integrated reflow preference check into the book opening workflow to automatically load the preferred view.
- Updated `AppNavigation` and `EpubReaderScreen` to support the new view switching state.
* Implemented background processing and incremental loading for PDF reflow mode.
- Added `reflowProgress` to `MainViewModel` to track and display PDF-to-Markdown conversion progress in the UI.
- Refactored `PdfToMarkdownGenerator` to generate a skeleton EPUB structure immediately while processing page content (text and images) asynchronously.
- Switched PDF text extraction to use `PDFBox` with optimized memory settings and JPEG compression for images.
- Implemented priority page processing in reflow mode, starting with the user's current page.
- Added "Clear Reflow Cache" debug option to the Home Screen.
- Enhanced `BookPaginator` to support lazy loading of chapter content from disk and improved cache hit detection.
* Refactored PDF Reflow Mode to generate standalone Markdown files instead of temporary EPUB books.
* perf(reflow): optimize PDF-to-Markdown conversion and fix viewing lag
- Re-architected PdfToMarkdownGenerator to use a single-pass stream (O(N) complexity), fixing performance bottlenecks and timeouts on large PDFs.
- Implemented "Virtual Chaptering" in SingleFileImporter for Markdown files to split content into page-level HTML files, eliminating UI lag during reading.
- Simplified ReflowWorker to delegate progress tracking and looping to the generator.
- Enhanced PdfViewerScreen with a prominent top-bar progress indicator and a completion snackbar with an "OPEN" action.
* Optimized EPUB parsing performance and fixed PDF viewer UI layout.
- Optimized `EpubParser` by implementing parallel chapter parsing using coroutines and a semaphore to limit concurrency.
- Reduced memory usage in `EpubParser` and `SingleFileImporter` by no longer storing full HTML content in memory for chapters.
- Updated `EpubXMLFileParser` to support an existing `Document` object to avoid redundant Jsoup parsing.
- Fixed an issue in `PdfViewerScreen` where the snackbar was appearing under the bottom app bar.
* feat: rework Folder Sync architecture to separate Managed vs Linked books
- Introduced "Managed" (imported to app storage) vs "Linked" (SAF URI) book logic.
- Disabled Google Drive/Metadata synchronization for Folder-Linked books to respect privacy and storage.
- Updated deletion logic: Folder books are now marked as deleted in the DB to blacklist them from future auto-scans, while Managed books are permanently purged from local and cloud storage.
- Enhanced folder sync discoverability by adding a direct "Sync Folder" navigation button in Home screen.
- Implemented reactive pager navigation in MainScreen and LibraryScreen via LaunchedEffect to allow programmatic tab switching from the ViewModel.
* Implemented a local folder synchronization system to track and update book metadata across devices.
Key changes:
- Added `FolderBookMetadata` and `LocalSyncUtils` for serializing and managing metadata files in a `.episteme` directory.
- Implemented bidirectional sync in `FolderSyncWorker` to reconcile local database state with folder-based metadata using timestamps and Syncthing conflict resolution.
- Updated `MainViewModel` to trigger folder metadata sync when closing a book and verify for remote updates upon opening.
- Enhanced folder management with manual scan support via `WorkManager` and automatic cleanup of database entries when a folder is disconnected.
- Added `RecentFileDao` methods to support bulk deletion and prefix-based file lookups.
* Removed API 34 restriction for chapter processing and updated local folder sync directory name
* Increased TTS timeouts, added edge-to-edge support in MainScreen, and improved TtsChunk mapping safety
* Improved folder synchronization and metadata management.
- Added metadata-only sync option and triggered it on app start.
- Implemented hidden metadata filenames (prefixed with `.`) to reduce file clutter.
- Added automatic creation of `.nomedia` files in the sync directory.
- Enhanced sync conflict resolution by picking the latest metadata and cleaning up obsolete or orphaned files.
- Added "Sync Metadata" button to the Library screen.
- Updated UI labels for local folder sync to clarify Google Drive integration.
- Refactored `FolderSyncWorker` to support targeted metadata-only synchronization.
* Implement folder sync migration and refactoring
- Added a migration dialog to inform users about the folder sync refactor, where books are now read directly from external storage.
- Updated `MainViewModel` to handle migration state and trigger a full scan upon completion or dismissal of the dialog.
- Modified `FolderSyncWorker` to support legacy book matching during migration, updating file URIs and cleaning up internal app storage for migrated books.
- Improved synchronization logic between local and remote metadata, including cleanup of orphaned metadata files.
- Refined `RecentFileItem` updates during sync to preserve progress and bookmarks based on last modified timestamps.
* Implemented pull-to-refresh for library sync and enhanced folder file deletion.
- Added `isRefreshing` state to `MainViewModel` and integrated `PullToRefreshBox` in `HomeScreen`.
- Implemented `refreshLibrary` to trigger cloud and folder metadata synchronization.
- Updated deletion logic to physically remove files and metadata from synced local folders.
- Added a warning to the delete confirmation dialog when removing folder-synced items.
- Improved folder sync reliability by performing lazy cleanup of missing files during interaction and sync.
- Fixed a bug where sync loading indicators would not retract on failure or cancellation.
* Improved bookmark navigation and scroll synchronization in EPUB reader
- Refined bookmark navigation logic for vertical scroll mode to handle chunk injection more reliably.
- Added `isNavigatingToBookmark` state to show a loading overlay during long jumps.
- Implemented `onScrollFinished` callback in `CfiJsBridge` to synchronize UI state with WebView scroll completion.
- Updated `ChapterWebView` to use `rememberUpdatedState` for JavaScript bridge callbacks to ensure data consistency.
- Improved `getCurrentCfi` and `scrollToCfi` in `epub_reader.js` with better visibility probing and retry logic for detached nodes.
* Implemented background metadata extraction for folder sync.
Key changes:
- Added `MetadataExtractionWorker` to handle heavy metadata and cover extraction for files in the background.
- Refactored `FolderSyncWorker` to perform fast file discovery using placeholders, enqueuing the metadata worker upon completion.
- Added `getFolderBooksWithoutCovers` query to `RecentFileDao`.
- Updated UI components (`EmptyState`, `MainViewModel`) to improve user feedback during sync and provide clear setup actions.
- Enhanced `EmptyState` composable to support secondary actions and custom button text.
* Updated Library Screen UI
Aryan