Implement complete modularization of reader code by separating format-specific
functionality into dedicated modules. This replaces the monolithic structure
with a clean, maintainable architecture that separates concerns by format type.
## New Architecture
### Format-Specific Modules
- **formats/reflowable/**: EPUB, FB2, TXT, HTML (page-based pagination)
- types.ts: Shared type definitions for reflowable formats
- page-calculator.ts: Word-count based pagination with HTML slicing
- navigation.ts: Page-based navigation logic
- progress-tracker.ts: CFI-based progress tracking
- content-renderer.ts: DOM rendering for page content
- parser.ts: Unified parser interface for all reflowable formats
- ebook/**: Migrated ebook-specific features
- **formats/pdf/**: PDF format support
- Core PDF functionality (navigation, text selection, annotations)
- Advanced features (bookmarks, search, outlines, dual-page)
- Page cache and rendering optimizations
- **formats/comic/**: Comic format support
- Background color, chapter markers, page caching
- Page ordering, gap adjustments
- **formats/manga/**: Manga format support
- RTL navigation, vertical scrolling, reading direction
## Key Improvements
1. **Separation of Concerns**: Each format has its own dedicated module
2. **No Circular Dependencies**: Clean import structure
3. **Type Safety**: Comprehensive TypeScript types throughout
4. **Functional Programming**: Pure functions, no OOP complexity
5. **Scalability**: Easy to add new formats without touching core code
## Migration Path
- Old format-specific code in reader/, ebook/, pdf/, comic/, manga/
- New code in formats/[format]/ structure
- Maintains backward compatibility during transition
- Core reader logic remains format-agnostic
This change enables the implementation of page-based pagination for reflowable
formats while keeping PDF, comic, and manga functionality unchanged.
john-okeefe
e4c18e51f9