# DEV_STATE.md - Lumacs Development State

## Architecture
```
    [Lua 5.4 Engine]
         ^  |
         |  v
    [Lua API Bridge] <-- C++ bindings for buffers, windows, keybindings, themes
         ^  |
         |  v
    [Editor Core] <-- Buffer management, kill ring, face system
         ^  |
         |  v
    [UI Interface] <-- Abstract UI layer
         ^  |
         |  v
    [GTK4 Frontend] <-- Primary GUI (with TUI fallback available)
         |
         v
    [Terminal/Display]
```

## Current Module
**GTK4 Frontend Completion** - Currently in Phase 6 with stable basic functionality. The editor has working text input, cursor movement, basic editing operations, and clean shutdown.

## File Manifest
```
Lumacs/
├── CMakeLists.txt           # Build configuration
├── init.lua                 # Main Lua initialization
├── themes.lua              # Theme definitions
├── include/lumacs/         # C++ headers
│   ├── editor_core.hpp     # Core editor logic
│   ├── buffer.hpp          # Text buffer management
│   ├── lua_api.hpp         # C++/Lua bridge
│   ├── gtk_editor.hpp      # GTK4 frontend
│   ├── tui_editor.hpp      # TUI fallback
│   ├── keybinding.hpp      # Key handling
│   ├── theme.hpp           # Theme/face system
│   └── [other headers]
├── src/                    # C++ implementation
│   ├── main.cpp            # Entry point
│   ├── editor_core.cpp     # Core functionality
│   ├── lua_api.cpp         # Lua bindings
│   ├── gtk_editor.cpp      # GTK implementation
│   └── [other .cpp files]
├── tests/                  # Unit tests
├── examples/               # Test files and demos
├── scripts/                # Build/test scripts
└── documentation/          # Project docs
```

## Done
- ✅ **Phase 1-5**: Complete Emacs-like core functionality
- ✅ **Phase 6 Core**: GTK4 frontend with text rendering
- ✅ **Input System**: Full keyboard input with modifiers working
- ✅ **Cursor System**: Emacs-style blinking block cursor with color inversion
- ✅ **Text Editing**: Basic insertion, deletion, movement operations working
- ✅ **Keybinding System**: Fixed conflicts, C-n, C-p, C-f, C-b, C-a, C-e, C-s, C-k working
- ✅ **Clean Exit**: Fixed shutdown crashes and memory issues
- ✅ **Syntax Highlighting**: Face system with Pango rendering
- ✅ **Text-Cursor Alignment**: Fixed text rendering offset issues
- ✅ **Scrolling System**: Full vertical and horizontal scrolling with Page Up/Down support
- ✅ **Kill Ring System**: Complete implementation with push/yank/yank-pop operations
- ✅ **Mark & Region**: Full mark/region system in Buffer (set_mark, deactivate_mark, get_region)
- ✅ **Buffer Management**: Complete buffer switching, listing, and management in EditorCore
- ✅ **Core Emacs Features**: Registers, keyboard macros, rectangles, kill operations
- ✅ **GTK Segfault Fix**: Resolved double-free on exit with proper cleanup handling
- ✅ **GTK Window Splits**: Dynamic container layout with Gtk::Paned matching EditorCore's window tree
- ✅ **Window Split Crash Fix**: Resolved window split crashes and text rendering issues
- ✅ **Multi-Window Text Rendering**: Fixed text rendering in split windows with proper font metrics
- ✅ **Split Window UI Polish**: Fixed modeline display, focus stability, and split ratio calculations

## Todo  
1. **Phase 7**: Performance optimization and tuning
2. **Phase 8**: Mouse support and advanced UI features
3. **Window Focusing API**: Add proper `set_active_window` method to EditorCore instead of cycling through next_window

## Technical Debt/Notes
- **Lua Bridge**: The lua_api.cpp contains the critical C++/Lua boundary code
- **GTK Threading**: All GTK operations must stay on main thread
- **Memory Management**: Using RAII and smart pointers throughout C++ code
- **Face System**: Themes are fully integrated with Pango text rendering
- **Cursor Implementation**: Blinking timer with 500ms intervals, proper cleanup on exit
- **Scrolling Architecture**: Viewport system with 3-line vertical and 5-column horizontal margins
- **Build System**: CMake-based with proper dependency management
- **Testing**: Unit test framework in place for core components

## Current Focus
**Phase 6 GTK4 Frontend - FULLY COMPLETED**: All functionality implemented including:
- Text rendering with syntax highlighting
- Full keyboard input and cursor management  
- Window splitting with dynamic GTK containers
- Clean exit without segfaults
- Ready for Phase 7 performance optimization