# Theme System Improvements

## Overview
The Lumacs UI has been enhanced with a comprehensive theme framework that provides:
- Remove tilde characters from empty lines for a cleaner look
- Configurable color schemes through Lua API
- Built-in Everforest dark theme
- Extensible theme system for custom themes

## Features Added

### 1. Theme Framework (C++)
- **Color class**: RGB color representation with ncurses integration
- **ThemeElement enum**: Defines themed UI elements (Normal, Keyword, String, Comment, etc.)
- **Theme class**: Manages colors for different UI elements
- **ThemeManager class**: Handles multiple themes and switching between them

### 2. Built-in Themes
- **Everforest Dark**: Beautiful dark theme with carefully chosen colors
- **Default Theme**: Simple theme using basic colors as fallback

### 3. Lua API Integration
- Theme configuration through Lua scripts
- Runtime theme switching with `editor:set_theme(name)`
- Theme listing with `editor:theme_manager():theme_names()`
- Custom theme creation capabilities

### 4. UI Improvements
- Removed tilde characters from empty lines
- Themed status line, message line, cursor, and search highlighting
- Syntax highlighting colors now use theme system
- Consistent color scheme throughout the interface

## Usage

### Switching Themes from Lua
```lua
-- Switch to Everforest dark theme
editor:set_theme("everforest-dark")

-- Switch to default theme
editor:set_theme("default")

-- List available themes
local themes = editor:theme_manager():theme_names()
for _, name in ipairs(themes) do
    print("Available theme: " .. name)
end
```

### Key Bindings (in themes.lua)
- `C-x t e` - Switch to Everforest theme
- `C-x t d` - Switch to default theme  
- `C-x t l` - List all available themes

### Creating Custom Themes
```lua
-- Example of how to customize theme colors via Lua
local theme = editor:active_theme()
if theme then
    theme:set_color(lumacs.ThemeElement.Keyword, lumacs.Color(255, 100, 100))
    theme:set_color(lumacs.ThemeElement.String, lumacs.Color(100, 255, 100))
end
```

## Architecture

### Theme Elements
The following UI elements are themeable:

**Text Elements:**
- Normal text
- Keywords, Strings, Comments
- Functions, Types, Numbers, Constants
- Error text

**UI Elements:**
- Status line (active/inactive)
- Message line
- Line numbers
- Cursor
- Search matches (success/fail)
- Window borders

### Color System
- RGB colors with automatic ncurses color mapping
- Fallback to nearest basic colors when terminal doesn't support custom colors
- Efficient color pair caching

## Files Modified/Added

### New Files:
- `include/lumacs/theme.hpp` - Theme system headers
- `src/theme.cpp` - Theme implementation
- `themes.lua` - Example theme configuration

### Modified Files:
- `include/lumacs/editor_core.hpp` - Added theme manager
- `src/editor_core.cpp` - Initialize themes
- `include/lumacs/lua_api.hpp` - Added theme support
- `src/lua_api.cpp` - Theme Lua bindings
- `src/main_ncurses.cpp` - Updated UI rendering
- `CMakeLists.txt` - Added theme.cpp to build

## Everforest Theme Colors

The Everforest dark theme uses these color values:
- Background: `#2d3139`
- Foreground: `#d3c6aa` 
- Keywords: `#e67e80` (red)
- Strings: `#a7c080` (green)
- Comments: `#928374` (grey)
- Functions: `#7fbbb3` (blue)
- Types: `#dbbc7f` (yellow)
- Numbers: `#d699b5` (purple)

## Next Steps

The theme system is ready for Phase 4 features and can be easily extended with:
- More built-in themes (light themes, other popular themes)
- Theme loading from external files
- Per-filetype color customization
- Advanced styling (bold, italic, underline)