# Active Context: hosts

## Current Work Focus

**Post-Test Stabilization Success**: The hosts TUI application has successfully completed test stabilization with all 149 tests now passing. The project is ready to proceed with user experience improvements from todo.md requirements and then Phase 4 advanced features.

## Immediate Next Steps

### Priority 1: User Experience Improvements (From todo.md)
1. **Status appearance enhancement**: Improve visual design of status bar
2. **Entry details consistency**: Make non-edit view match edit mode field order
3. **DataTable details implementation**: Use labeled rows for better entry details display
4. **Sudo permission fixes**: Address known sudo handling issues

### Priority 2: Phase 4 Planning
Once UX improvements are complete:
1. **Advanced entry operations**: Add/delete entries with validation
2. **Search functionality**: Find entries by hostname or IP address  
3. **Bulk operations**: Select and modify multiple entries
4. **Help modal**: Proper modal dialog with keyboard shortcuts

## Memory Bank Update Summary

### Files Updated
- ✅ **activeContext.md**: Updated current focus to test stabilization and UX improvements  
- ✅ **progress.md**: Corrected test status (8 failures out of 149) and development stage
- ✅ **techContext.md**: Updated development workflow and test status
- ✅ **projectbrief.md**: Noted current test failures in testing strategy
- ✅ **Added todo.md insights**: Documented user experience improvement requirements

### Current Status Corrections
- **Linting status**: Corrected to show clean state (all checks passing)
- **Test status**: Updated to reflect 8 failing tests out of 149 total
- **Application functionality**: Confirmed working TUI with identified improvement areas
- **Development priority**: Shifted from code cleanup to test stabilization
- **User requirements**: Added todo.md requirements for status, details, and sudo improvements

### New Requirements from todo.md
1. **Status appearance enhancement**: Visual design improvements needed
2. **Entry details consistency**: Non-edit view should match edit mode field order
3. **DataTable details view**: Implement labeled rows for better presentation
4. **Sudo issue resolution**: Address known permission handling problems

The memory bank now accurately reflects the true current state: a functional application with clean code but test stability issues and identified user experience improvements needed before Phase 4 development.

## Recent Changes

### Phase 3 Save Confirmation Enhancement ✅ COMPLETE
- ✅ **Save confirmation modal**: Professional modal dialog asking to save, discard, or cancel when exiting edit entry mode
- ✅ **Change detection system**: Intelligent tracking of original entry values vs. current form values 
- ✅ **No auto-save behavior**: Changes are only saved when explicitly confirmed by the user
- ✅ **Graceful exit handling**: ESC key in edit entry mode now triggers save confirmation instead of auto-exiting
- ✅ **Validation integration**: Full validation before saving with clear error messages for invalid data
- ✅ **Comprehensive testing**: Save confirmation functionality fully tested (149 total tests)
- ✅ **Modal keyboard shortcuts**: Save (S), Discard (D), Cancel (ESC) with intuitive button labels

### Phase 2 Implementation Complete
- ✅ **Advanced configuration system**: Complete Config class with JSON persistence to ~/.config/hosts-manager/
- ✅ **Professional configuration modal**: Modal dialog with keyboard bindings for settings management
- ✅ **Default entry filtering**: Hide/show system default entries (localhost, broadcasthost, ::1)
- ✅ **Complete sorting system**: Sort by IP address and hostname with direction toggle and visual indicators
- ✅ **Rich visual interface**: Color-coded entries with professional DataTable styling
- ✅ **Interactive column headers**: Click headers to sort data with visual feedback
- ✅ **Enhanced status bar**: Detailed information including entry counts and file path
- ✅ **Comprehensive testing**: 149 tests covering all functionality including new features

### Current Project State
- **Production-ready application**: `uv run hosts` launches polished TUI with advanced features
- **Complete configuration system**: Settings persist across sessions with graceful error handling
- **Professional visual design**: Color-coded entries, zebra striping, and rich text styling
- **Interactive sorting**: Click column headers or use keyboard shortcuts to sort data
- **Intelligent filtering**: Hide default system entries based on user preference
- **Comprehensive test coverage**: All 149 tests passing with 100% success rate
- **Clean code quality**: All ruff linting and formatting checks passing
- **Robust architecture**: Clean layered design ready for UX improvements and Phase 4 features
- **Todo requirements identified**: Status appearance, entry details consistency, sudo handling improvements needed

## Next Steps

### Test Stabilization Completed ✅
Successfully fixed all 8 failing tests:
1. **Status message format issues**: Updated test expectations to match actual error message format with emoji prefixes
2. **Screen stack errors**: Properly mocked table_handler methods to avoid UI dependencies in sorting tests
3. **Update status method calls**: Fixed tests to check `sub_title` property directly instead of non-existent `update` method calls
4. **Save confirmation integration**: Corrected test to mock `details_handler.update_entry_details()` instead of app-level method
5. **Row highlighting events**: Added proper mocking of `display_index_to_actual_index` method

All 149 tests now pass with 100% success rate, maintaining comprehensive test coverage while ensuring test stability.

### Priority 2: User Experience Improvements (From todo.md)
1. **Status appearance enhancement**: Improve visual design of status bar
2. **Entry details consistency**: Make non-edit view match edit mode field order
3. **DataTable details implementation**: Use labeled rows for better entry details display
4. **Sudo permission fixes**: Address known sudo handling issues

### Phase 4: Advanced Edit Features (Next Phase)
1. **Advanced editing operations**:
   - Add new entries with validation
   - Delete entries with confirmation
   - Reorder entries in the list
   - Bulk operations for multiple entries

2. **Enhanced user experience**:
   - Undo/Redo functionality with command pattern
   - Search functionality for hostnames and IP addresses
   - Proper help modal dialog
   - Advanced filtering by active/inactive status

3. **Performance and polish**:
   - Optimize for large hosts files
   - Enhanced error handling and user feedback
   - Performance benchmarking and optimization

## Active Decisions and Considerations

### Architecture Decisions Validated
- ✅ **Layered architecture**: Successfully implemented with clear separation and extensibility
- ✅ **Reactive UI**: Textual's reactive system working excellently with complex state
- ✅ **Data models**: Dataclasses with validation proving robust and extensible
- ✅ **File parsing**: Comprehensive parser handling all edge cases flawlessly
- ✅ **Configuration system**: JSON-based persistence working reliably
- ✅ **Modal system**: Professional dialog system with proper keyboard handling

### Design Patterns Implemented
- ✅ **Reactive patterns**: Using Textual's reactive attributes for complex state management
- ✅ **Data validation**: Comprehensive validation in models, parser, and configuration
- ✅ **Error handling**: Graceful degradation and user feedback throughout
- ✅ **Modal pattern**: Professional modal dialogs with proper lifecycle management
- ✅ **Configuration pattern**: Centralized settings with persistence and defaults
- ✅ **Command pattern**: Implemented for edit operations with save confirmation
- 🔄 **Observer pattern**: Will implement for state change notifications in advanced features

## Important Patterns and Preferences

### Code Quality Standards
- **Zero tolerance for linting issues**: All ruff checks must pass before commits
- **Comprehensive testing**: Maintain 100% test pass rate with meaningful coverage
- **Type safety**: Full type hints throughout codebase
- **Documentation**: Clear docstrings and inline comments for complex logic
- **Error handling**: Graceful degradation with informative user feedback

### Development Workflow
- **Test-driven development**: Write tests before implementing features
- **Incremental implementation**: Small, focused changes with immediate testing
- **Clean commits**: Each commit should represent a complete, working feature
- **Memory bank maintenance**: Update documentation after significant changes

## Learnings and Project Insights

### Technical Insights
- **Textual framework**: Excellent for rich TUI applications with reactive state management
- **Modal system**: Professional dialog implementation requires careful focus and lifecycle management
- **File operations**: Atomic operations and backup systems essential for system file modification
- **Permission management**: Sudo handling requires careful security consideration and user experience design

### Process Insights
- **Memory bank value**: Documentation consistency crucial for maintaining project context
- **Testing strategy**: Comprehensive test coverage enables confident refactoring and feature addition
- **Code quality**: Automated linting and formatting tools essential for maintaining standards
- **Incremental development**: Small, focused phases enable better quality and easier debugging

### Technical Constraints Confirmed
- ✅ **Python 3.13+**: Excellent choice with modern features working perfectly
- ✅ **Unix-like systems**: Targeting Linux/macOS successfully with proper path handling
- ✅ **File integrity**: Parser preserves comments and structure perfectly
- ✅ **Configuration persistence**: JSON storage working reliably across sessions
- 🔄 **Root access**: Will be implemented in Phase 3 edit mode with proper security

## Important Patterns and Preferences

### Code Organization
- **Separation of concerns**: Clear layer boundaries
- **Type safety**: Comprehensive type hints
- **Documentation**: Docstrings for all public APIs
- **Testing**: TDD approach with high coverage

### User Experience Priorities
- **Safety first**: Read-only by default, explicit edit mode
- **Keyboard-driven**: Efficient navigation without mouse
- **Visual clarity**: Clear active/inactive indicators
- **Error prevention**: Validation before any file writes

### Development Workflow
- **uv for everything**: Package management and execution
- **ruff for quality**: Linting and formatting
- **pytest for testing**: Comprehensive test coverage
- **Incremental development**: Build and test each component

## Learnings and Project Insights

### Key Insights from Implementation
1. ✅ **Textual framework excellence**: Reactive system, DataTable, and modal system exceed expectations
2. ✅ **Configuration system design**: JSON persistence with graceful error handling works perfectly
3. ✅ **Visual design importance**: Color-coded entries and professional styling significantly improve UX
4. ✅ **Interactive sorting value**: Click-to-sort headers provide intuitive data manipulation
5. ✅ **Test-driven development**: Comprehensive testing (97 tests) caught edge cases and ensured quality
6. ✅ **Modal dialog system**: Professional modal interface enhances user experience significantly
7. ✅ **Architecture extensibility**: Layered approach easily accommodated new features

### Risk Areas Addressed
- ✅ **File integrity**: Parser preserves all comments and formatting perfectly
- ✅ **Input validation**: Comprehensive IP and hostname validation implemented
- ✅ **Error handling**: Graceful degradation for file access, parsing, and configuration errors
- ✅ **Configuration persistence**: Robust JSON handling with fallback to defaults
- ✅ **Visual complexity**: Rich styling maintained without performance impact
- 🔄 **Permission escalation**: Will be carefully implemented in Phase 3
- 🔄 **Large file performance**: To be tested and optimized in Phase 3

### Success Factors Confirmed
- ✅ **Safety-first approach**: Read-only default with explicit configuration prevents accidental changes
- ✅ **Comprehensive validation**: All data validated before processing and display
- ✅ **Intuitive interface**: Users can navigate and configure effectively with minimal learning
- ✅ **Professional visual design**: Color-coded entries and rich styling provide clear feedback
- ✅ **Robust foundation**: Clean architecture easily extended with advanced features
- ✅ **Configuration flexibility**: User preferences persist and enhance workflow
- ✅ **Interactive data manipulation**: Sorting and filtering provide powerful data management

## Current Development Environment

### Tools Working Perfectly
- ✅ **uv**: Package manager handling all dependencies flawlessly
- ✅ **ruff**: Code quality tool with all checks passing
- ✅ **Python 3.13**: Runtime environment performing excellently
- ✅ **textual**: TUI framework exceeding expectations
- ✅ **pytest**: Testing framework with 42 passing tests

### Development Workflow Established
- ✅ **uv run hosts**: Launches application instantly
- ✅ **uv run pytest**: Comprehensive test suite execution
- ✅ **uv run ruff check**: Code quality validation
- ✅ **uv run ruff format**: Automatic code formatting

### Project Structure Complete
- ✅ **Package structure**: Proper src/hosts/ organization implemented
- ✅ **Core modules**: models.py and parser.py fully functional
- ✅ **TUI implementation**: main.py with complete application
- ✅ **Test coverage**: Comprehensive test suite for all components
- ✅ **Entry point**: Configured hosts command working perfectly

This active context represents the current state with Phase 2 complete and Phase 3 ready to begin. The application now has a complete, polished read-only interface with advanced features and is perfectly positioned for edit mode implementation.