# Progress: hosts-go

## What Works

### ✅ Memory Bank Foundation
- **Project documentation**: Complete memory bank structure established
- **Architecture planning**: Clear technical design documented
- **Development approach**: TDD strategy and patterns defined
- **Technology stack**: Bubble Tea ecosystem selected and documented

### ✅ Project Definition
- **Core requirements**: Two-pane TUI for hosts file management clearly defined
- **User experience**: Safety-first approach with explicit edit mode
- **Technical constraints**: Permission model and file safety requirements established
- **Directory structure**: Planned layout for Go project organization

### ✅ Foundation Implementation (COMPLETED)
- **Go module initialization**: ✅ `go.mod` created with all core dependencies
- **Directory structure**: ✅ Complete project structure (`cmd/`, `internal/`, `tests/`)
- **Core data models**: ✅ `internal/core/models.go` with HostEntry and HostsFile structs
- **Validation system**: ✅ IP address and hostname validation with RFC compliance
- **Test suite**: ✅ Comprehensive tests (44 test cases, 100% passing)
- **Demo application**: ✅ Working `cmd/hosts/main.go` demonstrating functionality

## What's Left to Build

### 🚧 Core Functionality (Phase 1 - Current Priority)
- [ ] **Hosts file parser**: Read and parse `/etc/hosts` file format
  - [ ] Parse IP addresses, hostnames, comments
  - [ ] Handle disabled entries (commented out)
  - [ ] Preserve original formatting and comments
- [ ] **File operations**: Read hosts file with error handling
- [ ] **Round-trip parsing**: Parse → modify → write back with format preservation

### 🎨 Basic TUI (Phase 2)  
- [ ] **Main Bubble Tea model**: Core application state and structure
- [ ] **Two-pane layout**: Left list + right detail view
- [ ] **Entry list display**: Show active status, IP, hostname columns
- [ ] **Entry selection**: Navigate and select entries with keyboard
- [ ] **View mode**: Safe browsing without modification capability

### 🔧 Edit Functionality (Phase 3)
- [ ] **Edit mode transition**: Explicit mode switching with visual indicators
- [ ] **Permission handling**: Request sudo access when entering edit mode
- [ ] **Entry modification**: Add, edit, delete, toggle active status
- [ ] **File writing**: Atomic updates with backup and rollback
- [ ] **Input validation**: Real-time validation of IP and hostname inputs

### 🌐 Advanced Features (Phase 4)
- [ ] **DNS resolution**: Background hostname to IP resolution
- [ ] **IP comparison**: Compare resolved vs current IP addresses
- [ ] **Entry reordering**: Manual drag/drop or move commands
- [ ] **Sorting options**: Sort by IP, hostname, or custom order
- [ ] **Search/filter**: Find entries quickly in large files

### 🧪 Testing & Quality (Ongoing)
- [ ] **Parser tests**: Round-trip parsing, edge cases, malformed files
- [ ] **Model tests**: Data validation, entry manipulation
- [ ] **TUI tests**: User interactions, state transitions
- [ ] **Integration tests**: Complete workflows, file operations
- [ ] **Permission tests**: sudo scenarios, graceful degradation

## Current Status

### Project Phase: **Foundation Complete → Core Functionality**
- **Completion**: ~25% (foundation and core models complete)
- **Active work**: Ready to implement hosts file parser (Phase 1)
- **Blockers**: None - solid foundation established

### Development Readiness
- ✅ **Architecture designed**: Clear technical approach documented
- ✅ **Requirements defined**: User experience and functionality specified  
- ✅ **Technology selected**: Bubble Tea stack confirmed and installed
- ✅ **Testing strategy**: TDD approach implemented and proven
- ✅ **Project scaffolding**: Complete Go module with all dependencies
- ✅ **Development environment**: Fully functional with comprehensive tests

### Risk Assessment
- **Low risk**: Well-established technology stack (Go + Bubble Tea)
- **Medium risk**: Permission handling complexity (sudo integration)
- **Low risk**: File format parsing (well-defined `/etc/hosts` format)
- **Medium risk**: TUI responsiveness with large files

## Known Issues

### Technical Challenges
- **Permission elevation**: Need to handle sudo gracefully across platforms
- **File locking**: Prevent concurrent modifications to `/etc/hosts`
- **Large file performance**: Ensure responsiveness with large hosts files
- **Terminal compatibility**: Test across different terminal applications

### Implementation Decisions Needed
- **Configuration storage**: Where to store user preferences and settings
- **Backup strategy**: How many backups to keep and where to store them
- **DNS timeout handling**: How to handle slow or unresponsive DNS queries
- **Error recovery**: How to handle corrupted hosts files or write failures

## Evolution of Project Decisions

### Initial Scope
- Started with comprehensive feature set including DNS resolution
- Planned for cross-platform compatibility from day one
- Emphasized safety and validation throughout

### Refined Approach
- **TDD emphasis**: Write tests first to ensure reliability
- **Incremental development**: Build core functionality before advanced features
- **Safety first**: Default to read-only mode, explicit edit mode transition
- **User experience focus**: Two-pane interface for efficiency

### Technology Evolution
- **Framework choice**: Bubble Tea selected for maturity and documentation
- **Architecture pattern**: MVU pattern from Bubble Tea ecosystem
- **Testing approach**: Comprehensive coverage with mocked dependencies
- **Development workflow**: Standard Go tooling with additional quality tools

## Success Metrics & Milestones

### Milestone 1: Basic Functionality (Target: Week 1)
- [ ] Parse and display existing hosts file entries
- [ ] Navigate entries with keyboard
- [ ] View entry details in right pane
- **Success criteria**: Can safely browse hosts file without editing

### Milestone 2: Core Editing (Target: Week 2)  
- [ ] Toggle entries active/inactive
- [ ] Add new entries with validation
- [ ] Edit existing entries
- **Success criteria**: Can perform basic hosts file modifications safely

### Milestone 3: Advanced Features (Target: Week 3)
- [ ] DNS resolution and IP updates
- [ ] Entry reordering and sorting
- [ ] Search and filtering
- **Success criteria**: Full feature parity with manual editing plus enhancements

### Milestone 4: Polish & Release (Target: Week 4)
- [ ] Comprehensive testing and bug fixes
- [ ] Documentation and usage examples
- [ ] Cross-platform testing and compatibility
- **Success criteria**: Production-ready tool suitable for daily use

## Next Immediate Actions

### ✅ COMPLETED Foundation Tasks
1. ✅ **Initialize Go project** (`go mod init hosts-go`)
2. ✅ **Add core dependencies** (Bubble Tea, Bubbles, Lip Gloss, testify)
3. ✅ **Create directory structure** according to projectbrief.md
4. ✅ **Create core data models** with comprehensive validation
5. ✅ **Implement test suite** (44 tests, 100% passing)
6. ✅ **Create demo application** proving foundation works

### 🚧 NEXT Phase 1 Actions (Hosts File Parser)
1. **Write parser tests** for `/etc/hosts` file format parsing
2. **Implement hosts file reader** (`internal/core/parser.go`)
3. **Add line-by-line parsing logic** with comment preservation
4. **Test round-trip parsing** (read → parse → write)
5. **Handle edge cases** (malformed entries, various formats)

The foundation is now solid and ready for implementing the core parsing functionality.