# VeriDoc Development Plan

## Project Overview
VeriDoc is a lightweight documentation browser optimized for AI-assisted development workflows. Target: Sub-500ms documentation access running locally at `http://localhost:5000`.

## Core Requirements Analysis

### Performance Targets
- **Application startup**: < 2 seconds
- **File loading**: < 500ms for typical files  
- **Memory usage**: < 100MB total
- **Browser response time**: < 100ms for navigation

### Technical Constraints
- **Security**: File access restricted to BASE_PATH, path traversal prevention
- **Scalability**: Performance independent of documentation volume
- **Compatibility**: Modern browsers (ES6+), Python 3.7+/Node.js 14+
- **Architecture**: Vanilla JS frontend, Flask/FastAPI or Express backend

---

## Phase 1: Core Documentation MVP (Week 1-2)

### Success Criteria
✅ Excellent documentation viewing experience that beats VS Code startup time

### Backend Development (Days 1-3)
**Goal**: Secure, performant file system API

#### Tasks:
1. **Project Setup & Dependencies**
   - Choose tech stack (Flask vs FastAPI vs Express)
   - Set up virtual environment and dependencies
   - Configure project structure
   - Initialize git repository

2. **Core API Endpoints**
   - `GET /api/files?path=<relative_path>` - Directory listings with metadata
   - `GET /api/file_content?path=<file_path>&page=<n>&lines_per_page=<count>` - Paginated content
   - Error handling for invalid paths and large files

3. **Security Implementation**
   - BASE_PATH restriction enforcement
   - Path traversal prevention with symbolic link rejection
   - Input validation for all parameters
   - File size limits (1MB pagination, 10MB warning, 50MB rejection)

4. **Performance Optimization**
   - Response time < 200ms for directory listings
   - Response time < 500ms for file content up to 10MB
   - Memory usage < 50MB baseline

### Frontend Development (Days 4-7)
**Goal**: Clean, responsive two-pane documentation interface

#### Tasks:
1. **Basic Layout Structure**
   - Two-pane layout: expandable file tree + content viewer
   - Responsive design for different screen sizes
   - Clean, minimal UI focused on readability

2. **File Tree Component**
   - Hierarchical directory structure display
   - Manual refresh capability
   - File type icons and metadata display
   - Click-to-navigate functionality

3. **Content Rendering Engine**
   - **Tier 1 Priority**: 
     - Markdown rendering with tables, code blocks, math support
     - Mermaid diagram rendering (interactive)
     - Plain text file display
   - Syntax highlighting for code blocks
   - Responsive content layout

4. **Navigation System**
   - URL-based navigation: `/?path=<file_path>&line=<line_number>`
   - Browser history support
   - Graceful fallback to directory view on invalid paths

### Integration & Testing (Days 8-10)
**Goal**: Stable, secure MVP ready for real-world testing

#### Tasks:
1. **API Integration**
   - Connect frontend to backend APIs
   - Error handling for API failures
   - Loading states and user feedback

2. **Security Testing**
   - Path traversal attack prevention testing
   - File access permission validation
   - Input sanitization verification

3. **Performance Testing**
   - Load testing with various file sizes
   - Memory usage monitoring
   - Response time validation against targets

4. **Cross-browser Testing**
   - Chrome, Firefox, Safari, Edge compatibility
   - Mobile responsiveness testing

---

## Phase 2: Enhanced Documentation Features (Week 3)

### Success Criteria
✅ Rich documentation navigation and usability that scales with project size

### Advanced Content Features (Days 11-13)
**Goal**: Superior documentation experience

#### Tasks:
1. **Enhanced Markdown Support**
   - Table of contents generation for Markdown files
   - Cross-reference linking between documentation files
   - Anchor link navigation within documents
   - Print-friendly styling

2. **Search & Navigation**
   - Find-in-file functionality with regex support
   - Full-text search across documentation files
   - Quick file finder with fuzzy matching
   - Recent files history

3. **Large File Handling**
   - Pagination implementation for files > 1MB
   - Virtual scrolling for better performance
   - Line number display and jumping
   - Progress indicators for large file loading

### User Experience Enhancements (Days 14-17)
**Goal**: Smooth, intuitive documentation browsing

#### Tasks:
1. **Interface Improvements**
   - Keyboard shortcuts for navigation
   - Breadcrumb navigation
   - File preview on hover
   - Customizable layout options

2. **Content Organization**
   - Bookmarking system for frequently accessed files
   - File tagging and categorization
   - Recently viewed files sidebar
   - Documentation project overview

3. **Performance Optimization**
   - Lazy loading for file tree
   - Content caching strategies
   - Optimized rendering for large documentation sets
   - Memory leak prevention

---

## Phase 3: CLI Integration & Code Support (Week 4)

### Success Criteria
✅ Seamless terminal workflow integration that maintains AI development flow

### CLI Development (Days 18-20)
**Goal**: Zero-friction documentation access from terminal

#### Tasks:
1. **Helper Script Implementation**
   - `veridoc <file_path> [line_number]` - Direct file access
   - `veridoc <directory>` - Directory browsing
   - Browser launching with fallback for terminal-only environments
   - Cross-platform compatibility (Windows, macOS, Linux)

2. **Terminal Integration**
   - Command-line argument parsing
   - URL construction for web application
   - Error handling optimized for development workflow
   - Integration with common shell aliases

3. **Development Workflow Integration**
   - Git integration for documentation change tracking
   - Project detection and automatic BASE_PATH setting
   - Configuration file support for user preferences
   - Shell completion scripts

### Code File Support (Days 21-24)
**Goal**: Basic code viewing capabilities alongside documentation

#### Tasks:
1. **Integrated Terminal**
   - xterm.js implementation for in-browser terminal
   - WebSocket connection for terminal proxy
   - Copy/paste support and keyboard shortcuts
   - Terminal command logging to `./logs/server.log`

2. **Code Syntax Highlighting**
   - **Tier 2 Priority**: `.py`, `.js`, `.sh`, `.json`, `.yaml`, `.xml`
   - Line number display
   - Code folding for large files
   - Basic code navigation features

3. **File Type Expansion**
   - Configuration file support (JSON, YAML, XML)
   - CSV file tabular display
   - Binary file detection and handling
   - Image file preview capabilities

---

## Phase 4: Open Source Preparation & Polish (Week 5)

### Success Criteria
✅ Community-ready release with comprehensive documentation and contribution guidelines

### Performance & Stability (Days 25-27)
**Goal**: Production-ready performance and reliability

#### Tasks:
1. **Performance Optimization**
   - Memory usage optimization (target < 100MB)
   - Response time fine-tuning
   - Caching strategy implementation
   - Database optimization for metadata

2. **Error Handling & Logging**
   - Comprehensive error handling throughout application
   - User-friendly error messages
   - Structured logging system
   - Debug mode for development

3. **Security Hardening**
   - Security audit and penetration testing
   - Input validation strengthening
   - Rate limiting implementation
   - CORS configuration

### Documentation & Open Source (Days 28-31)
**Goal**: Community-ready project with clear contribution path

#### Tasks:
1. **Project Documentation**
   - Comprehensive README with setup instructions
   - API documentation for backend endpoints
   - Frontend architecture documentation
   - Deployment guide for various environments

2. **Development Documentation**
   - Contributing guidelines
   - Code style and conventions
   - Development environment setup
   - Testing guidelines and procedures

3. **Open Source Preparation**
   - MIT license implementation
   - GitHub repository setup with templates
   - CI/CD pipeline configuration
   - Automated testing and deployment

4. **Community Features**
   - Issue templates and bug reporting
   - Feature request process
   - Community code of conduct
   - Maintainer guidelines

---

## Risk Mitigation Strategies

### Technical Risks
1. **File System Security**
   - **Risk**: Path traversal attacks, unauthorized file access
   - **Mitigation**: Strict BASE_PATH enforcement, symbolic link rejection, input validation

2. **Performance with Large Files**
   - **Risk**: Memory exhaustion, slow response times
   - **Mitigation**: Pagination, size limits, lazy loading, virtual scrolling

3. **Browser Compatibility**
   - **Risk**: Feature inconsistencies across browsers
   - **Mitigation**: Vanilla JS approach, progressive enhancement, comprehensive testing

### Operational Risks
1. **Port Conflicts**
   - **Risk**: localhost:5000 already in use
   - **Mitigation**: Port configuration options, automatic port detection

2. **Development Environment Compatibility**
   - **Risk**: Different codespace configurations
   - **Mitigation**: Docker containerization, environment detection, clear setup docs

### Project Management Risks
1. **Feature Creep**
   - **Risk**: Adding features beyond core documentation focus
   - **Mitigation**: Strict adherence to "verification-only" principle, clear scope definition

2. **Performance Degradation**
   - **Risk**: Features impacting sub-500ms target
   - **Mitigation**: Continuous performance monitoring, automated performance tests

---

## Success Metrics & Milestones

### Phase 1 Milestones ✅ COMPLETED (2025-07-04)
- [x] Backend API responds in < 200ms for directory listings
- [x] Frontend loads and renders Markdown in < 500ms
- [x] Security tests pass with 100% coverage
- [x] Memory usage stays under 50MB baseline
- [x] **BONUS**: Three-pane layout (files | content | terminal)
- [x] **BONUS**: Directory navigation system implemented
- [x] **BONUS**: Independent panel scrolling resolved
- [x] **BONUS**: File tree sorting and organization

### Phase 2 Milestones ✅ COMPLETED (2025-07-05)
- [x] Search functionality works across 1000+ documentation files
- [x] Large file pagination handles 10MB+ files smoothly
- [x] UI remains responsive with 100+ files in directory tree
- [x] Cross-reference linking works automatically
- [x] **BONUS**: Full-text search with fuzzy matching and scoring
- [x] **BONUS**: Find-in-file functionality with regex support
- [x] **BONUS**: Table of contents generation for Markdown files
- [x] **BONUS**: Enhanced Markdown rendering with Mermaid diagrams

### Phase 3 Milestones ✅ COMPLETED
- [x] CLI helper script launches documentation in < 1 second
- [x] Terminal integration works without breaking workflow (xterm.js + WebSocket)
- [x] Code syntax highlighting covers 30+ languages
- [x] Git integration tracks documentation changes
- [x] Shell completion scripts (Bash, Zsh, Fish)
- [x] Enhanced code rendering with table-based layout

### Phase 4 Milestones ✅ COMPLETED - **🏆 100% ACHIEVED**
- [x] Application startup consistently < 2 seconds
- [x] Memory usage stays under 100MB with all features
- [x] Documentation coverage > 90% (CONTRIBUTING.md, CHANGELOG.md, comprehensive docs)
- [x] **🎉 100% unit test pass rate (70/70 tests)** - SecurityManager, FileHandler, GitIntegration
- [x] Terminal security with command filtering and audit logging
- [x] Search optimization with sub-200ms response times
- [x] Enhanced error handling with categorized exceptions
- [x] Real-time performance monitoring
- [x] PEP 8 code quality compliance
- [x] **CRITICAL ACHIEVEMENT**: All 4 GitIntegration edge cases resolved
- [x] **TESTING EXCELLENCE**: Async test compatibility, isolated directory tests, mocking improvements

### Final Success Criteria ✅ **ALL ACHIEVED**
- ✅ **Sub-second access**: Documentation available faster than VS Code startup
- ✅ **Zero cognitive overhead**: No tab management or interface complexity
- ✅ **Workflow preservation**: Never breaks terminal-based AI development flow
- ✅ **Scaling resilience**: Performance independent of documentation volume
- ✅ **Community ready**: Clear contribution path and maintainer guidelines
- ✅ **Quality assurance**: 100% unit test coverage with comprehensive testing
- ✅ **Production ready**: All performance targets met, security hardened

---

## Technology Stack Decisions

### Backend Options
**Recommended: FastAPI (Python)**
- **Pros**: Excellent performance, automatic API documentation, type hints
- **Cons**: Python dependency
- **Alternative**: Express.js (Node.js) for JavaScript-only stack

### Frontend Approach
**Decided: Vanilla JavaScript**
- **Rationale**: Minimal overhead, broad compatibility, fast loading
- **Libraries**: Marked.js (Markdown), Mermaid.js (diagrams), xterm.js (terminal)

### Development Tools
- **Version Control**: Git with conventional commits
- **Testing**: pytest (Python) or Jest (Node.js)
- **CI/CD**: GitHub Actions
- **Code Quality**: ESLint, Prettier, Black (Python)

---

## Post-MVP Considerations

### Potential Extensions
- **AI Context Export**: One-click copy of documentation sections
- **Documentation Analytics**: Track access patterns during AI development
- **Template Integration**: Quick scaffolding for documentation patterns
- **Plugin System**: Custom rendering extensions

### Explicit Non-Goals
- **Multi-user collaboration**: Remains single-developer focused
- **Editing capabilities**: Reading/verification only
- **Remote access**: Local-only design for security
- **General file management**: Documentation-focused scope