Personal Scheduler

A high-performance personal scheduling application built with SOLID principles featuring a C++ backend API server and React frontend. Optimized for enterprise-grade performance with comprehensive testing and benchmarking suite.

⚡ Performance

Production-Ready Performance Metrics:

• API Layer: 13,042 RPS (4,500x improvement from baseline)
• Model Layer: 20,000 events/second (50ms for 1000 events)
• Database: 185,000 inserts/second with SQLite
• Memory Usage: 11-37MB peak (highly efficient)
• Response Caching: Sub-millisecond cache hits
• Thread Pool: Hardware-optimized concurrency

Benchmarked on Apple Silicon with optimized builds

📊 View Performance Benchmark Results →

🏗️ SOLID Architecture

This project demonstrates enterprise-grade software design following SOLID principles:

✅ Single Responsibility Principle

• EventService: Pure event operations
• EventsHandler: HTTP request handling only
• Router: Route matching and dispatch
• PerformanceMonitor: Metrics collection

✅ Open/Closed Principle

• Extensible handler system via IRequestHandler
• Plugin-based notification and action system
• Configurable performance monitors

✅ Liskov Substitution Principle

• Interface-based dependency injection
• Polymorphic event types (OneTime/Recurring)
• Substitutable calendar integrations

✅ Interface Segregation Principle

• IEventService for clean business logic
• IPerformanceMonitor for metrics
• IRequestHandler for HTTP handling

✅ Dependency Inversion Principle

• Constructor injection throughout
• Abstract interfaces over concrete implementations
• DependencyContainer for IoC management

🚀 Features

Backend (C++)

• SOLID-Compliant Architecture with dependency injection
• Ultra-High Performance API (13K+ RPS with optimizations)
• Advanced Caching System with TTL and cache metrics
• Thread Pool Architecture for concurrent processing
• Comprehensive Security (Auth, Rate Limiting, CORS)
• Zero-Copy Optimizations and fast serialization
• Production Monitoring with detailed performance metrics
• Extensive Unit Tests for all SOLID components

Frontend (React)

• Modern React UI with TypeScript and Tailwind CSS
• Multiple Calendar Views (Day, Week, Month)
• Interactive Event Management with recurring event support
• Real-time Dashboard with today's events and statistics
• 12-hour Time Display with proper formatting
• Responsive Design optimized for desktop and mobile

🧪 Testing Framework

Comprehensive Test Suite:

• Unit Tests: EventService, Handlers, Router, Security
• Integration Tests: Full API and database testing
• Performance Tests: Benchmarking and load testing
• Security Tests: Auth, Rate Limiting, Input validation

# Run all unit tests
make unit-tests

# Run individual test suites
make event_service_tests    # EventService component tests
make handlers_tests         # API handlers tests  
make router_tests          # Router component tests
make security_tests        # Auth and RateLimiter tests

# Run performance benchmarks
make benchmark
./benchmark

# Run comprehensive test script
./run_benchmark.sh

📦 Installation

Prerequisites

• C++17 compiler (g++ or clang++)
• Node.js 16+ and npm
• SQLite3 development libraries
• libcurl for HTTP client functionality

Quick Start

1. Clone and setup:

   git clone https://github.com/ostepan8/personal-scheduler.git
   cd personal-scheduler
   cp .env.example .env

2. Build and run server:

   make clean && make server
   ./scheduler_server

3. Setup frontend:

   cd frontend
   npm install
   cp .env.example .env.local
   PORT=3004 npm start

4. Access application:

   • Frontend: http://localhost:3004
   • API: http://localhost:8080

Environment Configuration

.env (Backend):

API_KEY=your-secret-api-key
ADMIN_API_KEY=your-admin-key
HOST=127.0.0.1
PORT=8080
CORS_ORIGIN=http://localhost:3004
RATE_LIMIT=100
RATE_WINDOW=60

frontend/.env.local:

REACT_APP_API_URL=http://localhost:8080
REACT_APP_API_KEY=your-secret-api-key

🏗️ Architecture Overview

┌─────────────────┐    ┌──────────────────┐    ┌─────────────────┐
│   React Frontend │────│   C++ API Server  │────│  SQLite Database │
│   (Port 3004)    │    │   (Port 8080)     │    │   (events.db)    │
│                  │    │                   │    │                  │
│  - TypeScript    │    │  SOLID Architecture│    │  - WAL Mode      │
│  - Tailwind CSS  │    │  - Dependency      │    │  - Auto Schema   │
│  - Calendar Views│    │    Injection      │    │  - Prepared Stmts│
└─────────────────┘    │  - Thread Pools    │    └─────────────────┘
                       │  - Response Cache  │
                       │  - Security Layer  │
                       └──────────────────┘
                              │
                       ┌──────────────────┐
                       │ Optional Services │
                       │ - Google Calendar │
                       │ - Notifications   │
                       │ - Custom Actions  │
                       └──────────────────┘

🔧 Development

Available Make Targets

make help           # Show all available targets
make server         # Build SOLID-compliant server
make benchmark      # Build performance benchmark
make unit-tests     # Build and run all unit tests
make clean          # Clean build artifacts
make install        # Install to /usr/local/bin

Performance Benchmarking

# Build and run comprehensive benchmarks
make benchmark
./benchmark

# Run specific benchmark categories
./benchmark --model     # Model layer performance
./benchmark --api       # API performance  
./benchmark --full      # Full system benchmark

# Use benchmark script for load testing
./run_benchmark.sh

# Results automatically saved to benchmark_results/

Project Structure

scheduler/
├── main.cpp                    # SOLID-compliant server entry point
├── Makefile                    # Build system with test targets
├── benchmark.cpp               # Comprehensive performance testing
├── run_benchmark.sh           # Load testing script
│
├── api/                       # API layer (SOLID-compliant)
│   ├── ApiServer.h/cpp        # Main HTTP server with DI
│   ├── handlers/              # Request handlers (SRP)
│   │   ├── EventsHandler.*    # Event operations handler
│   │   └── StatsHandler.*     # Statistics handler
│   ├── routing/               # Route management (OCP)
│   │   └── Router.*           # Route matching and dispatch
│   ├── interfaces/            # Abstract interfaces (DIP)
│   │   ├── IEventService.h    # Event service interface
│   │   ├── IRequestHandler.h  # Handler interface
│   │   └── IPerformanceMonitor.h # Monitoring interface
│   └── performance/           # Performance monitoring
│       └── PerformanceMonitor.* # Metrics collection
│
├── services/                  # Business logic layer
│   └── EventService.*         # Event operations (SRP + DIP)
│
├── model/                     # Domain models
│   ├── Model.*                # Event aggregation
│   ├── OneTimeEvent.*         # Single events
│   ├── RecurringEvent.*       # Recurring events
│   └── recurrence/            # Recurrence patterns
│
├── database/                  # Data persistence
│   ├── SQLiteScheduleDatabase.* # SQLite implementation
│   └── SettingsStore.*        # Configuration storage
│
├── security/                  # Security components
│   ├── Auth.*                 # Authentication
│   └── RateLimiter.*          # Rate limiting
│
├── utils/                     # Utilities
│   ├── ResponseCache.*        # HTTP response caching
│   ├── FastSerializer.*       # Optimized JSON serialization
│   ├── ThreadPool.*           # Concurrent processing
│   └── DependencyContainer.*  # IoC container
│
├── tests/                     # Comprehensive test suite
│   ├── services/              # Service layer tests
│   ├── api/                   # API layer tests
│   ├── security/              # Security tests
│   └── test_utils.h           # Test utilities
│
├── frontend/                  # React application
│   ├── src/
│   │   ├── components/        # React components
│   │   ├── services/          # API client
│   │   └── types/            # TypeScript interfaces
│   └── public/               # Static assets
│
└── benchmark_results/         # Performance test outputs

🛠️ API Documentation

Authentication

All requests require the Authorization header:

curl -H 'Authorization: your-api-key' http://localhost:8080/events

Core Endpoints

• GET /events - List all events
• POST /events - Create new event
• GET /events/next/{count} - Get next N events
• GET /stats - Performance and cache statistics
• OPTIONS /* - CORS preflight support

Response Format

{
  "status": "ok",
  "data": [...],
  "meta": {
    "cache_hit": true,
    "response_time_ms": 1.2
  }
}

🔒 Security Features

• Multi-layer Authentication (API keys + Admin keys)
• Configurable Rate Limiting (per-IP protection)
• CORS Security with configurable origins
• Input Sanitization for all user data
• Secure Headers (HTTPS-ready)
• Dependency Injection for secure component isolation
• Production-Safe Logging (no sensitive data)

⚡ Performance Optimizations

Phase 1: Response Caching & Fast Serialization

• Response Cache: TTL-based caching with hit/miss metrics
• Fast JSON: Custom serialization avoiding nlohmann overhead
• Connection Keep-Alive: HTTP connection reuse

Phase 2: Thread Pools & Async Processing

• Thread Pool: Hardware-optimized worker threads
• Async Handlers: Non-blocking request processing
• Database Pooling: Connection reuse and optimization

Phase 3: Zero-Copy & Memory Optimization

• Zero-Copy Streaming: Direct buffer operations
• Lock-Free Structures: Concurrent data access
• Memory Pools: Pre-allocated object management

Result: 13,042 RPS (4,500x improvement from baseline 2.9 RPS)

🧪 Quality Assurance

Test Coverage

• Unit Tests: 100% coverage of SOLID components
• Integration Tests: Full API workflow testing
• Performance Tests: Continuous benchmarking
• Security Tests: Auth, rate limiting, input validation
• Load Tests: High-concurrency validation

Continuous Integration Ready

• Automated test execution with make unit-tests
• Performance regression detection
• Code quality validation
• Build artifact management

🚀 Deployment

Production Build

# Backend
make clean && make server
sudo make install  # Installs to /usr/local/bin

# Frontend  
cd frontend
npm run build

Docker Support (Future)

The SOLID architecture makes containerization straightforward:

• Clean dependency injection
• Environment-based configuration
• Stateless request handling
• Health check endpoints

🤝 Contributing

1. Fork the repository
2. Create feature branch (git checkout -b feature/amazing-feature)
3. Follow SOLID principles in your code
4. Add unit tests for new components
5. Run test suite (make unit-tests)
6. Benchmark performance impact (make benchmark)
7. Commit changes (git commit -m 'Add SOLID feature')
8. Push to branch (git push origin feature/amazing-feature)
9. Open Pull Request

Code Standards

• SOLID Principles: All new code must follow SOLID design
• Unit Tests: New components require comprehensive tests
• Performance: No regressions in benchmark results
• Documentation: Update README for new features

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• httplib for lightweight C++ HTTP server
• nlohmann/json for JSON processing
• SQLite for embedded database excellence
• React ecosystem for modern frontend
• SOLID Principles by Robert C. Martin
• Clean Architecture design patterns

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Built with ❤️ following SOLID principles and modern C++ best practices