🌤️ WeatherTracker

A modern cross-platform weather application built with a Flutter frontend and a Python FastAPI backend.

This project demonstrates the development of a production-style application featuring responsive UI, REST API integration, MQTT communication, Cubit state management, feature-based architecture, and native Android plugin development.

✨ Features

• 🔐 User Authentication: Secure login and registration system using JWT.
• 🌤️ Real-time Weather Data: Current weather conditions and forecasts via OpenMeteo integration.
• 📡 Live Updates: Real-time data synchronization using the MQTT protocol.
• 📍 Location Management: Save and manage multiple locations.
• 👤 User Profile: Personalized user settings and saved places.
• 🌐 Network Monitoring: Real-time network connectivity status monitoring.
• 🔦 Native Integration: Device flashlight control via a custom Android plugin.
• 📱 Responsive UI: Optimized for mobile, tablet, and web viewing.

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🏗️ Full-Stack Architecture

This project consists of two main components, ensuring a clear separation of concerns:

1. Frontend (Flutter)

• State Management: Uses flutter_bloc (Cubit) for reactive state management. Business logic is strictly separated from the UI.
• Architecture: Feature-Based Architecture combined with a shared core module.
• Dependency Injection: Implemented via RepositoryProvider to keep the application loosely coupled.

2. Backend (Python FastAPI)

• API: RESTful API built with the high-performance FastAPI framework.
• Database: SQLite database for persistent storage (managed via SQLAlchemy).
• Security: JWT authentication and bcrypt password hashing for secure user sessions.

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🚀 Technologies

Category	Technologies
Frontend Framework	Flutter, Dart
State Management	flutter_bloc (Cubit)
Frontend Networking	http, mqtt_client, internet_connection_checker_plus
Native Integration	Kotlin, MethodChannel (flashlight_plugin)
Backend Framework	Python, FastAPI, Uvicorn
Backend DB & Auth	SQLAlchemy, PyJWT, passlib, bcrypt
External APIs	OpenMeteo SDK

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📁 Project Structure

Frontend (Flutter)

lib/
├── core/
│   ├── theme/           # App theming and colors
│   ├── data/            # Shared data repositories
│   ├── models/          # Data models
│   ├── services/        # API, Network, and MQTT services
│   ├── cubit/           # Global state management
│   ├── widgets/         # Reusable UI components
│   └── utils/           # Utility functions and helpers
│
├── features/
│   ├── auth/            # Authentication feature (Login/Register)
│   ├── home/            # Weather dashboard and main screen
│   └── profile/         # User profile and settings
│
└── main.dart            # App entry point

Backend (Python FastAPI)

weather_backend/
├── api/
│   ├── weather_router.py    # Weather data endpoints
│   └── auth_router.py       # Authentication endpoints
├── core/
│   └── security.py          # JWT and security utilities
├── services/
│   ├── auth_service.py      # Authentication logic
│   └── weather_service.py   # Weather data processing
├── repository/
│   ├── database.py          # Database configuration
│   └── user_repository.py   # User database operations
├── main.py                  # FastAPI app entry point
├── requirements.txt         # Python dependencies
└── weather.db               # SQLite database

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⚙️ Installation & Getting Started

Prerequisites

• Flutter SDK 3.11.1 or higher
• Python 3.8+
• Android Studio / VS Code

1. Running the Backend

Navigate to the backend directory and set up the Python environment:

cd weather_backend

# Create and activate virtual environment
python -m venv .venv

# Windows:
.venv\Scripts\activate
# macOS/Linux:
source .venv/bin/activate

# Install dependencies
pip install -r requirements.txt

# Start the server
uvicorn main:app --reload

*The API will be available at http://localhost:8000* *Swagger API documentation: http://localhost:8000/docs*

2. Running the Frontend

Open a new terminal, navigate to the project root, and run:

# Install Flutter dependencies
flutter pub get

# Run the app
flutter run

Note: During dependency installation, Flutter will automatically download the custom flashlight_plugin directly from GitHub.

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🔦 Easter Egg & Native Plugin

The application contains a hidden feature demonstrating native platform integration via a custom Flutter plugin.

To activate it:

1. Launch the application on a physical Android device or Emulator.
2. Locate the blue cloud ☁️ icon in the Top Navigation Bar.
3. Perform a long press on the icon.
4. This invokes the custom MethodChannel implementation and toggles the device flashlight. (On unsupported platforms like Web or iOS, an informational dialog is displayed instead).

👉 Plugin Repository: Leskiv1/flashlight_plugin

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🎓 Academic Background & Progression

This project was originally developed as part of a University Mobile Application Development course. Throughout the course, the application was progressively enhanced:

• Labs 1-3: Responsive UI development, custom design system, and routing.
• Labs 4-5: REST API integration and real-time MQTT communication.
• Lab 6: Complete architectural refactoring to 3-Tier Architecture, implementing Cubit state management and Dependency Injection.
• Lab 7: Native Android plugin development using MethodChannel and safe platform handling (dart:ffi concepts).

🙏 Acknowledgements & Course Materials: * Course Repository: DenysDoskochynskyi/IoT-flutter

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