Brasil Cripto 🇧🇷

A modern Flutter application for tracking cryptocurrency prices and managing your favorite digital assets.

🇧🇷 Leia em Português

✨ Features

🔍 Cryptocurrency Search & Discovery

• Search for any cryptocurrency by name or symbol
• Browse trending and popular cryptocurrencies
• Real-time price updates and market data
• View market cap rankings and 24h price changes

📊 Interactive Price Charts

• Beautiful, interactive price charts with touch support
• Multiple time periods: 24h, 7d, 30d, 90d, 1y
• Price trend indicators (positive/negative changes)
• Chart statistics including min/max prices and percentage changes
• Fallback chart data generation for offline reliability

❤️ Favorites Management

• Add/remove cryptocurrencies to your favorites list
• Persistent storage using secure local storage
• Quick access to your preferred coins
• Real-time synchronization across the app

🌐 Internationalization

• Multi-language support (English/Portuguese)
• Localized currency formatting
• Adaptive date and number formatting

🔒 Data Security

• Secure local storage for user preferences
• Privacy-focused design with no personal data collection
• Offline capability with fallback data

🚀 Installation

Prerequisites

• Flutter SDK (>= 3.7.0)
• Dart SDK (>= 3.7.0)
• Android Studio / VS Code with Flutter extensions
• Android/iOS device or emulator

Step by Step

1. Clone the repository

   git clone https://github.com/yourusername/brasil-cripto.git
   cd brasil-cripto

2. Install dependencies

   flutter pub get

3. Generate necessary files

   flutter packages pub run build_runner build

4. Run the app

   # For debug mode
   flutter run
   
   # For release mode
   flutter run --release

Build for Production

Android APK

flutter build apk --release

Android App Bundle

flutter build appbundle --release

iOS

flutter build ios --release

🏗️ Project Structure

lib/
├── main.dart                 # App entry point
├── app_widget.dart          # Main app widget
├── app_injector.dart        # Dependency injection
├── model/                   # Data models and repositories
│   ├── models/             # Data models (CoinModel, CoinChartModel)
│   ├── repositories/       # Data repositories
│   └── service/           # API services and HTTP client
├── view/                   # UI components
│   ├── pages/             # Screen pages
│   ├── widgets/           # Reusable widgets
│   └── utils/             # UI utilities and routing
├── view_model/            # Business logic and state management
│   ├── services/          # Business services
│   └── utils/             # Utilities (formatters, storage)
└── l10n/                  # Internationalization files

📱 Screenshots

Initial Page	Search Page	Coin Details	Favorites
🏠 Browse trending cryptocurrencies	🔍 Search for specific coins	📊 Detailed price charts and stats	❤️ Manage your favorite coins

🔌 API Integration

This app uses the CoinGecko API for cryptocurrency data:

📡 Free API with Rate Limits

• Base URL: https://api.coingecko.com/api/v3/
• Rate Limit: 10-30 requests per minute (free tier)
• Data includes: Current prices, market caps, 24h changes, historical data

🎯 Endpoints Used

• GET /coins/markets - Get cryptocurrency market data
• GET /coins/{id}/market_chart - Get historical price data for charts

⚠️ Important Notes

• The API has rate limiting on the free tier
• If rate limits are exceeded, the app will show appropriate error messages
• The app includes fallback chart data generation when API requests fail

🔄 Error Handling

• Network error handling with user-friendly messages
• Rate limit detection with upgrade suggestions
• Automatic retry mechanisms
• Offline chart data generation as fallback

🛠️ Technologies Used

• Framework: Flutter 3.7.2
• Language: Dart
• State Management: Provider + ChangeNotifier
• HTTP Client: Dio
• Routing: GoRouter
• Local Storage: FlutterSecureStorage
• Dependency Injection: GetIt
• Testing: Mockito + FlutterTest
• Internationalization: Flutter Intl
• Functional Programming: Dartz (Either, Option)

🧪 Testing

Run the test suite:

# Run all tests
flutter test

# Run tests with coverage
flutter test --coverage

# Run integration tests
flutter drive --target=test_driver/app.dart

The project includes:

• Unit tests for models and view models
• Mock services for isolated testing

📄 License

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

⚡ Performance Notes

• Efficient memory management with proper widget disposal
• Optimized image loading with caching
• Minimal API calls with smart caching strategies
• Smooth animations with proper performance monitoring

🙋‍♂️ Support

If you have any questions or need help, please:

1. Check the Issues page
2. Create a new issue with detailed information
3. Feel free to contact me on my professional email

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