Library Management System 🛠️

Welcome to the Library Management System, a project demonstrating the Domain-Driven Design (DDD) pattern implemented with .NET 8, PostgreSQL, Entity Framework Core, and Swagger for API documentation.

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What is Domain-Driven Design (DDD)? 🤔

DDD is a software design philosophy that emphasizes focusing on the core domain and domain logic of an application. It’s about aligning your code with the real-world problem you're solving, ensuring that your application structure mirrors the business processes and rules.

Key Concepts in DDD:

1. Domain Layer: The heart of your application. Contains entities, value objects, and domain logic.
2. Application Layer: Coordinates tasks and delegates work to the domain. It contains use cases (e.g., BorrowBookHandler).
3. Infrastructure Layer: Handles communication with external resources like databases and APIs.
4. Clean Architecture: Layers your application to ensure separation of concerns and flexibility.

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Project Features ✨

• Implements DDD and Clean Architecture principles.
• Uses PostgreSQL as the database.
• Entity Framework Core for data access and migrations.
• Swagger for API exploration and testing.
• CRUD operations for managing books in a library.
• Implements a use case for borrowing a book.

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Technologies Used 🛠️

• .NET 8
• PostgreSQL
• Entity Framework Core
• Swagger (Swashbuckle)

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Setup Instructions ⚙️

1. Clone the Repository

git clone https://github.com/your-username/library-management-ddd.git
cd library-management-ddd

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2. Install Dependencies

Ensure you have the following installed on your machine:

• .NET 8 SDK
• PostgreSQL
• Any IDE or text editor (e.g., Visual Studio, Visual Studio Code)

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3. Configure PostgreSQL

1. Install PostgreSQL locally if not already installed.
2. Update the appsettings.json file with your PostgreSQL credentials:

   {
     "ConnectionStrings": {
       "LibraryDatabase": "Host=localhost;Port=5432;Database=LibraryManagement;Username=postgres;Password=yourpassword"
     }
   }

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4. Run Migrations

To create the database schema and seed data, run the following commands:

1. Add Migrations (already included in the project):

   dotnet ef migrations add InitialCreate

2. Apply Migrations:

   dotnet ef database update

This will create the Books table in the LibraryManagement database and populate it with seed data.

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5. Run the Project

Run the application:

dotnet run

The project will start on http://localhost:5000 (or another port if configured).

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6. Test the API with Swagger

Navigate to the Swagger UI to explore and test the API:

http://localhost:5000/swagger

Available Endpoints:

• GET /api/books: Retrieve all books.
• POST /api/books/{id}/borrow: Borrow a book by its ID.

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Project Architecture 🏗️

Folders and Layers

1. Domain: Core logic (e.g., Book entity).
2. Application: Use cases (e.g., BorrowBookHandler).
3. Infrastructure: Database setup and EF Core repositories.
4. Controller: Entry point for HTTP requests.

Why Use DDD?

• Aligns code with business processes.
• Reduces technical debt by focusing on the domain.
• Improves code maintainability and scalability.

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Testing the Application ✅

After running migrations and starting the application:

1. Use Swagger to test the endpoints.
2. Verify the database changes using your PostgreSQL client (e.g., pgAdmin or DBeaver).

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Future Enhancements 🚀

• Add authentication and authorization.
• Extend domain logic for returning books.
• Introduce a search feature for books.
• Add pagination and filtering for large datasets.

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Contributing 🤝

Feel free to fork the repository and submit pull requests. Contributions and feedback are always welcome!

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License 📜

This project is licensed under the MIT License.

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Enjoy exploring Domain-Driven Design with this project! 🎉