☁️ CornerShop (Modular E-commerce Solution)

CornerShop is a modular e-commerce solution that demonstrates a Clean Architecture approach. It separates the domain logic into a shared core library, accessed by multiple client interfaces including a WPF Desktop App and an Admin Web API.

🏗 Architecture & Design Patterns

The solution is structured into three distinct layers to ensure Separation of Concerns (SoC) and high maintainability:

1. 📦 CornerShop.Core (Shared Logic)

This is the heart of the application, serving as a shared class library.

• Repository Pattern: The ShopRepository.cs encapsulates all MongoDB database operations, ensuring that the UI layers are decoupled from direct database access.
• Domain Models: Centralized entity definitions (Product, User, CartItem) used across the entire solution.
• Database Configuration: Centralized DBConfig for managing MongoDB connections.

2. 🖥️ CornerShop (WPF Client)

A rich desktop client built using the MVVM (Model-View-ViewModel) design pattern.

• ViewModels: Contains the presentation logic, handling state and commands (e.g., RelayCommand), keeping the code-behind (.xaml.cs) clean.
• Views: Pure XAML user interfaces bound to ViewModels via DataBinding.
• Async UI: Utilizes async/await for all repository calls to maintain a responsive UI.

3. 🌐 CornerShop.AdminAPI (Web API)

A RESTful API project built with ASP.NET Core.

• Provides endpoints for administrative tasks.
• Reuses the same CornerShop.Core library, demonstrating code reusability between Desktop and Web environments.

📸 Cloud & Interface Preview

1. Desktop UI (WPF) The user interface listing products fetched directly from the cloud.

2. Cloud Backend (MongoDB Atlas) Real-time data persistence verification in the MongoDB Atlas Cluster.

🛠 Tech Stack

• Language: C# 10 / .NET 8
• Database: MongoDB Atlas (Cloud NoSQL)
• ORM/Driver: MongoDB.Driver
• Desktop UI: WPF (Windows Presentation Foundation) with MVVM
• Web Services: ASP.NET Core Web API
• Tools: Visual Studio 2022, Swagger (for API testing)

💻 Code Highlight: The Repository Pattern

The application uses a generic-style repository approach in ShopRepository.cs to handle CRUD operations asynchronously:

public async Task<List<Product>> GetAllProductsAsync()
{
    // Accessing the collection via the shared Core library configuration
    var collection = _db.GetCollection<Product>("Products");
    return await collection.Find(_ => true).ToListAsync();
}

## 🚀 How to Run

To run this solution locally, you need to configure the database connection string in the code.

1.  **Clone the repository**
    ```bash
    git clone https://github.com/Qian1507/CornerShop.git
    ```

2.  **Configuration (Critical Step!)**
    - Navigate to `CornerShop.Core/Data/DBConfig.cs`.
    - Locate the `CloudConnection` variable.
    - **Replace the placeholder string** with your own **MongoDB Atlas Connection String**:
      ```csharp
      // inside DBConfig.cs
      private const string CloudConnection = "mongodb+srv://<username>:<password>@cluster...";
      ```
    - *Note:* You can also set `public static bool UseCloud = false;` to use a local MongoDB instance (`localhost:27017`).

3.  **Run the Application**
    - Open the solution in **Visual Studio**.
    - Set **CornerShop** (WPF) as the startup project to run the Desktop App.
    - Set **CornerShop.AdminAPI** as the startup project if you want to test the Backend API (Swagger).

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**⚠️ Security Note:** The connection string has been removed from the source code for security reasons. You must provide your own database credentials to run the app.