🛍️ Doqon — Modular Retail POS System

Doqon is a modern, clean-architecture-based Point-of-Sale system for retail stores.
Built with CQRS, MediatR, and layered architecture, it supports sales, inventory management, customer debts, and multi-currency operations.
Initially developed for WPF, designed for future transition to .NET MAUI and web interfaces.

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📸 Preview (coming soon...)

UI screenshots will be placed here once the MVP is deployed.

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⚙️ Technologies Used

• .NET 9 (.NET MAUI + WPF + ASP.NET Core Web API)
• Clean Architecture (Domain, Application, Infrastructure, Presentation)
• CQRS + MediatR (Command and Query responsibility segregation)
• FluentValidation (Input validation)
• AutoMapper (DTO to Entity mapping)
• EF Core + PostgreSQL (Database and persistence)
• Refit (Typed HTTP clients)
• Serilog (Structured logging)
• JWT Authentication
• XUnit + Moq (Testing)

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🏗️ Project Structure

/src
  ├── Core
  │   ├── Doqon.Domain           # Entities, ValueObjects, Aggregates, Events
  │   ├── Doqon.Application      # CQRS handlers, DTOs, Interfaces
  │   └── Doqon.Contracts        # API request/response models for clients
  │
  ├── Shared
  │   └── Doqon.Common           # Result<T>, Exceptions, Utilities
  │
  ├── Backend
  │   ├── Doqon.Infrastructure  # EF Core + external services
  │   └── Doqon.Api             # ASP.NET Core Web API
  │
  ├── Client
  │   ├── Doqon.ApiClient       # Refit interfaces for MAUI
  │   └── Doqon.Maui            # Cross-platform frontend (in progress)
  │
  └── Tests                     # Full test coverage per layer

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🚀 Getting Started

1. Clone the repo

git clone https://github.com/yourusername/doqon.git
cd doqon

2. Setup database (PostgreSQL)

• Create a DB: doqon_db
• Set connection string in appsettings.Development.json

{
  "ConnectionStrings": {
    "DefaultConnection": "Host=localhost;Database=doqon_db;Username=postgres;Password=yourpassword"
  }
}

3. Run EF Core migrations

cd src/Backend/Doqon.Infrastructure
dotnet ef database update

4. Run the API

cd ../../Doqon.Api
dotnet run

5. (Optional) Run the WPF or MAUI client

Initial version is WPF based. MAUI version coming soon.

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🧪 Running Tests

dotnet test

Test projects are placed under /Tests with coverage across all layers.

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📈 Roadmap

• ✅ Sales, Inventory, Debts module
• ✅ JWT Auth & Roles
• 🔄 Currency Exchange module
• 🖥️ WPF client (initial version)
• 📱 MAUI mobile/desktop client (in progress)
• 🌐 BlazorAdmin dashboard (future)
• 📤 Telegram bot support for inventory alerts (future)
• 📦 Publish Doqon.Common & Contracts as NuGet (future)

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🧠 Credits

Inspired by principles of:

• Robert C. Martin — Clean Architecture
• Jimmy Bogard — Vertical Slice Architecture
• Microsoft .NET Architecture Guides

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📄 License

MIT License © 2025 — Doqon Team