🏗️ 1. Create Clean Architecture Project Structure

[hootanht]

🎯 Sprint 1 - Task 1: Create Clean Architecture Project Structure

Epic: #121
Sprint: 1 (2 weeks)
Estimated Effort: 5 days

📋 Description

Create the foundational project structure for Clean Architecture migration. This involves setting up separate class library projects for each layer and establishing proper dependency relationships.

🏗️ Architecture Overview

New Project Structure

Solution: Refhub.sln
├── src/
│   ├── Refhub.Domain/              # Class Library (.NET 9)
│   ├── Refhub.Application/         # Class Library (.NET 9)  
│   ├── Refhub.Infrastructure/      # Class Library (.NET 9)
│   └── Refhub.Web/                # Web App (.NET 9)
└── tests/
    ├── Refhub.Domain.Tests/        # xUnit Test Project
    ├── Refhub.Application.Tests/   # xUnit Test Project
    ├── Refhub.Infrastructure.Tests/# xUnit Test Project
    └── Refhub.Web.Tests/          # xUnit Test Project

Dependency Flow (Clean Architecture Rules)

Refhub.Web        → Refhub.Application → Refhub.Domain
       ↓                    ↓
Refhub.Infrastructure ──────┘

No project should reference projects to its right or below

✅ Acceptance Criteria

1. Project Structure Setup

• Create Refhub.Domain class library project
• Create Refhub.Application class library project
• Create Refhub.Infrastructure class library project
• Rename existing Refhub project to Refhub.Web
• Update solution file with proper project organization

2. Project References Configuration

• Refhub.Domain: No external dependencies (only .NET 9)
• Refhub.Application: References only Refhub.Domain
• Refhub.Infrastructure: References Refhub.Domain and Refhub.Application
• Refhub.Web: References Refhub.Application and Refhub.Infrastructure

3. Basic Folder Structure

Refhub.Domain/
├── Entities/
├── ValueObjects/
├── Interfaces/
├── Specifications/
├── Events/
└── Common/

Refhub.Application/
├── Commands/
├── Queries/
├── DTOs/
├── Interfaces/
├── Services/
├── Validators/
└── Common/

Refhub.Infrastructure/
├── Data/
│   ├── Context/
│   ├── Configurations/
│   └── Repositories/
├── Services/
├── Migrations/
└── Common/

Refhub.Web/
├── Controllers/
├── Areas/
├── Models/
├── wwwroot/
└── Configuration/

4. Package Dependencies

• Install core packages in each project
• Configure proper package versions
• Remove unnecessary dependencies

📦 Required NuGet Packages

Refhub.Domain

<PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="9.0.5" />

Refhub.Application

<PackageReference Include="MediatR" Version="12.4.1" />
<PackageReference Include="FluentValidation.DependencyInjectionExtensions" Version="11.8.0" />
<PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="9.0.5" />

Refhub.Infrastructure

<PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="9.0.5" />
<PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="9.0.5" />
<PackageReference Include="AWSSDK.S3" Version="4.0.4.2" />

Refhub.Web (Existing packages + new ones)

<PackageReference Include="MediatR" Version="12.4.1" />
<PackageReference Include="FluentValidation.AspNetCore" Version="11.3.0" />

🔧 Implementation Steps

Day 1-2: Project Creation and Structure

1. Create new class library projects

   # Navigate to solution root
   cd c:\Users\Hootan\source\repos\Refhub
   
   # Create new projects
   dotnet new classlib -n Refhub.Domain -o src/Refhub.Domain
   dotnet new classlib -n Refhub.Application -o src/Refhub.Application  
   dotnet new classlib -n Refhub.Infrastructure -o src/Refhub.Infrastructure
   
   # Create test projects
   dotnet new xunit -n Refhub.Domain.Tests -o tests/Refhub.Domain.Tests
   dotnet new xunit -n Refhub.Application.Tests -o tests/Refhub.Application.Tests
   dotnet new xunit -n Refhub.Infrastructure.Tests -o tests/Refhub.Infrastructure.Tests
   dotnet new xunit -n Refhub.Web.Tests -o tests/Refhub.Web.Tests

2. Update solution file

   # Add projects to solution
   dotnet sln add src/Refhub.Domain/Refhub.Domain.csproj
   dotnet sln add src/Refhub.Application/Refhub.Application.csproj
   dotnet sln add src/Refhub.Infrastructure/Refhub.Infrastructure.csproj
   dotnet sln add tests/Refhub.Domain.Tests/Refhub.Domain.Tests.csproj
   dotnet sln add tests/Refhub.Application.Tests/Refhub.Application.Tests.csproj
   dotnet sln add tests/Refhub.Infrastructure.Tests/Refhub.Infrastructure.Tests.csproj
   dotnet sln add tests/Refhub.Web.Tests/Refhub.Web.Tests.csproj

Day 3: Configure Project References

# Application references Domain
dotnet add src/Refhub.Application/Refhub.Application.csproj reference src/Refhub.Domain/Refhub.Domain.csproj

# Infrastructure references Domain and Application
dotnet add src/Refhub.Infrastructure/Refhub.Infrastructure.csproj reference src/Refhub.Domain/Refhub.Domain.csproj
dotnet add src/Refhub.Infrastructure/Refhub.Infrastructure.csproj reference src/Refhub.Application/Refhub.Application.csproj

# Web references Application and Infrastructure
dotnet add Refhub/Refhub.csproj reference src/Refhub.Application/Refhub.Application.csproj
dotnet add Refhub/Refhub.csproj reference src/Refhub.Infrastructure/Refhub.Infrastructure.csproj

Day 4-5: Package Installation and Folder Creation

1. Install required packages in each project
2. Create folder structures
3. Add placeholder classes with proper namespaces
4. Update existing project structure

📝 Example Files to Create

Refhub.Domain/Common/BaseEntity.cs

namespace Refhub.Domain.Common;

public abstract class BaseEntity
{
    public long Id { get; set; }
    public DateTime CreatedAt { get; set; }
    public DateTime? UpdatedAt { get; set; }
    public string? CreatedBy { get; set; }
    public string? UpdatedBy { get; set; }
}

Refhub.Application/Common/IRepository.cs

namespace Refhub.Application.Common;

public interface IRepository<T> where T : class
{
    Task<T?> GetByIdAsync(long id, CancellationToken cancellationToken = default);
    Task<IEnumerable<T>> GetAllAsync(CancellationToken cancellationToken = default);
    Task<T> AddAsync(T entity, CancellationToken cancellationToken = default);
    Task UpdateAsync(T entity, CancellationToken cancellationToken = default);
    Task DeleteAsync(T entity, CancellationToken cancellationToken = default);
}

🎯 Testing Criteria

• Solution builds successfully
• All project references work correctly
• No circular dependencies
• Test projects run (even with placeholder tests)
• Existing functionality still works

🔗 Related Tasks

• Follows: 🏗️ Clean Architecture Migration - Epic: Project Structure Reorganization #121 (Epic)
• Precedes: Domain Entities Migration (#TBD)
• Parallel: N/A

📚 Resources

• Clean Architecture by Robert C. Martin
• .NET Clean Architecture Template
• Microsoft Clean Architecture Guide

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Sprint: 1 | Assignee: @hootanht | Priority: High | Size: Large