# Code Structure

## Build System
- **Type**: .NET SDK (MSBuild / dotnet CLI)
- **Configuration**: `SlpModularCms.sln` — solution file referencing all projects
- **Target Framework**: `net10.0`

## Project Structure

```mermaid
graph TD
    Root["SlpModularCms/"]
    Src["src/"]
    Api["SlpModularCms.Api\n(API host)"]
    ApiExt["Extensions/\nServiceCollectionExtensions.cs"]
    ApiInfra["Infrastructure/\nGlobal exception handler"]
    ApiProg["Program.cs\nApp startup + module loading"]

    Core["SlpModularCms.Core\n(Shared core)"]
    CoreAvail["Availability/\nAvailabilityOptions.cs\nAvailabilityStatus.cs"]
    CoreData["Data/\nApplicationDbContext.cs"]
    CoreIdentity["Identity/\nEntities, Models, Services\nAuthorization/"]
    CoreMigrations["Migrations/\nEF Core migrations"]
    CoreModules["Modules/\nIModule.cs, ModuleInfo.cs"]

    ModIdentity["SlpModularCms.Modules.Identity\n(Identity module)"]
    ModIdentityCtrl["Controllers/\nAuthController\nSetupController\nUsersController"]

    ModAvail["SlpModularCms.Modules.Availability\n(Availability module)"]
    ModAvailCtrl["Controllers/\nAvailabilityController"]
    ModAvailSvc["Services/\nPersistentAvailabilityService"]

    Tests1["SlpModularCms.Core.Tests"]
    Tests2["SlpModularCms.Modules.Availability.Tests"]
    Docs["aidlc-docs/\nAI-DLC workflow documentation"]

    Root --> Src
    Root --> Docs
    Src --> Api
    Src --> Core
    Src --> ModIdentity
    Src --> ModAvail
    Src --> Tests1
    Src --> Tests2
    Api --> ApiExt
    Api --> ApiInfra
    Api --> ApiProg
    Core --> CoreAvail
    Core --> CoreData
    Core --> CoreIdentity
    Core --> CoreMigrations
    Core --> CoreModules
    ModIdentity --> ModIdentityCtrl
    ModAvail --> ModAvailCtrl
    ModAvail --> ModAvailSvc

    style Api fill:#4CAF50,stroke:#2E7D32,color:#fff
    style ApiExt fill:#4CAF50,stroke:#2E7D32,color:#fff
    style ApiInfra fill:#4CAF50,stroke:#2E7D32,color:#fff
    style ApiProg fill:#4CAF50,stroke:#2E7D32,color:#fff
    style Core fill:#FFC107,stroke:#F57F17,color:#000
    style CoreAvail fill:#FFC107,stroke:#F57F17,color:#000
    style CoreData fill:#FFC107,stroke:#F57F17,color:#000
    style CoreIdentity fill:#FFC107,stroke:#F57F17,color:#000
    style CoreMigrations fill:#FFC107,stroke:#F57F17,color:#000
    style CoreModules fill:#FFC107,stroke:#F57F17,color:#000
    style ModIdentity fill:#4CAF50,stroke:#2E7D32,color:#fff
    style ModIdentityCtrl fill:#4CAF50,stroke:#2E7D32,color:#fff
    style ModAvail fill:#4CAF50,stroke:#2E7D32,color:#fff
    style ModAvailCtrl fill:#4CAF50,stroke:#2E7D32,color:#fff
    style ModAvailSvc fill:#4CAF50,stroke:#2E7D32,color:#fff
    style Tests1 fill:#9E9E9E,stroke:#424242,color:#fff
    style Tests2 fill:#9E9E9E,stroke:#424242,color:#fff
    style Docs fill:#CE93D8,stroke:#6A1B9A,color:#000
```

## Key Classes/Modules

### Core Domain Entities
- `ApplicationUser` — extends `IdentityUser<Guid>` with `IsActive`, `CreatedAt`, `Naam`
- `ApplicationRole` — extends `IdentityRole<Guid>`
- `RefreshToken` — linked to user; has `Token`, `ExpiryDate`, `IsRevoked`, `IsActive`
- `Invitation` — linked to user (invitee); has `Token`, `ExpiryDate`, `IsUsed`, `Role`
- `GlobalAvailabilityState` — singleton-ish entity storing `Status`, `Message`, `LastUpdatedAt`, `UpdatedBy`

### Core Services
- `IAuthService` / `AuthService` — `AuthenticateAsync`, `RefreshTokenAsync`, `RevokeTokenAsync`
- `IInvitationService` / `InvitationService` — `CreateInvitationAsync`, `CompleteInvitationAsync`, `ValidateInvitationAsync`
- `ISetupService` / `SetupService` — `IsSystemInitializedAsync`, `CreateInitialOwnerAsync`
- `IAvailabilityService` / `PersistentAvailabilityService` — `IsAvailableAsync`, `UpdateStatusAsync`

### Module System
- `IModule` — interface: `RegisterServices(IServiceCollection)`, `UseModule(IApplicationBuilder)`
- Modules discovered at startup and invoked in sequence

## Design Patterns
### Module Pattern
- **Location**: `SlpModularCms.Core/Modules/`, `SlpModularCms.Api/Program.cs`
- **Purpose**: Allows features to be developed, tested, and deployed independently
- **Implementation**: Each module class implements `IModule` and is registered in the API host

### Repository Pattern via EF Core
- **Location**: `ApplicationDbContext` used directly in services
- **Purpose**: Centralized persistence with Entity Framework

### JWT with Refresh Token Rotation
- **Location**: `AuthService.cs`, `AuthController.cs`
- **Purpose**: Stateless auth with token refresh capability

## Critical Dependencies
### ASP.NET Core Identity
- **Version**: .NET 10 built-in
- **Usage**: User/Role management, password hashing
- **Purpose**: Provides authentication primitives

### Entity Framework Core
- **Version**: .NET 10 built-in
- **Usage**: Data persistence with SQL Server provider
- **Purpose**: ORM for all domain entities