Complete Phase 2: Domain Layer implementation

Updated ROADMAP.md to mark Phase 2 as completed and added detailed descriptions of completed tasks. Introduced three new value objects (`Base64String`, `TenantId`, and `PdfMetadata`) in the `DocumentOperator.Domain.Models.ValueObjects` namespace. These classes ensure type safety, immutability, and encapsulated validation.

- `Base64String`: Handles Base64 string creation, validation, and conversion.
- `TenantId`: Represents a tenant identifier with validation and normalization.
- `PdfMetadata`: Represents PDF metadata with computed properties.

Updated `DocumentOperator.Domain.csproj` to reflect the addition of these value objects. The project is now ready to begin Phase 3 (Infrastructure Layer).

DocumentOperator.API/ROADMAP.md

@@ -726,10 +726,12 @@ DocumentOperator.Tests/
 
 ---
 
-### ?? PHASE 2: Domain Layer (Minimal) - **IN PROGRESS**
+### ? PHASE 2: Domain Layer (Minimal) - **COMPLETED**
 
 **Ziel:** Nur was wirklich gebraucht wird!
 
+**Status:** ? **Alle Steps abgeschlossen!**
+
 ---
 
 #### ? Step 2.1: Domain Exceptions erstellen - **COMPLETED**
@@ -802,7 +804,7 @@ DocumentOperator.Tests/
 
 ---
 
-#### ?? Step 2.3: Value Objects erstellen - **NEXT**
+#### ? Step 2.3: Value Objects erstellen - **COMPLETED**
 
 **Aufgabe:** Typsichere, selbst-validierende Wert-Objekte
 
@@ -812,38 +814,44 @@ DocumentOperator.Tests/
 - ? Immutable (keine Änderungen nach Erstellung)
 - ? Wiederverwendbar (in Domain, Application, Infrastructure)
 
-**Was du erstellen wirst:**
+**Was du erstellt hast:**
 
-1. **Base64String.cs**
+1. **Base64String.cs** ?
    - Factory Method: `Create(string value)`
    - Validierung: Gültiges Base64-Format
    - Konvertierung: `ToByteArray()`, `FromByteArray(byte[])`
    - Wirft `DomainValidationException` bei Fehler
 
-2. **TenantId.cs**
+2. **TenantId.cs** ?
    - Factory Method: `Create(string value)`
    - Validierung: Nicht leer, Max 100 Zeichen
    - Normalisierung: `.ToLowerInvariant()`
    - Wirft `DomainValidationException` bei Fehler
 
-3. **PdfMetadata.cs**
+3. **PdfMetadata.cs** ?
    - Properties: PageCount, FileSizeBytes, PdfVersion, HasAttachments, AttachmentCount
    - Computed Property: `FileSizeMB`
    - Keine Validierung (nur Daten-Container)
 
 **Wo:** `Domain/Models/ValueObjects/`
 
-**Detaillierte Anleitung kommt in Step 2.3!**
+**Status:** ? **COMPLETED** (17.01.2025)
+- ? Base64String.cs erstellt (sealed, Factory Methods, Validierung, Equality)
+- ? TenantId.cs erstellt (sealed, Normalisierung, Validierung, Equality)
+- ? PdfMetadata.cs erstellt (sealed, Computed Property, ToString())
+- ? Build erfolgreich
+
+**?? Phase 2 (Domain Layer) komplett abgeschlossen!**
 
 ---
 
-### ? PHASE 3: Infrastructure Layer (Outside-In!)
+### ? PHASE 3: Infrastructure Layer (Outside-In!) - **NEXT**
 
 **Ziel:** DevExpress Services implementieren (wir sehen **echten** Code!)
 
 ---
 
-#### ? Step 3.1: IPdfProcessor Interface erstellen
+#### ?? Step 3.1: IPdfProcessor Interface erstellen - **NEXT**
 
 **Aufgabe:** Abstraction für PDF-Operationen
 
@@ -1271,6 +1279,23 @@ public async Task POST_ValidatePdf_InvalidPdf_Returns400() { }
 ## ?? CURRENT STATUS
 
 ### ? Completed
+- **Phase 1:** Foundation & Clean Architecture Setup ?
+  - Dependencies ?
+  - Packages ?
+  - Folder Structure ?
+  - Configuration ?
+  - Serilog ?
+
+- **Phase 2:** Domain Layer (Minimal) ?
+  - ? Step 2.1 - Domain Exceptions (4 Exceptions erstellt)
+  - ? Step 2.2 - Enums (DocumentOperationType, ProcessingStatus)
+  - ? Step 2.3 - Value Objects (Base64String, TenantId, PdfMetadata)
+
+### ?? In Progress
+- **Phase 3:** Infrastructure Layer (Outside-In!)
+  - **NEXT:** Step 3.1 - IPdfProcessor Interface erstellen
+
+### ? Pending
 - **Phase 1:** Foundation & Clean Architecture Setup
   - Dependencies ?
   - Packages ?

DocumentOperator.Domain/DocumentOperator.Domain.csproj

@@ -9,7 +9,6 @@
   <ItemGroup>
     <Folder Include="Common\Results\" />
     <Folder Include="Constants\" />
-    <Folder Include="Models\ValueObjects\" />
   </ItemGroup>
 
 </Project>

DocumentOperator.Domain/Models/ValueObjects/Base64String.cs

@@ -0,0 +1,59 @@
+namespace DocumentOperator.Domain.Models.ValueObjects;
+
+public sealed class Base64String
+{
+    public string Value { get; }
+
+    private Base64String(string value)
+    {
+        Value = value;
+    }
+
+    public static Base64String Create(string value)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+            throw new Common.Exceptions.DomainValidationException("Base64 string cannot be empty.");
+
+        // Validierung: Ist es gültiges Base64?
+        try
+        {
+            Convert.FromBase64String(value);
+        }
+        catch (FormatException)
+        {
+            throw new Common.Exceptions.DomainValidationException("Invalid Base64 format.");
+        }
+
+        return new Base64String(value);
+    }
+
+    public static Base64String FromByteArray(byte[] bytes)
+    {
+        if (bytes == null || bytes.Length == 0)
+            throw new Common.Exceptions.DomainValidationException("Byte array cannot be null or empty.");
+
+        var base64 = Convert.ToBase64String(bytes);
+        return new Base64String(base64);
+    }
+
+    public byte[] ToByteArray()
+    {
+        return Convert.FromBase64String(Value);
+    }
+
+    public override string ToString() => Value;
+
+    // Equality (wichtig für Value Objects!)
+    public override bool Equals(object? obj)
+    {
+        if (obj is not Base64String other)
+            return false;
+
+        return Value == other.Value;
+    }
+
+    public override int GetHashCode()
+    {
+        return Value.GetHashCode();
+    }
+}

DocumentOperator.Domain/Models/ValueObjects/PdfMetadata.cs

@@ -0,0 +1,32 @@
+namespace DocumentOperator.Domain.Models.ValueObjects;
+
+public sealed class PdfMetadata
+{
+    public int PageCount { get; }
+    public long FileSizeBytes { get; }
+    public string PdfVersion { get; }
+    public bool HasAttachments { get; }
+    public int AttachmentCount { get; }
+
+    // Computed Property (berechnet aus FileSizeBytes)
+    public double FileSizeMB => FileSizeBytes / 1024.0 / 1024.0;
+
+    public PdfMetadata(
+        int pageCount,
+        long fileSizeBytes,
+        string pdfVersion,
+        bool hasAttachments,
+        int attachmentCount)
+    {
+        PageCount = pageCount;
+        FileSizeBytes = fileSizeBytes;
+        PdfVersion = pdfVersion;
+        HasAttachments = hasAttachments;
+        AttachmentCount = attachmentCount;
+    }
+
+    public override string ToString()
+    {
+        return $"PDF: {PageCount} pages, {FileSizeMB:F2} MB, Version {PdfVersion}, Attachments: {AttachmentCount}";
+    }
+}

DocumentOperator.Domain/Models/ValueObjects/TenantId.cs

@@ -0,0 +1,41 @@
+namespace DocumentOperator.Domain.Models.ValueObjects;
+
+public sealed class TenantId
+{
+    public string Value { get; }
+
+    private TenantId(string value)
+    {
+        Value = value;
+    }
+
+    public static TenantId Create(string value)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+            throw new Common.Exceptions.DomainValidationException("TenantId cannot be empty.");
+
+        if (value.Length > 100)
+            throw new Common.Exceptions.DomainValidationException("TenantId cannot exceed 100 characters.");
+
+        // Normalisierung: Lowercase
+        var normalized = value.Trim().ToLowerInvariant();
+
+        return new TenantId(normalized);
+    }
+
+    public override string ToString() => Value;
+
+    // Equality
+    public override bool Equals(object? obj)
+    {
+        if (obj is not TenantId other)
+            return false;
+
+        return Value == other.Value;
+    }
+
+    public override int GetHashCode()
+    {
+        return Value.GetHashCode();
+    }
+}