Add watermarking features and embedded font support

- Updated project file to include DejaVuSerif font as an embedded resource.
- Enhanced InputParameter class with properties for watermark positioning and customization.
- Modified CropOperationHandler to validate new properties for cropping.
- Improved WatermarkOperationHandler to validate watermark parameters and support embedded fonts.
- Updated unit tests to utilize new InputParameter properties for cropping and watermarking functionality.

#3

Author: ziagham

src/FlowSynx.Plugins.Media.ImageProcessing.csproj

@@ -11,6 +11,16 @@
 		<DebugType>None</DebugType>
 	</PropertyGroup>
 
+	<ItemGroup>
+	  <None Remove="Fonts\DejaVuSerif.ttf" />
+	</ItemGroup>
+
+	<ItemGroup>
+	  <EmbeddedResource Include="Fonts\DejaVuSerif.ttf">
+	    <CopyToOutputDirectory>Never</CopyToOutputDirectory>
+	  </EmbeddedResource>
+	</ItemGroup>
+
 	<ItemGroup>
 		<PackageReference Include="FlowSynx.PluginCore" Version="1.3.4" />
 		<PackageReference Include="SixLabors.ImageSharp" Version="3.1.11" />

src/Fonts/DejaVuSerif.ttf

@@ -11,6 +11,10 @@ internal class InputParameter
     public int Width { get; set; }
     public int Height { get; set; }
 
+    // Crop / Watermark
+    public int Top { get; set; } = 10;
+    public int Left { get; set; } = 10;
+
     // Rotate
     public float Angle { get; set; }
 
@@ -25,6 +29,9 @@ internal class InputParameter
 
     // Watermark
     public string WatermarkText { get; set; } = string.Empty;
+    public string WatermarkFontName { get; set; } = string.Empty;
+    public int WatermarkFontSize { get; set; } = 24;
+    public string WatermarkColor { get; set; } = "#FFFFFF";
 
     public string FromColor { get; set; } = string.Empty;
     public string ToColor { get; set; } = string.Empty;

src/Models/InputParameter.cs

@@ -11,6 +11,12 @@ public void Handle(Image image, InputParameter parameter)
         if (parameter.Width == 0 || parameter.Height == 0)
             throw new ArgumentException("Crop requires positive Width and Height.");
 
-        image.Mutate(x => x.Crop(new Rectangle(0, 0, parameter.Width, parameter.Height)));
+        if (parameter.Top < 0)
+            throw new ArgumentException("Crop location top must be zero or a positive value.");
+
+        if (parameter.Left < 0)
+            throw new ArgumentException("Crop location left must be zero or a positive value.");
+
+        image.Mutate(x => x.Crop(new Rectangle(parameter.Left, parameter.Top, parameter.Width, parameter.Height)));
     }
 }

src/Services/CropOperationHandler.cs

@@ -1,8 +1,10 @@
-using FlowSynx.Plugins.Media.ImageProcessing.Models;
+using FlowSynx.Plugins.Media.ImageProcessing.Helpers;
+using FlowSynx.Plugins.Media.ImageProcessing.Models;
+using SixLabors.Fonts;
 using SixLabors.ImageSharp;
-using SixLabors.ImageSharp.Processing;
 using SixLabors.ImageSharp.Drawing.Processing;
-using SixLabors.Fonts;
+using SixLabors.ImageSharp.Processing;
+using System.Reflection;
 
 namespace FlowSynx.Plugins.Media.ImageProcessing.Services;
 
@@ -11,11 +13,42 @@ internal class WatermarkOperationHandler : IImageOperationHandler
     public void Handle(Image image, InputParameter parameter)
     {
         if (string.IsNullOrWhiteSpace(parameter.WatermarkText))
-            throw new ArgumentException("WatermarkText is required.");
+            throw new ArgumentException("WatermarkText must not be empty.");
+
+        if (parameter.WatermarkFontSize <= 0)
+            throw new ArgumentException("Watermark font size must be greater than zero.");
+
+        if (parameter.Top < 0)
+            throw new ArgumentException("Watermark location top must be zero or a positive value.");
+
+        if (parameter.Left < 0)
+            throw new ArgumentException("Watermark location left must be zero or a positive value.");
+
+
+        Font font;
+        if (string.IsNullOrWhiteSpace(parameter.WatermarkFontName))
+        {
+            // Use embedded font as default
+            font = LoadEmbeddedFont("FlowSynx.Plugins.Media.ImageProcessing.Fonts.DejaVuSerif.ttf", parameter.WatermarkFontSize);
+        }
+        else
+        {
+            font = SystemFonts.CreateFont(parameter.WatermarkFontName, parameter.WatermarkFontSize);
+        }
 
         image.Mutate(x => x.DrawText(parameter.WatermarkText,
-                                     SystemFonts.CreateFont("Arial", 24),
-                                     Color.White,
-                                     new PointF(10, 10)));
+                                     font,
+                                     ColorHelper.ParseToRgba32(parameter.WatermarkColor),
+                                     new PointF(parameter.Left, parameter.Top)));
+    }
+
+    private static Font LoadEmbeddedFont(string resourceName, float fontSize)
+    {
+        var assembly = Assembly.GetExecutingAssembly();
+        using Stream fontStream = assembly.GetManifestResourceStream(resourceName)
+            ?? throw new InvalidOperationException($"Font resource '{resourceName}' not found.");
+        var fontCollection = new FontCollection();
+        var fontFamily = fontCollection.Add(fontStream);
+        return fontFamily.CreateFont(fontSize);
     }
 }

src/Services/WatermarkOperationHandler.cs

@@ -11,7 +11,7 @@ public void Handle_CropsImage_WhenWidthAndHeightProvided()
         {
             var handler = new CropOperationHandler();
             using var image = new Image<SixLabors.ImageSharp.PixelFormats.Rgba32>(10, 10);
-            var param = new InputParameter { Width = 5, Height = 5 };
+            var param = new InputParameter { Width = 5, Height = 5, Left = 1, Top = 1 };
             handler.Handle(image, param);
             Assert.Equal(5, image.Width);
             Assert.Equal(5, image.Height);

tests/CropOperationHandlerTests.cs

@@ -11,7 +11,7 @@ public void Handle_AddsWatermark_WhenTextProvided()
         {
             var handler = new WatermarkOperationHandler();
             using var image = new Image<SixLabors.ImageSharp.PixelFormats.Rgba32>(10, 10);
-            var param = new InputParameter { WatermarkText = "Test" };
+            var param = new InputParameter { WatermarkText = "Test",  };
             handler.Handle(image, param);
             // No exception means success
         }