feat: add ImageConfig and new FinishReason values

firebaseai/src/Candidate.cs

@@ -63,6 +63,26 @@ public enum FinishReason {
   /// Token generation was stopped because the function call generated by the model was invalid.
   /// </summary>
   MalformedFunctionCall,
+  /// <summary>
+  /// Image generation stopped because of safety reasons.
+  /// </summary>
+  ImageSafety,
+  /// <summary>
+  /// Image generation stopped because generated images has other prohibited content.
+  /// </summary>
+  ImageProhibitedContent,
+  /// <summary>
+  /// Image generation stopped due to recitation.
+  /// </summary>
+  ImageRecitation,
+  /// <summary>
+  /// Image generation stopped because of other miscellaneous issue.
+  /// </summary>
+  ImageOther,
+  /// <summary>
+  /// The model was expected to generate an image, but none was generated.
+  /// </summary>
+  NoImage,
 }
 
 /// <summary>
@@ -130,6 +150,11 @@ private static FinishReason ParseFinishReason(string str) {
       "PROHIBITED_CONTENT" => Firebase.AI.FinishReason.ProhibitedContent,
       "SPII" => Firebase.AI.FinishReason.SPII,
       "MALFORMED_FUNCTION_CALL" => Firebase.AI.FinishReason.MalformedFunctionCall,
+      "IMAGE_SAFETY" => Firebase.AI.FinishReason.ImageSafety,
+      "IMAGE_PROHIBITED_CONTENT" => Firebase.AI.FinishReason.ImageProhibitedContent,
+      "IMAGE_RECITATION" => Firebase.AI.FinishReason.ImageRecitation,
+      "IMAGE_OTHER" => Firebase.AI.FinishReason.ImageOther,
+      "NO_IMAGE" => Firebase.AI.FinishReason.NoImage,
       _ => Firebase.AI.FinishReason.Unknown,
     };
   }

firebaseai/src/GenerationConfig.cs

@@ -38,6 +38,7 @@ public readonly struct GenerationConfig {
     private readonly Schema _responseSchema;
     private readonly List<ResponseModality> _responseModalities;
     private readonly ThinkingConfig? _thinkingConfig;
+    private readonly ImageConfig? _imageConfig;
 
     /// <summary>
     /// Creates a new `GenerationConfig` value.
@@ -168,7 +169,8 @@ public GenerationConfig(
         string responseMimeType = null,
         Schema responseSchema = null,
         IEnumerable<ResponseModality> responseModalities = null,
-        ThinkingConfig? thinkingConfig = null) {
+        ThinkingConfig? thinkingConfig = null,
+        ImageConfig? imageConfig = null) {
       _temperature = temperature;
       _topP = topP;
       _topK = topK;
@@ -182,6 +184,7 @@ public GenerationConfig(
       _responseModalities = responseModalities != null ?
           new List<ResponseModality>(responseModalities) : null;
       _thinkingConfig = thinkingConfig;
+      _imageConfig = imageConfig;
     }
 
     /// <summary>
@@ -205,6 +208,7 @@ internal Dictionary<string, object> ToJson() {
             _responseModalities.Select(EnumConverters.ResponseModalityToString).ToList();
       }
       if (_thinkingConfig != null) jsonDict["thinkingConfig"] = _thinkingConfig?.ToJson();
+      if (_imageConfig != null) jsonDict["imageConfig"] = _imageConfig?.ToJson();
 
       return jsonDict;
     }

firebaseai/src/ImageConfig.cs

@@ -0,0 +1,107 @@
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may not obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Firebase.AI {
+
+/// <summary>
+/// An aspect ratio for images.
+/// </summary>
+public enum AspectRatio {
+  /// <summary>
+  /// Square (1:1) aspect ratio.
+  /// </summary>
+  SQUARE_1_1,
+  /// <summary>
+  /// Portrait (2:3) aspect ratio.
+  /// </summary>
+  PORTRAIT_2_3,
+  /// <summary>
+  /// Landscape (3:2) aspect ratio.
+  /// </summary>
+  LANDSCAPE_3_2,
+  /// <summary>
+  /// Portrait (3:4) aspect ratio.
+  /// </summary>
+  PORTRAIT_3_4,
+  /// <summary>
+  /// Landscape (4:3) aspect ratio.
+  /// </summary>
+  LANDSCAPE_4_3,
+  /// <summary>
+  /// Portrait (4:5) aspect ratio.
+  /// </summary>
+  PORTRAIT_4_5,
+  /// <summary>
+  /// Landscape (5:4) aspect ratio.
+  /// </summary>
+  LANDSCAPE_5_4,
+  /// <summary>
+  /// Portrait (9:16) aspect ratio.
+  /// </summary>
+  PORTRAIT_9_16,
+  /// <summary>
+  /// Landscape (16:9) aspect ratio.
+  /// </summary>
+  LANDSCAPE_16_9,
+  /// <summary>
+  /// Landscape (21:9) aspect ratio.
+  /// </summary>
+  LANDSCAPE_21_9,
+}
+
+/// <summary>
+/// Configuration options for generating images.
+/// </summary>
+public readonly struct ImageConfig {
+  /// <summary>
+  /// The aspect ratio of generated images.
+  /// </summary>
+  public AspectRatio? AspectRatio { get; }
+
+  /// <summary>
+  /// Initializes configuration options for generating images.
+  /// </summary>
+  /// <param name="aspectRatio">The aspect ratio of generated images.</param>
+  public ImageConfig(AspectRatio? aspectRatio = null) {
+    AspectRatio = aspectRatio;
+  }
+
+  private static string ConvertAspectRatio(AspectRatio aspectRatio) {
+    return aspectRatio switch {
+      AspectRatio.SQUARE_1_1 => "1:1",
+      AspectRatio.PORTRAIT_2_3 => "2:3",
+      AspectRatio.LANDSCAPE_3_2 => "3:2",
+      AspectRatio.PORTRAIT_3_4 => "3:4",
+      AspectRatio.LANDSCAPE_4_3 => "4:3",
+      AspectRatio.PORTRAIT_4_5 => "4:5",
+      AspectRatio.LANDSCAPE_5_4 => "5:4",
+      AspectRatio.PORTRAIT_9_16 => "9:16",
+      AspectRatio.LANDSCAPE_16_9 => "16:9",
+      AspectRatio.LANDSCAPE_21_9 => "21:9",
+      _ => aspectRatio.ToString(), // Fallback
+    };
+  }
+
+  internal Dictionary<string, object> ToJson() {
+    var jsonDict = new System.Collections.Generic.Dictionary<string, object>();
+    if (AspectRatio.HasValue) {
+      jsonDict["aspectRatio"] = ConvertAspectRatio(AspectRatio.Value);
+    }
+    return jsonDict;
+  }
+}
+
+}