Finish up all functionality

packages/firebase_vertexai/firebase_vertexai/example/lib/pages/imagen_page.dart

@@ -41,11 +41,15 @@ class _ImagenPageState extends State<ImagenPage> {
   @override
   void initState() {
     super.initState();
+    var generationConfig = ImagenGenerationConfig(
+      negativePrompt: 'frog',
+      numberOfImages: 1,
+      aspectRatio: ImagenAspectRatio.square1x1,
+      imageFormat: ImagenFormat.jpeg(compressionQuality: 75),
+    );
     _imagenModel = FirebaseVertexAI.instance.imageModel(
       modelName: 'imagen-3.0-generate-001',
-      generationConfig: ImagenGenerationConfig(
-        imageFormat: ImagenFormat.jpeg(compressionQuality: 75),
-      ),
+      generationConfig: generationConfig,
       safetySettings: ImagenSafetySettings(
         ImagenSafetyFilterLevel.blockLowAndAbove,
         ImagenPersonFilterLevel.allowAdult,
@@ -133,15 +137,7 @@ class _ImagenPageState extends State<ImagenPage> {
       _loading = true;
     });
 
-    var generationConfig = ImagenGenerationConfig(
-        negativePrompt: 'frog',
-        numberOfImages: 1,
-        aspectRatio: ImagenAspectRatio.square1x1);
-
-    var response = await _imagenModel.generateImages(
-      prompt,
-      generationConfig: generationConfig,
-    );
+    var response = await _imagenModel.generateImages(prompt);
 
     if (response.images.isNotEmpty) {
       var imagenImage = response.images[0];

packages/firebase_vertexai/firebase_vertexai/lib/src/base_model.dart

@@ -42,17 +42,14 @@ abstract class BaseModel {
     required FirebaseApp app,
     required ApiClient client,
   })  : _model = normalizeModelName(model),
-        _app = app,
-        _location = location,
         _projectUri = _vertexUri(app, location),
         _client = client;
 
   static const _baseUrl = 'firebasevertexai.googleapis.com';
   static const _apiVersion = 'v1beta';
 
   final ({String prefix, String name}) _model;
-  final FirebaseApp _app;
-  final String _location;
+
   final Uri _projectUri;
   final ApiClient _client;
 

packages/firebase_vertexai/firebase_vertexai/lib/src/firebase_vertexai.dart

@@ -114,6 +114,10 @@ class FirebaseVertexAI extends FirebasePluginPlatform {
     );
   }
 
+  /// Create a [ImagenModel].
+  ///
+  /// The optional [safetySettings] can be used to control and guide the
+  /// generation. See [ImagenSafetySettings] for details.
   ImagenModel imageModel(
       {required String modelName,
       ImagenGenerationConfig? generationConfig,

packages/firebase_vertexai/firebase_vertexai/lib/src/imagen_api.dart

@@ -12,18 +12,21 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-///
+/// Specifies the level of safety filtering for image generation.
+/// If not specified, default will be "block_medium_and_above".
 enum ImagenSafetyFilterLevel {
-  ///
+  /// Strongest filtering level, most strict blocking.
   blockLowAndAbove('block_low_and_above'),
 
-  ///
+  /// Block some problematic prompts and responses.
   blockMediumAndAbove('block_medium_and_above'),
 
-  ///
+  /// Reduces the number of requests blocked due to safety filters.
+  /// May increase objectionable content generated by Imagen.
   blockOnlyHigh('block_only_high'),
 
-  ///
+  /// Block very few problematic prompts and responses.
+  /// Access to this feature is restricted.
   blockNone('block_none');
 
   const ImagenSafetyFilterLevel(this._jsonString);
@@ -49,15 +52,16 @@ enum ImagenSafetyFilterLevel {
   String toString() => name;
 }
 
-///
+/// Allow generation of people by the model.
+/// If not specified, the default value is "allow_adult".
 enum ImagenPersonFilterLevel {
-  ///
+  /// Disallow the inclusion of people or faces in images.
   blockAll('dont_allow'),
 
-  ///
+  /// Allow generation of adults only.
   allowAdult('allow_adult'),
 
-  ///
+  /// Allow generation of people of all ages.
   allowAll('allow_all');
 
   const ImagenPersonFilterLevel(this._jsonString);
@@ -82,15 +86,17 @@ enum ImagenPersonFilterLevel {
   String toString() => name;
 }
 
+/// A class representing safety settings for image generation.
 ///
+/// It includes a safety filter level and a person filter level.
 final class ImagenSafetySettings {
   /// Constructor
   ImagenSafetySettings(this.safetyFilterLevel, this.personFilterLevel);
 
-  ///
+  /// The safety filter level
   final ImagenSafetyFilterLevel? safetyFilterLevel;
 
-  ///
+  /// The person filter level
   final ImagenPersonFilterLevel? personFilterLevel;
 
   /// Convert to json format.
@@ -102,21 +108,21 @@ final class ImagenSafetySettings {
       };
 }
 
-///
+/// The aspect ratio for the image. The default value is "1:1".
 enum ImagenAspectRatio {
-  ///
+  /// Square (1:1).
   square1x1('1:1'),
 
-  ///
+  /// Portrait (9:16).
   portrait9x16('9:16'),
 
-  ///
+  /// Landscape (16:9).
   landscape16x9('16:9'),
 
-  ///
+  /// Portrait (3:4).
   portrait3x4('3:4'),
 
-  ///
+  /// Landscape (4:3).
   landscape4x3('4:3');
 
   const ImagenAspectRatio(this._jsonString);
@@ -143,17 +149,31 @@ enum ImagenAspectRatio {
   String toString() => name;
 }
 
+/// Configuration options for image generation.
 final class ImagenGenerationConfig {
+  /// Constructor
   ImagenGenerationConfig(
-      {this.negativePrompt,
-      this.numberOfImages,
+      {this.numberOfImages,
+      this.negativePrompt,
       this.aspectRatio,
       this.imageFormat,
       this.addWatermark});
-  final String? negativePrompt;
+
+  /// The number of images to generate. Default is 1.
   final int? numberOfImages;
+
+  /// A description of what to discourage in the generated images.
+  final String? negativePrompt;
+
+  /// The aspect ratio for the image. The default value is "1:1".
   final ImagenAspectRatio? aspectRatio;
+
+  /// The image format of the generated images.
   final ImagenFormat? imageFormat;
+
+  /// Add an invisible watermark to the generated images.
+  /// Default value for each imagen model can be found in
+  /// https://cloud.google.com/vertex-ai/generative-ai/docs/model-reference/imagen-api#generate_images
   final bool? addWatermark;
 
   /// Convert to json format.
@@ -166,15 +186,26 @@ final class ImagenGenerationConfig {
       };
 }
 
+/// Represents the image format and compression quality.
 final class ImagenFormat {
+  /// Constructor
   ImagenFormat(this.mimeType, this.compressionQuality);
 
-  ImagenFormat.png() : this("image/png", null);
+  /// Constructor for png
+  ImagenFormat.png() : this('image/png', null);
+
+  /// Constructor for jpeg
   ImagenFormat.jpeg({int? compressionQuality})
-      : this("image/jpeg", compressionQuality);
+      : this('image/jpeg', compressionQuality);
+
+  /// The MIME type of the image format. The default value is "image/png".
   final String mimeType;
+
+  /// The level of compression if the output type is "image/jpeg".
+  /// Accepted values are 0 through 100. The default value is 75.
   final int? compressionQuality;
 
+  /// Convert to json format.
   Map<String, dynamic> toJson() => {
         'mimeType': mimeType,
         if (compressionQuality != null)

packages/firebase_vertexai/firebase_vertexai/lib/src/imagen_content.dart

@@ -15,62 +15,69 @@ import 'dart:convert';
 import 'dart:typed_data';
 import 'error.dart';
 
-///
+/// Base type of Imagen Image.
 sealed class ImagenImage {
+  /// Constructor
+  ImagenImage({required this.mimeType});
+
+  /// The MIME type of the image format.
   final String mimeType;
 
   /// Convert the [ImagenImage] content to json format.
   Object toJson();
-
-  ImagenImage({required this.mimeType});
 }
 
+/// Represents an image stored as a base64-encoded string.
 final class ImagenInlineImage implements ImagenImage {
-  /// Data contents in bytes.
-  final Uint8List bytesBase64Encoded;
-
-  @override
-  final String mimeType;
-
+  /// Constructor
   ImagenInlineImage({
     required this.bytesBase64Encoded,
     required this.mimeType,
   });
 
+  /// The data contents in bytes, encoded as base64.
+  final Uint8List bytesBase64Encoded;
+
+  @override
+  final String mimeType;
+
   @override
   Object toJson() => {
         'mimeType': mimeType,
         'bytesBase64Encoded': bytesBase64Encoded,
       };
 }
 
+/// Represents an image stored in Google Cloud Storage.
 final class ImagenGCSImage implements ImagenImage {
-  @override
-  final String mimeType;
-
-  final String gcsUri;
-
+  /// Constructor
   ImagenGCSImage({
     required this.gcsUri,
     required this.mimeType,
   });
 
+  /// The storage URI of the image.
+  final String gcsUri;
+
+  @override
+  final String mimeType;
+
   @override
   Object toJson() => {
         'mimeType': mimeType,
         'gcsUri': gcsUri,
       };
 }
 
+/// Represents the response from an image generation request.
 final class ImagenGenerationResponse<T extends ImagenImage> {
+  /// Constructor
   ImagenGenerationResponse({
     required this.images,
     this.filteredReason,
   });
 
-  final List<T> images;
-  final String? filteredReason;
-
+  /// Factory method to create an ImagenGenerationResponse from a JSON object.
   factory ImagenGenerationResponse.fromJson(Map<String, dynamic> json) {
     final filteredReason = json['filteredReason'] as String?;
     final imagesJson = json['predictions'] as List<dynamic>;
@@ -102,6 +109,12 @@ final class ImagenGenerationResponse<T extends ImagenImage> {
       throw ArgumentError('Unsupported ImagenImage type: $T');
     }
   }
+
+  /// A list of generated images. The type of the images depends on the T parameter.
+  final List<T> images;
+
+  /// If the generation was filtered due to safety reasons, a message explaining the reason.
+  final String? filteredReason;
 }
 
 /// Parse the json to [ImagenGenerationResponse]