[Vertex AI] Make ImageGenerationResponse generic and add image types

FirebaseVertexAI/Sources/Types/Internal/Imagen/ImageGenerationResponse.swift

@@ -15,15 +15,15 @@
 import Foundation
 
 @available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
-struct ImageGenerationResponse {
-  let images: [InternalImagenImage]
-  let raiFilteredReason: String?
+public struct ImageGenerationResponse<ImageType: ImagenImageRepresentable> {
+  public let images: [ImageType]
+  public let raiFilteredReason: String?
 }
 
 // MARK: - Codable Conformances
 
 @available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
-extension ImageGenerationResponse: Decodable {
+extension ImageGenerationResponse: Decodable where ImageType: Decodable {
   enum CodingKeys: CodingKey {
     case predictions
   }
@@ -38,15 +38,15 @@ extension ImageGenerationResponse: Decodable {
     }
     var predictionsContainer = try container.nestedUnkeyedContainer(forKey: .predictions)
 
-    var images = [InternalImagenImage]()
+    var images = [ImageType]()
     var raiFilteredReasons = [String]()
     while !predictionsContainer.isAtEnd {
-      if let image = try? predictionsContainer.decode(InternalImagenImage.self) {
+      if let image = try? predictionsContainer.decode(ImageType.self) {
         images.append(image)
       } else if let filterReason = try? predictionsContainer.decode(RAIFilteredReason.self) {
         raiFilteredReasons.append(filterReason.raiFilteredReason)
       } else if let _ = try? predictionsContainer.decode(JSONObject.self) {
-        // TODO: Log or throw unsupported prediction type
+        // TODO(#14221): Log or throw unsupported prediction type
       } else {
         // This should never be thrown since JSONObject accepts any valid JSON.
         throw DecodingError.dataCorruptedError(
@@ -58,6 +58,6 @@ extension ImageGenerationResponse: Decodable {
 
     self.images = images
     raiFilteredReason = raiFilteredReasons.first
-    // TODO: Log if more than one RAI Filtered Reason; unexpected behaviour.
+    // TODO(#14221): Log if more than one RAI Filtered Reason; unexpected behaviour.
   }
 }

FirebaseVertexAI/Sources/Types/Internal/Imagen/InternalImagenImage.swift

@@ -26,7 +26,4 @@ struct InternalImagenImage {
 }
 
 @available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
-extension InternalImagenImage: DecodableImagenImage {}
-
-@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
-extension InternalImagenImage: Equatable {}
+extension InternalImagenImage: ImagenImage {}

FirebaseVertexAI/Sources/Types/Public/Imagen/ImagenFileDataImage.swift

@@ -0,0 +1,53 @@
+// Copyright 2024 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 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.
+
+import Foundation
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+public struct ImagenFileDataImage {
+  public let mimeType: String
+  public let gcsURI: String
+
+  init(mimeType: String, gcsURI: String) {
+    self.mimeType = mimeType
+    self.gcsURI = gcsURI
+  }
+}
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+extension ImagenFileDataImage: ImagenImageRepresentable {
+  public var imagenImage: any ImagenImage {
+    InternalImagenImage(mimeType: mimeType, bytesBase64Encoded: nil, gcsURI: gcsURI)
+  }
+}
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+extension ImagenFileDataImage: Equatable {}
+
+// MARK: - Codable Conformances
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+extension ImagenFileDataImage: Decodable {
+  enum CodingKeys: String, CodingKey {
+    case mimeType
+    case gcsURI = "gcsUri"
+  }
+
+  public init(from decoder: any Decoder) throws {
+    let container = try decoder.container(keyedBy: CodingKeys.self)
+    let mimeType = try container.decode(String.self, forKey: .mimeType)
+    let gcsURI = try container.decode(String.self, forKey: .gcsURI)
+    self.init(mimeType: mimeType, gcsURI: gcsURI)
+  }
+}

FirebaseVertexAI/Sources/Types/Public/Imagen/ImagenInlineDataImage.swift

@@ -0,0 +1,61 @@
+// Copyright 2024 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 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.
+
+import Foundation
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+public struct ImagenInlineDataImage {
+  public let mimeType: String
+  public let data: Data
+
+  init(mimeType: String, bytesBase64Encoded: String) {
+    self.mimeType = mimeType
+    guard let data = Data(base64Encoded: bytesBase64Encoded) else {
+      // TODO(#14221): Add error handling for invalid base64 bytes.
+      fatalError("Creating a `Data` from `bytesBase64Encoded` failed.")
+    }
+    self.data = data
+  }
+}
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+extension ImagenInlineDataImage: ImagenImageRepresentable {
+  public var imagenImage: any ImagenImage {
+    InternalImagenImage(
+      mimeType: mimeType,
+      bytesBase64Encoded: data.base64EncodedString(),
+      gcsURI: nil
+    )
+  }
+}
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+extension ImagenInlineDataImage: Equatable {}
+
+// MARK: - Codable Conformances
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+extension ImagenInlineDataImage: Decodable {
+  enum CodingKeys: CodingKey {
+    case mimeType
+    case bytesBase64Encoded
+  }
+
+  public init(from decoder: any Decoder) throws {
+    let container = try decoder.container(keyedBy: CodingKeys.self)
+    let mimeType = try container.decode(String.self, forKey: .mimeType)
+    let bytesBase64Encoded = try container.decode(String.self, forKey: .bytesBase64Encoded)
+    self.init(mimeType: mimeType, bytesBase64Encoded: bytesBase64Encoded)
+  }
+}