[Vertex AI] Add ImageGenerationResponse for decoding PredictResponse

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

@@ -0,0 +1,62 @@
+// 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.
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+protocol DecodableImagenImage: ImagenImage, Decodable {
+  init(mimeType: String, bytesBase64Encoded: String?, gcsURI: String?)
+}
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+enum ImagenImageCodingKeys: String, CodingKey {
+  case mimeType
+  case bytesBase64Encoded
+  case gcsURI = "gcsUri"
+}
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+extension DecodableImagenImage {
+  init(from decoder: any Decoder) throws {
+    let container = try decoder.container(keyedBy: ImagenImageCodingKeys.self)
+    let mimeType = try container.decode(String.self, forKey: .mimeType)
+    let bytesBase64Encoded = try container.decodeIfPresent(
+      String.self,
+      forKey: .bytesBase64Encoded
+    )
+    let gcsURI = try container.decodeIfPresent(String.self, forKey: .gcsURI)
+    guard bytesBase64Encoded != nil || gcsURI != nil else {
+      throw DecodingError.dataCorrupted(
+        DecodingError.Context(
+          codingPath: [ImagenImageCodingKeys.bytesBase64Encoded, ImagenImageCodingKeys.gcsURI],
+          debugDescription: """
+          Expected one of \(ImagenImageCodingKeys.bytesBase64Encoded.rawValue) or \
+          \(ImagenImageCodingKeys.gcsURI.rawValue); both are nil.
+          """
+        )
+      )
+    }
+    guard bytesBase64Encoded == nil || gcsURI == nil else {
+      throw DecodingError.dataCorrupted(
+        DecodingError.Context(
+          codingPath: [ImagenImageCodingKeys.bytesBase64Encoded, ImagenImageCodingKeys.gcsURI],
+          debugDescription: """
+          Expected one of \(ImagenImageCodingKeys.bytesBase64Encoded.rawValue) or \
+          \(ImagenImageCodingKeys.gcsURI.rawValue); both are specified.
+          """
+        )
+      )
+    }
+
+    self.init(mimeType: mimeType, bytesBase64Encoded: bytesBase64Encoded, gcsURI: gcsURI)
+  }
+}

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

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+// 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, *)
+struct ImageGenerationResponse {
+  let images: [InternalImagenImage]
+  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 {
+  enum CodingKeys: CodingKey {
+    case predictions
+  }
+
+  public init(from decoder: any Decoder) throws {
+    let container = try decoder.container(keyedBy: CodingKeys.self)
+    guard container.contains(.predictions) else {
+      images = []
+      raiFilteredReason = nil
+      // TODO: Log warning if no predictions.
+      return
+    }
+    var predictionsContainer = try container.nestedUnkeyedContainer(forKey: .predictions)
+
+    var images = [InternalImagenImage]()
+    var raiFilteredReasons = [String]()
+    while !predictionsContainer.isAtEnd {
+      if let image = try? predictionsContainer.decode(InternalImagenImage.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
+      } else {
+        // This should never be thrown since JSONObject accepts any valid JSON.
+        throw DecodingError.dataCorruptedError(
+          in: predictionsContainer,
+          debugDescription: "Failed to decode Prediction."
+        )
+      }
+    }
+
+    self.images = images
+    raiFilteredReason = raiFilteredReasons.first
+    // TODO: Log if more than one RAI Filtered Reason; unexpected behaviour.
+  }
+}

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

@@ -0,0 +1,32 @@
+// 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.
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+struct InternalImagenImage {
+  let mimeType: String
+  let bytesBase64Encoded: String?
+  let gcsURI: String?
+
+  init(mimeType: String, bytesBase64Encoded: String?, gcsURI: String?) {
+    self.mimeType = mimeType
+    self.bytesBase64Encoded = bytesBase64Encoded
+    self.gcsURI = gcsURI
+  }
+}
+
+@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 {}

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

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+// 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.
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+struct RAIFilteredReason {
+  let raiFilteredReason: String
+}
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+extension RAIFilteredReason: Decodable {
+  enum CodingKeys: CodingKey {
+    case raiFilteredReason
+  }
+}

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

@@ -0,0 +1,22 @@
+// 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 protocol ImagenImage: ImagenImageRepresentable {
+  var mimeType: String { get }
+  var bytesBase64Encoded: String? { get }
+  var gcsURI: String? { get }
+}

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

@@ -0,0 +1,27 @@
+// 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 protocol ImagenImageRepresentable {
+  var imagenImage: any ImagenImage { get }
+}
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+public extension ImagenImage {
+  var imagenImage: any ImagenImage {
+    return self
+  }
+}