Add code for error scenarios

Author: thisisabhash

HostApp/HostApp.xcodeproj/project.pbxproj

@@ -131,6 +131,7 @@
 				9070FFBD285112B5009867D5 /* HostAppUITests */,
 				9070FFA1285112B4009867D5 /* Products */,
 				90215EED291E9FB60050F2AD /* Frameworks */,
+				A5A9AF5054D0FF13505B212A /* AmplifyConfig */,
 			);
 			sourceTree = "<group>";
 		};
@@ -213,6 +214,15 @@
 			path = Model;
 			sourceTree = "<group>";
 		};
+		A5A9AF5054D0FF13505B212A /* AmplifyConfig */ = {
+			isa = PBXGroup;
+			children = (
+				973619242BA378690003A590 /* awsconfiguration.json */,
+				973619232BA378690003A590 /* amplifyconfiguration.json */,
+			);
+			name = AmplifyConfig;
+			sourceTree = "<group>";
+		};
 /* End PBXGroup section */
 
 /* Begin PBXNativeTarget section */

HostApp/HostApp/Views/ExampleLivenessView.swift

@@ -23,7 +23,7 @@ struct ExampleLivenessView: View {
             FaceLivenessDetectorView(
                 sessionID: viewModel.sessionID,
                 region: "us-east-1",
-                cameraPosition: .front,
+                cameraPosition: .back,
                 isPresented:  Binding(
                     get: { viewModel.presentationState == .liveness },
                     set: { _ in }

Sources/FaceLiveness/Views/Liveness/FaceLivenessDetectionError.swift

@@ -125,6 +125,12 @@ public struct FaceLivenessDetectionError: Error, Equatable {
         message: "The signature on the request is invalid.",
         recoverySuggestion: "Ensure the device time is correct and try again."
     )
+    
+    public static let invalidCameraPositionSelected = FaceLivenessDetectionError(
+        code: 18,
+        message: "The camera position selected is incompatible with the liveness challenge type requested.",
+        recoverySuggestion: "Please ensure the camera position is supported for the liveness challenge type requested."
+    )
 
     public static let cameraNotAvailable = FaceLivenessDetectionError(
         code: 18,

Sources/FaceLiveness/Views/Liveness/FaceLivenessDetectionView.swift

@@ -30,7 +30,7 @@ public struct FaceLivenessDetectorView: View {
         credentialsProvider: AWSCredentialsProvider? = nil,
         region: String,
         disableStartView: Bool = false,
-        cameraPosition: LivenessCaptureDevicePosition,
+        cameraPosition: LivenessCaptureDevicePosition = .front,
         isPresented: Binding<Bool>,
         onCompletion: @escaping (Result<Void, FaceLivenessDetectionError>) -> Void
     ) {        
@@ -59,15 +59,14 @@ public struct FaceLivenessDetectorView: View {
             assetWriterDelegate: VideoChunker.AssetWriterDelegate(),
             assetWriterInput: LivenessAVAssetWriterInput()
         )
-
-        let avCpatureDevice = AVCaptureDevice.DiscoverySession(
-            deviceTypes: [.builtInWideAngleCamera],
-            mediaType: .video,
-            position: cameraPosition == .front ? .front : .back
-        ).devices.first
+        
+        let avCaptureDevice = AVCaptureDevice.default(
+                                .builtInWideAngleCamera,
+                                for: .video,
+                                position: cameraPosition == .front ? .front : .back)
 
         let captureSession = LivenessCaptureSession(
-            captureDevice: .init(avCaptureDevice: avCpatureDevice),
+            captureDevice: .init(avCaptureDevice: avCaptureDevice),
             outputDelegate: OutputSampleBufferCapturer(
                 faceDetector: faceDetector,
                 videoChunker: videoChunker
@@ -82,7 +81,8 @@ public struct FaceLivenessDetectorView: View {
                 videoChunker: videoChunker,
                 closeButtonAction: { onCompletion(.failure(.userCancelled)) },
                 sessionID: sessionID,
-                isPreviewScreenEnabled: !disableStartView
+                isPreviewScreenEnabled: !disableStartView,
+                cameraPosition: cameraPosition
             )
         )
     }
@@ -124,7 +124,8 @@ public struct FaceLivenessDetectorView: View {
                 videoChunker: captureSession.outputSampleBufferCapturer!.videoChunker,
                 closeButtonAction: { onCompletion(.failure(.userCancelled)) },
                 sessionID: sessionID,
-                isPreviewScreenEnabled: !disableStartView
+                isPreviewScreenEnabled: !disableStartView,
+                cameraPosition: cameraPosition
             )
         )
     }

Sources/FaceLiveness/Views/Liveness/FaceLivenessDetectionViewModel.swift

@@ -44,6 +44,7 @@ class FaceLivenessDetectionViewModel: ObservableObject {
     var initialClientEvent: InitialClientEvent?
     var faceMatchedTimestamp: UInt64?
     var noFitStartTime: Date?
+    let cameraPosition: LivenessCaptureDevicePosition
 
     static var attemptCount: Int = 0
     static var attemptIdTimeStamp: Date = Date()
@@ -64,7 +65,8 @@ class FaceLivenessDetectionViewModel: ObservableObject {
         stateMachine: LivenessStateMachine = .init(state: .initial),
         closeButtonAction: @escaping () -> Void,
         sessionID: String,
-        isPreviewScreenEnabled: Bool
+        isPreviewScreenEnabled: Bool,
+        cameraPosition: LivenessCaptureDevicePosition
     ) {
         self.closeButtonAction = closeButtonAction
         self.videoChunker = videoChunker
@@ -74,6 +76,7 @@ class FaceLivenessDetectionViewModel: ObservableObject {
         self.faceDetector = faceDetector
         self.faceInOvalMatching = faceInOvalMatching
         self.isPreviewScreenEnabled = isPreviewScreenEnabled
+        self.cameraPosition = cameraPosition
 
         self.closeButtonAction = { [weak self] in
             guard let self else { return }
@@ -124,7 +127,18 @@ class FaceLivenessDetectionViewModel: ObservableObject {
         livenessService?.register(
             listener: { [weak self] _challenge in
                 self?.challenge = _challenge
-                onChallengeTypeReceived(_challenge)
+                guard _challenge.type == .faceMovementAndLightChallenge,
+                      self?.cameraPosition == .back else {
+                    onChallengeTypeReceived(_challenge)
+                    return
+                }
+                
+                // incompatible camera position with challenge type
+                // return error
+                DispatchQueue.main.async {
+                    self?.livenessState
+                        .unrecoverableStateEncountered(.invalidCameraPositionSelecteed)
+                }
             },
             on: .challenge)
     }

Tests/FaceLivenessTests/CredentialsProviderTestCase.swift

@@ -42,7 +42,8 @@ final class CredentialsProviderTestCase: XCTestCase {
             videoChunker: videoChunker,
             closeButtonAction: {},
             sessionID: UUID().uuidString,
-            isPreviewScreenEnabled: false
+            isPreviewScreenEnabled: false,
+            cameraPosition: .front
         )
 
         self.videoChunker = videoChunker

Tests/FaceLivenessTests/LivenessTests.swift

@@ -33,7 +33,8 @@ final class FaceLivenessDetectionViewModelTestCase: XCTestCase {
             videoChunker: videoChunker,
             closeButtonAction: {},
             sessionID: UUID().uuidString,
-            isPreviewScreenEnabled: false
+            isPreviewScreenEnabled: false,
+            cameraPosition: .front
         )
 
         self.videoChunker = videoChunker