feat(authenticator): Add passwordless sign in flows (#287)

Author: mattcreaser

authenticator/api/authenticator.api

@@ -15,12 +15,14 @@
 
 package com.amplifyframework.ui.authenticator
 
+import com.amplifyframework.ui.authenticator.data.AuthenticationFlow
 import com.amplifyframework.ui.authenticator.enums.AuthenticatorInitialStep
 import com.amplifyframework.ui.authenticator.forms.SignUpFormBuilder
 import com.amplifyframework.ui.authenticator.options.TotpOptions
 
 internal data class AuthenticatorConfiguration(
     val initialStep: AuthenticatorInitialStep,
     val signUpForm: SignUpFormBuilder.() -> Unit,
-    val totpOptions: TotpOptions?
+    val totpOptions: TotpOptions?,
+    val authenticationFlow: AuthenticationFlow
 )

authenticator/src/main/java/com/amplifyframework/ui/authenticator/AuthenticatorConfiguration.kt

@@ -22,12 +22,15 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
+import androidx.compose.ui.platform.LocalContext
 import androidx.lifecycle.viewmodel.compose.viewModel
+import com.amplifyframework.ui.authenticator.data.AuthenticationFlow
 import com.amplifyframework.ui.authenticator.enums.AuthenticatorInitialStep
 import com.amplifyframework.ui.authenticator.enums.AuthenticatorStep
 import com.amplifyframework.ui.authenticator.forms.SignUpFormBuilder
 import com.amplifyframework.ui.authenticator.options.TotpOptions
 import com.amplifyframework.ui.authenticator.util.AuthenticatorMessage
+import com.amplifyframework.ui.authenticator.util.findActivity
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
@@ -46,18 +49,22 @@ import kotlinx.coroutines.flow.onEach
 fun rememberAuthenticatorState(
     initialStep: AuthenticatorInitialStep = AuthenticatorStep.SignIn,
     signUpForm: SignUpFormBuilder.() -> Unit = {},
-    totpOptions: TotpOptions? = null
+    totpOptions: TotpOptions? = null,
+    authenticationFlow: AuthenticationFlow = AuthenticationFlow.Password
 ): AuthenticatorState {
     val viewModel = viewModel<AuthenticatorViewModel>()
     val scope = rememberCoroutineScope()
+    val context = LocalContext.current
+
     return remember {
         val configuration = AuthenticatorConfiguration(
             initialStep = initialStep,
             signUpForm = signUpForm,
-            totpOptions = totpOptions
+            totpOptions = totpOptions,
+            authenticationFlow = authenticationFlow
         )
 
-        viewModel.start(configuration)
+        viewModel.start(configuration, context.findActivity())
         AuthenticatorStateImpl(viewModel).also { state ->
             viewModel.stepState.onEach { state.stepState = it }.launchIn(scope)
         }
@@ -102,9 +109,7 @@ interface AuthenticatorState {
     val messages: Flow<AuthenticatorMessage>
 }
 
-internal class AuthenticatorStateImpl constructor(
-    private val viewModel: AuthenticatorViewModel
-) : AuthenticatorState {
+internal class AuthenticatorStateImpl constructor(private val viewModel: AuthenticatorViewModel) : AuthenticatorState {
     override var stepState by mutableStateOf<AuthenticatorStepState>(LoadingState)
 
     override val messages: Flow<AuthenticatorMessage>

authenticator/src/main/java/com/amplifyframework/ui/authenticator/AuthenticatorState.kt

@@ -23,6 +23,8 @@ import com.amplifyframework.auth.AuthUser
 import com.amplifyframework.auth.AuthUserAttribute
 import com.amplifyframework.auth.MFAType
 import com.amplifyframework.auth.result.AuthSignOutResult
+import com.amplifyframework.auth.result.AuthWebAuthnCredential
+import com.amplifyframework.ui.authenticator.data.AuthFactor
 import com.amplifyframework.ui.authenticator.enums.AuthenticatorInitialStep
 import com.amplifyframework.ui.authenticator.enums.AuthenticatorStep
 import com.amplifyframework.ui.authenticator.forms.MutableFormState
@@ -38,6 +40,17 @@ interface AuthenticatorStepState {
     val step: AuthenticatorStep
 }
 
+/**
+ * A state holder for the UI that has multiple possible actions that may be in progress.
+ */
+@Stable
+interface AuthenticatorActionState<T> {
+    /**
+     * The action in progress, or null if state is idle
+     */
+    val action: T?
+}
+
 /**
  * The Authenticator is loading the current state of the user's Auth session.
  */
@@ -93,6 +106,73 @@ interface SignInState : AuthenticatorStepState {
     suspend fun signIn()
 }
 
+/**
+ * The user has entered their username and must select the authentication factor they'd like to use to sign in
+ */
+@Stable
+interface SignInSelectAuthFactorState :
+    AuthenticatorStepState,
+    AuthenticatorActionState<SignInSelectAuthFactorState.Action> {
+
+    sealed interface Action {
+        /**
+         * User has selected an auth factor
+         */
+        data class SelectAuthFactor(val factor: AuthFactor) : Action
+    }
+
+    /**
+     * The input form state holder for this step.
+     */
+    val form: MutableFormState
+
+    /**
+     * The username entered in the SignIn step
+     */
+    val username: String
+
+    /**
+     * The available types to select how to sign in.
+     */
+    val availableAuthFactors: Set<AuthFactor>
+
+    /**
+     * Move the user to a different [AuthenticatorInitialStep].
+     */
+    fun moveTo(step: AuthenticatorInitialStep)
+
+    /**
+     * Initiate a sign in with one of the available sign in types
+     */
+    suspend fun select(authFactor: AuthFactor)
+}
+
+/**
+ * A user has entered their username and must enter their password to continue signing in
+ */
+@Stable
+interface SignInConfirmPasswordState : AuthenticatorStepState {
+    /**
+     * The input form state holder for this step.
+     */
+    val form: MutableFormState
+
+    /**
+     * The username entered in the SignIn step
+     */
+    val username: String
+
+    /**
+     * Move the user to a different [AuthenticatorInitialStep].
+     */
+    fun moveTo(step: AuthenticatorInitialStep)
+
+    /**
+     * Initiate a sign in with the information entered into the [form].
+     */
+    suspend fun signIn()
+}
+
 /**
  * The user has completed the initial Sign In step, and needs to enter the confirmation code from an MFA
  * message to complete the sign in process.
@@ -460,3 +540,59 @@ interface VerifyUserConfirmState : AuthenticatorStepState {
      */
     fun skip()
 }
+
+/**
+ * The user is being shown a prompt to create a passkey, encouraging them to use this as a way to sign in quickly
+ * via biometrics
+ */
+@Stable
+interface PromptToCreatePasskeyState :
+    AuthenticatorStepState,
+    AuthenticatorActionState<PromptToCreatePasskeyState.Action> {
+    sealed interface Action {
+        /**
+         * User is creating a passkey
+         */
+        class CreatePasskey : Action
+
+        /**
+         * User has selected the Skip button
+         */
+        class Skip : Action
+    }
+
+    /**
+     * Create a passkey
+     */
+    suspend fun createPasskey()
+
+    /**
+     * Skip passkey creation and continue to the next step
+     */
+    suspend fun skip()
+}
+
+/**
+ * The user is being shown a confirmation screen after creating a passkey
+ */
+@Stable
+interface PasskeyCreatedState :
+    AuthenticatorStepState,
+    AuthenticatorActionState<PasskeyCreatedState.Action> {
+    sealed interface Action {
+        /**
+         * User has selected the Done button
+         */
+        class ContinueSignIn : Action
+    }
+
+    /**
+     * A list of existing passkeys for this user, including the one they've just created
+     */
+    val passkeys: List<AuthWebAuthnCredential>
+
+    /**
+     * Continue to the next step
+     */
+    suspend fun continueSignIn()
+}