Configure the account provider homeserver only once when signing in

features/login/impl/src/main/kotlin/io/element/android/features/login/impl/changeserver/ChangeServerPresenter.kt

@@ -22,6 +22,7 @@ import io.element.android.libraries.architecture.AsyncData
 import io.element.android.libraries.architecture.Presenter
 import io.element.android.libraries.architecture.runCatchingUpdatingState
 import io.element.android.libraries.matrix.api.auth.MatrixAuthenticationService
+import io.element.android.libraries.matrix.api.auth.MatrixHomeServerDetails
 
 @Inject
 class ChangeServerPresenter(
@@ -32,7 +33,7 @@ class ChangeServerPresenter(
 ) : Presenter<ChangeServerState> {
     @Composable
     override fun present(): ChangeServerState {
-        val changeServerAction: MutableState<AsyncData<Unit>> = remember {
+        val changeServerAction: MutableState<AsyncData<MatrixHomeServerDetails>> = remember {
             mutableStateOf(AsyncData.Uninitialized)
         }
 
@@ -59,7 +60,7 @@ class ChangeServerPresenter(
 
     private suspend fun changeServer(
         data: AccountProvider,
-        changeServerAction: MutableState<AsyncData<Unit>>,
+        changeServerAction: MutableState<AsyncData<MatrixHomeServerDetails>>,
     ) {
         suspend {
             defaultAccountProviderAccessControl.assertIsAllowedToConnectToAccountProvider(
@@ -72,6 +73,8 @@ class ChangeServerPresenter(
             }
             // Homeserver is valid, remember user choice
             accountProviderDataSource.setAccountProvider(data)
+            // Return the resolved details so the caller can sign in without configuring the homeserver again.
+            details
         }.runCatchingUpdatingState(changeServerAction, errorTransform = ChangeServerError::from)
     }
 }

features/login/impl/src/main/kotlin/io/element/android/features/login/impl/changeserver/ChangeServerState.kt

@@ -9,10 +9,13 @@
 package io.element.android.features.login.impl.changeserver
 
 import io.element.android.libraries.architecture.AsyncData
+import io.element.android.libraries.matrix.api.auth.MatrixHomeServerDetails
 import io.element.android.libraries.permissions.api.localnetwork.LocalNetworkPermissionDialog
 
 data class ChangeServerState(
-    val changeServerAction: AsyncData<Unit>,
+    // On success, carries the resolved homeserver details so the caller can proceed with login without
+    // configuring (and re-networking) the homeserver a second time.
+    val changeServerAction: AsyncData<MatrixHomeServerDetails>,
     val localNetworkPermissionDialog: LocalNetworkPermissionDialog,
     val eventSink: (ChangeServerEvents) -> Unit
 )

features/login/impl/src/main/kotlin/io/element/android/features/login/impl/changeserver/ChangeServerStateProvider.kt

@@ -11,6 +11,7 @@ package io.element.android.features.login.impl.changeserver
 import androidx.compose.ui.tooling.preview.PreviewParameterProvider
 import io.element.android.features.login.impl.error.ChangeServerError
 import io.element.android.libraries.architecture.AsyncData
+import io.element.android.libraries.matrix.api.auth.MatrixHomeServerDetails
 import io.element.android.libraries.permissions.api.localnetwork.LocalNetworkPermissionDialog
 
 open class ChangeServerStateProvider : PreviewParameterProvider<ChangeServerState> {
@@ -45,7 +46,7 @@ open class ChangeServerStateProvider : PreviewParameterProvider<ChangeServerStat
 }
 
 fun aChangeServerState(
-    changeServerAction: AsyncData<Unit> = AsyncData.Uninitialized,
+    changeServerAction: AsyncData<MatrixHomeServerDetails> = AsyncData.Uninitialized,
     localNetworkPermissionDialog: LocalNetworkPermissionDialog = LocalNetworkPermissionDialog.None,
 ) = ChangeServerState(
     changeServerAction = changeServerAction,

features/login/impl/src/main/kotlin/io/element/android/features/login/impl/login/LoginModeEvent.kt

@@ -7,12 +7,18 @@
 
 package io.element.android.features.login.impl.login
 
+import io.element.android.libraries.matrix.api.auth.MatrixHomeServerDetails
+
 sealed interface LoginModeEvent {
     data class Submit(
         val isAccountCreation: Boolean,
         val homeserverUrl: String,
         val resolvedHomeserverUrl: String?,
         val loginHint: String?,
+        // When the caller has already configured the homeserver (e.g. the account provider screen validated
+        // it first), these are its resolved details. When set, login reuses them instead of calling
+        // setHomeserver again, avoiding a redundant network round-trip.
+        val preConfiguredDetails: MatrixHomeServerDetails? = null,
     ) : LoginModeEvent
 
     data object ClearError : LoginModeEvent

features/login/impl/src/main/kotlin/io/element/android/features/login/impl/login/LoginModePresenter.kt

@@ -75,26 +75,28 @@ class LoginModePresenter(
 
     private suspend fun performSubmit(request: LoginModeEvent.Submit, loginMode: MutableState<AsyncData<LoginMode>>) {
         suspend {
-            authenticationService.setHomeserver(request.homeserverUrl).recoverCatching {
-                // Fallback to the well-known-resolved URL if the primary URL failed and the caller supplied one.
-                if (request.resolvedHomeserverUrl != null && request.resolvedHomeserverUrl != request.homeserverUrl) {
-                    authenticationService.setHomeserver(request.resolvedHomeserverUrl).getOrThrow()
-                } else {
-                    throw it
-                }
-            }.map { matrixHomeServerDetails ->
-                when {
-                    matrixHomeServerDetails.supportsOAuthLogin -> {
-                        val oAuthPrompt = if (request.isAccountCreation) OAuthPrompt.Create else OAuthPrompt.Login
-                        LoginMode.OAuth(
-                            authenticationService.getOAuthUrl(prompt = oAuthPrompt, loginHint = request.loginHint).getOrThrow()
-                        )
+            // Reuse the details the caller already resolved when it configured the homeserver, so we don't
+            // run setHomeserver (a network round-trip) again. Otherwise configure the homeserver ourselves.
+            val matrixHomeServerDetails = request.preConfiguredDetails
+                ?: authenticationService.setHomeserver(request.homeserverUrl).recoverCatching {
+                    // Fallback to the well-known-resolved URL if the primary URL failed and the caller supplied one.
+                    if (request.resolvedHomeserverUrl != null && request.resolvedHomeserverUrl != request.homeserverUrl) {
+                        authenticationService.setHomeserver(request.resolvedHomeserverUrl).getOrThrow()
+                    } else {
+                        throw it
                     }
-                    request.isAccountCreation -> throw AccountCreationNotSupported()
-                    matrixHomeServerDetails.supportsPasswordLogin -> LoginMode.PasswordLogin
-                    else -> error("Unsupported authentication flow")
+                }.getOrThrow()
+            when {
+                matrixHomeServerDetails.supportsOAuthLogin -> {
+                    val oAuthPrompt = if (request.isAccountCreation) OAuthPrompt.Create else OAuthPrompt.Login
+                    LoginMode.OAuth(
+                        authenticationService.getOAuthUrl(prompt = oAuthPrompt, loginHint = request.loginHint).getOrThrow()
+                    )
                 }
-            }.getOrThrow()
+                request.isAccountCreation -> throw AccountCreationNotSupported()
+                matrixHomeServerDetails.supportsPasswordLogin -> LoginMode.PasswordLogin
+                else -> error("Unsupported authentication flow")
+            }
         }.runCatchingUpdatingState(
             state = loginMode,
             errorTransform = {

features/login/impl/src/main/kotlin/io/element/android/features/login/impl/screens/confirmaccountprovider/ConfirmAccountProviderPresenter.kt

@@ -27,7 +27,6 @@ import io.element.android.features.login.impl.changeserver.ChangeServerEvents
 import io.element.android.features.login.impl.changeserver.ChangeServerState
 import io.element.android.features.login.impl.login.LoginModeEvent
 import io.element.android.features.login.impl.login.LoginModeState
-import io.element.android.libraries.architecture.AsyncData
 import io.element.android.libraries.architecture.Presenter
 import io.element.android.libraries.core.uri.ensureProtocol
 import io.element.android.libraries.preferences.api.store.AppPreferencesStore
@@ -81,14 +80,17 @@ class ConfirmAccountProviderPresenter(
         val latestSubmittedAccountProvider by rememberUpdatedState(submittedAccountProvider)
 
         // Once the chosen account provider has been validated and persisted, proceed with the actual sign in / sign up.
+        // Reuse the details resolved while validating, so login does not configure (and re-network) the homeserver again.
         LaunchedEffect(changeServerState.changeServerAction) {
-            if (changeServerState.changeServerAction is AsyncData.Success) {
+            val homeServerDetails = changeServerState.changeServerAction.dataOrNull()
+            if (homeServerDetails != null) {
                 loginModeState.eventSink(
                     LoginModeEvent.Submit(
                         isAccountCreation = params.isAccountCreation,
                         homeserverUrl = latestSubmittedAccountProvider.orEmpty().trim(),
                         resolvedHomeserverUrl = null,
                         loginHint = null,
+                        preConfiguredDetails = homeServerDetails,
                     )
                 )
             }

features/login/impl/src/test/kotlin/io/element/android/features/login/impl/changeserver/ChangeServerPresenterTest.kt

@@ -73,7 +73,7 @@ class ChangeServerPresenterTest {
             val loadingState = awaitItem()
             assertThat(loadingState.changeServerAction).isInstanceOf(AsyncData.Loading::class.java)
             val successState = awaitItem()
-            assertThat(successState.changeServerAction).isEqualTo(AsyncData.Success(Unit))
+            assertThat(successState.changeServerAction).isEqualTo(AsyncData.Success(aMatrixHomeServerDetails(supportsOAuthLogin = true)))
         }
     }
 
@@ -252,7 +252,7 @@ class ChangeServerPresenterTest {
             while (finalState.changeServerAction !is AsyncData.Success) {
                 finalState = awaitItem()
             }
-            assertThat(finalState.changeServerAction).isEqualTo(AsyncData.Success(Unit))
+            assertThat(finalState.changeServerAction).isEqualTo(AsyncData.Success(aMatrixHomeServerDetails(supportsOAuthLogin = true)))
         }
     }
 

features/login/impl/src/test/kotlin/io/element/android/features/login/impl/screens/confirmaccountprovider/ConfirmAccountProviderPresenterTest.kt

@@ -396,6 +396,29 @@ class ConfirmAccountProviderPresenterTest {
         }
     }
 
+    @Test
+    fun `present - continue configures the homeserver only once`() = runTest {
+        // The consolidated Continue flow validates the account provider and then signs in. Login reuses the
+        // details resolved during validation, so setHomeserver runs exactly once rather than once per phase.
+        val submittedUrls = mutableListOf<String>()
+        val authenticationService = FakeMatrixAuthenticationService(
+            setHomeserverResult = { url ->
+                submittedUrls.add(url)
+                Result.success(aMatrixHomeServerDetails(supportsOAuthLogin = true))
+            },
+        )
+        val presenter = createConfirmAccountProviderPresenter(
+            matrixAuthenticationService = authenticationService,
+        )
+        presenter.test {
+            val initialState = awaitItem()
+            initialState.eventSink(ConfirmAccountProviderEvents.Continue(AuthenticationConfig.MATRIX_ORG_URL))
+            awaitLoginMode { it is AsyncData.Success }
+            assertThat(submittedUrls).containsExactly(AuthenticationConfig.MATRIX_ORG_URL)
+            cancelAndIgnoreRemainingEvents()
+        }
+    }
+
     /**
      * Awaits until the emitted state's login mode matches [predicate], skipping the intermediate
      * account-provider validation states, and returns that state.