feat: Support for login and registration via a browser custom tab

This change adds support for logging in and registering a new account using the
browser. This can be useful for cases where the only way to log into the
instatance is via a custom third-party auth provider.

Author: xitij2000

app/src/main/AndroidManifest.xml

@@ -36,6 +36,12 @@
 
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+                <data android:scheme="${applicationId}"  />
+            </intent-filter>
         </activity>
 
         <provider

app/src/main/java/org/openedx/app/AppActivity.kt

@@ -2,6 +2,7 @@ package org.openedx.app
 
 import android.content.res.Configuration
 import android.graphics.Color
+import android.net.Uri
 import android.os.Bundle
 import android.view.View
 import android.view.WindowManager
@@ -50,6 +51,14 @@ class AppActivity : AppCompatActivity(), InsetHolder, WindowSizeHolder {
     private var _insetCutout = 0
 
     private var _windowSize = WindowSize(WindowType.Compact, WindowType.Compact)
+    private val authCode: String?
+        get() {
+            val data = intent?.data
+            if (data is Uri && data.scheme == BuildConfig.APPLICATION_ID && data.host == "oauth2Callback") {
+                return data.getQueryParameter("code")
+            }
+            return null
+        }
 
     override fun onSaveInstanceState(outState: Bundle) {
         outState.putInt(TOP_INSET, topInset)
@@ -112,10 +121,15 @@ class AppActivity : AppCompatActivity(), InsetHolder, WindowSizeHolder {
         if (savedInstanceState == null) {
             when {
                 corePreferencesManager.user == null -> {
-                    if (viewModel.isLogistrationEnabled) {
+                    val authCode = authCode;
+                    if (viewModel.isLogistrationEnabled && authCode == null) {
                         addFragment(LogistrationFragment())
                     } else {
-                        addFragment(SignInFragment())
+                        val bundle = Bundle()
+                        bundle.putString("auth_code", authCode)
+                        val fragment = SignInFragment()
+                        fragment.arguments = bundle
+                        addFragment(fragment)
                     }
                 }
 

app/src/main/java/org/openedx/app/di/AppModule.kt

@@ -20,6 +20,7 @@ import org.openedx.app.room.DATABASE_NAME
 import org.openedx.app.system.notifier.AppNotifier
 import org.openedx.auth.presentation.AuthAnalytics
 import org.openedx.auth.presentation.AuthRouter
+import org.openedx.auth.presentation.sso.BrowserAuthHelper
 import org.openedx.auth.presentation.sso.FacebookAuthHelper
 import org.openedx.auth.presentation.sso.GoogleAuthHelper
 import org.openedx.auth.presentation.sso.MicrosoftAuthHelper
@@ -153,4 +154,5 @@ val appModule = module {
     factory { FacebookAuthHelper() }
     factory { GoogleAuthHelper(get()) }
     factory { MicrosoftAuthHelper() }
+    factory { BrowserAuthHelper(get()) }
 }

app/src/main/java/org/openedx/app/di/ScreenModule.kt

@@ -74,6 +74,7 @@ val screenModule = module {
             get(),
             get(),
             get(),
+            get(),
             courseId,
         )
     }

auth/build.gradle

@@ -55,6 +55,7 @@ android {
 dependencies {
     implementation project(path: ':core')
 
+    implementation 'androidx.browser:browser:1.7.0'
     implementation "androidx.credentials:credentials:1.2.0"
     implementation "androidx.credentials:credentials-play-services-auth:1.2.0"
     implementation "com.facebook.android:facebook-login:16.2.0"

auth/src/main/java/org/openedx/auth/data/api/AuthApi.kt

@@ -32,6 +32,14 @@ interface AuthApi {
         @Field("asymmetric_jwt") isAsymmetricJwt: Boolean = true,
     ): AuthResponse
 
+    @FormUrlEncoded
+    @POST(ApiConstants.URL_ACCESS_TOKEN)
+    suspend fun getAccessTokenFromCode(
+        @Field("grant_type") grantType: String,
+        @Field("client_id") clientId: String,
+        @Field("code") code: String,
+    ): AuthResponse
+
     @FormUrlEncoded
     @POST(ApiConstants.URL_ACCESS_TOKEN)
     fun refreshAccessToken(

auth/src/main/java/org/openedx/auth/data/model/AuthType.kt

@@ -13,4 +13,5 @@ enum class AuthType(val postfix: String, val methodName: String) {
     GOOGLE(ApiConstants.AUTH_TYPE_GOOGLE, "Google"),
     FACEBOOK(ApiConstants.AUTH_TYPE_FB, "Facebook"),
     MICROSOFT(ApiConstants.AUTH_TYPE_MICROSOFT, "Microsoft"),
+    BROWSER(ApiConstants.AUTH_TYPE_BROWSER, "Browser")
 }

auth/src/main/java/org/openedx/auth/data/repository/AuthRepository.kt

@@ -1,5 +1,6 @@
 package org.openedx.auth.data.repository
 
+import android.util.Log
 import org.openedx.auth.data.api.AuthApi
 import org.openedx.auth.data.model.AuthType
 import org.openedx.auth.data.model.ValidationFields
@@ -43,6 +44,14 @@ class AuthRepository(
             .processAuthResponse()
     }
 
+    suspend fun browserAuthCodeLogin(code: String) {
+        api.getAccessTokenFromCode(
+            grantType = ApiConstants.GRANT_TYPE_CODE,
+            clientId = config.getOAuthClientId(),
+            code = code,
+        ).mapToDomain().processAuthResponse()
+    }
+
     suspend fun getRegistrationFields(): List<RegistrationField> {
         return api.getRegistrationFields().fields?.map { it.mapToDomain() } ?: emptyList()
     }

auth/src/main/java/org/openedx/auth/domain/interactor/AuthInteractor.kt

@@ -18,6 +18,10 @@ class AuthInteractor(private val repository: AuthRepository) {
         repository.socialLogin(token, authType)
     }
 
+    suspend fun loginAuthCode(authCode: String) {
+        repository.browserAuthCodeLogin(authCode)
+    }
+
     suspend fun getRegistrationFields(): List<RegistrationField> {
         return repository.getRegistrationFields()
     }

auth/src/main/java/org/openedx/auth/presentation/logistration/LogistrationFragment.kt

@@ -1,6 +1,8 @@
 package org.openedx.auth.presentation.logistration
 
+import android.content.Intent
 import android.content.res.Configuration
+import android.net.Uri
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.ViewGroup
@@ -41,18 +43,22 @@ import androidx.fragment.app.Fragment
 import org.koin.android.ext.android.inject
 import org.openedx.auth.R
 import org.openedx.auth.presentation.AuthRouter
+import org.openedx.core.config.Config
+import org.openedx.core.presentation.dialog.alert.ActionDialogFragment
 import org.openedx.core.ui.AuthButtonsPanel
 import org.openedx.core.ui.SearchBar
 import org.openedx.core.ui.displayCutoutForLandscape
 import org.openedx.core.ui.noRippleClickable
 import org.openedx.core.ui.theme.OpenEdXTheme
 import org.openedx.core.ui.theme.appColors
 import org.openedx.core.ui.theme.appTypography
+import org.openedx.core.utils.UrlUtils
 import org.openedx.core.R as coreR
 
 class LogistrationFragment : Fragment() {
 
     private val router: AuthRouter by inject()
+    private val config: Config by inject()
 
     override fun onCreateView(
         inflater: LayoutInflater,
@@ -68,7 +74,15 @@ class LogistrationFragment : Fragment() {
                         router.navigateToSignIn(parentFragmentManager, courseId)
                     },
                     onRegisterClick = {
-                        router.navigateToSignUp(parentFragmentManager, courseId)
+                        if (config.isBrowserRegistrationEnabled()) {
+                            UrlUtils.openInBrowser(
+                                activity = context,
+                                apiHostUrl = config.getApiHostURL(),
+                                url = "/register",
+                            )
+                        } else {
+                            router.navigateToSignUp(parentFragmentManager, courseId)
+                        }
                     },
                     onSearchClick = { querySearch ->
                         router.navigateToDiscoverCourses(parentFragmentManager, querySearch)