FxA webchannel support and account manager integration

components/concept/sync/src/main/java/mozilla/components/concept/sync/OAuthAccount.kt

@@ -20,13 +20,21 @@ enum class AuthExceptionType(val msg: String) {
  */
 class AuthException(type: AuthExceptionType, cause: Exception? = null) : Throwable(type.msg, cause)
 
+/**
+ * An object that represents a login flow initiated by [OAuthAccount].
+ * @property state OAuth state parameter, identifying a specific authentication flow.
+ * This string is randomly generated during [OAuthAccount.beginOAuthFlowAsync] and [OAuthAccount.beginPairingFlowAsync].
+ * @property url Url which needs to be loaded to go through the authentication flow identified by [state].
+ */
+data class AuthFlowUrl(val state: String, val url: String)
+
 /**
  * Facilitates testing consumers of FirefoxAccount.
  */
 @SuppressWarnings("TooManyFunctions")
 interface OAuthAccount : AutoCloseable {
-    fun beginOAuthFlowAsync(scopes: Set<String>): Deferred<String?>
-    fun beginPairingFlowAsync(pairingUrl: String, scopes: Set<String>): Deferred<String?>
+    fun beginOAuthFlowAsync(scopes: Set<String>): Deferred<AuthFlowUrl?>
+    fun beginPairingFlowAsync(pairingUrl: String, scopes: Set<String>): Deferred<AuthFlowUrl?>
     fun getProfileAsync(ignoreCache: Boolean): Deferred<Profile?>
     fun getProfileAsync(): Deferred<Profile?>
     fun completeOAuthFlowAsync(code: String, state: String): Deferred<Boolean>
@@ -50,6 +58,43 @@ interface StatePersistenceCallback {
     fun persist(data: String)
 }
 
+sealed class AuthType {
+    /**
+     * Account restored from hydrated state on disk.
+     */
+    object Existing : AuthType()
+
+    /**
+     * Account created in response to a sign-in.
+     */
+    object Signin : AuthType()
+
+    /**
+     * Account created in response to a sign-up.
+     */
+    object Signup : AuthType()
+
+    /**
+     * Account created via pairing (similar to sign-in, but without requiring credentials).
+     */
+    object Pairing : AuthType()
+
+    /**
+     * Account was created for an unknown external reason, identified by [action].
+     */
+    data class OtherExternal(val action: String) : AuthType()
+
+    /**
+     * Account created via a shared account state from another app.
+     */
+    object Shared : AuthType()
+
+    /**
+     * Existing account was recovered from an authentication problem.
+     */
+    object Recovered : AuthType()
+}
+
 /**
  * Observer interface which lets its users monitor account state changes and major events.
  */
@@ -61,10 +106,11 @@ interface AccountObserver {
 
     /**
      * Account was successfully authenticated.
+     *
      * @param account An authenticated instance of a [OAuthAccount].
-     * @param newAccount True if an account was just signed in.
+     * @param authType Describes what kind of authentication event caused this invocation.
      */
-    fun onAuthenticated(account: OAuthAccount, newAccount: Boolean) = Unit
+    fun onAuthenticated(account: OAuthAccount, authType: AuthType) = Unit
 
     /**
      * Account's profile is now available.

components/feature/accounts/src/main/assets/extensions/fxawebchannel/fxawebchannel.js

@@ -0,0 +1,29 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+Establish communication with native application.
+*/
+let port = browser.runtime.connectNative("mozacWebchannel");
+
+/*
+Handle messages from native application, dispatch them to FxA via an event.
+*/
+port.onMessage.addListener((event) => {
+  window.dispatchEvent(new CustomEvent('WebChannelMessageToContent', {
+    detail: JSON.stringify(event)
+  }));
+});
+
+// We should use pagehide/pageshow events instead, to better handle page navigation events.
+// See https://github.com/mozilla-mobile/android-components/issues/2984.
+window.addEventListener("unload", (event) => { port.disconnect() }, false);
+
+/*
+Handle messages from FxA. Messages are posted to the native application for processing.
+*/
+window.addEventListener('WebChannelMessageToChrome', function (e) {
+  const detail = JSON.parse(e.detail);
+  port.postMessage(detail);
+});

components/feature/accounts/src/main/assets/extensions/fxawebchannel/manifest.json

@@ -0,0 +1,17 @@
+{
+  "manifest_version": 2,
+  "name": "Mozilla Android Components - Firefox Accounts WebChannel",
+  "version": "1.0",
+  "content_scripts": [
+    {
+      "matches": ["https://acounts.firefox.com/*"],
+      "js": ["fxawebchannel.js"],
+      "run_at": "document_start"
+    }
+  ],
+  "permissions": [
+    "mozillaAddons",
+    "geckoViewAddons",
+    "nativeMessaging"
+  ]
+}

components/feature/accounts/src/main/java/mozilla/components/feature/accounts/FirefoxAccountsAuthFeature.kt

@@ -11,7 +11,9 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import mozilla.components.concept.engine.EngineSession
 import mozilla.components.concept.engine.request.RequestInterceptor
+import mozilla.components.service.fxa.FxaAuthData
 import mozilla.components.service.fxa.manager.FxaAccountManager
+import mozilla.components.service.fxa.toAuthType
 import kotlin.coroutines.CoroutineContext
 
 /**
@@ -66,10 +68,15 @@ class FirefoxAccountsAuthFeature(
                 val code = parsedUri.getQueryParameter("code")
 
                 if (code != null) {
+                    val authType = parsedUri.getQueryParameter("action")!!.toAuthType()
                     val state = parsedUri.getQueryParameter("state") as String
 
                     // Notify the state machine about our success.
-                    accountManager.finishAuthenticationAsync(code, state)
+                    accountManager.finishAuthenticationAsync(FxaAuthData(
+                        authType = authType,
+                        code = code,
+                        state = state
+                    ))
 
                     return RequestInterceptor.InterceptionResponse.Url(redirectUrl)
                 }