Issue mozilla-mobile#5818: Try to migrate default search engine.

Author: pocmo

components/support/migration/build.gradle

@@ -64,9 +64,11 @@ tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile).all {
 
 dependencies {
     implementation project(':concept-engine')
-    implementation project(':browser-session')
 
+    implementation project(':browser-search')
+    implementation project(':browser-session')
     implementation project(':browser-storage-sync')
+
     implementation project(':service-firefox-accounts')
     implementation project(':service-sync-logins')
     implementation project(':service-glean')

components/support/migration/docs/metrics.md

@@ -52,12 +52,15 @@ The following metrics are added to the ping:
 | migration.logins.failure_reason |[counter](https://mozilla.github.io/glean/book/user/metrics/counter.html) |Why this migration failed. See codes in TelemetryHelpers.kt  |[1](https://github.com/mozilla-mobile/android-components/pull/5483#issuecomment-573971458)||2020-10-01 |
 | migration.logins.success_reason |[counter](https://mozilla.github.io/glean/book/user/metrics/counter.html) |Why this migration succeeded. See codes in TelemetryHelpers.kt  |[1](https://github.com/mozilla-mobile/android-components/pull/5483#issuecomment-573971458)||2020-10-01 |
 | migration.logins.unsupported_db_version |[counter](https://mozilla.github.io/glean/book/user/metrics/counter.html) |If we couldn't migrate due to an unsupported db version, what was it?  |[1](https://github.com/mozilla-mobile/android-components/pull/5483#issuecomment-573971458)||2020-10-01 |
-| migration.migration_versions |[labeled_string](https://mozilla.github.io/glean/book/user/metrics/labeled_strings.html) |Versions of the migrations which were executed.  |[1](https://github.com/mozilla-mobile/android-components/pull/5483#issuecomment-573971458)|<ul><li>history</li><li>bookmarks</li><li>logins</li><li>open_tabs</li><li>fxa</li><li>gecko</li><li>settings</li><li>telemetry_identifiers</li><li>addons</li></ul>|2020-10-01 |
+| migration.migration_versions |[labeled_string](https://mozilla.github.io/glean/book/user/metrics/labeled_strings.html) |Versions of the migrations which were executed.  |[1](https://github.com/mozilla-mobile/android-components/pull/5483#issuecomment-573971458)|<ul><li>history</li><li>bookmarks</li><li>logins</li><li>open_tabs</li><li>fxa</li><li>gecko</li><li>settings</li><li>telemetry_identifiers</li><li>addons</li><li>search</li></ul>|2020-10-01 |
 | migration.open_tabs.any_failures |[boolean](https://mozilla.github.io/glean/book/user/metrics/boolean.html) |Did this migration encounter any failures (exceptions)?  |[1](https://github.com/mozilla-mobile/android-components/pull/5483#issuecomment-573971458)||2020-10-01 |
 | migration.open_tabs.detected |[counter](https://mozilla.github.io/glean/book/user/metrics/counter.html) |Number of detected open tabs.  |[1](https://github.com/mozilla-mobile/android-components/pull/5483#issuecomment-573971458)||2020-10-01 |
 | migration.open_tabs.failure_reason |[counter](https://mozilla.github.io/glean/book/user/metrics/counter.html) |Why this migration failed. See codes in TelemetryHelpers.kt  |[1](https://github.com/mozilla-mobile/android-components/pull/5655#pullrequestreview-346359792)||2020-10-01 |
 | migration.open_tabs.migrated |[counter](https://mozilla.github.io/glean/book/user/metrics/counter.html) |Number of migrated open tabs.  |[1](https://github.com/mozilla-mobile/android-components/pull/5483#issuecomment-573971458)||2020-10-01 |
 | migration.open_tabs.success_reason |[counter](https://mozilla.github.io/glean/book/user/metrics/counter.html) |Why this migration succeeded. See codes in TelemetryHelpers.kt  |[1](https://github.com/mozilla-mobile/android-components/pull/5655#pullrequestreview-346359792)||2020-10-01 |
+| migration.search.any_failures |[boolean](https://mozilla.github.io/glean/book/user/metrics/boolean.html) |Did this migration encounter any failures (exceptions)?  |[1](TODO)||2020-10-01 |
+| migration.search.failure_reason |[counter](https://mozilla.github.io/glean/book/user/metrics/counter.html) |Why this migration failed. See codes in TelemetryHelpers.kt  |[1](TODO)||2020-10-01 |
+| migration.search.success_reason |[counter](https://mozilla.github.io/glean/book/user/metrics/counter.html) |Why this migration succeeded. See codes in TelemetryHelpers.kt  |[1](TODO)||2020-10-01 |
 | migration.settings.any_failures |[boolean](https://mozilla.github.io/glean/book/user/metrics/boolean.html) |Did this migration encounter any failures (exceptions)?  |[1](https://github.com/mozilla-mobile/android-components/pull/5483#issuecomment-573971458)||2020-10-01 |
 | migration.settings.failure_reason |[counter](https://mozilla.github.io/glean/book/user/metrics/counter.html) |Why this migration failed. See codes in TelemetryHelpers.kt  |[1](https://github.com/mozilla-mobile/android-components/pull/5483#issuecomment-573971458)||2020-10-01 |
 | migration.settings.success_reason |[counter](https://mozilla.github.io/glean/book/user/metrics/counter.html) |Why this migration succeeded. See codes in TelemetryHelpers.kt  |[1](https://github.com/mozilla-mobile/android-components/pull/5483#issuecomment-573971458)||2020-10-01 |

components/support/migration/metrics.yaml

@@ -19,6 +19,7 @@ migration:
       - settings
       - telemetry_identifiers
       - addons
+      - search
     send_in_pings:
       - migration
     bugs:
@@ -745,3 +746,47 @@ migration.addons:
       - [email protected]
     expires: 2020-10-01
     lifetime: ping
+
+migration.search:
+  any_failures:
+    type: boolean
+    description: >
+      Did this migration encounter any failures (exceptions)?
+    send_in_pings:
+      - migration
+    bugs:
+      - https://github.com/mozilla-mobile/android-components/issues/5818
+    data_reviews:
+      - https://github.com/mozilla-mobile/android-components/pull/5819#pullrequestreview-353890362
+    notification_emails:
+      - [email protected]
+    expires: 2020-10-01
+    lifetime: ping
+  failure_reason:
+    type: counter
+    description: >
+      Why this migration failed. See codes in TelemetryHelpers.kt
+    send_in_pings:
+      - migration
+    bugs:
+      - https://github.com/mozilla-mobile/android-components/issues/5818
+    data_reviews:
+      - https://github.com/mozilla-mobile/android-components/pull/5819#pullrequestreview-353890362
+    notification_emails:
+      - [email protected]
+    expires: 2020-10-01
+    lifetime: ping
+  success_reason:
+    type: counter
+    description: >
+      Why this migration succeeded. See codes in TelemetryHelpers.kt
+    send_in_pings:
+      - migration
+    bugs:
+      - https://github.com/mozilla-mobile/android-components/issues/5818
+    data_reviews:
+      - https://github.com/mozilla-mobile/android-components/pull/5819#pullrequestreview-353890362
+    notification_emails:
+      - [email protected]
+    expires: 2020-10-01
+    lifetime: ping

components/support/migration/src/main/java/mozilla/components/support/migration/FennecMigrator.kt

@@ -16,6 +16,7 @@ import kotlinx.coroutines.asCoroutineDispatcher
 import kotlinx.coroutines.async
 import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.withContext
+import mozilla.components.browser.search.SearchEngineManager
 import mozilla.components.browser.session.SessionManager
 import mozilla.components.browser.storage.sync.PlacesBookmarksStorage
 import mozilla.components.browser.storage.sync.PlacesHistoryStorage
@@ -40,8 +41,10 @@ import mozilla.components.support.migration.GleanMetrics.MigrationHistory
 import mozilla.components.support.migration.GleanMetrics.MigrationLogins
 import mozilla.components.support.migration.GleanMetrics.MigrationTelemetryIdentifiers
 import mozilla.components.support.migration.GleanMetrics.MigrationOpenTabs
+import mozilla.components.support.migration.GleanMetrics.MigrationSearch
 import mozilla.components.support.migration.GleanMetrics.MigrationSettings
 import java.io.File
+import java.lang.AssertionError
 import java.lang.Exception
 import java.util.Date
 import java.util.UUID
@@ -97,6 +100,11 @@ sealed class Migration(val currentVersion: Int) {
      * Migrates Fennec's telemetry identifiers.
      */
     object TelemetryIdentifiers : Migration(currentVersion = 1)
+
+    /**
+     * Migrates Fennec's default search engine.
+     */
+    object SearchEngine : Migration(currentVersion = 1)
 }
 
 /**
@@ -167,6 +175,12 @@ sealed class FennecMigratorException(cause: Exception) : Exception(cause) {
      * @param cause Original exception which caused the problem.
      */
     class TelemetryIdentifierException(cause: Exception) : FennecMigratorException(cause)
+
+    /**
+     * Unexpected exception while migrating the default search engine.
+     * @param cause Original exception which caused the problem.
+     */
+    class MigrateSearchEngineException(cause: Exception) : FennecMigratorException(cause)
 }
 
 /**
@@ -188,6 +202,7 @@ class FennecMigrator private constructor(
     private val loginsStorage: AsyncLoginsStorage?,
     private val loginsStorageKey: String?,
     private val sessionManager: SessionManager?,
+    private val searchEngineManager: SearchEngineManager?,
     private val accountManager: FxaAccountManager?,
     private val engine: Engine?,
     private val addonCollectionProvider: AddonCollectionProvider?,
@@ -209,6 +224,7 @@ class FennecMigrator private constructor(
         private var loginsStorage: AsyncLoginsStorage? = null
         private var loginsStorageKey: String? = null
         private var sessionManager: SessionManager? = null
+        private var searchEngineManager: SearchEngineManager? = null
         private var accountManager: FxaAccountManager? = null
         private var engine: Engine? = null
         private var addonCollectionProvider: AddonCollectionProvider? = null
@@ -303,6 +319,22 @@ class FennecMigrator private constructor(
             return this
         }
 
+        /**
+         * Enable default search engine migration.
+         *
+         * @param searchEngineManager An instance of [SearchEngineManager] used for restoring the
+         * migrated default search engine.
+         * @param version Version of the migration; defaults to the current version.
+         */
+        fun migrateSearchEngine(
+            searchEngineManager: SearchEngineManager,
+            version: Int = Migration.SearchEngine.currentVersion
+        ): Builder {
+            this.searchEngineManager = searchEngineManager
+            migrations.add(VersionedMigration(Migration.SearchEngine, version))
+            return this
+        }
+
         /**
          * Enable FxA state migration.
          *
@@ -366,6 +398,7 @@ class FennecMigrator private constructor(
                 loginsStorage,
                 loginsStorageKey,
                 sessionManager,
+                searchEngineManager,
                 accountManager,
                 engine,
                 addonCollectionProvider,
@@ -536,6 +569,7 @@ class FennecMigrator private constructor(
                 Migration.Settings -> migrateSharedPrefs()
                 Migration.Addons -> migrateAddons()
                 Migration.TelemetryIdentifiers -> migrateTelemetryIdentifiers()
+                Migration.SearchEngine -> migrateSearchEngine()
             }
 
             val migrationRun = when (migrationResult) {
@@ -555,6 +589,7 @@ class FennecMigrator private constructor(
                         Migration.Settings -> MigrationSettings.anyFailures.set(true)
                         Migration.Addons -> MigrationAddons.anyFailures.set(true)
                         Migration.TelemetryIdentifiers -> MigrationTelemetryIdentifiers.anyFailures.set(true)
+                        Migration.SearchEngine -> MigrationSearch.anyFailures.set(true)
                     }
                     setFailure(versionedMigration.migration)
 
@@ -959,6 +994,50 @@ class FennecMigrator private constructor(
         }
     }
 
+    @SuppressWarnings("TooGenericExceptionCaught")
+    private suspend fun migrateSearchEngine(): Result<SearchEngineMigrationResult> {
+        val manager = searchEngineManager
+            ?: throw AssertionError("Migrating search engines without search engine manager set")
+
+        try {
+            val result = SearchEngineMigration.migrate(context, manager)
+
+            if (result is Result.Failure<SearchEngineMigrationResult>) {
+                val migrationFailureWrapper = result.throwables.first() as SearchEngineMigrationException
+                return when (val failure = migrationFailureWrapper.failure) {
+                    is SearchEngineMigrationResult.Failure.NoDefault -> {
+                        logger.error("Missing search engine default: $failure")
+                        crashReporter.submitCaughtException(migrationFailureWrapper)
+                        MigrationSearch.failureReason.add(FailureReasonTelemetryCodes.SEARCH_NO_DEFAULT.code)
+                        result
+                    }
+
+                    is SearchEngineMigrationResult.Failure.NoMatch -> {
+                        logger.error("Could not find matching search engine: $failure")
+                        crashReporter.submitCaughtException(migrationFailureWrapper)
+                        MigrationSearch.failureReason.add(FailureReasonTelemetryCodes.SEARCH_NO_MATCH.code)
+                        result
+                    }
+                }
+            }
+
+            val migrationSuccess = result as Result.Success<SearchEngineMigrationResult>
+            return when (migrationSuccess.value as SearchEngineMigrationResult.Success) {
+                is SearchEngineMigrationResult.Success.SearchEngineMigrated -> {
+                    logger.debug("Migrated default search engine")
+                    MigrationSearch.successReason.add(SuccessReasonTelemetryCodes.SEARCH_MIGRATED.code)
+                    result
+                }
+            }
+        } catch (e: Exception) {
+            crashReporter.submitCaughtException(
+                FennecMigratorException.MigrateSearchEngineException(e)
+            )
+            MigrationSearch.failureReason.add(FailureReasonTelemetryCodes.SEARCH_EXCEPTION.code)
+            return Result.Failure(e)
+        }
+    }
+
     @SuppressWarnings("TooGenericExceptionCaught", "NestedBlockDepth", "ComplexMethod")
     private suspend fun migrateAddons(): Result<AddonMigrationResult> {
         return try {

components/support/migration/src/main/java/mozilla/components/support/migration/MigrationResultsStore.kt

@@ -63,6 +63,7 @@ internal class MigrationResultsStore(context: Context) : SharedPreferencesCache<
                 Migration.Settings.javaClass.simpleName -> Migration.Settings
                 Migration.Addons.javaClass.simpleName -> Migration.Addons
                 Migration.TelemetryIdentifiers.javaClass.simpleName -> Migration.TelemetryIdentifiers
+                Migration.SearchEngine.javaClass.simpleName -> Migration.SearchEngine
                 else -> throw IllegalStateException("Unrecognized migration type: $migrationName")
             }
             result[migration] = MigrationRun(version = migrationVersion, success = migrationSuccess)

components/support/migration/src/main/java/mozilla/components/support/migration/SearchEngineMigration.kt

@@ -0,0 +1,113 @@
+/* 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/. */
+
+package mozilla.components.support.migration
+
+import android.content.Context
+import mozilla.components.browser.search.SearchEngineManager
+import mozilla.components.support.base.log.logger.Logger
+
+private const val PREF_FENNEC_DEFAULT_ENGINE_KEY = "search.engines.defaultname"
+private const val PREF_FENIX_DEFAULT_ENGINE_KEY = "pref_key_search_engine"
+
+/**
+ * Implementation for migrating the default search engine from Fennec to Fenix.
+ *
+ * This is a "best effort" migration. We will recover the default search engine name from Fennec and
+ * then try to find a matching search engine in the search engine manager for the current Fenix
+ * installation. If we find a match we will update the default search engine to that; otherwise
+ * the regular default search engine for this installation will be used.
+ */
+internal object SearchEngineMigration {
+    private val logger = Logger("SearchEngineMigration")
+
+    /**
+     * Tries to migrate the default search engine from Fennec to Fenix.
+     */
+    suspend fun migrate(
+        context: Context,
+        searchEngineManager: SearchEngineManager
+    ): Result<SearchEngineMigrationResult> {
+        val fennecSearchEngine = retrieveFennecDefaultSearchEngineName(context)
+        if (fennecSearchEngine == null) {
+            logger.debug("Could not locate Fennec search engine preference")
+            return Result.Failure(
+                SearchEngineMigrationException(SearchEngineMigrationResult.Failure.NoDefault))
+        }
+
+        logger.debug("Found search engine from Fennec: $fennecSearchEngine")
+
+        return determineNewDefault(context, searchEngineManager, fennecSearchEngine)
+    }
+
+    private suspend fun determineNewDefault(
+        context: Context,
+        searchEngineManager: SearchEngineManager,
+        name: String
+    ): Result<SearchEngineMigrationResult> {
+        val searchEngines = searchEngineManager.getSearchEnginesAsync(context)
+
+        logger.debug("Got ${searchEngines.size} search engines from SearchEngineManager.")
+
+        // We will try to find a search engine that has a matching name in the list of search engines
+        // for this Fenix installation (which depends on locale/region). If we find a match then we
+        // update Fenix to use this search engine. If there's no match then we leave it to Fenix to
+        // pick a default search engine.
+        searchEngines.forEach { engine ->
+            logger.debug(" - Fennec: $name - Comparing with Fenix search engine: ${engine.name}")
+
+            if (engine.name.contains(name, ignoreCase = true)) {
+                logger.debug("Setting new default: ${engine.name}")
+
+                val fenixPreferences = context.getSharedPreferences(
+                    FennecSettingsMigration.FENIX_SHARED_PREFS_NAME,
+                    Context.MODE_PRIVATE
+                )
+
+                fenixPreferences.edit()
+                    .putString(PREF_FENIX_DEFAULT_ENGINE_KEY, engine.name)
+                    .apply()
+
+                searchEngineManager.defaultSearchEngine = engine
+
+                return Result.Success(SearchEngineMigrationResult.Success.SearchEngineMigrated)
+            }
+        }
+
+        logger.debug("Could not find matching search engine")
+        return Result.Failure(SearchEngineMigrationException(
+            SearchEngineMigrationResult.Failure.NoMatch
+        ))
+    }
+
+    private fun retrieveFennecDefaultSearchEngineName(context: Context): String? {
+        val fennecPreferences = context.getSharedPreferences(
+            FennecSettingsMigration.FENNEC_APP_SHARED_PREFS_NAME,
+            Context.MODE_PRIVATE
+        )
+
+        return fennecPreferences.getString(PREF_FENNEC_DEFAULT_ENGINE_KEY, null)
+    }
+}
+
+/**
+ * Result of the default search engine migration.
+ */
+internal sealed class SearchEngineMigrationResult {
+    internal sealed class Success : SearchEngineMigrationResult() {
+        internal object SearchEngineMigrated : Success()
+    }
+
+    internal sealed class Failure : SearchEngineMigrationResult() {
+        internal object NoDefault : SearchEngineMigrationResult.Failure()
+        internal object NoMatch : SearchEngineMigrationResult.Failure()
+    }
+}
+
+/**
+ * Wraps [SearchEngineMigrationResult] in an exception so that it can be returned via [Result.Failure].
+ */
+internal class SearchEngineMigrationException(
+    val failure: SearchEngineMigrationResult.Failure
+) : Exception(failure.toString())

components/support/migration/src/main/java/mozilla/components/support/migration/TelemetryHelpers.kt

@@ -16,6 +16,7 @@ internal fun Migration.telemetryIdentifier(): String {
         Migration.Settings -> "settings"
         Migration.Addons -> "addons"
         Migration.TelemetryIdentifiers -> "telemetry_identifiers"
+        Migration.SearchEngine -> "search"
     }
 }
 
@@ -64,6 +65,10 @@ internal enum class FailureReasonTelemetryCodes(val code: Int) {
 
     TELEMETRY_IDENTIFIERS_MISSING_PROFILE(29),
     TELEMETRY_IDENTIFIERS_MIGRATE_EXCEPTION(30),
+
+    SEARCH_NO_DEFAULT(31),
+    SEARCH_NO_MATCH(32),
+    SEARCH_EXCEPTION(33)
 }
 
 @SuppressWarnings("MagicNumber")
@@ -94,4 +99,5 @@ internal enum class SuccessReasonTelemetryCodes(val code: Int) {
     TELEMETRY_IDENTIFIERS_MIGRATED(16),
 
     FXA_WILL_RETRY(17),
+    SEARCH_MIGRATED(18)
 }