Move code to validate identities and folders

app/core/src/main/java/com/fsck/k9/preferences/AccountSettingsValidator.kt

@@ -4,6 +4,9 @@ import com.fsck.k9.preferences.ServerTypeConverter.toServerSettingsType
 import com.fsck.k9.preferences.Settings.InvalidSettingValueException
 
 internal class AccountSettingsValidator {
+    private val identitySettingsValidator = IdentitySettingsValidator()
+    private val folderSettingsValidator = FolderSettingsValidator()
+
     fun validate(contentVersion: Int, account: SettingsFile.Account): ValidatedSettings.Account {
         val validatedSettings = AccountSettingsDescriptions.validate(contentVersion, account.settings!!, true)
 
@@ -16,9 +19,34 @@ internal class AccountSettingsValidator {
             incoming = incomingServer,
             outgoing = outgoingServer,
             settings = validatedSettings,
+            identities = validateIdentities(contentVersion, account.identities),
+            folders = validateFolders(contentVersion, account.folders),
         )
     }
 
+    private fun validateIdentities(
+        contentVersion: Int,
+        identities: List<SettingsFile.Identity>?,
+    ): List<ValidatedSettings.Identity> {
+        if (identities.isNullOrEmpty()) {
+            throw InvalidSettingValueException("Missing identities, there should be at least one.")
+        }
+
+        return identities.map { identity ->
+            identitySettingsValidator.validate(contentVersion, identity)
+        }
+    }
+
+    private fun validateFolders(
+        contentVersion: Int,
+        folders: List<SettingsFile.Folder>?,
+    ): List<ValidatedSettings.Folder> {
+        return folders.orEmpty()
+            .map { folder ->
+                folderSettingsValidator.validate(contentVersion, folder)
+            }
+    }
+
     private fun validateIncomingServer(incoming: SettingsFile.Server?): ValidatedSettings.Server {
         if (incoming == null) {
             throw InvalidSettingValueException("Missing incoming server settings")

app/core/src/main/java/com/fsck/k9/preferences/SettingsImporter.kt

@@ -33,8 +33,6 @@ class SettingsImporter internal constructor(
     private val context: Context,
 ) {
     private val generalSettingsValidator = GeneralSettingsValidator()
-    private val folderSettingsValidator = FolderSettingsValidator()
-    private val identitySettingsValidator = IdentitySettingsValidator()
     private val accountSettingsValidator = AccountSettingsValidator()
 
     private val generalSettingsUpgrader = GeneralSettingsUpgrader()
@@ -260,18 +258,11 @@ class SettingsImporter internal constructor(
         val uuid = accountMapping.second.uuid
 
         // Write identities
-        if (account.identities != null) {
-            importIdentities(editor, contentVersion, uuid, account)
-        } else {
-            // Require accounts to at least have one identity
-            throw InvalidSettingValueException("Missing identities, there should be at least one.")
-        }
+        importIdentities(editor, contentVersion, uuid, currentAccount.identities)
 
         // Write folder settings
-        if (account.folders != null) {
-            for (folder in account.folders) {
-                importFolder(editor, contentVersion, uuid, folder)
-            }
+        for (folder in currentAccount.folders) {
+            importFolder(editor, contentVersion, uuid, folder)
         }
 
         return AccountDescriptionPair(
@@ -289,11 +280,9 @@ class SettingsImporter internal constructor(
         editor: StorageEditor,
         contentVersion: Int,
         uuid: String,
-        folder: SettingsFile.Folder,
+        folder: ValidatedSettings.Folder,
     ) {
-        val validatedFolder = folderSettingsValidator.validate(contentVersion, folder)
-
-        val currentFolder = folderSettingsUpgrader.upgrade(contentVersion, validatedFolder)
+        val currentFolder = folderSettingsUpgrader.upgrade(contentVersion, folder)
 
         folderSettingsWriter.write(editor, uuid, currentFolder)
     }
@@ -303,10 +292,10 @@ class SettingsImporter internal constructor(
         editor: StorageEditor,
         contentVersion: Int,
         uuid: String,
-        account: SettingsFile.Account,
+        identities: List<ValidatedSettings.Identity>,
     ) {
         // Write identities
-        for ((index, identity) in account.identities!!.withIndex()) {
+        for ((index, identity) in identities.withIndex()) {
             importIdentity(editor, contentVersion, uuid, index, identity)
         }
     }
@@ -316,11 +305,9 @@ class SettingsImporter internal constructor(
         contentVersion: Int,
         accountUuid: String,
         index: Int,
-        identity: SettingsFile.Identity,
+        identity: ValidatedSettings.Identity,
     ) {
-        val validatedIdentity = identitySettingsValidator.validate(contentVersion, identity)
-
-        val currentIdentity = identitySettingsUpgrader.upgrade(contentVersion, validatedIdentity)
+        val currentIdentity = identitySettingsUpgrader.upgrade(contentVersion, identity)
 
         identitySettingsWriter.write(editor, accountUuid, index, currentIdentity)
     }

app/core/src/main/java/com/fsck/k9/preferences/ValidatedSettings.kt

@@ -9,8 +9,8 @@ interface ValidatedSettings {
         val incoming: Server,
         val outgoing: Server,
         val settings: InternalSettingsMap,
-//        val identities: List<Identity>,
-//        val folders: List<Folder>,
+        val identities: List<Identity>,
+        val folders: List<Folder>,
     )
 
     data class Server(