refactor: add a class to handle the migration logic.

It should cover upgrade, downgrade as well as upgrade from unbranded to branded,
from legacy to branded and from legacy to unbranded.

Signed-off-by: Camila Ayres <hello@camilasan.com>

Author: camilasan

src/libsync/CMakeLists.txt

@@ -164,6 +164,8 @@ set(libsync_SRCS
     creds/keychainchunk.cpp
     caseclashconflictsolver.h
     caseclashconflictsolver.cpp
+    settings/migration.h
+    settings/migration.cpp
 )
 
 if (WIN32)

src/libsync/settings/migration.cpp

@@ -0,0 +1,130 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include <QLoggingCategory>
+
+#include "migration.h"
+#include "theme.h"
+#include "configfile.h"
+#include "version.h"
+
+namespace OCC {
+
+Q_LOGGING_CATEGORY(lcMigration, "nextcloud.settings.migration", QtInfoMsg)
+
+Migration::Migration()
+{
+    _migrationPhase = MigrationPhase::NotStarted;
+    _migrationType = MigrationType::UnbrandedToUnbranded;
+    _versionChangeType = VersionChangeType::NoVersionChange;
+}
+
+QVersionNumber Migration::currentVersion() const
+{
+    return QVersionNumber::fromString(MIRALL_VERSION_STRING);
+}
+
+QVersionNumber Migration::previousVersion() const
+{
+    return QVersionNumber::fromString(ConfigFile().clientPreviousVersionString());
+}
+
+QVersionNumber Migration::configVersion() const
+{
+    return QVersionNumber::fromString(ConfigFile().clientVersionString());
+}
+
+void Migration::setMigrationPhase(const MigrationPhase phase)
+{
+    // do not rollback
+    if (phase > _migrationPhase) {
+        _migrationPhase = phase;
+    }
+}
+
+Migration::MigrationPhase Migration::migrationPhase() const
+{
+    return _migrationPhase;
+}
+
+void Migration::setMigrationType(const MigrationType type)
+{
+    _migrationType = type;
+}
+
+Migration::MigrationType Migration::migrationType() const
+{
+    return _migrationType;
+}
+
+Migration::VersionChangeType Migration::versionChangeType() const
+{
+    return _versionChangeType;
+}
+
+void Migration::setVersionChangeType(const VersionChangeType type)
+{
+    _versionChangeType = type;
+}
+
+bool Migration::isUpgrade()
+{
+    const auto isUpgrade = currentVersion() > previousVersion();
+    if (isUpgrade) {
+        setVersionChangeType(VersionChangeType::Upgrade);
+    }
+    return versionChangeType() == VersionChangeType::Upgrade;
+}
+
+bool Migration::isDowngrade()
+{
+    const auto isDowngrade = previousVersion() > currentVersion();
+    if (isDowngrade) {
+        setVersionChangeType(VersionChangeType::Downgrade);
+    }
+    return versionChangeType() == VersionChangeType::Downgrade;
+}
+
+bool Migration::versionChanged()
+{
+    return isUpgrade() || isDowngrade();
+}
+
+bool Migration::shouldTryUnbrandedToBrandedMigration() const
+{
+    const auto isUnbrandedToBranded = migrationPhase() == Migration::MigrationPhase::SetupFolders
+        && Theme::instance()->appName() != ConfigFile::unbrandedAppName;
+    if (isUnbrandedToBranded) {
+        Migration().setMigrationType(MigrationType::UnbrandedToBranded);
+    }
+    return migrationType() == MigrationType::UnbrandedToBranded;
+}
+
+bool Migration::isUnbrandedToBrandedMigration() const
+{
+    return isInProgress() && migrationType() == MigrationType::UnbrandedToBranded;
+}
+
+bool Migration::shouldTryToMigrate()
+{
+    return !isClientVersionSet() && (isUpgrade() || isDowngrade());
+}
+
+bool Migration::isClientVersionSet() const
+{
+    const auto configVersionNumber = configVersion();
+    const auto previousVersionNumber = previousVersion();
+    return !configVersionNumber.isNull() && !previousVersionNumber.isNull()
+        && configVersionNumber == previousVersionNumber;
+}
+
+bool Migration::isInProgress() const
+{
+    const auto currentPhase = migrationPhase();
+    return currentPhase != MigrationPhase::NotStarted
+        && currentPhase != MigrationPhase::Done;
+}
+
+}

src/libsync/settings/migration.h

@@ -0,0 +1,67 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef MIGRATION_H
+#define MIGRATION_H
+
+#include <QVersionNumber>
+#include "owncloudlib.h"
+
+namespace OCC {
+
+class OWNCLOUDSYNC_EXPORT Migration
+{
+public:
+    Migration();
+
+    enum MigrationPhase {
+        NotStarted,
+        SetupConfigFile,
+        SetupUsers,
+        SetupFolders,
+        Done
+    };
+
+    enum MigrationType {
+        UnbrandedToUnbranded,
+        UnbrandedToBranded,
+        LegacyToUnbranded,
+        LegacyToBranded
+    };
+
+    enum VersionChangeType {
+        NoVersionChange,
+        Upgrade,
+        Downgrade
+    };
+
+    [[nodiscard]] QVersionNumber previousVersion() const;
+    [[nodiscard]] QVersionNumber currentVersion() const;
+    [[nodiscard]] QVersionNumber configVersion() const;
+
+    [[nodiscard]] MigrationPhase migrationPhase() const;
+    [[nodiscard]] MigrationType migrationType() const;
+    [[nodiscard]] VersionChangeType versionChangeType() const;
+
+    void setMigrationPhase(const MigrationPhase phase);
+    void setMigrationType(const MigrationType type);
+    void setVersionChangeType(const VersionChangeType type);
+
+    [[nodiscard]] bool isUpgrade();
+    [[nodiscard]] bool isDowngrade();
+    [[nodiscard]] bool versionChanged();
+    [[nodiscard]] bool shouldTryUnbrandedToBrandedMigration() const;
+    [[nodiscard]] bool isUnbrandedToBrandedMigration() const;
+    [[nodiscard]] bool shouldTryToMigrate();
+    [[nodiscard]] bool isClientVersionSet() const;
+    [[nodiscard]] bool isInProgress() const;
+
+private:
+    MigrationPhase _migrationPhase;
+    MigrationType _migrationType;
+    VersionChangeType _versionChangeType;
+};
+}
+#endif // MIGRATION_H