#14: Add option to merge into an existing backup directory

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## Unreleased
 
 * Added:
+  * Option to merge into an existing backup directory.
   * `--api` flag in CLI mode.
   * `--by-steam-id` flag in CLI mode.
 * Fixed:

README.md

@@ -93,6 +93,9 @@ If you are on Mac:
 * You can press `back up` to perform the backup for real.
   * If the target folder already exists, it will be deleted first,
     then recreated.
+    <!--
+    However, if you've enabled the merge option, then it will not be deleted first.
+    -->
   * Within the target folder, for every game with data to back up,
     a subfolder will be created with the game's name encoded as
     [Base64](https://en.wikipedia.org/wiki/Base64).
@@ -260,6 +263,10 @@ Here are the available settings (all are required unless otherwise noted):
     This can be overridden in the CLI with `--path`.
   * `ignoredGames` (optional, array of strings): Names of games to skip when backing up.
     This can be overridden in the CLI by passing a list of games.
+  <!--
+  * `merge` (optional, boolean): Whether to merge save data into the target
+    directory rather than deleting the directory first. Default: false.
+  -->
 * `restore` (map):
   * `path` (string): Full path to a directory from which to restore data.
     This can be overridden in the CLI with `--path`.

src/cli.rs

@@ -40,6 +40,18 @@ pub enum Subcommand {
         #[structopt(long)]
         force: bool,
 
+        /// Merge into existing directory instead of deleting/recreating it.
+        /// Within the target directory, the subdirectories for individual
+        /// games will still be cleared out first, though.
+        /// When not specified, this defers to Ludusavi's config file.
+        #[structopt(long)]
+        merge: bool,
+
+        /// Don't merge; delete and recreate the target directory.
+        /// When not specified, this defers to Ludusavi's config file.
+        #[structopt(long, conflicts_with("merge"))]
+        no_merge: bool,
+
         /// Download the latest copy of the manifest.
         #[structopt(long)]
         update: bool,
@@ -357,6 +369,8 @@ pub fn run_cli(sub: Subcommand) -> Result<(), Error> {
             preview,
             path,
             force,
+            merge,
+            no_merge,
             update,
             by_steam_id,
             api,
@@ -377,9 +391,18 @@ pub fn run_cli(sub: Subcommand) -> Result<(), Error> {
             let roots = &config.roots;
 
             if !preview {
-                if !force && backup_dir.exists() {
+                if !force && !merge && backup_dir.exists() {
                     return Err(crate::prelude::Error::CliBackupTargetExists { path: backup_dir });
-                } else if let Err(e) = prepare_backup_target(&backup_dir) {
+                } else if let Err(e) = prepare_backup_target(
+                    &backup_dir,
+                    if merge {
+                        true
+                    } else if no_merge {
+                        false
+                    } else {
+                        config.backup.merge
+                    },
+                ) {
                     return Err(e);
                 }
             }
@@ -633,6 +656,8 @@ mod tests {
                         preview: false,
                         path: None,
                         force: false,
+                        merge: false,
+                        no_merge: false,
                         update: false,
                         by_steam_id: false,
                         api: false,
@@ -652,6 +677,7 @@ mod tests {
                     "--path",
                     "tests/backup",
                     "--force",
+                    "--merge",
                     "--update",
                     "--by-steam-id",
                     "--api",
@@ -663,6 +689,8 @@ mod tests {
                         preview: true,
                         path: Some(StrictPath::new(s("tests/backup"))),
                         force: true,
+                        merge: true,
+                        no_merge: false,
                         update: true,
                         by_steam_id: true,
                         api: true,
@@ -681,6 +709,28 @@ mod tests {
                         preview: false,
                         path: Some(StrictPath::new(s("tests/fake"))),
                         force: false,
+                        merge: false,
+                        no_merge: false,
+                        update: false,
+                        by_steam_id: false,
+                        api: false,
+                        games: vec![],
+                    }),
+                },
+            );
+        }
+
+        #[test]
+        fn accepts_cli_backup_with_no_merge() {
+            check_args(
+                &["ludusavi", "backup", "--no-merge"],
+                Cli {
+                    sub: Some(Subcommand::Backup {
+                        preview: false,
+                        path: None,
+                        force: false,
+                        merge: false,
+                        no_merge: true,
                         update: false,
                         by_steam_id: false,
                         api: false,

src/gui.rs

@@ -128,6 +128,7 @@ enum Message {
     BackupComplete,
     RestoreComplete,
     EditedBackupTarget(String),
+    EditedBackupMerge(bool),
     EditedRestoreSource(String),
     EditedRoot(EditAction),
     SelectedRootStore(usize, Store),
@@ -307,8 +308,11 @@ impl ModalComponent {
                                 .align_items(Align::Center)
                                 .push(Text::new(match theme {
                                     ModalTheme::Error { variant } => translator.handle_error(variant),
-                                    ModalTheme::ConfirmBackup => translator
-                                        .modal_confirm_backup(&config.backup.path, config.backup.path.exists()),
+                                    ModalTheme::ConfirmBackup => translator.modal_confirm_backup(
+                                        &config.backup.path,
+                                        config.backup.path.exists(),
+                                        config.backup.merge,
+                                    ),
                                     ModalTheme::ConfirmRestore => {
                                         translator.modal_confirm_restore(&config.restore.path)
                                     }
@@ -1063,6 +1067,11 @@ impl BackupScreenComponent {
                             )
                             .padding(5),
                         )
+                        .push(Checkbox::new(
+                            config.backup.merge,
+                            translator.backup_merge_label(),
+                            Message::EditedBackupMerge,
+                        ))
                         .push(
                             Button::new(&mut self.backup_target_browse_button, Icon::FolderOpen.as_text())
                                 .on_press(match operation {
@@ -1371,7 +1380,7 @@ impl Application for App {
 
                 let backup_path = &self.config.backup.path;
                 if !preview {
-                    if let Err(e) = prepare_backup_target(&backup_path) {
+                    if let Err(e) = prepare_backup_target(&backup_path, self.config.backup.merge) {
                         self.modal_theme = Some(ModalTheme::Error { variant: e });
                         return Command::none();
                     }
@@ -1613,6 +1622,10 @@ impl Application for App {
                 self.config.save();
                 Command::none()
             }
+            Message::EditedBackupMerge(enabled) => {
+                self.config.backup.merge = enabled;
+                Command::none()
+            }
             Message::EditedRestoreSource(text) => {
                 self.restore_screen.restore_source_history.push(&text);
                 self.config.restore.path.reset(text);

src/lang.rs

@@ -373,6 +373,13 @@ impl Translator {
         .into()
     }
 
+    pub fn backup_merge_label(&self) -> String {
+        match self.language {
+            Language::English => "Merge",
+        }
+        .into()
+    }
+
     pub fn restore_source_label(&self) -> String {
         match self.language {
             Language::English => "Restore from:",
@@ -425,10 +432,11 @@ impl Translator {
         .into()
     }
 
-    pub fn modal_confirm_backup(&self, target: &StrictPath, target_exists: bool) -> String {
-        match (self.language, target_exists) {
-            (Language::English, false) => format!("Are you sure you want to proceed with the backup? The target folder does not already exist, so it will be created: {}", target.render()),
-            (Language::English, true) => format!("Are you sure you want to proceed with the backup? The target folder already exists, so it will be deleted and recreated from scratch: {}", target.render()),
+    pub fn modal_confirm_backup(&self, target: &StrictPath, target_exists: bool, merge: bool) -> String {
+        match (self.language, target_exists, merge) {
+            (Language::English, false, _) => format!("Are you sure you want to proceed with the backup? The target folder will be created: {}", target.render()),
+            (Language::English, true, false) => format!("Are you sure you want to proceed with the backup? The target folder will be deleted and recreated from scratch: {}", target.render()),
+            (Language::English, true, true) => format!("Are you sure you want to proceed with the backup? New save data will be merged into the target folder: {}", target.render()),
         }
     }
 

src/prelude.rs

@@ -560,10 +560,15 @@ fn scan_game_for_restoration(name: &str, source: &StrictPath) -> ScanInfo {
     }
 }
 
-pub fn prepare_backup_target(target: &StrictPath) -> Result<(), Error> {
-    target
-        .remove()
-        .map_err(|_| Error::CannotPrepareBackupTarget { path: target.clone() })?;
+pub fn prepare_backup_target(target: &StrictPath, merge: bool) -> Result<(), Error> {
+    if !merge {
+        target
+            .remove()
+            .map_err(|_| Error::CannotPrepareBackupTarget { path: target.clone() })?;
+    } else if target.exists() && !target.is_dir() {
+        return Err(Error::CannotPrepareBackupTarget { path: target.clone() });
+    }
+
     let p = target.as_std_path_buf();
     std::fs::create_dir_all(&p).map_err(|_| Error::CannotPrepareBackupTarget { path: target.clone() })?;
 
@@ -575,9 +580,23 @@ pub fn back_up_game(info: &ScanInfo, target: &StrictPath, name: &str) -> BackupI
     #[allow(unused_mut)]
     let mut failed_registry = std::collections::HashSet::new();
 
-    for file in &info.found_files {
+    let mut unable_to_prepare = false;
+    if !info.found_files.is_empty() || !info.found_registry_keys.is_empty() {
         let target_game = game_backup_dir(&target, &name);
-        if !target_game.as_path().is_dir() && std::fs::create_dir(target_game).is_err() {
+        match StrictPath::from_std_path_buf(&target_game).remove() {
+            Ok(_) => {
+                if std::fs::create_dir(target_game).is_err() {
+                    unable_to_prepare = true;
+                }
+            }
+            Err(_) => {
+                unable_to_prepare = true;
+            }
+        }
+    }
+
+    for file in &info.found_files {
+        if unable_to_prepare {
             failed_files.insert(file.clone());
             continue;
         }
@@ -592,6 +611,11 @@ pub fn back_up_game(info: &ScanInfo, target: &StrictPath, name: &str) -> BackupI
     #[cfg(target_os = "windows")]
     {
         for reg_path in &info.found_registry_keys {
+            if unable_to_prepare {
+                failed_registry.insert(reg_path.to_string());
+                continue;
+            }
+
             let mut hives = crate::registry::Hives::default();
             match hives.store_key_from_full_path(&reg_path) {
                 Err(_) => {