Clean old incremental backup codes.

31 files changed, 311 insertions, 630 deletions

diff --git a/README.md b/README.md
index 2c34c2f..7152430 100644
--- a/README.md
+++ b/README.md
@@ -51,14 +51,8 @@ done
 
 ## 3. To-Do List:
 
-- New version checker.
-- Refactor code.
-- More thorough test.
-- Implement incremental backup.
-    + Restore: trace-back (recursively, then generate file dependence tree)
-        - Implement unZipRecursively (unzip a .zip.inc file recursively until reaches the root (i.e. the last full backup).)
-    + Backup: base-diff (select most recently backup as the base, then diff)
-        - Implement zipDiff (make a new zip with the latest backup as the base, store diff-table in zip comment (A:Add, M:Modification, D:Deletion))
-- Optimize help menu. (colored command help menu)
-- Add op login hint in the next start after restoring.
-- Implement incremental backup.
+- Incremental backup
+- Code refactor
+- Op login hint in the next start after restoring
+- Optimized help menu (colored command help menu)
+- New version checker
diff --git a/gradle.properties b/gradle.properties
index a131c0a..4d7ec6c 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -4,11 +4,11 @@ org.gradle.jvmargs=-Xmx1G
 # check these on https://fabricmc.net/use
 minecraft_version=1.14.4
 yarn_mappings=1.14.4+build.18
-loader_version=0.10.8
+loader_version=0.11.0
 # Mod Properties
-mod_version=1.3.3
+mod_version=1.4.0
 maven_group=com.keuin.kbackupfabric
 archives_base_name=kbackup-fabric
 # Dependencies
 # currently not on the main fabric site, check on the maven: https://maven.fabricmc.net/net/fabricmc/fabric-api/fabric-api
-fabric_version=0.23.2+1.14
+fabric_version=0.28.4+1.14
diff --git a/src/main/java/com/keuin/kbackupfabric/KBCommands.java b/src/main/java/com/keuin/kbackupfabric/KBCommands.java
index 571333f..ef4a401 100644
--- a/src/main/java/com/keuin/kbackupfabric/KBCommands.java
+++ b/src/main/java/com/keuin/kbackupfabric/KBCommands.java
@@ -5,13 +5,9 @@ import com.keuin.kbackupfabric.operation.BackupOperation;
 import com.keuin.kbackupfabric.operation.DeleteOperation;
 import com.keuin.kbackupfabric.operation.RestoreOperation;
 import com.keuin.kbackupfabric.operation.abstracts.i.Invokable;
-import com.keuin.kbackupfabric.operation.backup.BackupMethod;
-import com.keuin.kbackupfabric.operation.backup.IncrementalBackupMethod;
 import com.keuin.kbackupfabric.operation.backup.PrimitiveBackupMethod;
 import com.keuin.kbackupfabric.util.PrintUtil;
 import com.keuin.kbackupfabric.util.backup.BackupFilesystemUtil;
-import com.keuin.kbackupfabric.util.backup.BackupNameTimeFormatter;
-import com.keuin.kbackupfabric.util.backup.BackupType;
 import com.keuin.kbackupfabric.util.backup.suggestion.BackupNameSuggestionProvider;
 import com.mojang.brigadier.arguments.StringArgumentType;
 import com.mojang.brigadier.context.CommandContext;
@@ -33,10 +29,11 @@ public final class KBCommands {
     private static final int SUCCESS = 1;
     private static final int FAILED = -1;
     private static final String DEFAULT_BACKUP_NAME = "noname";
+    private static boolean notifiedPreviousRestoration = false;
 
     //private static final Logger LOGGER = LogManager.getLogger();
 
-    private static final List<String> backupNameList = new ArrayList<>(); // index -> backupName
+    private static final List<String> backupFileNameList = new ArrayList<>(); // index -> backupName
     private static Invokable pendingOperation = null;
     //private static BackupMethod activatedBackupMethod = new PrimitiveBackupMethod(); // The backup method we currently using
 
@@ -65,8 +62,9 @@ public final class KBCommands {
      */
     public static int kb(CommandContext<ServerCommandSource> context) {
         int statCode = list(context);
-        if (MetadataHolder.hasMetadata()) {
+        if (MetadataHolder.hasMetadata() && !notifiedPreviousRestoration) {
             // Output metadata info
+            notifiedPreviousRestoration = true;
             msgStress(context, "Restored from backup " + MetadataHolder.getMetadata().getBackupName());
         }
         return statCode;
@@ -84,19 +82,20 @@ public final class KBCommands {
                 (dir, name) -> dir.isDirectory() && name.toLowerCase().endsWith(".zip") && name.toLowerCase().startsWith(getBackupFileNamePrefix())
         );
 
-        backupNameList.clear();
+        backupFileNameList.clear();
         if (files != null) {
             if (files.length != 0) {
                 msgInfo(context, "Available backups: (file is not checked, manipulation may affect this plugin)");
             } else {
-                msgInfo(context, "There are no available backups. To make a new backup, check /kb backup.");
+                msgInfo(context, "There are no available backups. To make a new backup, run /kb backup.");
             }
             int i = 0;
             for (File file : files) {
                 ++i;
-                String backupName = getBackupName(file.getName());
-                backupNameList.add(backupName);
-                msgInfo(context, String.format("[%d] %s, size: %.1fMB", i, backupName, file.length() * 1.0 / 1024 / 1024));
+                String backupFileName = file.getName();
+                String sizeString = getFriendlyFileSizeString(file.length());
+                msgInfo(context, String.format("[%d] %s, size: %s", i, backupFileName, sizeString));
+                backupFileNameList.add(backupFileName);
             }
         } else {
             msgErr(context, "Error: failed to list files in backup folder.");
@@ -112,13 +111,13 @@ public final class KBCommands {
      */
     public static int primitiveBackup(CommandContext<ServerCommandSource> context) {
         //KBMain.backup("name")
-        String backupName = StringArgumentType.getString(context, "backupName");
-        if (backupName.matches("[0-9]*")) {
+        String customBackupName = StringArgumentType.getString(context, "backupName");
+        if (customBackupName.matches("[0-9]*")) {
             // Numeric param is not allowed
-            backupName = String.format("a%s", backupName);
-            msgWarn(context, String.format("Pure numeric name is not allowed. Renaming to %s", backupName));
+            customBackupName = String.format("a%s", customBackupName);
+            msgWarn(context, String.format("Pure numeric name is not allowed. Renaming to %s", customBackupName));
         }
-        return doBackup(context, backupName, PrimitiveBackupMethod.getInstance());
+        return doBackup(context, customBackupName);
     }
 
     /**
@@ -128,23 +127,23 @@ public final class KBCommands {
      * @return stat code.
      */
     public static int primitiveBackupWithDefaultName(CommandContext<ServerCommandSource> context) {
-        return doBackup(context, DEFAULT_BACKUP_NAME, PrimitiveBackupMethod.getInstance());
+        return doBackup(context, DEFAULT_BACKUP_NAME);
     }
 
-    public static int incrementalBackup(CommandContext<ServerCommandSource> context) {
-        //KBMain.backup("name")
-        String backupName = StringArgumentType.getString(context, "backupName");
-        if (backupName.matches("[0-9]*")) {
-            // Numeric param is not allowed
-            backupName = String.format("a%s", backupName);
-            msgWarn(context, String.format("Pure numeric name is not allowed. Renaming to %s", backupName));
-        }
-        return doBackup(context, backupName, IncrementalBackupMethod.getInstance());
-    }
-
-    public static int incrementalBackupWithDefaultName(CommandContext<ServerCommandSource> context) {
-        return doBackup(context, DEFAULT_BACKUP_NAME, IncrementalBackupMethod.getInstance());
-    }
+//    public static int incrementalBackup(CommandContext<ServerCommandSource> context) {
+//        //KBMain.backup("name")
+//        String backupName = StringArgumentType.getString(context, "backupName");
+//        if (backupName.matches("[0-9]*")) {
+//            // Numeric param is not allowed
+//            backupName = String.format("a%s", backupName);
+//            msgWarn(context, String.format("Pure numeric name is not allowed. Renaming to %s", backupName));
+//        }
+//        return doBackup(context, backupName, IncrementalBackupMethod.getInstance());
+//    }
+//
+//    public static int incrementalBackupWithDefaultName(CommandContext<ServerCommandSource> context) {
+//        return doBackup(context, DEFAULT_BACKUP_NAME, IncrementalBackupMethod.getInstance());
+//    }
 
     /**
      * Delete an existing backup with context parameter backupName.
@@ -155,14 +154,14 @@ public final class KBCommands {
      */
     public static int delete(CommandContext<ServerCommandSource> context) {
 
-        String backupName = parseBackupName(context, StringArgumentType.getString(context, "backupName"));
+        String backupFileName = parseBackupFileName(context, StringArgumentType.getString(context, "backupName"));
         MinecraftServer server = context.getSource().getMinecraftServer();
 
-        if (backupName == null)
+        if (backupFileName == null)
             return list(context); // Show the list and return
 
         // Validate backupName
-        if (!isBackupNameValid(backupName, server)) {
+        if (!isBackupFileExists(backupFileName, server)) {
             // Invalid backupName
             msgErr(context, "Invalid backup name! Please check your input. The list index number is also valid.");
             return FAILED;
@@ -170,9 +169,9 @@ public final class KBCommands {
 
         // Update pending task
         //pendingOperation = AbstractConfirmableOperation.createDeleteOperation(context, backupName);
-        pendingOperation = new DeleteOperation(context, backupName);
+        pendingOperation = new DeleteOperation(context, backupFileName);
 
-        msgWarn(context, String.format("DELETION WARNING: The deletion is irreversible! You will lose the backup %s permanently. Use /kb confirm to start or /kb cancel to abort.", backupName), true);
+        msgWarn(context, String.format("DELETION WARNING: The deletion is irreversible! You will lose the backup %s permanently. Use /kb confirm to start or /kb cancel to abort.", backupFileName), true);
         return SUCCESS;
     }
 
@@ -187,14 +186,14 @@ public final class KBCommands {
     public static int restore(CommandContext<ServerCommandSource> context) {
         //KBMain.restore("name")
         MinecraftServer server = context.getSource().getMinecraftServer();
-        String backupName = parseBackupName(context, StringArgumentType.getString(context, "backupName"));
-        backupName = parseBackupName(context, backupName);
+        String backupFileName = parseBackupFileName(context, StringArgumentType.getString(context, "backupName"));
+        backupFileName = parseBackupFileName(context, backupFileName);
 
-        if (backupName == null)
+        if (backupFileName == null)
             return list(context); // Show the list and return
 
         // Validate backupName
-        if (!isBackupNameValid(backupName, server)) {
+        if (!isBackupFileExists(backupFileName, server)) {
             // Invalid backupName
             msgErr(context, "Invalid backup name! Please check your input. The list index number is also valid.", false);
             return FAILED;
@@ -205,22 +204,22 @@ public final class KBCommands {
 
         // Update pending task
         //pendingOperation = AbstractConfirmableOperation.createRestoreOperation(context, backupName);
-        File backupFile = new File(getBackupSaveDirectory(server), getBackupFileName(backupName));
-        pendingOperation = new RestoreOperation(context, backupFile.getAbsolutePath(), getLevelPath(server), backupName);
+//        File backupFile = new File(getBackupSaveDirectory(server), getBackupFileName(backupName));
+        pendingOperation = new RestoreOperation(context, getBackupSaveDirectory(server).getAbsolutePath(), getLevelPath(server), backupFileName);
 
-        msgWarn(context, String.format("RESET WARNING: You will LOSE YOUR CURRENT WORLD PERMANENTLY! The worlds will be replaced with backup %s . Use /kb confirm to start or /kb cancel to abort.", backupName), true);
+        msgWarn(context, String.format("RESET WARNING: You will LOSE YOUR CURRENT WORLD PERMANENTLY! The worlds will be replaced with backup %s . Use /kb confirm to start or /kb cancel to abort.", backupFileName), true);
         return SUCCESS;
     }
 
-    private static int doBackup(CommandContext<ServerCommandSource> context, String customBackupName, BackupMethod backupMethod) {
+    private static int doBackup(CommandContext<ServerCommandSource> context, String customBackupName) {
         // Real backup name (compatible with legacy backup): date_name, such as 2020-04-23_21-03-00_test
         //KBMain.backup("name")
-        String backupName = BackupNameTimeFormatter.getTimeString() + "_" + customBackupName;
+//        String backupName = BackupNameTimeFormatter.getTimeString() + "_" + customBackupName;
 
         // Validate file name
         final char[] ILLEGAL_CHARACTERS = {'/', '\n', '\r', '\t', '\0', '\f', '`', '?', '*', '\\', '<', '>', '|', '\"', ':'};
         for (char c : ILLEGAL_CHARACTERS) {
-            if (backupName.contains(String.valueOf(c))) {
+            if (customBackupName.contains(String.valueOf(c))) {
                 msgErr(context, String.format("Name cannot contain special character \"%c\".", c));
                 return FAILED;
             }
@@ -229,7 +228,7 @@ public final class KBCommands {
         // Do backup
         PrintUtil.info("Invoking backup worker ...");
         //BackupWorker.invoke(context, backupName, metadata);
-        BackupOperation operation = new BackupOperation(context, backupName, backupMethod);
+        BackupOperation operation = new BackupOperation(context, customBackupName, PrimitiveBackupMethod.getInstance());
         if (operation.invoke()) {
             return SUCCESS;
         } else if (operation.isBlocked()) {
@@ -293,15 +292,15 @@ public final class KBCommands {
             files.removeIf(f -> !f.getName().startsWith(BackupFilesystemUtil.getBackupFileNamePrefix()));
             files.sort((x, y) -> (int) (BackupFilesystemUtil.getBackupTimeFromBackupFileName(y.getName()) - BackupFilesystemUtil.getBackupTimeFromBackupFileName(x.getName())));
             File prevBackupFile = files.get(0);
-            String backupName = getBackupName(prevBackupFile.getName());
-            int i = backupNameList.indexOf(backupName);
+            String backupFileName = prevBackupFile.getName();
+            int i = backupFileNameList.indexOf(backupFileName);
             if (i == -1) {
-                backupNameList.add(backupName);
-                i = backupNameList.size();
+                backupFileNameList.add(backupFileName);
+                i = backupFileNameList.size();
             } else {
                 ++i;
             }
-            msgInfo(context, String.format("The most recent backup: [%d] %s , size: %s", i, backupName, getFriendlyFileSizeString(prevBackupFile.length())));
+            msgInfo(context, String.format("The most recent backup: [%d] %s , size: %s", i, backupFileName, getFriendlyFileSizeString(prevBackupFile.length())));
         } catch (NullPointerException e) {
             msgInfo(context, "There are no backups available.");
         } catch (SecurityException ignored) {
@@ -311,35 +310,35 @@ public final class KBCommands {
         return SUCCESS;
     }
 
-    /**
-     * Select the backup method we use.
-     * @param context the context.
-     * @return stat code.
-     */
-    public static int setMethod(CommandContext<ServerCommandSource> context) {
-        String desiredMethodName = StringArgumentType.getString(context, "backupMethod");
-        List<BackupType> backupMethods = Arrays.asList(BackupType.PRIMITIVE_ZIP_BACKUP, BackupType.OBJECT_TREE_BACKUP);
-        for (BackupType method : backupMethods) {
-            if(method.getName().equals(desiredMethodName)) {
-                // Incremental backup
-//                activatedBackupMethod =
-                msgInfo(context, String.format("Backup method is set to: %s", desiredMethodName));
-                return SUCCESS;
-            }
-        }
-
-        return SUCCESS;
-    }
-
-
-    private static String parseBackupName(CommandContext<ServerCommandSource> context, String userInput) {
+//    /**
+//     * Select the backup method we use.
+//     * @param context the context.
+//     * @return stat code.
+//     */
+//    public static int setMethod(CommandContext<ServerCommandSource> context) {
+//        String desiredMethodName = StringArgumentType.getString(context, "backupMethod");
+//        List<BackupType> backupMethods = Arrays.asList(BackupType.PRIMITIVE_ZIP_BACKUP, BackupType.OBJECT_TREE_BACKUP);
+//        for (BackupType method : backupMethods) {
+//            if(method.getName().equals(desiredMethodName)) {
+//                // Incremental backup
+////                activatedBackupMethod =
+//                msgInfo(context, String.format("Backup method is set to: %s", desiredMethodName));
+//                return SUCCESS;
+//            }
+//        }
+//
+//        return SUCCESS;
+//    }
+
+
+    private static String parseBackupFileName(CommandContext<ServerCommandSource> context, String userInput) {
         try {
             String backupName = StringArgumentType.getString(context, "backupName");
 
             if (backupName.matches("[0-9]*")) {
                 // If numeric input
                 int index = Integer.parseInt(backupName) - 1;
-                return backupNameList.get(index); // Replace input number with real backup name.
+                return backupFileNameList.get(index); // Replace input number with real backup file name.
             }
         } catch (NumberFormatException | IndexOutOfBoundsException ignored) {
         }
diff --git a/src/main/java/com/keuin/kbackupfabric/KBCommandsRegister.java b/src/main/java/com/keuin/kbackupfabric/KBCommandsRegister.java
index 3376ac9..4154464 100644
--- a/src/main/java/com/keuin/kbackupfabric/KBCommandsRegister.java
+++ b/src/main/java/com/keuin/kbackupfabric/KBCommandsRegister.java
@@ -1,8 +1,7 @@
 package com.keuin.kbackupfabric;
 
-import com.keuin.kbackupfabric.util.backup.suggestion.BackupMethodSuggestionProvider;
-import com.keuin.kbackupfabric.util.backup.suggestion.BackupNameSuggestionProvider;
 import com.keuin.kbackupfabric.util.PermissionValidator;
+import com.keuin.kbackupfabric.util.backup.suggestion.BackupNameSuggestionProvider;
 import com.mojang.brigadier.CommandDispatcher;
 import com.mojang.brigadier.arguments.StringArgumentType;
 import net.minecraft.server.command.CommandManager;
@@ -19,19 +18,12 @@ public final class KBCommandsRegister {
         // register /kb list for showing the backup list. OP is required.
         dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("list").requires(PermissionValidator::op).executes(KBCommands::list)));
 
-        // register /kb backup zip [name] as a alias
-        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("backup").then(
-                CommandManager.literal("zip").then(
-                        CommandManager.argument("backupName", StringArgumentType.greedyString()).requires(PermissionValidator::op).executes(KBCommands::primitiveBackup)
-                ).requires(PermissionValidator::op).executes(KBCommands::primitiveBackupWithDefaultName)))
-        );
-
-        // register /kb backup incremental [name]
-        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("backup").then(
-                CommandManager.literal("incremental").then(
-                        CommandManager.argument("backupName", StringArgumentType.greedyString()).requires(PermissionValidator::op).executes(KBCommands::incrementalBackup)
-                ).requires(PermissionValidator::op).executes(KBCommands::incrementalBackupWithDefaultName)))
-        );
+//        // register /kb backup incremental [name]
+//        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("backup").then(
+//                CommandManager.literal("incremental").then(
+//                        CommandManager.argument("backupName", StringArgumentType.greedyString()).requires(PermissionValidator::op).executes(KBCommands::incrementalBackup)
+//                ).requires(PermissionValidator::op).executes(KBCommands::incrementalBackupWithDefaultName)))
+//        );
 
         // register /kb backup [name] for performing backup. OP is required.
         dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("backup").then(
@@ -53,7 +45,7 @@ public final class KBCommandsRegister {
         // register /kb prev for showing the latest backup.
         dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("prev").requires(PermissionValidator::op).executes(KBCommands::prev)));
 
-        // register /kb setMethod for selecting backup method (zip, incremental)
-        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("setMethod").then(CommandManager.argument("backupMethod", StringArgumentType.string()).suggests(BackupMethodSuggestionProvider.getProvider()).requires(PermissionValidator::op).executes(KBCommands::setMethod))));
+//        // register /kb setMethod for selecting backup method (zip, incremental)
+//        dispatcher.register(CommandManager.literal("kb").then(CommandManager.literal("setMethod").then(CommandManager.argument("backupMethod", StringArgumentType.string()).suggests(BackupMethodSuggestionProvider.getProvider()).requires(PermissionValidator::op).executes(KBCommands::setMethod))));
     }
 }
diff --git a/src/main/java/com/keuin/kbackupfabric/operation/BackupOperation.java b/src/main/java/com/keuin/kbackupfabric/operation/BackupOperation.java
index 465b293..f8736c8 100644
--- a/src/main/java/com/keuin/kbackupfabric/operation/BackupOperation.java
+++ b/src/main/java/com/keuin/kbackupfabric/operation/BackupOperation.java
@@ -2,6 +2,7 @@ package com.keuin.kbackupfabric.operation;
 
 import com.keuin.kbackupfabric.operation.abstracts.InvokableAsyncBlockingOperation;
 import com.keuin.kbackupfabric.operation.backup.BackupMethod;
+import com.keuin.kbackupfabric.operation.backup.feedback.PrimitiveBackupFeedback;
 import com.keuin.kbackupfabric.util.PrintUtil;
 import com.mojang.brigadier.context.CommandContext;
 import net.minecraft.server.MinecraftServer;
@@ -19,16 +20,16 @@ import static com.keuin.kbackupfabric.util.backup.BackupFilesystemUtil.*;
 public class BackupOperation extends InvokableAsyncBlockingOperation {
 
     private final CommandContext<ServerCommandSource> context;
-    private final String backupName;
+    private final String customBackupName;
     private final Map<World, Boolean> oldWorldsSavingDisabled = new HashMap<>();
     private final BackupMethod backupMethod;
     private long startTime;
 
 
-    public BackupOperation(CommandContext<ServerCommandSource> context, String backupName, BackupMethod backupMethod) {
+    public BackupOperation(CommandContext<ServerCommandSource> context, String customBackupName, BackupMethod backupMethod) {
         super("BackupWorker");
         this.context = context;
-        this.backupName = backupName;
+        this.customBackupName = customBackupName;
         this.backupMethod = backupMethod;
     }
 
@@ -49,18 +50,16 @@ public class BackupOperation extends InvokableAsyncBlockingOperation {
 
             // Make zip
             String levelPath = getLevelPath(server);
-            String backupFileName = getBackupFileName(backupName);
+            String backupFileName = getBackupFileName(customBackupName);
 
-            BackupMethod.BackupResult result = backupMethod.backup(backupName,levelPath,backupSaveDirectory);
+            PrimitiveBackupFeedback result = backupMethod.backup(customBackupName,levelPath,backupSaveDirectory);
             if(result.isSuccess()) {
-                // Restore old autosave switch stat
+                // Restore old auto-save switch stat
                 server.getWorlds().forEach(world -> world.savingDisabled = oldWorldsSavingDisabled.getOrDefault(world, true));
 
                 // Print finish message: time elapsed and file size
                 long timeElapsedMillis = System.currentTimeMillis() - startTime;
-                String msgText = String.format("Backup finished. Time elapsed: %.2fs.", timeElapsedMillis / 1000.0);
-                File backupZipFile = new File(backupSaveDirectory, backupFileName);
-                msgText += String.format(" File size: %s.", getFriendlyFileSizeString(result.getBackupSizeBytes()));
+                String msgText = String.format("Backup finished. Time elapsed: %.2fs. ", timeElapsedMillis / 1000.0) + result.getFeedback();
                 PrintUtil.msgInfo(context, msgText, true);
             } else {
                 // failed
@@ -77,7 +76,7 @@ public class BackupOperation extends InvokableAsyncBlockingOperation {
     protected boolean sync() {
         //// Save world, save old autosave configs
 
-        PrintUtil.broadcast(String.format("Making backup %s, please wait ...", backupName));
+        PrintUtil.broadcast(String.format("Making backup %s, please wait ...", customBackupName));
 
         // Get server
         MinecraftServer server = context.getSource().getMinecraftServer();
diff --git a/src/main/java/com/keuin/kbackupfabric/operation/DeleteOperation.java b/src/main/java/com/keuin/kbackupfabric/operation/DeleteOperation.java
index 444ca9a..3ae09f5 100644
--- a/src/main/java/com/keuin/kbackupfabric/operation/DeleteOperation.java
+++ b/src/main/java/com/keuin/kbackupfabric/operation/DeleteOperation.java
@@ -1,8 +1,8 @@
 package com.keuin.kbackupfabric.operation;
 
 import com.keuin.kbackupfabric.operation.abstracts.InvokableAsyncBlockingOperation;
-import com.keuin.kbackupfabric.util.backup.suggestion.BackupNameSuggestionProvider;
 import com.keuin.kbackupfabric.util.PrintUtil;
+import com.keuin.kbackupfabric.util.backup.suggestion.BackupNameSuggestionProvider;
 import com.mojang.brigadier.context.CommandContext;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.command.ServerCommandSource;
@@ -10,27 +10,26 @@ import net.minecraft.server.command.ServerCommandSource;
 import java.io.File;
 import java.io.IOException;
 
-import static com.keuin.kbackupfabric.util.backup.BackupFilesystemUtil.getBackupFileName;
-import static com.keuin.kbackupfabric.util.backup.BackupFilesystemUtil.getBackupSaveDirectory;
 import static com.keuin.kbackupfabric.util.PrintUtil.msgErr;
 import static com.keuin.kbackupfabric.util.PrintUtil.msgInfo;
+import static com.keuin.kbackupfabric.util.backup.BackupFilesystemUtil.getBackupSaveDirectory;
 import static org.apache.commons.io.FileUtils.forceDelete;
 
 public class DeleteOperation extends InvokableAsyncBlockingOperation {
 
     //private static final Logger LOGGER = LogManager.getLogger();
-    private final String backupName;
+    private final String backupFileName;
     private final CommandContext<ServerCommandSource> context;
 
-    public DeleteOperation(CommandContext<ServerCommandSource> context, String backupName) {
+    public DeleteOperation(CommandContext<ServerCommandSource> context, String backupFileName) {
         super("BackupDeletingWorker");
-        this.backupName = backupName;
+        this.backupFileName = backupFileName;
         this.context = context;
     }
 
     @Override
     public String toString() {
-        return String.format("deletion of %s", backupName);
+        return String.format("deletion of %s", backupFileName);
     }
 
     @Override
@@ -41,8 +40,7 @@ public class DeleteOperation extends InvokableAsyncBlockingOperation {
 
     private void delete() {
         MinecraftServer server = context.getSource().getMinecraftServer();
-        String backupFileName = getBackupFileName(backupName);
-        PrintUtil.info("Deleting backup " + backupName);
+        PrintUtil.info("Deleting backup file " + this.backupFileName);
         File backupFile = new File(getBackupSaveDirectory(server), backupFileName);
         int tryCounter = 0;
         do {
@@ -59,7 +57,7 @@ public class DeleteOperation extends InvokableAsyncBlockingOperation {
             }
             ++tryCounter;
         } while (backupFile.exists());
-        PrintUtil.info("Deleted backup " + backupName);
-        msgInfo(context, "Deleted backup " + backupName);
+        PrintUtil.info("Successfully deleted backup file " + this.backupFileName);
+        msgInfo(context, "Successfully deleted backup file " + this.backupFileName);
     }
 }
diff --git a/src/main/java/com/keuin/kbackupfabric/operation/RestoreOperation.java b/src/main/java/com/keuin/kbackupfabric/operation/RestoreOperation.java
index 22397a1..b95c767 100644
--- a/src/main/java/com/keuin/kbackupfabric/operation/RestoreOperation.java
+++ b/src/main/java/com/keuin/kbackupfabric/operation/RestoreOperation.java
@@ -1,9 +1,9 @@
 package com.keuin.kbackupfabric.operation;
 
-import com.keuin.kbackupfabric.exception.ZipUtilException;
 import com.keuin.kbackupfabric.operation.abstracts.InvokableBlockingOperation;
+import com.keuin.kbackupfabric.operation.backup.BackupMethod;
+import com.keuin.kbackupfabric.operation.backup.PrimitiveBackupMethod;
 import com.keuin.kbackupfabric.util.PrintUtil;
-import com.keuin.kbackupfabric.util.ZipUtil;
 import com.mojang.brigadier.context.CommandContext;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.command.ServerCommandSource;
@@ -13,33 +13,33 @@ import java.io.IOException;
 
 import static com.keuin.kbackupfabric.util.backup.BackupFilesystemUtil.getBackupFileName;
 import static com.keuin.kbackupfabric.util.backup.BackupFilesystemUtil.getBackupSaveDirectory;
-import static org.apache.commons.io.FileUtils.forceDelete;
 
 public class RestoreOperation extends InvokableBlockingOperation {
 
     //private static final Logger LOGGER = LogManager.getLogger();
-    private final String backupName;
+    private final String backupFileName;
     private final Thread serverThread;
-    private final String backupFilePath;
-    private final String levelDirectory;
+    private final String backupSavePath;
+    private final String levelPath;
     private final CommandContext<ServerCommandSource> context;
     private final MinecraftServer server;
+    private final BackupMethod backupMethod = PrimitiveBackupMethod.getInstance();
 
-    public RestoreOperation(CommandContext<ServerCommandSource> context, String backupFilePath, String levelDirectory, String backupName) {
+    public RestoreOperation(CommandContext<ServerCommandSource> context, String backupSavePath, String levelPath, String backupFileName) {
         server = context.getSource().getMinecraftServer();
-        this.backupName = backupName;
+        this.backupFileName = backupFileName;
         this.serverThread = server.getThread();
-        this.backupFilePath = backupFilePath;
-        this.levelDirectory = levelDirectory;
+        this.backupSavePath = backupSavePath;
+        this.levelPath = levelPath;
         this.context = context;
     }
 
     @Override
     protected boolean blockingContext() {
         // do restore to backupName
-        PrintUtil.broadcast(String.format("Restoring to previous world %s ...", backupName));
+        PrintUtil.broadcast(String.format("Restoring to backup %s ...", backupFileName));
 
-        String backupFileName = getBackupFileName(backupName);
+        String backupFileName = getBackupFileName(this.backupFileName);
         PrintUtil.debug("Backup file name: " + backupFileName);
         File backupFile = new File(getBackupSaveDirectory(server), backupFileName);
 
@@ -67,7 +67,7 @@ public class RestoreOperation extends InvokableBlockingOperation {
 
     @Override
     public String toString() {
-        return String.format("restoration from %s", backupName);
+        return String.format("restoration from %s", backupFileName);
     }
 
     private class WorkerThread implements Runnable {
@@ -94,12 +94,16 @@ public class RestoreOperation extends InvokableBlockingOperation {
                 }while(--cnt > 0);
 
                 ////////////////////
+                backupMethod.restore(backupFileName, levelPath, backupSavePath);
 
                 //ServerRestartUtil.forkAndRestart();
                 System.exit(111);
 
             } catch (SecurityException e) {
                 PrintUtil.error("An exception occurred while restoring: " + e.getMessage());
+            } catch (IOException e) {
+                PrintUtil.error(e.toString());
+                PrintUtil.error("Failed to restore.");
             }
         }
     }
diff --git a/src/main/java/com/keuin/kbackupfabric/operation/backup/BackupMethod.java b/src/main/java/com/keuin/kbackupfabric/operation/backup/BackupMethod.java
index 4e9eb6c..b65a076 100644
--- a/src/main/java/com/keuin/kbackupfabric/operation/backup/BackupMethod.java
+++ b/src/main/java/com/keuin/kbackupfabric/operation/backup/BackupMethod.java
@@ -1,7 +1,6 @@
 package com.keuin.kbackupfabric.operation.backup;
 
-import com.keuin.kbackupfabric.util.backup.builder.BackupFileNameBuilder;
-import com.keuin.kbackupfabric.util.backup.formatter.BackupFileNameFormatter;
+import com.keuin.kbackupfabric.operation.backup.feedback.PrimitiveBackupFeedback;
 
 import java.io.IOException;
 
@@ -16,29 +15,8 @@ public interface BackupMethod {
      * @param backupName the backup name.
      * @return if the backup operation succeed.
      */
-    BackupResult backup(String backupName, String levelPath, String backupSaveDirectory) throws IOException;
+    PrimitiveBackupFeedback backup(String backupName, String levelPath, String backupSaveDirectory) throws IOException;
 
     boolean restore(String backupName, String levelPath, String backupSaveDirectory) throws IOException;
 
-    BackupFileNameBuilder getBackupFileNameBuilder();
-
-    BackupFileNameFormatter getBackupFileNameFormatter();
-
-    class BackupResult {
-        private final boolean success;
-        private final long backupSizeBytes;
-
-        public BackupResult(boolean success, long backupSizeBytes) {
-            this.success = success;
-            this.backupSizeBytes = backupSizeBytes;
-        }
-
-        public boolean isSuccess() {
-            return success;
-        }
-
-        public long getBackupSizeBytes() {
-            return backupSizeBytes;
-        }
-    }
 }
diff --git a/src/main/java/com/keuin/kbackupfabric/operation/backup/IncrementalBackupMethod.java b/src/main/java/com/keuin/kbackupfabric/operation/backup/IncrementalBackupMethod.java
deleted file mode 100644
index 4a87bb3..0000000
--- a/src/main/java/com/keuin/kbackupfabric/operation/backup/IncrementalBackupMethod.java
+++ /dev/null
@@ -1,62 +0,0 @@
-package com.keuin.kbackupfabric.operation.backup;
-
-import com.google.gson.JsonObject;
-import com.keuin.kbackupfabric.util.PrintUtil;
-import com.keuin.kbackupfabric.util.backup.builder.BackupFileNameBuilder;
-import com.keuin.kbackupfabric.util.backup.builder.ObjectTreeBackupFileNameBuilder;
-import com.keuin.kbackupfabric.util.backup.formatter.BackupFileNameFormatter;
-import com.keuin.kbackupfabric.util.backup.formatter.ObjectTreeBackupFileNameFormatter;
-
-import java.io.File;
-import java.io.IOException;
-import java.nio.file.Paths;
-import java.time.LocalDateTime;
-
-public class IncrementalBackupMethod implements BackupMethod {
-
-    private static final IncrementalBackupMethod INSTANCE = new IncrementalBackupMethod();
-
-    public static IncrementalBackupMethod getInstance() {
-        return INSTANCE;
-    }
-
-    @Override
-    public BackupResult backup(String backupName, String levelPath, String backupSaveDirectory) throws IOException {
-        /*
-        1. Analyze the save directory, to get a json containing md5 values of all files.
-        2. Copy new files which we do not have in our backup repository.
-        3. Save the above json as a backup file. When restoring from this,
-           what we have to do is just copy all files back from the repository,
-           based on their md5 digests.
-         */
-
-        boolean success = true;
-        // Generate JSON
-        JsonObject hashJson = IncrementalBackupUtil.generateDirectoryJsonObject(levelPath);
-        // Copy files
-        long newFilesSizeBytes = IncrementalBackupUtil.saveNewFiles(backupSaveDirectory, levelPath, hashJson);
-        if(newFilesSizeBytes < 0) {
-            success = false;
-            PrintUtil.error("Failed to copy new files to object tree.");
-        }
-        // Save JSON tree
-        File jsonFile = new File(String.valueOf(Paths.get(backupSaveDirectory, BackupFileNameBuilder.objectTreeBackup().build(LocalDateTime.now(), backupName))));
-        // TODO
-        return new BackupResult(success, newFilesSizeBytes);
-    }
-
-    @Override
-    public boolean restore(String backupName, String levelPath, String backupSaveDirectory) throws IOException {
-        return false;
-    }
-
-    @Override
-    public BackupFileNameBuilder getBackupFileNameBuilder() {
-        return null;
-    }
-
-    @Override
-    public BackupFileNameFormatter getBackupFileNameFormatter() {
-        return null;
-    }
-}
diff --git a/src/main/java/com/keuin/kbackupfabric/operation/backup/IncrementalBackupUtil.java b/src/main/java/com/keuin/kbackupfabric/operation/backup/IncrementalBackupUtil.java
deleted file mode 100644
index f90aef1..0000000
--- a/src/main/java/com/keuin/kbackupfabric/operation/backup/IncrementalBackupUtil.java
+++ /dev/null
@@ -1,90 +0,0 @@
-package com.keuin.kbackupfabric.operation.backup;
-
-import com.google.gson.JsonElement;
-import com.google.gson.JsonObject;
-import com.keuin.kbackupfabric.util.FilesystemUtil;
-import org.apache.commons.codec.digest.DigestUtils;
-
-import java.io.File;
-import java.io.IOException;
-import java.io.InputStream;
-import java.nio.file.*;
-import java.util.Map;
-
-public class IncrementalBackupUtil {
-    /**
-     * Generate a json object representing a directory and its all sub files and directories.
-     * @param path path to the directory.
-     * @return a json object.
-     */
-    public static JsonObject generateDirectoryJsonObject(String path) throws IOException {
-        JsonObject json = new JsonObject();
-        File directory = new File(path);
-        if (!(directory.isDirectory() && directory.exists()))
-            throw new IOException(String.format("Path %s is not a valid directory.", path));
-
-        // Iterate all sub files using BFS.
-        try (DirectoryStream<Path> directoryStream = Files.newDirectoryStream(Paths.get(path))) {
-            for (Path sub : directoryStream) {
-                if (sub.toFile().isFile()) {
-                    // A sub file
-                    // Just hash and add it as a string
-                    try (InputStream is = Files.newInputStream(sub)) {
-                        String md5 = org.apache.commons.codec.digest.DigestUtils.md5Hex(is);
-                        json.addProperty(sub.getFileName().toString(), md5);
-                    }
-                } else {
-                    // A sub directory
-                    // Search into
-                    json.addProperty(String.valueOf(sub.getFileName()), sub.toString());
-                }
-            }
-        }
-
-        return json;
-    }
-
-    /**
-     * Save new (or modified) files to target path, based on hash json.
-     * @param targetSavePath where we should save new files.
-     * @param sourcePath where new files come from. This path must be the base directory of given hash json.
-     * @param hashJson the json object obtained by calling generateDirectoryJsonObject method.
-     * @return total size of new files. If failed, will return -1.
-     */
-    public static long saveNewFiles(String targetSavePath, String sourcePath, JsonObject hashJson) throws IOException {
-        long bytesCopied = 0;
-        for (Map.Entry<String, JsonElement> entry : hashJson.entrySet()) {
-            String key = entry.getKey();
-            JsonElement value = entry.getValue();
-            if (value.isJsonPrimitive() && value.getAsJsonPrimitive().isString()) {
-                // A sub file
-                // key is file name
-                // value is file md5
-                String md5 = value.getAsJsonPrimitive().getAsString();
-                File saveTarget = new File(targetSavePath, md5);
-                if (!saveTarget.exists()) {
-                    // Target file does not exist. We have to copy this to the target.
-                    File sourceFile = new File(sourcePath, key);
-                    Files.copy(sourceFile.toPath(), saveTarget.toPath(), StandardCopyOption.REPLACE_EXISTING, StandardCopyOption.COPY_ATTRIBUTES);
-                    try {
-                        bytesCopied += sourceFile.length();
-                    } catch (SecurityException ignored) {
-                        // failed to get the file size. Just ignore this.
-                    }
-                }
-            } else if (value.isJsonObject()) {
-                // A sub directory
-                // key is directory name
-                // value is directory json object
-                // Go into
-                if(!value.isJsonObject())
-                    throw new IllegalArgumentException(String.format("Hash json contains illegal argument of a directory item: %s -> %s.", key, value));
-                Path pathSource = Paths.get(sourcePath, key);
-                bytesCopied += saveNewFiles(targetSavePath, pathSource.toString(), value.getAsJsonObject());
-            } else {
-                throw new IllegalArgumentException(String.format("Hash json contains illegal element: %s -> %s.", key, value));
-            }
-        }
-        return bytesCopied;
-    }
-}
diff --git a/src/main/java/com/keuin/kbackupfabric/operation/backup/PrimitiveBackupMethod.java b/src/main/java/com/keuin/kbackupfabric/operation/backup/PrimitiveBackupMethod.java
index 854355d..9c065a6 100644
--- a/src/main/java/com/keuin/kbackupfabric/operation/backup/PrimitiveBackupMethod.java
+++ b/src/main/java/com/keuin/kbackupfabric/operation/backup/PrimitiveBackupMethod.java
@@ -2,11 +2,13 @@ package com.keuin.kbackupfabric.operation.backup;
 
 import com.keuin.kbackupfabric.exception.ZipUtilException;
 import com.keuin.kbackupfabric.metadata.BackupMetadata;
+import com.keuin.kbackupfabric.operation.backup.feedback.PrimitiveBackupFeedback;
 import com.keuin.kbackupfabric.util.FilesystemUtil;
 import com.keuin.kbackupfabric.util.PrintUtil;
 import com.keuin.kbackupfabric.util.ZipUtil;
-import com.keuin.kbackupfabric.util.backup.builder.BackupFileNameBuilder;
-import com.keuin.kbackupfabric.util.backup.formatter.BackupFileNameFormatter;
+import com.keuin.kbackupfabric.util.backup.BackupFilesystemUtil;
+import com.keuin.kbackupfabric.util.backup.BackupNameTimeFormatter;
+import com.keuin.kbackupfabric.util.backup.name.PrimitiveBackupFileNameEncoder;
 
 import java.io.File;
 import java.io.IOException;
@@ -23,27 +25,32 @@ public class PrimitiveBackupMethod implements BackupMethod {
         return INSTANCE;
     }
 
+    @Deprecated
+    private String getBackupFileName(LocalDateTime time, String backupName) {
+        String timeString = BackupNameTimeFormatter.localDateTimeToString(time);
+        return String.format("%s%s_%s%s", BackupFilesystemUtil.getBackupFileNamePrefix(), timeString, backupName, ".zip");
+    }
+
     @Override
-    public BackupResult backup(String backupName, String levelPath, String backupSaveDirectory) throws IOException {
-        String backupFileName = BackupFileNameBuilder.primitiveZipBackup().build(LocalDateTime.now(),backupName);
+    public PrimitiveBackupFeedback backup(String customBackupName, String levelPath, String backupSavePath) throws IOException {
+//        String backupFileName = getBackupFileName(LocalDateTime.now(),backupName);
+        String backupFileName = new PrimitiveBackupFileNameEncoder().encode(customBackupName, LocalDateTime.now());
         try {
-            BackupMetadata backupMetadata = new BackupMetadata(System.currentTimeMillis(), backupName);
-
-            PrintUtil.info(String.format("zip(srcPath=%s, destPath=%s)", levelPath, backupSaveDirectory));
+            BackupMetadata backupMetadata = new BackupMetadata(System.currentTimeMillis(), customBackupName);
+            PrintUtil.info(String.format("zip(srcPath=%s, destPath=%s)", levelPath, backupSavePath));
             PrintUtil.info("Compressing level ...");
-            ZipUtil.makeBackupZip(levelPath, backupSaveDirectory, backupFileName, backupMetadata);
-
+            ZipUtil.makeBackupZip(levelPath, backupSavePath, backupFileName, backupMetadata);
         } catch (ZipUtilException exception) {
             PrintUtil.info("Infinite recursive of directory tree detected, backup was aborted.");
-            return new BackupResult(false, 0);
+            return new PrimitiveBackupFeedback(false, 0);
         }
 
         // Get backup file size and return
-        return new BackupResult(true, FilesystemUtil.getFileSizeBytes(backupSaveDirectory, backupFileName));
+        return new PrimitiveBackupFeedback(true, FilesystemUtil.getFileSizeBytes(backupSavePath, backupFileName));
     }
 
     @Override
-    public boolean restore(String backupName, String levelDirectory, String backupSaveDirectory) throws IOException {
+    public boolean restore(String backupFileName, String levelDirectory, String backupSaveDirectory) throws IOException {
         // Delete old level
         PrintUtil.info("Server stopped. Deleting old level ...");
         File levelDirFile = new File(levelDirectory);
@@ -73,10 +80,10 @@ public class PrimitiveBackupMethod implements BackupMethod {
         // TODO: Refactor this to the concrete BackupMethod.
         // Decompress archive
         PrintUtil.info("Decompressing archived level ...");
-        ZipUtil.unzip(Paths.get(backupSaveDirectory, backupName).toString(), levelDirectory, false);
+        ZipUtil.unzip(Paths.get(backupSaveDirectory, backupFileName).toString(), levelDirectory, false);
         long endTime = System.currentTimeMillis();
         PrintUtil.info(String.format("Restore complete! (%.2fs) Please restart the server manually.", (endTime - startTime) / 1000.0));
-        PrintUtil.info("If you want to restart automatically after restoring, please visit the project manual at: https://github.com/keuin/KBackup-Fabric/blob/master/README.md");
+        PrintUtil.info("If you want to restart automatically after restoring, please check the manual at: https://github.com/keuin/KBackup-Fabric/blob/master/README.md");
 
 //        try {
 //            Thread.sleep(1000);
@@ -85,14 +92,4 @@ public class PrimitiveBackupMethod implements BackupMethod {
 
         return true;
     }
-
-    @Override
-    public BackupFileNameBuilder getBackupFileNameBuilder() {
-        return BackupFileNameBuilder.primitiveZipBackup();
-    }
-
-    @Override
-    public BackupFileNameFormatter getBackupFileNameFormatter() {
-        return BackupFileNameFormatter.primitiveZipBackup();
-    }
 }
diff --git a/src/main/java/com/keuin/kbackupfabric/operation/backup/feedback/BackupFeedback.java b/src/main/java/com/keuin/kbackupfabric/operation/backup/feedback/BackupFeedback.java
new file mode 100644
index 0000000..92a9f39
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/operation/backup/feedback/BackupFeedback.java
@@ -0,0 +1,5 @@
+package com.keuin.kbackupfabric.operation.backup.feedback;
+
+public interface BackupFeedback {
+    String getFeedback();
+}
diff --git a/src/main/java/com/keuin/kbackupfabric/operation/backup/feedback/PrimitiveBackupFeedback.java b/src/main/java/com/keuin/kbackupfabric/operation/backup/feedback/PrimitiveBackupFeedback.java
new file mode 100644
index 0000000..6d7a15b
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/operation/backup/feedback/PrimitiveBackupFeedback.java
@@ -0,0 +1,29 @@
+package com.keuin.kbackupfabric.operation.backup.feedback;
+
+import static com.keuin.kbackupfabric.util.backup.BackupFilesystemUtil.getFriendlyFileSizeString;
+
+public class PrimitiveBackupFeedback implements BackupFeedback {
+    private final boolean success;
+    private final long backupSizeBytes;
+
+    public PrimitiveBackupFeedback(boolean success, long backupSizeBytes) {
+        this.success = success;
+        this.backupSizeBytes = backupSizeBytes;
+    }
+
+    public boolean isSuccess() {
+        return success;
+    }
+
+    public long getBackupSizeBytes() {
+        return backupSizeBytes;
+    }
+
+    @Override
+    public String getFeedback() {
+        if (success && backupSizeBytes >= 0)
+            return String.format(" File size: %s.", getFriendlyFileSizeString(backupSizeBytes));
+        else
+            return "";
+    }
+}
diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/BackupFilesystemUtil.java b/src/main/java/com/keuin/kbackupfabric/util/backup/BackupFilesystemUtil.java
index d0c7500..c1aa5fe 100644
--- a/src/main/java/com/keuin/kbackupfabric/util/backup/BackupFilesystemUtil.java
+++ b/src/main/java/com/keuin/kbackupfabric/util/backup/BackupFilesystemUtil.java
@@ -17,6 +17,7 @@ public final class BackupFilesystemUtil {
     private static final String backupSaveDirectoryName = "backups";
     private static final String backupFileNamePrefix = "kbackup-";
 
+    @Deprecated
     public static String getBackupFileNamePrefix() {
         return backupFileNamePrefix;
     }
@@ -26,18 +27,18 @@ public final class BackupFilesystemUtil {
         return backupFileNamePrefix + backupName + ".zip";
     }
 
-    @Deprecated
-    public static String getBackupName(String backupFileName) {
-        try {
-            if (backupFileName.matches(backupFileNamePrefix + ".+\\.zip"))
-                return backupFileName.substring(backupFileNamePrefix.length(), backupFileName.length() - 4);
-        } catch (IndexOutOfBoundsException ignored) {
-        }
-        return backupFileName;
-    }
+//    @Deprecated
+//    public static String getBackupName(String backupFileName) {
+//        try {
+//            if (backupFileName.matches(backupFileNamePrefix + ".+\\.zip"))
+//                return backupFileName.substring(backupFileNamePrefix.length(), backupFileName.length() - 4);
+//        } catch (IndexOutOfBoundsException ignored) {
+//        }
+//        return backupFileName;
+//    }
 
-    public static boolean isBackupNameValid(String backupName, MinecraftServer server) {
-        File backupFile = new File(getBackupSaveDirectory(server), getBackupFileName(backupName));
+    public static boolean isBackupFileExists(String backupFileName, MinecraftServer server) {
+        File backupFile = new File(getBackupSaveDirectory(server), backupFileName);
         return backupFile.isFile();
     }
 
@@ -70,8 +71,8 @@ public final class BackupFilesystemUtil {
         return -1;
     }
 
-    public static String getFriendlyFileSizeString(long size) {
-        double fileSize = size * 1.0 / 1024 / 1024; // Default unit is MB
+    public static String getFriendlyFileSizeString(long sizeBytes) {
+        double fileSize = sizeBytes * 1.0 / 1024 / 1024; // Default unit is MB
         if (fileSize > 1000)
             //msgInfo(context, String.format("File size: %.2fGB", fileSize / 1024));
             return String.format("%.2fGB", fileSize / 1024);
diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/BackupType.java b/src/main/java/com/keuin/kbackupfabric/util/backup/BackupType.java
deleted file mode 100644
index d02ce77..0000000
--- a/src/main/java/com/keuin/kbackupfabric/util/backup/BackupType.java
+++ /dev/null
@@ -1,33 +0,0 @@
-package com.keuin.kbackupfabric.util.backup;
-
-/**
- * Representing the backup type.
- * Should only be used in BackupFileNameBuilder and BackupFileNameFormatter
- */
-@Deprecated
-public enum BackupType {
-
-    PRIMITIVE_ZIP_BACKUP("Primitive Zip Backup", "zip"),
-    OBJECT_TREE_BACKUP("Object Tree Backup", "incremental");
-
-    private final String friendlyName; // e.g. Primitive Zip Backup
-    private final String name; // e.g. zip
-
-    BackupType(String friendlyName, String name) {
-        this.friendlyName = friendlyName;
-        this.name = name;
-    }
-
-    /**
-     * Get name used in command.
-     * @return name (such as "zip", "incremental").
-     */
-    public String getName() {
-        return name;
-    }
-
-    @Override
-    public String toString() {
-        return friendlyName;
-    }
-}
diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/builder/BackupFileNameBuilder.java b/src/main/java/com/keuin/kbackupfabric/util/backup/builder/BackupFileNameBuilder.java
deleted file mode 100644
index f57302c..0000000
--- a/src/main/java/com/keuin/kbackupfabric/util/backup/builder/BackupFileNameBuilder.java
+++ /dev/null
@@ -1,24 +0,0 @@
-package com.keuin.kbackupfabric.util.backup.builder;
-
-
-import java.time.LocalDateTime;
-
-public interface BackupFileNameBuilder {
-
-    static BackupFileNameBuilder primitiveZipBackup() {
-        return PrimitiveZipBackupFileNameBuilder.getInstance();
-    }
-
-    static BackupFileNameBuilder objectTreeBackup() {
-        return ObjectTreeBackupFileNameBuilder.getInstance();
-    }
-
-    /**
-     * Build a backup file name based on given information.
-     * @param time when the backup was created.
-     * @param backupName the custom name of this backup. Note that this should be a valid file name in current file system.
-     * @return the backup file name string.
-     */
-    String build(LocalDateTime time, String backupName);
-
-}
diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/builder/ObjectTreeBackupFileNameBuilder.java b/src/main/java/com/keuin/kbackupfabric/util/backup/builder/ObjectTreeBackupFileNameBuilder.java
deleted file mode 100644
index c3d8257..0000000
--- a/src/main/java/com/keuin/kbackupfabric/util/backup/builder/ObjectTreeBackupFileNameBuilder.java
+++ /dev/null
@@ -1,20 +0,0 @@
-package com.keuin.kbackupfabric.util.backup.builder;
-
-import com.keuin.kbackupfabric.util.backup.BackupFilesystemUtil;
-import com.keuin.kbackupfabric.util.backup.BackupNameTimeFormatter;
-
-import java.time.LocalDateTime;
-
-public class ObjectTreeBackupFileNameBuilder implements BackupFileNameBuilder {
-    private static final ObjectTreeBackupFileNameBuilder instance = new ObjectTreeBackupFileNameBuilder();
-
-    public static ObjectTreeBackupFileNameBuilder getInstance() {
-        return instance;
-    }
-
-    @Override
-    public String build(LocalDateTime time, String backupName) {
-        String timeString = BackupNameTimeFormatter.localDateTimeToString(time);
-        return String.format("%s%s_%s%s", BackupFilesystemUtil.getBackupFileNamePrefix(), timeString, backupName, ".json");
-    }
-}
diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/builder/PrimitiveZipBackupFileNameBuilder.java b/src/main/java/com/keuin/kbackupfabric/util/backup/builder/PrimitiveZipBackupFileNameBuilder.java
deleted file mode 100644
index 6d8b5f5..0000000
--- a/src/main/java/com/keuin/kbackupfabric/util/backup/builder/PrimitiveZipBackupFileNameBuilder.java
+++ /dev/null
@@ -1,22 +0,0 @@
-package com.keuin.kbackupfabric.util.backup.builder;
-
-import com.keuin.kbackupfabric.util.backup.BackupFilesystemUtil;
-import com.keuin.kbackupfabric.util.backup.BackupNameTimeFormatter;
-
-import java.time.LocalDateTime;
-
-public class PrimitiveZipBackupFileNameBuilder implements BackupFileNameBuilder {
-
-    private static final PrimitiveZipBackupFileNameBuilder instance = new PrimitiveZipBackupFileNameBuilder();
-
-    public static PrimitiveZipBackupFileNameBuilder getInstance() {
-        return instance;
-    }
-
-    @Override
-    public String build(LocalDateTime time, String backupName) {
-        String timeString = BackupNameTimeFormatter.localDateTimeToString(time);
-        return String.format("%s%s_%s%s", BackupFilesystemUtil.getBackupFileNamePrefix(), timeString, backupName, ".zip");
-    }
-
-}
diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/formatter/BackupFileNameFormatter.java b/src/main/java/com/keuin/kbackupfabric/util/backup/formatter/BackupFileNameFormatter.java
deleted file mode 100644
index a437629..0000000
--- a/src/main/java/com/keuin/kbackupfabric/util/backup/formatter/BackupFileNameFormatter.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package com.keuin.kbackupfabric.util.backup.formatter;
-
-import com.keuin.kbackupfabric.util.backup.BackupNameTimeFormatter;
-
-import java.time.LocalDateTime;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-
-public interface BackupFileNameFormatter {
-
-    BackupFileName format(String fileName);
-
-    class BackupFileName {
-        public final LocalDateTime time;
-        public final String name;
-
-        public BackupFileName(LocalDateTime time, String name) {
-            this.time = time;
-            this.name = name;
-        }
-    }
-
-    static BackupFileNameFormatter objectTreeBackup() {
-        return ObjectTreeBackupFileNameFormatter.getInstance();
-    }
-
-    static BackupFileNameFormatter primitiveZipBackup() {
-        return PrimitiveZipBackupFileNameFormatter.getInstance();
-    }
-
-}
diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/formatter/ObjectTreeBackupFileNameFormatter.java b/src/main/java/com/keuin/kbackupfabric/util/backup/formatter/ObjectTreeBackupFileNameFormatter.java
deleted file mode 100644
index 08805b2..0000000
--- a/src/main/java/com/keuin/kbackupfabric/util/backup/formatter/ObjectTreeBackupFileNameFormatter.java
+++ /dev/null
@@ -1,44 +0,0 @@
-package com.keuin.kbackupfabric.util.backup.formatter;
-
-import com.keuin.kbackupfabric.util.backup.BackupFilesystemUtil;
-import com.keuin.kbackupfabric.util.backup.BackupNameTimeFormatter;
-import org.spongepowered.asm.mixin.Overwrite;
-
-import java.time.LocalDateTime;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-
-public class ObjectTreeBackupFileNameFormatter implements BackupFileNameFormatter {
-
-    private static final ObjectTreeBackupFileNameFormatter instance = new ObjectTreeBackupFileNameFormatter();
-
-    public static ObjectTreeBackupFileNameFormatter getInstance() {
-        return instance;
-    }
-
-    @Override
-    public BackupFileNameFormatter.BackupFileName format(String fileName) {
-        LocalDateTime time = getTime(fileName);
-        String name = getBackupName(fileName);
-        return new BackupFileNameFormatter.BackupFileName(time,name);
-    }
-
-    private LocalDateTime getTime(String fileName) {
-        Matcher matcher = Pattern.compile("[0-9]{4}-[0-9]{2}-[0-9]{2}_[0-9]{2}-[0-9]{2}-[0-9]{2}").matcher(fileName);
-        if (matcher.find()) {
-            String timeString = matcher.group(0);
-            return BackupNameTimeFormatter.timeStringToLocalDateTime(timeString);
-        }
-        return null;
-    }
-
-    private String getBackupName(String backupFileName) {
-        try {
-            if (backupFileName.matches(BackupFilesystemUtil.getBackupFileNamePrefix() + ".+\\.json"))
-                return backupFileName.substring(BackupFilesystemUtil.getBackupFileNamePrefix().length(), backupFileName.length() - 4);
-        } catch (IndexOutOfBoundsException ignored) {
-        }
-        return backupFileName;
-    }
-
-}
diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/formatter/PrimitiveZipBackupFileNameFormatter.java b/src/main/java/com/keuin/kbackupfabric/util/backup/formatter/PrimitiveZipBackupFileNameFormatter.java
deleted file mode 100644
index 2d50d17..0000000
--- a/src/main/java/com/keuin/kbackupfabric/util/backup/formatter/PrimitiveZipBackupFileNameFormatter.java
+++ /dev/null
@@ -1,43 +0,0 @@
-package com.keuin.kbackupfabric.util.backup.formatter;
-
-import com.keuin.kbackupfabric.util.backup.BackupFilesystemUtil;
-import com.keuin.kbackupfabric.util.backup.BackupNameTimeFormatter;
-
-import java.time.LocalDateTime;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-
-public class PrimitiveZipBackupFileNameFormatter implements BackupFileNameFormatter {
-
-    private static final PrimitiveZipBackupFileNameFormatter instance = new PrimitiveZipBackupFileNameFormatter();
-
-    public static PrimitiveZipBackupFileNameFormatter getInstance() {
-        return instance;
-    }
-
-    @Override
-    public BackupFileNameFormatter.BackupFileName format(String fileName) {
-        LocalDateTime time = getTime(fileName);
-        String name = getBackupName(fileName);
-        return new BackupFileNameFormatter.BackupFileName(time,name);
-    }
-
-    private LocalDateTime getTime(String fileName) {
-        Matcher matcher = Pattern.compile("[0-9]{4}-[0-9]{2}-[0-9]{2}_[0-9]{2}-[0-9]{2}-[0-9]{2}").matcher(fileName);
-        if (matcher.find()) {
-            String timeString = matcher.group(0);
-            return BackupNameTimeFormatter.timeStringToLocalDateTime(timeString);
-        }
-        return null;
-    }
-
-    private String getBackupName(String backupFileName) {
-        try {
-            if (backupFileName.matches(BackupFilesystemUtil.getBackupFileNamePrefix() + ".+\\.zip"))
-                return backupFileName.substring(BackupFilesystemUtil.getBackupFileNamePrefix().length(), backupFileName.length() - 4);
-        } catch (IndexOutOfBoundsException ignored) {
-        }
-        return backupFileName;
-    }
-
-}
diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/ObjectCollectionFactory.java b/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/ObjectCollectionFactory.java
index ea9edd9..ac87883 100644
--- a/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/ObjectCollectionFactory.java
+++ b/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/ObjectCollectionFactory.java
@@ -1,6 +1,6 @@
 package com.keuin.kbackupfabric.util.backup.incremental;
 
-import com.keuin.kbackupfabric.util.backup.incremental.identifier.FileIdentifierFactory;
+import com.keuin.kbackupfabric.util.backup.incremental.identifier.FileIdentifierProvider;
 import com.keuin.kbackupfabric.util.backup.incremental.identifier.ObjectIdentifier;
 
 import java.io.File;
@@ -17,9 +17,9 @@ import java.util.*;
  */
 public class ObjectCollectionFactory <T extends ObjectIdentifier> {
 
-    private final FileIdentifierFactory<T> identifierFactory;
+    private final FileIdentifierProvider<T> identifierFactory;
 
-    public ObjectCollectionFactory(FileIdentifierFactory<T> identifierFactory) {
+    public ObjectCollectionFactory(FileIdentifierProvider<T> identifierFactory) {
         this.identifierFactory = identifierFactory;
     }
 
diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/ObjectCollectionSerializer.java b/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/ObjectCollectionSerializer.java
index cc77837..6f9b792 100644
--- a/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/ObjectCollectionSerializer.java
+++ b/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/ObjectCollectionSerializer.java
@@ -3,6 +3,9 @@ package com.keuin.kbackupfabric.util.backup.incremental;
 import java.io.*;
 import java.util.Objects;
 
+/**
+ * Serialize and deserialize ObjectCollection from/to the disk file.
+ */
 public class ObjectCollectionSerializer {
     public static ObjectCollection fromFile(File file) throws IOException {
         Objects.requireNonNull(file);
diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/identifier/FileIdentifierFactory.java b/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/identifier/FileIdentifierProvider.java
index 34ad9a0..9a03371 100644
--- a/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/identifier/FileIdentifierFactory.java
+++ b/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/identifier/FileIdentifierProvider.java
@@ -3,6 +3,6 @@ package com.keuin.kbackupfabric.util.backup.incremental.identifier;
 import java.io.File;
 import java.io.IOException;
 
-public interface FileIdentifierFactory<T extends ObjectIdentifier> {
+public interface FileIdentifierProvider<T extends ObjectIdentifier> {
     T fromFile(File file) throws IOException;
 }
diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/identifier/Sha256Identifier.java b/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/identifier/Sha256Identifier.java
index 9ecf2d3..cbf1bb9 100644
--- a/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/identifier/Sha256Identifier.java
+++ b/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/identifier/Sha256Identifier.java
@@ -15,7 +15,7 @@ public class Sha256Identifier extends SingleHashIdentifier {
 
     private static final int SHA256_LENGTH = 32;
     private static final Sha256Identifier DUMMY = new Sha256Identifier(new byte[SHA256_LENGTH]); // only for using its hash method
-    private static final FileIdentifierFactory<Sha256Identifier> factory = Sha256Identifier::fromFile;
+    private static final FileIdentifierProvider<Sha256Identifier> factory = Sha256Identifier::fromFile;
 
     public static Sha256Identifier fromFile(File file) throws IOException {
         if (!Objects.requireNonNull(file).isFile()) {
@@ -24,7 +24,7 @@ public class Sha256Identifier extends SingleHashIdentifier {
         return new Sha256Identifier(DUMMY.hash(file));
     }
 
-    public static FileIdentifierFactory<Sha256Identifier> getFactory() {
+    public static FileIdentifierProvider<Sha256Identifier> getFactory() {
         return factory;
     }
 
diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/name/BackupFileNameEncoder.java b/src/main/java/com/keuin/kbackupfabric/util/backup/name/BackupFileNameEncoder.java
new file mode 100644
index 0000000..83967b7
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/util/backup/name/BackupFileNameEncoder.java
@@ -0,0 +1,49 @@
+package com.keuin.kbackupfabric.util.backup.name;
+
+import java.time.LocalDateTime;
+
+/**
+ * Encode and decode backup file name for a specific backup type.
+ */
+public interface BackupFileNameEncoder {
+
+    /**
+     * Construct full backup file name from custom name and creation time.
+     * @param customName the custom name. If the custom name contains invalid chars, an exception will be thrown.
+     * @param time the creation time.
+     * @return the file name.
+     */
+    String encode(String customName, LocalDateTime time);
+
+    /**
+     * Extract custom and backup time from backup file name.
+     * @param fileName the backup file name.
+     * @return the information. If the given file name is invalid, return null.
+     */
+    BackupBasicInformation decode(String fileName);
+
+    /**
+     * Check if the given string is a valid custom backup name.
+     * @param customName the custom backup name.
+     * @return if the name is valid.
+     */
+    default boolean isValidCustomName(String customName) {
+        final char[] ILLEGAL_CHARACTERS = {'/', '\n', '\r', '\t', '\0', '\f', '`', '?', '*', '\\', '<', '>', '|', '\"', ':'};
+        for (char c : ILLEGAL_CHARACTERS) {
+            if (customName.contains(String.valueOf(c))) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    class BackupBasicInformation {
+        public final String customName;
+        public final LocalDateTime time;
+
+        BackupBasicInformation(String customName, LocalDateTime time) {
+            this.customName = customName;
+            this.time = time;
+        }
+    }
+}
diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/name/PrimitiveBackupFileNameEncoder.java b/src/main/java/com/keuin/kbackupfabric/util/backup/name/PrimitiveBackupFileNameEncoder.java
new file mode 100644
index 0000000..39c2403
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/util/backup/name/PrimitiveBackupFileNameEncoder.java
@@ -0,0 +1,34 @@
+package com.keuin.kbackupfabric.util.backup.name;
+
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class PrimitiveBackupFileNameEncoder implements BackupFileNameEncoder {
+
+    private static final String backupFileNamePrefix = "kbackup";
+    private static final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd_HH-mm-ss");
+
+    @Override
+    public String encode(String customName, LocalDateTime time) {
+        if (!isValidCustomName(customName))
+            throw new IllegalArgumentException("Invalid custom name");
+        String timeString = time.format(formatter);
+        return backupFileNamePrefix + "-" + timeString + "_" + customName + ".zip";
+    }
+
+    @Override
+    public BackupBasicInformation decode(String fileName) {
+        Pattern pattern = Pattern.compile(
+                backupFileNamePrefix + "-" + "([0-9]{4}-[0-9]{2}-[0-9]{2}_[0-9]{2}-[0-9]{2}-[0-9]{2})_(.+)\\.zip"
+        );
+        Matcher matcher = pattern.matcher(fileName);
+        if (matcher.find()) {
+            String timeString = matcher.group(1);
+            String customName = matcher.group(2);
+            return new BackupBasicInformation(customName, LocalDateTime.parse(timeString, formatter));
+        }
+        return null;
+    }
+}
diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/suggestion/BackupMethodSuggestionProvider.java b/src/main/java/com/keuin/kbackupfabric/util/backup/suggestion/BackupMethodSuggestionProvider.java
deleted file mode 100644
index 320d9bf..0000000
--- a/src/main/java/com/keuin/kbackupfabric/util/backup/suggestion/BackupMethodSuggestionProvider.java
+++ /dev/null
@@ -1,36 +0,0 @@
-package com.keuin.kbackupfabric.util.backup.suggestion;
-
-import com.keuin.kbackupfabric.util.backup.BackupType;
-import com.mojang.brigadier.suggestion.SuggestionProvider;
-import com.mojang.brigadier.suggestion.Suggestions;
-import com.mojang.brigadier.suggestion.SuggestionsBuilder;
-import net.minecraft.server.command.ServerCommandSource;
-
-import java.util.Arrays;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Locale;
-import java.util.concurrent.CompletableFuture;
-
-public class BackupMethodSuggestionProvider {
-
-    private static final List<String> suggestions = Arrays.asList(
-            BackupType.OBJECT_TREE_BACKUP.getName(),
-            BackupType.PRIMITIVE_ZIP_BACKUP.getName()
-    ); // All backup methods
-
-    public static SuggestionProvider<ServerCommandSource> getProvider() {
-        return (context, builder) -> getCompletableFuture(builder);
-    }
-
-    private static CompletableFuture<Suggestions> getCompletableFuture(SuggestionsBuilder builder) {
-        String remaining = builder.getRemaining().toLowerCase(Locale.ROOT);
-        for (String string : suggestions) { // Iterate through the supplied list
-            if (string.toLowerCase(Locale.ROOT).startsWith(remaining)) {
-                builder.suggest(string); // Add every single entry to suggestions list.
-            }
-        }
-        return builder.buildFuture(); // Create the CompletableFuture containing all the suggestions
-    }
-
-}
diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/suggestion/BackupNameSuggestionProvider.java b/src/main/java/com/keuin/kbackupfabric/util/backup/suggestion/BackupNameSuggestionProvider.java
index f6f4056..01152c2 100644
--- a/src/main/java/com/keuin/kbackupfabric/util/backup/suggestion/BackupNameSuggestionProvider.java
+++ b/src/main/java/com/keuin/kbackupfabric/util/backup/suggestion/BackupNameSuggestionProvider.java
@@ -1,6 +1,5 @@
 package com.keuin.kbackupfabric.util.backup.suggestion;
 
-import com.keuin.kbackupfabric.util.backup.BackupFilesystemUtil;
 import com.mojang.brigadier.suggestion.SuggestionProvider;
 import com.mojang.brigadier.suggestion.Suggestions;
 import com.mojang.brigadier.suggestion.SuggestionsBuilder;
@@ -38,7 +37,7 @@ public class BackupNameSuggestionProvider {
                 if (files == null)
                     return;
                 for (File f : files)
-                    candidateCacheList.add(BackupFilesystemUtil.getBackupName(f.getName()));
+                    candidateCacheList.add(f.getName());
                 cacheUpdateTime = System.currentTimeMillis();
             } catch (NullPointerException ignored) {
             }
diff --git a/src/test/java/IncrementalBackupUtilTest.java b/src/test/java/IncrementalBackupUtilTest.java
deleted file mode 100644
index b050a91..0000000
--- a/src/test/java/IncrementalBackupUtilTest.java
+++ /dev/null
@@ -1,16 +0,0 @@
-import com.keuin.kbackupfabric.operation.backup.IncrementalBackupUtil;
-
-import java.io.IOException;
-
-public class IncrementalBackupUtilTest {
-
-    @org.junit.Test
-    public void generateDirectoryJsonObject() {
-        try {
-            System.out.println(IncrementalBackupUtil.generateDirectoryJsonObject("D:\\1"));
-        } catch (IOException exception) {
-            exception.printStackTrace();
-        }
-
-    }
-}
\ No newline at end of file
diff --git a/src/test/java/com/keuin/kbackupfabric/util/backup/name/PrimitiveBackupFileNameEncoderTest.java b/src/test/java/com/keuin/kbackupfabric/util/backup/name/PrimitiveBackupFileNameEncoderTest.java
new file mode 100644
index 0000000..4823575
--- /dev/null
+++ b/src/test/java/com/keuin/kbackupfabric/util/backup/name/PrimitiveBackupFileNameEncoderTest.java
@@ -0,0 +1,21 @@
+package com.keuin.kbackupfabric.util.backup.name;
+
+import org.junit.Test;
+
+import java.time.LocalDateTime;
+import java.time.ZoneOffset;
+
+import static org.junit.Assert.assertEquals;
+
+public class PrimitiveBackupFileNameEncoderTest {
+
+    @Test
+    public void testConsistency() {
+        LocalDateTime time = LocalDateTime.ofEpochSecond(System.currentTimeMillis()/1000, 0, ZoneOffset.UTC);
+        String name = "Test Na_me";
+        PrimitiveBackupFileNameEncoder encoder = new PrimitiveBackupFileNameEncoder();
+        BackupFileNameEncoder.BackupBasicInformation information = encoder.decode(encoder.encode(name, time));
+        assertEquals(time, information.time);
+        assertEquals(name, information.customName);
+    }
+}
\ No newline at end of file