Merge remote-tracking branch 'origin/master'

# Conflicts:
#	src/main/java/com/keuin/kbackupfabric/operation/backup/PrimitiveBackupMethod.java

13 files changed, 337 insertions, 361 deletions

diff --git a/src/main/java/com/keuin/kbackupfabric/operation/BackupOperation.java b/src/main/java/com/keuin/kbackupfabric/operation/BackupOperation.java
index d03c347..b38921d 100644
--- a/src/main/java/com/keuin/kbackupfabric/operation/BackupOperation.java
+++ b/src/main/java/com/keuin/kbackupfabric/operation/BackupOperation.java
@@ -1,39 +1,32 @@
 package com.keuin.kbackupfabric.operation;
 
-import com.keuin.kbackupfabric.exception.ZipUtilException;
-import com.keuin.kbackupfabric.metadata.BackupMetadata;
 import com.keuin.kbackupfabric.operation.abstracts.InvokableAsyncBlockingOperation;
-import com.keuin.kbackupfabric.operation.backup.BackupMethod;
+import com.keuin.kbackupfabric.operation.backup.feedback.BackupFeedback;
+import com.keuin.kbackupfabric.operation.backup.method.ConfiguredBackupMethod;
 import com.keuin.kbackupfabric.util.PrintUtil;
-import com.keuin.kbackupfabric.util.backup.builder.BackupFileNameBuilder;
-import com.keuin.kbackupfabric.util.backup.formatter.BackupFileNameFormatter;
 import com.mojang.brigadier.context.CommandContext;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.command.ServerCommandSource;
 import net.minecraft.world.World;
 
-import java.io.File;
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
 
-import static com.keuin.kbackupfabric.util.backup.BackupFilesystemUtil.*;
 import static com.keuin.kbackupfabric.util.PrintUtil.msgInfo;
 
 public class BackupOperation extends InvokableAsyncBlockingOperation {
 
     private final CommandContext<ServerCommandSource> context;
-    private final String backupName;
     private final Map<World, Boolean> oldWorldsSavingDisabled = new HashMap<>();
-    private final BackupMethod backupMethod;
+    private final ConfiguredBackupMethod configuredBackupMethod;
     private long startTime;
 
 
-    public BackupOperation(CommandContext<ServerCommandSource> context, String backupName, BackupMethod backupMethod) {
+    public BackupOperation(CommandContext<ServerCommandSource> context, ConfiguredBackupMethod configuredBackupMethod) {
         super("BackupWorker");
         this.context = context;
-        this.backupName = backupName;
-        this.backupMethod = backupMethod;
+        this.configuredBackupMethod = configuredBackupMethod;
     }
 
     @Override
@@ -44,27 +37,20 @@ public class BackupOperation extends InvokableAsyncBlockingOperation {
             //// Do our main backup logic
 
             // Create backup saving directory
-            File backupSaveDirectoryFile = getBackupSaveDirectory(server);
-            backupSaveDirectory = backupSaveDirectoryFile.getName();
-            if (!backupSaveDirectoryFile.isDirectory() && !backupSaveDirectoryFile.mkdir()) {
-                msgInfo(context, String.format("Failed to create backup saving directory: %s. Failed to backup.", backupSaveDirectory));
+            if (!configuredBackupMethod.touch()) {
+                PrintUtil.msgErr(context, "Failed to create backup save directory. Cannot backup.");
                 return;
             }
 
-            // Make zip
-            String levelPath = getLevelPath(server);
-            String backupFileName = getBackupFileName(backupName);
-
-            BackupMethod.BackupResult result = backupMethod.backup(backupName,levelPath,backupSaveDirectory);
-            if(result.isSuccess()) {
-                // Restore old autosave switch stat
+            // Backup
+            BackupFeedback result = configuredBackupMethod.backup();
+            if (result.isSuccess()) {
+                // 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.", humanFileSize(result.getBackupSizeBytes()));
+                String msgText = String.format("Backup finished. Time elapsed: %.2fs. ", timeElapsedMillis / 1000.0) + result.getFeedback();
                 PrintUtil.msgInfo(context, msgText, true);
             } else {
                 // failed
@@ -79,14 +65,14 @@ public class BackupOperation extends InvokableAsyncBlockingOperation {
 
     @Override
     protected boolean sync() {
-        //// Save world, save old autosave configs
+        //// Save world, save old auto-save configs
 
-        PrintUtil.broadcast(String.format("Making backup %s, please wait ...", backupName));
+        PrintUtil.broadcast("Making backup, please wait ...");
 
         // Get server
         MinecraftServer server = context.getSource().getMinecraftServer();
 
-        // Save old autosave switch stat temporally
+        // Save old auto-save switch state for restoration after finished
         oldWorldsSavingDisabled.clear();
         server.getWorlds().forEach(world -> {
             oldWorldsSavingDisabled.put(world, world.savingDisabled);
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..b870746 100644
--- a/src/main/java/com/keuin/kbackupfabric/operation/RestoreOperation.java
+++ b/src/main/java/com/keuin/kbackupfabric/operation/RestoreOperation.java
@@ -1,47 +1,36 @@
 package com.keuin.kbackupfabric.operation;
 
-import com.keuin.kbackupfabric.exception.ZipUtilException;
 import com.keuin.kbackupfabric.operation.abstracts.InvokableBlockingOperation;
+import com.keuin.kbackupfabric.operation.backup.method.ConfiguredBackupMethod;
 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;
 
-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 org.apache.commons.io.FileUtils.forceDelete;
+import java.util.Objects;
 
 public class RestoreOperation extends InvokableBlockingOperation {
 
     //private static final Logger LOGGER = LogManager.getLogger();
-    private final String backupName;
     private final Thread serverThread;
-    private final String backupFilePath;
-    private final String levelDirectory;
     private final CommandContext<ServerCommandSource> context;
     private final MinecraftServer server;
+    private final ConfiguredBackupMethod configuredBackupMethod;
 
-    public RestoreOperation(CommandContext<ServerCommandSource> context, String backupFilePath, String levelDirectory, String backupName) {
-        server = context.getSource().getMinecraftServer();
-        this.backupName = backupName;
-        this.serverThread = server.getThread();
-        this.backupFilePath = backupFilePath;
-        this.levelDirectory = levelDirectory;
-        this.context = context;
+    public RestoreOperation(CommandContext<ServerCommandSource> context, ConfiguredBackupMethod configuredBackupMethod) {
+        server = Objects.requireNonNull(context.getSource().getMinecraftServer());
+        this.serverThread = Objects.requireNonNull(server.getThread());
+        this.context = Objects.requireNonNull(context);
+        this.configuredBackupMethod = Objects.requireNonNull(configuredBackupMethod);
     }
 
     @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 ...", configuredBackupMethod.getBackupFileName()));
 
-        String backupFileName = getBackupFileName(backupName);
-        PrintUtil.debug("Backup file name: " + backupFileName);
-        File backupFile = new File(getBackupSaveDirectory(server), backupFileName);
+        PrintUtil.debug("Backup file name: " + configuredBackupMethod.getBackupFileName());
 
         PrintUtil.msgInfo(context, "Server will shutdown in a few seconds, depending on world size and disk speed, the progress may take from seconds to minutes.", true);
         PrintUtil.msgInfo(context, "Please do not force the server stop, or the level would be broken.", true);
@@ -67,7 +56,7 @@ public class RestoreOperation extends InvokableBlockingOperation {
 
     @Override
     public String toString() {
-        return String.format("restoration from %s", backupName);
+        return String.format("restoration from %s", configuredBackupMethod.getBackupFileName());
     }
 
     private class WorkerThread implements Runnable {
@@ -80,7 +69,7 @@ public class RestoreOperation extends InvokableBlockingOperation {
                 while (serverThread.isAlive()) {
                     try {
                         serverThread.join();
-                    } catch (InterruptedException ignored) {
+                    } catch (InterruptedException | RuntimeException ignored) {
                     }
                 }
 
@@ -94,13 +83,30 @@ public class RestoreOperation extends InvokableBlockingOperation {
                 }while(--cnt > 0);
 
                 ////////////////////
-
-                //ServerRestartUtil.forkAndRestart();
-                System.exit(111);
+                long startTime = System.currentTimeMillis();
+                if (configuredBackupMethod.restore()) {
+                    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 check the manual at: https://github.com/keuin/KBackup-Fabric/blob/master/README.md");
+                    //ServerRestartUtil.forkAndRestart();
+                    System.exit(111);
+                } else {
+                    PrintUtil.error("Failed to restore! server will not restart automatically.");
+                }
 
             } catch (SecurityException e) {
                 PrintUtil.error("An exception occurred while restoring: " + e.getMessage());
+                e.printStackTrace();
+            } catch (IOException e) {
+                PrintUtil.error(e.toString());
+                PrintUtil.error("Failed to restore due to an unhandled I/O exception.");
+                e.printStackTrace();
             }
+            System.exit(0); // all failed restoration will eventually go here
         }
     }
 }
diff --git a/src/main/java/com/keuin/kbackupfabric/operation/backup/BackupMethod.java b/src/main/java/com/keuin/kbackupfabric/operation/backup/BackupMethod.java
deleted file mode 100644
index 4e9eb6c..0000000
--- a/src/main/java/com/keuin/kbackupfabric/operation/backup/BackupMethod.java
+++ /dev/null
@@ -1,44 +0,0 @@
-package com.keuin.kbackupfabric.operation.backup;
-
-import com.keuin.kbackupfabric.util.backup.builder.BackupFileNameBuilder;
-import com.keuin.kbackupfabric.util.backup.formatter.BackupFileNameFormatter;
-
-import java.io.IOException;
-
-/**
- * Provide specific backup method, which is implemented statelessly.
- */
-public interface BackupMethod {
-
-    /**
-     * Perform a backup with given method. The backup will be saved as the given name.
-     * Note: real file name depends on the backup type.
-     * @param backupName the backup name.
-     * @return if the backup operation succeed.
-     */
-    BackupResult 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
deleted file mode 100644
index 72e9cdb..0000000
--- a/src/main/java/com/keuin/kbackupfabric/operation/backup/PrimitiveBackupMethod.java
+++ /dev/null
@@ -1,99 +0,0 @@
-package com.keuin.kbackupfabric.operation.backup;
-
-import com.keuin.kbackupfabric.exception.ZipUtilException;
-import com.keuin.kbackupfabric.metadata.BackupMetadata;
-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 java.io.File;
-import java.io.IOException;
-import java.nio.file.Paths;
-import java.time.LocalDateTime;
-
-import static org.apache.commons.io.FileUtils.forceDelete;
-
-public class PrimitiveBackupMethod implements BackupMethod {
-
-    private static final PrimitiveBackupMethod INSTANCE = new PrimitiveBackupMethod();
-    private static int zipLevel = 9;
-
-    public static PrimitiveBackupMethod getInstance() {
-        return INSTANCE;
-    }
-
-    @Override
-    public BackupResult backup(String backupName, String levelPath, String backupSaveDirectory) throws IOException {
-        String backupFileName = BackupFileNameBuilder.primitiveZipBackup().build(LocalDateTime.now(),backupName);
-        try {
-            BackupMetadata backupMetadata = new BackupMetadata(System.currentTimeMillis(), backupName);
-
-            PrintUtil.info(String.format("zip(srcPath=%s, destPath=%s)", levelPath, backupSaveDirectory));
-            PrintUtil.info("Compressing level ...");
-            ZipUtil.makeBackupZip(levelPath, backupSaveDirectory, backupFileName, backupMetadata, zipLevel);
-
-        } catch (ZipUtilException exception) {
-            PrintUtil.info("Infinite recursive of directory tree detected, backup was aborted.");
-            return new BackupResult(false, 0);
-        }
-
-        // Get backup file size and return
-        return new BackupResult(true, FilesystemUtil.getFileSizeBytes(backupSaveDirectory, backupFileName));
-    }
-
-    @Override
-    public boolean restore(String backupName, String levelDirectory, String backupSaveDirectory) throws IOException {
-        // Delete old level
-        PrintUtil.info("Server stopped. Deleting old level ...");
-        File levelDirFile = new File(levelDirectory);
-        long startTime = System.currentTimeMillis();
-
-        int failedCounter = 0;
-        final int MAX_RETRY_TIMES = 20;
-        while (failedCounter < MAX_RETRY_TIMES) {
-            System.gc();
-            if (!levelDirFile.delete() && levelDirFile.exists()) {
-                System.gc();
-                forceDelete(levelDirFile); // Try to force delete.
-            }
-            if (!levelDirFile.exists())
-                break;
-            ++failedCounter;
-            try {
-                Thread.sleep(500);
-            } catch (InterruptedException ignored) {
-            }
-        }
-        if (levelDirFile.exists()) {
-            PrintUtil.error(String.format("Cannot restore: failed to delete old level %s .", levelDirFile.getName()));
-            return false;
-        }
-
-        // TODO: Refactor this to the concrete BackupMethod.
-        // Decompress archive
-        PrintUtil.info("Decompressing archived level ...");
-        ZipUtil.unzip(Paths.get(backupSaveDirectory, backupName).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");
-
-//        try {
-//            Thread.sleep(1000);
-//        } catch (InterruptedException ignored) {
-//        }
-
-        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..0fe0766
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/operation/backup/feedback/BackupFeedback.java
@@ -0,0 +1,6 @@
+package com.keuin.kbackupfabric.operation.backup.feedback;
+
+public interface BackupFeedback {
+    String getFeedback();
+    boolean isSuccess();
+}
diff --git a/src/main/java/com/keuin/kbackupfabric/operation/backup/feedback/IncrementalBackupFeedback.java b/src/main/java/com/keuin/kbackupfabric/operation/backup/feedback/IncrementalBackupFeedback.java
new file mode 100644
index 0000000..f39fde6
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/operation/backup/feedback/IncrementalBackupFeedback.java
@@ -0,0 +1,28 @@
+package com.keuin.kbackupfabric.operation.backup.feedback;
+
+public class IncrementalBackupFeedback implements BackupFeedback {
+    private final boolean success;
+    private final int newFilesAdded;
+
+    public IncrementalBackupFeedback(boolean success, int newFilesAdded) {
+        this.success = success;
+        this.newFilesAdded = newFilesAdded;
+    }
+
+    @Override
+    public boolean isSuccess() {
+        return success;
+    }
+
+    public long getNewFilesAdded() {
+        return newFilesAdded;
+    }
+
+    @Override
+    public String getFeedback() {
+        if (success && newFilesAdded >= 0)
+            return String.format("File(s) added: %d.", newFilesAdded);
+        else
+            return "";
+    }
+}
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..3bcd012
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/operation/backup/feedback/PrimitiveBackupFeedback.java
@@ -0,0 +1,30 @@
+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;
+    }
+
+    @Override
+    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/operation/backup/method/ConfiguredBackupMethod.java b/src/main/java/com/keuin/kbackupfabric/operation/backup/method/ConfiguredBackupMethod.java
new file mode 100644
index 0000000..bb80c80
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/operation/backup/method/ConfiguredBackupMethod.java
@@ -0,0 +1,37 @@
+package com.keuin.kbackupfabric.operation.backup.method;
+
+import com.keuin.kbackupfabric.operation.backup.feedback.BackupFeedback;
+
+import java.io.IOException;
+
+/**
+ * Provide specific backup method, which has been configured with proper settings,
+ * such as saving directory and level path.
+ */
+public interface ConfiguredBackupMethod {
+
+    /**
+     * Perform a backup with given method. The backup will be saved as the given name.
+     * Note: real file name depends on the backup type.
+     *
+     * @return backup result.
+     */
+    BackupFeedback backup() throws IOException;
+
+    boolean restore() throws IOException;
+
+    /**
+     * Create backup save directory and do some essential initialization before the backup process.
+     *
+     * @return false if failed, then the backup process won't proceed.
+     */
+    boolean touch();
+
+    /**
+     * Get the used backup file name.
+     *
+     * @return the file name.
+     */
+    String getBackupFileName();
+
+}
diff --git a/src/main/java/com/keuin/kbackupfabric/operation/backup/method/ConfiguredIncrementalBackupMethod.java b/src/main/java/com/keuin/kbackupfabric/operation/backup/method/ConfiguredIncrementalBackupMethod.java
new file mode 100644
index 0000000..b5d2463
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/operation/backup/method/ConfiguredIncrementalBackupMethod.java
@@ -0,0 +1,92 @@
+package com.keuin.kbackupfabric.operation.backup.method;
+
+import com.keuin.kbackupfabric.operation.backup.feedback.IncrementalBackupFeedback;
+import com.keuin.kbackupfabric.util.FilesystemUtil;
+import com.keuin.kbackupfabric.util.PrintUtil;
+import com.keuin.kbackupfabric.util.backup.incremental.ObjectCollection;
+import com.keuin.kbackupfabric.util.backup.incremental.ObjectCollectionFactory;
+import com.keuin.kbackupfabric.util.backup.incremental.ObjectCollectionSerializer;
+import com.keuin.kbackupfabric.util.backup.incremental.identifier.Sha256Identifier;
+import com.keuin.kbackupfabric.util.backup.incremental.manager.IncrementalBackupStorageManager;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Paths;
+import java.util.Arrays;
+import java.util.HashSet;
+
+public class ConfiguredIncrementalBackupMethod implements ConfiguredBackupMethod {
+
+    private final String backupIndexFileName;
+    private final String levelPath;
+    private final String backupIndexFileSaveDirectory;
+    private final String backupBaseDirectory;
+
+    public ConfiguredIncrementalBackupMethod(String backupIndexFileName, String levelPath, String backupIndexFileSaveDirectory, String backupBaseDirectory) {
+        this.backupIndexFileName = backupIndexFileName;
+        this.levelPath = levelPath;
+        this.backupIndexFileSaveDirectory = backupIndexFileSaveDirectory;
+        this.backupBaseDirectory = backupBaseDirectory;
+    }
+
+    @Override
+    public IncrementalBackupFeedback backup() throws IOException {
+        File levelPathFile = new File(levelPath);
+
+        // construct incremental backup index
+        PrintUtil.info("Hashing files...");
+        ObjectCollection collection = new ObjectCollectionFactory<>(Sha256Identifier.getFactory())
+                .fromDirectory(levelPathFile, new HashSet<>(Arrays.asList("session.lock", "kbackup_metadata")));
+
+        // update storage
+        PrintUtil.info("Copying files...");
+        IncrementalBackupStorageManager storageManager = new IncrementalBackupStorageManager(Paths.get(backupBaseDirectory));
+        int filesAdded = storageManager.addObjectCollection(collection, levelPathFile);
+
+        // save index file
+        PrintUtil.info("Saving index file...");
+        ObjectCollectionSerializer.toFile(collection, new File(backupIndexFileSaveDirectory, backupIndexFileName));
+
+        // return result
+        PrintUtil.info("Incremental backup finished.");
+        return new IncrementalBackupFeedback(filesAdded >= 0, filesAdded);
+    }
+
+    @Override
+    public boolean restore() throws IOException {
+        // load collection
+        PrintUtil.info("Loading file list...");
+        ObjectCollection collection = ObjectCollectionSerializer.fromFile(
+                new File(backupIndexFileSaveDirectory, backupIndexFileName)
+        );
+
+        // delete old level
+        File levelPathFile = new File(levelPath);
+        PrintUtil.info("Deleting old level...");
+        if (!FilesystemUtil.forceDeleteDirectory(levelPathFile)) {
+            PrintUtil.info("Failed to delete old level!");
+            return false;
+        }
+
+        // restore file
+        PrintUtil.info("Copying files...");
+        IncrementalBackupStorageManager storageManager = new IncrementalBackupStorageManager(Paths.get(backupBaseDirectory));
+        int restoreObjectCount = storageManager.restoreObjectCollection(collection, levelPathFile);
+
+        PrintUtil.info(String.format("%d file(s) restored.", restoreObjectCount));
+        return true;
+    }
+
+    @Override
+    public boolean touch() {
+        File baseDirectoryFile = new File(backupBaseDirectory);
+        return baseDirectoryFile.isDirectory() || baseDirectoryFile.mkdir();
+    }
+
+    @Override
+    public String getBackupFileName() {
+        return backupIndexFileName;
+    }
+
+
+}
diff --git a/src/main/java/com/keuin/kbackupfabric/operation/backup/method/ConfiguredPrimitiveBackupMethod.java b/src/main/java/com/keuin/kbackupfabric/operation/backup/method/ConfiguredPrimitiveBackupMethod.java
new file mode 100644
index 0000000..1c3c9f6
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/operation/backup/method/ConfiguredPrimitiveBackupMethod.java
@@ -0,0 +1,88 @@
+package com.keuin.kbackupfabric.operation.backup.method;
+
+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.BackupFilesystemUtil;
+import com.keuin.kbackupfabric.util.backup.BackupNameTimeFormatter;
+import com.keuin.kbackupfabric.util.backup.name.PrimitiveBackupFileNameEncoder;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Paths;
+import java.time.LocalDateTime;
+
+public class ConfiguredPrimitiveBackupMethod implements ConfiguredBackupMethod {
+
+    private final String backupFileName;
+    private final String levelPath;
+    private final String backupSavePath;
+
+    public ConfiguredPrimitiveBackupMethod(String backupFileName, String levelPath, String backupSavePath) {
+        this.backupFileName = backupFileName;
+        this.levelPath = levelPath;
+        this.backupSavePath = backupSavePath;
+    }
+
+    @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 PrimitiveBackupFeedback backup() throws IOException {
+        try {
+            String customBackupName = new PrimitiveBackupFileNameEncoder().decode(backupFileName).customName;
+            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, backupSavePath, backupFileName, backupMetadata);
+        } catch (ZipUtilException exception) {
+            PrintUtil.info("Infinite recursive of directory tree detected, backup was aborted.");
+            return new PrimitiveBackupFeedback(false, 0);
+        }
+
+        // Get backup file size and return
+        return new PrimitiveBackupFeedback(true, FilesystemUtil.getFileSizeBytes(backupSavePath, backupFileName));
+    }
+
+    @Override
+    public boolean restore() throws IOException {
+        // Delete old level
+        PrintUtil.info("Server stopped. Deleting old level ...");
+        if (!FilesystemUtil.forceDeleteDirectory(new File(levelPath))) {
+            PrintUtil.info("Failed to delete old level!");
+            return false;
+        }
+
+
+        // TODO: Refactor this to the concrete BackupMethod.
+        // Decompress archive
+        PrintUtil.info("Decompressing archived level ...");
+        ZipUtil.unzip(Paths.get(backupSavePath, backupFileName).toString(), levelPath, false);
+
+
+//        try {
+//            Thread.sleep(1000);
+//        } catch (InterruptedException ignored) {
+//        }
+
+        return true;
+    }
+
+    @Override
+    public boolean touch() {
+        File backupSaveDirectoryFile = new File(backupSavePath);
+        return backupSaveDirectoryFile.isDirectory() || backupSaveDirectoryFile.mkdir();
+    }
+
+    @Override
+    public String getBackupFileName() {
+        return backupFileName;
+    }
+
+}