Nearly finished (but the db updating still fails)

31 files changed, 1119 insertions, 1 deletions

diff --git a/build.gradle b/build.gradle
index 62083f9..2cb4da5 100644
--- a/build.gradle
+++ b/build.gradle
@@ -11,6 +11,9 @@ version = project.mod_version
 group = project.maven_group
 
 dependencies {
+
+	compile 'org.mongodb:mongo-java-driver:3.12.7'
+
 	// To change the versions see the gradle.properties file
 	minecraft "com.mojang:minecraft:${project.minecraft_version}"
 	mappings "net.fabricmc:yarn:${project.yarn_mappings}:v2"
diff --git a/development.md b/development.md
new file mode 100644
index 0000000..d64223c
--- /dev/null
+++ b/development.md
@@ -0,0 +1,33 @@
+# 数据库结构
+
+基于MongoDB。
+
+## Collection: logs
+
+```json
+{
+    "version": 1, // int
+    "subject": {
+        "uuid": player_uuid_bytes, // bytes
+        "id": player_id, // string
+        "pos": {
+            "world": world_id, // string
+            "x": pos_x, // float
+            "y": pos_y, // float
+            "z": pos_z, // float
+        }
+    },
+    "action": BLOCK_BREAK | BLOCK_PLACE | BLOCK_USE | ENTITY_USE | ENTITY_ATTACK | ITEM_USE, // int
+    "object": {
+        "type": OBJECT_BLOCK | OBJECT_ENTITY, // int
+        "id": object_id, // string
+        "pos": {
+            "world": world_id, // string
+            "x": pos_x, // float
+            "y": pos_y, // float
+            "z": pos_z, // float
+        }
+    }
+}
+```
+
diff --git a/src/main/java/com/keuin/blame/Blame.java b/src/main/java/com/keuin/blame/Blame.java
index 051a6b2..1e53a64 100644
--- a/src/main/java/com/keuin/blame/Blame.java
+++ b/src/main/java/com/keuin/blame/Blame.java
@@ -1,14 +1,55 @@
 package com.keuin.blame;
 
+import com.google.gson.Gson;
+import com.keuin.blame.adapter.*;
+import com.keuin.blame.config.BlameConfig;
+import com.keuin.blame.util.PrintUtil;
 import net.fabricmc.api.ModInitializer;
+import net.fabricmc.fabric.api.event.lifecycle.v1.ServerLifecycleEvents;
+import net.fabricmc.fabric.api.event.player.*;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.Reader;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.util.logging.Logger;
 
 public class Blame implements ModInitializer {
+
+	private final Logger logger = Logger.getLogger(Blame.class.getName());
+
+	public static BlameConfig config;
+
 	@Override
 	public void onInitialize() {
 		// This code runs as soon as Minecraft is in a mod-load-ready state.
 		// However, some things (like resources) may still be uninitialized.
 		// Proceed with mild caution.
 
-		System.out.println("Hello Fabric world!");
+		String configFileName = "blame.json";
+		try {
+			// load config
+			File configFile = new File(configFileName);
+			if (!configFile.exists()) {
+				logger.severe(String.format("Failed to read configuration file %s. Blame will be disabled.", configFileName));
+				return;
+			}
+
+			Reader reader = Files.newBufferedReader(configFile.toPath(), StandardCharsets.UTF_8);
+			config = (new Gson()).fromJson(reader, BlameConfig.class);
+		} catch (IOException exception) {
+			logger.severe(String.format("Failed to read configuration file %s: %s. " +
+					"Blame will be disabled.", configFileName, exception));
+			return;
+		}
+
+		AttackEntityCallback.EVENT.register(new AttackEntityAdapter(EventHandler.INSTANCE));
+		PlayerBlockBreakEvents.AFTER.register(new BreakBlockAdapter(EventHandler.INSTANCE));
+		UseBlockCallback.EVENT.register(new UseBlockAdapter(EventHandler.INSTANCE));
+		UseEntityCallback.EVENT.register(new UseEntityAdapter(EventHandler.INSTANCE));
+		UseItemCallback.EVENT.register(new UseItemAdapter(EventHandler.INSTANCE));
+
+		ServerLifecycleEvents.SERVER_STARTED.register(PrintUtil.INSTANCE);
 	}
 }
diff --git a/src/main/java/com/keuin/blame/EventHandler.java b/src/main/java/com/keuin/blame/EventHandler.java
new file mode 100644
index 0000000..a939759
--- /dev/null
+++ b/src/main/java/com/keuin/blame/EventHandler.java
@@ -0,0 +1,116 @@
+package com.keuin.blame;
+
+import com.keuin.blame.adapter.handler.*;
+import com.keuin.blame.data.LogEntry;
+import com.keuin.blame.data.LogEntryFactory;
+import com.keuin.blame.data.enums.ActionType;
+import com.keuin.blame.util.MinecraftUtil;
+import com.keuin.blame.util.PrintUtil;
+import net.minecraft.block.BlockState;
+import net.minecraft.block.entity.BlockEntity;
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.util.Hand;
+import net.minecraft.util.hit.BlockHitResult;
+import net.minecraft.util.hit.EntityHitResult;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.registry.Registry;
+import net.minecraft.world.World;
+import org.jetbrains.annotations.Nullable;
+
+public class EventHandler implements AttackEntityHandler, BreakBlockHandler, UseBlockHandler, UseEntityHandler, UseItemHandler {
+
+    public static final EventHandler INSTANCE = new EventHandler();
+
+    private EventHandler() {
+    }
+
+    @Override
+    public void onPlayerUseBlock(PlayerEntity playerEntity, World world, Hand hand, BlockHitResult blockHitResult) {
+        String worldString = MinecraftUtil.worldToString(world);
+        String blockId = Registry.BLOCK.getId(world.getBlockState(blockHitResult.getBlockPos()).getBlock()).toString();
+        LogEntry entry = LogEntryFactory.playerWithBlock(
+                playerEntity.getUuid(),
+                playerEntity.getPos(),
+                worldString,
+                blockId,
+                blockHitResult.getBlockPos(),
+                worldString,
+                ActionType.BLOCK_USE
+        );
+        SubmitWorker.INSTANCE.submit(entry);
+        PrintUtil.broadcast("use_block; block_id=" + blockId + "; world=" + worldString);
+        // TODO: 增加判断，事件触发的时候用户不一定真正使用了方块（也可能是无效的动作）。放置方块的时候也会触发这个事件
+//        PrintUtil.broadcast(String.format("player %s use block %s", playerEntity.getName().getString(), world.getBlockState(blockHitResult.getBlockPos())));
+    }
+
+    @Override
+    public void onPlayerBreakBlock(World world, PlayerEntity playerEntity, BlockPos blockPos, BlockState blockState, BlockEntity blockEntity) {
+        String worldString = MinecraftUtil.worldToString(world);
+        String blockId = Registry.BLOCK.getId(blockState.getBlock()).toString();
+        LogEntry entry = LogEntryFactory.playerWithBlock(
+                playerEntity.getUuid(),
+                playerEntity.getPos(),
+                worldString,
+                blockId,
+                blockPos,
+                worldString,
+                ActionType.BLOCK_BREAK
+        );
+        SubmitWorker.INSTANCE.submit(entry);
+        PrintUtil.broadcast("break_block; block_id=" + blockId + "; world=" + worldString);
+//        PrintUtil.broadcast(String.format("player %s break block %s", playerEntity.getName().getString(), blockState));
+    }
+
+    @Override
+    public void onPlayerAttackEntity(PlayerEntity playerEntity, World world, Hand hand, Entity entity, @Nullable EntityHitResult entityHitResult) {
+        String entityId = Registry.ENTITY_TYPE.getId(entity.getType()).toString();
+        String worldString = MinecraftUtil.worldToString(world);
+        LogEntry entry = LogEntryFactory.playerWithEntity(
+                playerEntity.getUuid(),
+                playerEntity.getPos(),
+                worldString,
+                entityId,
+                entity.getPos(),
+                worldString,
+                ActionType.ENTITY_ATTACK
+        );
+        SubmitWorker.INSTANCE.submit(entry);
+        PrintUtil.broadcast("attack_entity; entity_id=" + entityId);
+//        PrintUtil.broadcast(String.format("player %s attack entity %s", playerEntity.getName().getString(), entity));
+    }
+
+    @Override
+    public void onPlayerUseEntity(PlayerEntity playerEntity, World world, Hand hand, Entity entity, @Nullable EntityHitResult entityHitResult) {
+        String entityId = Registry.ENTITY_TYPE.getId(entity.getType()).toString();
+        String worldString = MinecraftUtil.worldToString(world);
+        LogEntry entry = LogEntryFactory.playerWithEntity(
+                playerEntity.getUuid(),
+                playerEntity.getPos(),
+                worldString,
+                entityId,
+                entity.getPos(),
+                worldString,
+                ActionType.ENTITY_USE
+        );
+        SubmitWorker.INSTANCE.submit(entry);
+        PrintUtil.broadcast("use_entity; entity_id=" + entityId);
+        // TODO: 增加判断，无效的时候也会触发这个事件
+        PrintUtil.broadcast(String.format("player %s use entity %s", playerEntity.getName().getString(), entity));
+    }
+
+    @Override
+    public void onPlayerUseItem(PlayerEntity playerEntity, World world, Hand hand) {
+        String itemId = Registry.ITEM.getId(playerEntity.getStackInHand(hand).getItem()).toString();
+        LogEntry entry = LogEntryFactory.playerWithItem(
+                playerEntity.getUuid(),
+                playerEntity.getPos(),
+                MinecraftUtil.worldToString(world),
+                itemId,
+                ActionType.ITEM_USE
+        );
+        SubmitWorker.INSTANCE.submit(entry);
+        PrintUtil.broadcast("use_item; item_id=" + itemId);
+//        PrintUtil.broadcast(String.format("player %s use item %s", playerEntity.getName().getString(), playerEntity.getStackInHand(hand)));
+    }
+}
diff --git a/src/main/java/com/keuin/blame/SubmitWorker.java b/src/main/java/com/keuin/blame/SubmitWorker.java
new file mode 100644
index 0000000..1c47aaf
--- /dev/null
+++ b/src/main/java/com/keuin/blame/SubmitWorker.java
@@ -0,0 +1,88 @@
+package com.keuin.blame;
+
+import com.keuin.blame.config.MongoConfig;
+import com.keuin.blame.data.LogEntry;
+import com.keuin.blame.data.enums.ActionType;
+import com.keuin.blame.data.enums.ObjectType;
+import com.keuin.blame.data.enums.codec.ActionTypeCodec;
+import com.keuin.blame.data.enums.codec.ObjectTypeCodec;
+import com.keuin.blame.data.enums.transformer.ActionTypeTransformer;
+import com.keuin.blame.data.enums.transformer.ObjectTypeTransformer;
+import com.mongodb.ConnectionString;
+import com.mongodb.MongoClientSettings;
+import com.mongodb.client.MongoClient;
+import com.mongodb.client.MongoClients;
+import com.mongodb.client.MongoCollection;
+import com.mongodb.client.MongoDatabase;
+import org.bson.BSON;
+import org.bson.codecs.configuration.CodecRegistries;
+import org.bson.codecs.configuration.CodecRegistry;
+
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingDeque;
+import java.util.logging.Logger;
+
+public class SubmitWorker {
+
+    public static final SubmitWorker INSTANCE = new SubmitWorker(Blame.config.getMongoConfig());
+    private final Logger logger = Logger.getLogger(SubmitWorker.class.getName());
+
+    private final BlockingQueue<LogEntry> queue = new LinkedBlockingDeque<>(4096);
+    private final Thread thread = new Thread(SubmitWorker.this::run);
+    private boolean run = true;
+
+    private final MongoConfig mongoConfig;
+    private final MongoClientSettings settings;
+
+
+    private SubmitWorker(MongoConfig mongoConfig) {
+        if (mongoConfig == null)
+            throw new IllegalArgumentException("mongo config cannot be null");
+        this.mongoConfig = mongoConfig;
+        logger.fine("Connecting to MongoDB server `" + mongoConfig.getAddress()
+                + "` with database `" + mongoConfig.getDatabaseName()
+                + "` and collection `" + mongoConfig.getLogCollectionName() + "`.");
+
+        BSON.addEncodingHook(ActionType.class, new ActionTypeTransformer());
+        BSON.addEncodingHook(ObjectType.class, new ObjectTypeTransformer());
+
+        CodecRegistry codecRegistry = CodecRegistries.fromRegistries(
+                com.mongodb.MongoClient.getDefaultCodecRegistry(),
+                CodecRegistries.fromCodecs(new ActionTypeCodec(), new ObjectTypeCodec())
+        );
+
+        settings = MongoClientSettings.builder()
+                .applyConnectionString(new ConnectionString(mongoConfig.getAddress()))
+                .codecRegistry(codecRegistry)
+                .build();
+        thread.start();
+    }
+
+    public void submit(LogEntry entry) {
+        if (entry == null)
+            throw new IllegalArgumentException("entry cannot be null");
+        queue.offer(entry);
+    }
+
+    public void stop() {
+        thread.interrupt();
+        this.run = false;
+    }
+
+    private void run() {
+        try (final MongoClient mongoClient = MongoClients.create(settings)) {
+            final MongoDatabase db = mongoClient.getDatabase(
+                    mongoConfig.getDatabaseName()
+            );
+            final MongoCollection<LogEntry> collection = db.getCollection(
+                    mongoConfig.getLogCollectionName(), LogEntry.class
+            );
+            while (this.run) {
+                LogEntry entry = queue.take();
+                collection.insertOne(entry);
+            }
+        } catch (InterruptedException ignored) {
+        }
+    }
+
+}
diff --git a/src/main/java/com/keuin/blame/adapter/AttackEntityAdapter.java b/src/main/java/com/keuin/blame/adapter/AttackEntityAdapter.java
new file mode 100644
index 0000000..f9016ae
--- /dev/null
+++ b/src/main/java/com/keuin/blame/adapter/AttackEntityAdapter.java
@@ -0,0 +1,26 @@
+package com.keuin.blame.adapter;
+
+import com.keuin.blame.adapter.handler.AttackEntityHandler;
+import net.fabricmc.fabric.api.event.player.AttackEntityCallback;
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.util.ActionResult;
+import net.minecraft.util.Hand;
+import net.minecraft.util.hit.EntityHitResult;
+import net.minecraft.world.World;
+import org.jetbrains.annotations.Nullable;
+
+public class AttackEntityAdapter implements AttackEntityCallback {
+
+    private final AttackEntityHandler handler;
+
+    public AttackEntityAdapter(AttackEntityHandler handler) {
+        this.handler = handler;
+    }
+
+    @Override
+    public ActionResult interact(PlayerEntity playerEntity, World world, Hand hand, Entity entity, @Nullable EntityHitResult entityHitResult) {
+        handler.onPlayerAttackEntity(playerEntity, world, hand, entity, entityHitResult);
+        return ActionResult.PASS;
+    }
+}
diff --git a/src/main/java/com/keuin/blame/adapter/BreakBlockAdapter.java b/src/main/java/com/keuin/blame/adapter/BreakBlockAdapter.java
new file mode 100644
index 0000000..58f402f
--- /dev/null
+++ b/src/main/java/com/keuin/blame/adapter/BreakBlockAdapter.java
@@ -0,0 +1,23 @@
+package com.keuin.blame.adapter;
+
+import com.keuin.blame.adapter.handler.BreakBlockHandler;
+import net.fabricmc.fabric.api.event.player.PlayerBlockBreakEvents;
+import net.minecraft.block.BlockState;
+import net.minecraft.block.entity.BlockEntity;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.World;
+
+public class BreakBlockAdapter implements PlayerBlockBreakEvents.After {
+
+    private final BreakBlockHandler handler;
+
+    public BreakBlockAdapter(BreakBlockHandler handler) {
+        this.handler = handler;
+    }
+
+    @Override
+    public void afterBlockBreak(World world, PlayerEntity playerEntity, BlockPos blockPos, BlockState blockState, BlockEntity blockEntity) {
+        handler.onPlayerBreakBlock(world, playerEntity, blockPos, blockState, blockEntity);
+    }
+}
diff --git a/src/main/java/com/keuin/blame/adapter/UseBlockAdapter.java b/src/main/java/com/keuin/blame/adapter/UseBlockAdapter.java
new file mode 100644
index 0000000..2ff10e2
--- /dev/null
+++ b/src/main/java/com/keuin/blame/adapter/UseBlockAdapter.java
@@ -0,0 +1,24 @@
+package com.keuin.blame.adapter;
+
+import com.keuin.blame.adapter.handler.UseBlockHandler;
+import net.fabricmc.fabric.api.event.player.UseBlockCallback;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.util.ActionResult;
+import net.minecraft.util.Hand;
+import net.minecraft.util.hit.BlockHitResult;
+import net.minecraft.world.World;
+
+public class UseBlockAdapter implements UseBlockCallback {
+
+    private final UseBlockHandler handler;
+
+    public UseBlockAdapter(UseBlockHandler handler) {
+        this.handler = handler;
+    }
+
+    @Override
+    public ActionResult interact(PlayerEntity playerEntity, World world, Hand hand, BlockHitResult blockHitResult) {
+        handler.onPlayerUseBlock(playerEntity, world, hand, blockHitResult);
+        return ActionResult.PASS;
+    }
+}
diff --git a/src/main/java/com/keuin/blame/adapter/UseEntityAdapter.java b/src/main/java/com/keuin/blame/adapter/UseEntityAdapter.java
new file mode 100644
index 0000000..867a292
--- /dev/null
+++ b/src/main/java/com/keuin/blame/adapter/UseEntityAdapter.java
@@ -0,0 +1,26 @@
+package com.keuin.blame.adapter;
+
+import com.keuin.blame.adapter.handler.UseEntityHandler;
+import net.fabricmc.fabric.api.event.player.UseEntityCallback;
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.util.ActionResult;
+import net.minecraft.util.Hand;
+import net.minecraft.util.hit.EntityHitResult;
+import net.minecraft.world.World;
+import org.jetbrains.annotations.Nullable;
+
+public class UseEntityAdapter implements UseEntityCallback {
+
+    private final UseEntityHandler handler;
+
+    public UseEntityAdapter(UseEntityHandler handler) {
+        this.handler = handler;
+    }
+
+    @Override
+    public ActionResult interact(PlayerEntity playerEntity, World world, Hand hand, Entity entity, @Nullable EntityHitResult entityHitResult) {
+        handler.onPlayerUseEntity(playerEntity, world, hand, entity, entityHitResult);
+        return ActionResult.PASS;
+    }
+}
diff --git a/src/main/java/com/keuin/blame/adapter/UseItemAdapter.java b/src/main/java/com/keuin/blame/adapter/UseItemAdapter.java
new file mode 100644
index 0000000..66adf99
--- /dev/null
+++ b/src/main/java/com/keuin/blame/adapter/UseItemAdapter.java
@@ -0,0 +1,24 @@
+package com.keuin.blame.adapter;
+
+import com.keuin.blame.adapter.handler.UseItemHandler;
+import net.fabricmc.fabric.api.event.player.UseItemCallback;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.item.ItemStack;
+import net.minecraft.util.Hand;
+import net.minecraft.util.TypedActionResult;
+import net.minecraft.world.World;
+
+public class UseItemAdapter implements UseItemCallback {
+
+    private final UseItemHandler handler;
+
+    public UseItemAdapter(UseItemHandler handler) {
+        this.handler = handler;
+    }
+
+    @Override
+    public TypedActionResult<ItemStack> interact(PlayerEntity playerEntity, World world, Hand hand) {
+        handler.onPlayerUseItem(playerEntity, world, hand);
+        return TypedActionResult.pass(ItemStack.EMPTY);
+    }
+}
diff --git a/src/main/java/com/keuin/blame/adapter/handler/AttackEntityHandler.java b/src/main/java/com/keuin/blame/adapter/handler/AttackEntityHandler.java
new file mode 100644
index 0000000..3e1f307
--- /dev/null
+++ b/src/main/java/com/keuin/blame/adapter/handler/AttackEntityHandler.java
@@ -0,0 +1,12 @@
+package com.keuin.blame.adapter.handler;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.util.Hand;
+import net.minecraft.util.hit.EntityHitResult;
+import net.minecraft.world.World;
+import org.jetbrains.annotations.Nullable;
+
+public interface AttackEntityHandler {
+    void onPlayerAttackEntity(PlayerEntity playerEntity, World world, Hand hand, Entity entity, @Nullable EntityHitResult entityHitResult);
+}
diff --git a/src/main/java/com/keuin/blame/adapter/handler/BreakBlockHandler.java b/src/main/java/com/keuin/blame/adapter/handler/BreakBlockHandler.java
new file mode 100644
index 0000000..4bf4d6b
--- /dev/null
+++ b/src/main/java/com/keuin/blame/adapter/handler/BreakBlockHandler.java
@@ -0,0 +1,11 @@
+package com.keuin.blame.adapter.handler;
+
+import net.minecraft.block.BlockState;
+import net.minecraft.block.entity.BlockEntity;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.World;
+
+public interface BreakBlockHandler {
+    void onPlayerBreakBlock(World world, PlayerEntity playerEntity, BlockPos blockPos, BlockState blockState, BlockEntity blockEntity);
+}
diff --git a/src/main/java/com/keuin/blame/adapter/handler/UseBlockHandler.java b/src/main/java/com/keuin/blame/adapter/handler/UseBlockHandler.java
new file mode 100644
index 0000000..163278a
--- /dev/null
+++ b/src/main/java/com/keuin/blame/adapter/handler/UseBlockHandler.java
@@ -0,0 +1,10 @@
+package com.keuin.blame.adapter.handler;
+
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.util.Hand;
+import net.minecraft.util.hit.BlockHitResult;
+import net.minecraft.world.World;
+
+public interface UseBlockHandler {
+    void onPlayerUseBlock(PlayerEntity playerEntity, World world, Hand hand, BlockHitResult blockHitResult);
+}
diff --git a/src/main/java/com/keuin/blame/adapter/handler/UseEntityHandler.java b/src/main/java/com/keuin/blame/adapter/handler/UseEntityHandler.java
new file mode 100644
index 0000000..d8a744f
--- /dev/null
+++ b/src/main/java/com/keuin/blame/adapter/handler/UseEntityHandler.java
@@ -0,0 +1,12 @@
+package com.keuin.blame.adapter.handler;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.util.Hand;
+import net.minecraft.util.hit.EntityHitResult;
+import net.minecraft.world.World;
+import org.jetbrains.annotations.Nullable;
+
+public interface UseEntityHandler {
+    void onPlayerUseEntity(PlayerEntity playerEntity, World world, Hand hand, Entity entity, @Nullable EntityHitResult entityHitResult);
+}
diff --git a/src/main/java/com/keuin/blame/adapter/handler/UseItemHandler.java b/src/main/java/com/keuin/blame/adapter/handler/UseItemHandler.java
new file mode 100644
index 0000000..ca4b965
--- /dev/null
+++ b/src/main/java/com/keuin/blame/adapter/handler/UseItemHandler.java
@@ -0,0 +1,9 @@
+package com.keuin.blame.adapter.handler;
+
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.util.Hand;
+import net.minecraft.world.World;
+
+public interface UseItemHandler {
+    void onPlayerUseItem(PlayerEntity playerEntity, World world, Hand hand);
+}
diff --git a/src/main/java/com/keuin/blame/config/BlameConfig.java b/src/main/java/com/keuin/blame/config/BlameConfig.java
new file mode 100644
index 0000000..ace8fa3
--- /dev/null
+++ b/src/main/java/com/keuin/blame/config/BlameConfig.java
@@ -0,0 +1,40 @@
+package com.keuin.blame.config;
+
+import com.google.gson.annotations.SerializedName;
+
+import java.util.Objects;
+
+public class BlameConfig {
+
+    @SerializedName("database")
+    private final MongoConfig mongoConfig;
+
+
+    public BlameConfig(MongoConfig mongoConfig) {
+        this.mongoConfig = mongoConfig;
+    }
+
+    public MongoConfig getMongoConfig() {
+        return mongoConfig;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        BlameConfig that = (BlameConfig) o;
+        return Objects.equals(mongoConfig, that.mongoConfig);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(mongoConfig);
+    }
+
+    @Override
+    public String toString() {
+        return "BlameConfig{" +
+                "mongoConfig=" + mongoConfig +
+                '}';
+    }
+}
diff --git a/src/main/java/com/keuin/blame/config/MongoConfig.java b/src/main/java/com/keuin/blame/config/MongoConfig.java
new file mode 100644
index 0000000..628af51
--- /dev/null
+++ b/src/main/java/com/keuin/blame/config/MongoConfig.java
@@ -0,0 +1,72 @@
+package com.keuin.blame.config;
+
+import com.google.gson.annotations.SerializedName;
+
+import java.util.Objects;
+
+public class MongoConfig {
+
+    private final String address;
+    private final String username;
+    private final String password;
+    @SerializedName("database")
+    private final String databaseName;
+    @SerializedName("collection")
+    private final String logCollectionName;
+
+    public MongoConfig(String address, String username, String password, String databaseName, String logCollectionName) {
+        this.address = address;
+        this.username = username;
+        this.password = password;
+        this.databaseName = databaseName;
+        this.logCollectionName = logCollectionName;
+    }
+
+    public String getAddress() {
+        return address;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public String getDatabaseName() {
+        return databaseName;
+    }
+
+    public String getLogCollectionName() {
+        return logCollectionName;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        MongoConfig that = (MongoConfig) o;
+        return Objects.equals(address, that.address) &&
+                Objects.equals(username, that.username) &&
+                Objects.equals(password, that.password) &&
+                Objects.equals(databaseName, that.databaseName) &&
+                Objects.equals(logCollectionName, that.logCollectionName);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(address, username, password, databaseName, logCollectionName);
+    }
+
+    @Override
+    public String toString() {
+        return "MongoConfig{" +
+                "address='" + address + '\'' +
+                ", username='" + username + '\'' +
+                ", password='" + password + '\'' +
+                ", databaseName='" + databaseName + '\'' +
+                ", logCollectionName='" + logCollectionName + '\'' +
+                '}';
+    }
+}
diff --git a/src/main/java/com/keuin/blame/data/LogEntry.java b/src/main/java/com/keuin/blame/data/LogEntry.java
new file mode 100644
index 0000000..30037c0
--- /dev/null
+++ b/src/main/java/com/keuin/blame/data/LogEntry.java
@@ -0,0 +1,130 @@
+package com.keuin.blame.data;
+
+import com.keuin.blame.data.enums.ActionType;
+import com.keuin.blame.data.enums.ObjectType;
+import org.bson.codecs.pojo.annotations.BsonProperty;
+
+import java.util.Objects;
+import java.util.UUID;
+
+public class LogEntry {
+
+    // {
+    //    "version": 1, // int
+    //    "subject": {
+    //        "uuid": player_uuid_bytes, // bytes
+    //        "id": player_id, // string
+    //        "pos": {
+    //            "world": world_id, // string
+    //            "x": pos_x, // float
+    //            "y": pos_y, // float
+    //            "z": pos_z, // float
+    //        }
+    //    },
+    //    "action": BLOCK_BREAK | BLOCK_PLACE | BLOCK_USE | ENTITY_USE | ENTITY_ATTACK | ITEM_USE, // int
+    //    "object": {
+    //        "type": OBJECT_BLOCK | OBJECT_ENTITY, // int
+    //        "id": object_id, // string
+    //        "pos": {
+    //            "world": world_id, // string
+    //            "x": pos_x, // float
+    //            "y": pos_y, // float
+    //            "z": pos_z, // float
+    //        }
+    //    }
+    //}
+
+    @BsonProperty("version")
+    private final int version = 1;
+    @BsonProperty("timestamp_millis")
+    private final long timeMillis;
+    @BsonProperty("subject_uuid")
+    private final String subjectUUID; // TODO: use Binary instead (BasicDBObject("_id", Binary(session.getIp().getAddress()))) (https://stackoverflow.com/questions/30566905/store-byte-in-mongodb-using-java/40843195)
+    @BsonProperty("subject_pos")
+    private final WorldPos subjectPos; // TODO: write codec and transformer for this
+    @BsonProperty("action_type")
+    private final ActionType actionType;
+    @BsonProperty("object_type")
+    private final ObjectType objectType;
+    @BsonProperty("object_id")
+    private final String objectId;
+    @BsonProperty("object_pos")
+    private final WorldPos objectPos;
+
+    public LogEntry(long timeMillis, UUID subjectUUID, WorldPos subjectPos, ActionType actionType, ObjectType objectType, String objectId, WorldPos objectPos) {
+//        this.subjectUUID = UuidUtils.asBytes(subjectUUID);
+//        this.subjectUUID
+        if (subjectUUID == null)
+            throw new IllegalArgumentException("subjectUUID cannot be null");
+        if (subjectPos == null)
+            throw new IllegalArgumentException("subjectPos cannot be null");
+        if (actionType == null)
+            throw new IllegalArgumentException("actionType cannot be null");
+        if (objectType == null)
+            throw new IllegalArgumentException("objectType cannot be null");
+        if (objectId == null)
+            throw new IllegalArgumentException("objectId cannot be null");
+        if (objectPos == null)
+            throw new IllegalArgumentException("objectPos cannot be null");
+
+        this.timeMillis = timeMillis;
+        this.subjectUUID = subjectUUID.toString();
+        this.subjectPos = subjectPos;
+        this.actionType = actionType;
+        this.objectType = objectType;
+        this.objectId = objectId;
+        this.objectPos = objectPos;
+    }
+
+    public int getVersion() {
+        return 1;
+    }
+
+    public long getTimeMillis() {
+        return timeMillis;
+    }
+
+    public UUID getSubjectUUID() {
+        return UUID.fromString(subjectUUID);
+    }
+
+    public WorldPos getSubjectPos() {
+        return subjectPos;
+    }
+
+    public ActionType getActionType() {
+        return actionType;
+    }
+
+    public ObjectType getObjectType() {
+        return objectType;
+    }
+
+    public String getObjectId() {
+        return objectId;
+    }
+
+    public WorldPos getObjectPos() {
+        return objectPos;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        LogEntry entry = (LogEntry) o;
+        return version == entry.version &&
+                timeMillis == entry.timeMillis &&
+                Objects.equals(subjectUUID, entry.subjectUUID) &&
+                Objects.equals(subjectPos, entry.subjectPos) &&
+                actionType == entry.actionType &&
+                objectType == entry.objectType &&
+                Objects.equals(objectId, entry.objectId) &&
+                Objects.equals(objectPos, entry.objectPos);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(version, timeMillis, subjectUUID, subjectPos, actionType, objectType, objectId, objectPos);
+    }
+}
diff --git a/src/main/java/com/keuin/blame/data/LogEntryFactory.java b/src/main/java/com/keuin/blame/data/LogEntryFactory.java
new file mode 100644
index 0000000..1e2d5d1
--- /dev/null
+++ b/src/main/java/com/keuin/blame/data/LogEntryFactory.java
@@ -0,0 +1,46 @@
+package com.keuin.blame.data;
+
+import com.keuin.blame.data.enums.ActionType;
+import com.keuin.blame.data.enums.ObjectType;
+import net.minecraft.util.math.Vec3d;
+import net.minecraft.util.math.Vec3i;
+
+import java.util.UUID;
+
+public class LogEntryFactory {
+    public static LogEntry playerWithBlock(UUID playerUUID, Vec3d playerPos, String playerWorld, String blockId, Vec3i blockPos, String blockWorld, ActionType actionType) {
+        return new LogEntry(
+                System.currentTimeMillis(),
+                playerUUID,
+                new WorldPos(playerWorld, playerPos.x, playerPos.y, playerPos.z),
+                actionType,
+                ObjectType.BLOCK,
+                blockId,
+                new WorldPos(blockWorld, blockPos.getX(), blockPos.getY(), blockPos.getZ())
+        );
+    }
+
+    public static LogEntry playerWithEntity(UUID playerUUID, Vec3d playerPos, String playerWorld, String entityId, Vec3d entityPos, String entityWorld, ActionType actionType) {
+        return new LogEntry(
+                System.currentTimeMillis(),
+                playerUUID,
+                new WorldPos(playerWorld, playerPos.x, playerPos.y, playerPos.z),
+                actionType,
+                ObjectType.ENTITY,
+                entityId,
+                new WorldPos(entityWorld, entityPos.x, entityPos.y, entityPos.z)
+        );
+    }
+
+    public static LogEntry playerWithItem(UUID playerUUID, Vec3d playerPos, String playerWorld, String itemId, ActionType actionType) {
+        return new LogEntry(
+                System.currentTimeMillis(),
+                playerUUID,
+                new WorldPos(playerWorld, playerPos.x, playerPos.y, playerPos.z),
+                actionType,
+                ObjectType.ENTITY,
+                itemId,
+                WorldPos.NULL_POS
+        );
+    }
+}
diff --git a/src/main/java/com/keuin/blame/data/WorldPos.java b/src/main/java/com/keuin/blame/data/WorldPos.java
new file mode 100644
index 0000000..aeda093
--- /dev/null
+++ b/src/main/java/com/keuin/blame/data/WorldPos.java
@@ -0,0 +1,56 @@
+package com.keuin.blame.data;
+
+import java.util.Objects;
+
+public class WorldPos {
+
+    // immutable
+
+    private final String world;
+    private final double x;
+    private final double y;
+    private final double z;
+
+    public static final WorldPos NULL_POS = new WorldPos("", 0, 0, 0);
+
+    public WorldPos(String world, double x, double y, double z) {
+        if (world == null)
+            throw new IllegalArgumentException("world string must not be null");
+        this.world = world;
+        this.x = x;
+        this.y = y;
+        this.z = z;
+    }
+
+    public String getWorld() {
+        return world;
+    }
+
+    public double getX() {
+        return x;
+    }
+
+    public double getY() {
+        return y;
+    }
+
+    public double getZ() {
+        return z;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        WorldPos worldPos = (WorldPos) o;
+        return Double.compare(worldPos.x, x) == 0 &&
+                Double.compare(worldPos.y, y) == 0 &&
+                Double.compare(worldPos.z, z) == 0 &&
+                world.equals(worldPos.world);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(world, x, y, z);
+    }
+}
diff --git a/src/main/java/com/keuin/blame/data/enums/ActionType.java b/src/main/java/com/keuin/blame/data/enums/ActionType.java
new file mode 100644
index 0000000..dcf2aa7
--- /dev/null
+++ b/src/main/java/com/keuin/blame/data/enums/ActionType.java
@@ -0,0 +1,37 @@
+package com.keuin.blame.data.enums;
+
+public enum ActionType implements IntegerEnum {
+
+    BLOCK_BREAK(1),
+    BLOCK_PLACE(2),
+    BLOCK_USE(3),
+    ENTITY_ATTACK(4),
+    ENTITY_USE(5),
+    ITEM_USE(6);
+
+    private final int value;
+
+    ActionType(int value) {
+        this.value = value;
+    }
+
+    public static ActionType parseInt(int value) {
+        for (ActionType actionType : ActionType.values()) {
+            if (actionType.value == value)
+                return actionType;
+        }
+        return null;
+    }
+
+    public int getValue() {
+        return value;
+    }
+
+    @Override
+    public String toString() {
+        return "ActionType{" +
+                "value=" + value +
+                '}';
+    }
+
+}
diff --git a/src/main/java/com/keuin/blame/data/enums/IntegerEnum.java b/src/main/java/com/keuin/blame/data/enums/IntegerEnum.java
new file mode 100644
index 0000000..6e9ea50
--- /dev/null
+++ b/src/main/java/com/keuin/blame/data/enums/IntegerEnum.java
@@ -0,0 +1,5 @@
+package com.keuin.blame.data.enums;
+
+public interface IntegerEnum {
+    int getValue();
+}
diff --git a/src/main/java/com/keuin/blame/data/enums/ObjectType.java b/src/main/java/com/keuin/blame/data/enums/ObjectType.java
new file mode 100644
index 0000000..b3b1d67
--- /dev/null
+++ b/src/main/java/com/keuin/blame/data/enums/ObjectType.java
@@ -0,0 +1,32 @@
+package com.keuin.blame.data.enums;
+
+public enum ObjectType implements IntegerEnum {
+
+    BLOCK(1), ENTITY(2);
+
+    private final int value;
+
+    ObjectType(int value) {
+        this.value = value;
+    }
+
+    public static ObjectType parseInt(int value) {
+        for (ObjectType objectType : ObjectType.values()) {
+            if (objectType.value == value)
+                return objectType;
+        }
+        return null;
+    }
+
+    public int getValue() {
+        return value;
+    }
+
+    @Override
+    public String toString() {
+        return "ObjectType{" +
+                "value=" + value +
+                '}';
+    }
+
+}
diff --git a/src/main/java/com/keuin/blame/data/enums/codec/AbstractIntegerEnumCodec.java b/src/main/java/com/keuin/blame/data/enums/codec/AbstractIntegerEnumCodec.java
new file mode 100644
index 0000000..98f871a
--- /dev/null
+++ b/src/main/java/com/keuin/blame/data/enums/codec/AbstractIntegerEnumCodec.java
@@ -0,0 +1,13 @@
+package com.keuin.blame.data.enums.codec;
+
+import com.keuin.blame.data.enums.IntegerEnum;
+import org.bson.BsonWriter;
+import org.bson.codecs.Codec;
+import org.bson.codecs.EncoderContext;
+
+public abstract class AbstractIntegerEnumCodec<T extends IntegerEnum> implements Codec<T> {
+    @Override
+    public void encode(BsonWriter writer, T value, EncoderContext encoderContext) {
+        writer.writeInt32(value.getValue());
+    }
+}
diff --git a/src/main/java/com/keuin/blame/data/enums/codec/ActionTypeCodec.java b/src/main/java/com/keuin/blame/data/enums/codec/ActionTypeCodec.java
new file mode 100644
index 0000000..a7fc228
--- /dev/null
+++ b/src/main/java/com/keuin/blame/data/enums/codec/ActionTypeCodec.java
@@ -0,0 +1,17 @@
+package com.keuin.blame.data.enums.codec;
+
+import com.keuin.blame.data.enums.ActionType;
+import org.bson.BsonReader;
+import org.bson.codecs.DecoderContext;
+
+public class ActionTypeCodec extends AbstractIntegerEnumCodec<ActionType> {
+    @Override
+    public ActionType decode(BsonReader reader, DecoderContext decoderContext) {
+        return ActionType.parseInt(reader.readInt32());
+    }
+
+    @Override
+    public Class<ActionType> getEncoderClass() {
+        return ActionType.class;
+    }
+}
diff --git a/src/main/java/com/keuin/blame/data/enums/codec/ObjectTypeCodec.java b/src/main/java/com/keuin/blame/data/enums/codec/ObjectTypeCodec.java
new file mode 100644
index 0000000..8b47cc6
--- /dev/null
+++ b/src/main/java/com/keuin/blame/data/enums/codec/ObjectTypeCodec.java
@@ -0,0 +1,17 @@
+package com.keuin.blame.data.enums.codec;
+
+import com.keuin.blame.data.enums.ObjectType;
+import org.bson.BsonReader;
+import org.bson.codecs.DecoderContext;
+
+public class ObjectTypeCodec extends AbstractIntegerEnumCodec<ObjectType> {
+    @Override
+    public ObjectType decode(BsonReader reader, DecoderContext decoderContext) {
+        return ObjectType.parseInt(reader.readInt32());
+    }
+
+    @Override
+    public Class<ObjectType> getEncoderClass() {
+        return ObjectType.class;
+    }
+}
diff --git a/src/main/java/com/keuin/blame/data/enums/transformer/ActionTypeTransformer.java b/src/main/java/com/keuin/blame/data/enums/transformer/ActionTypeTransformer.java
new file mode 100644
index 0000000..b50118d
--- /dev/null
+++ b/src/main/java/com/keuin/blame/data/enums/transformer/ActionTypeTransformer.java
@@ -0,0 +1,12 @@
+package com.keuin.blame.data.enums.transformer;
+
+import com.keuin.blame.data.enums.ActionType;
+import org.bson.Transformer;
+
+public class ActionTypeTransformer implements Transformer {
+    @Override
+    public Object transform(Object objectToTransform) {
+        ActionType actionType = (ActionType) objectToTransform;
+        return actionType.getValue();
+    }
+}
diff --git a/src/main/java/com/keuin/blame/data/enums/transformer/ObjectTypeTransformer.java b/src/main/java/com/keuin/blame/data/enums/transformer/ObjectTypeTransformer.java
new file mode 100644
index 0000000..e28b1b7
--- /dev/null
+++ b/src/main/java/com/keuin/blame/data/enums/transformer/ObjectTypeTransformer.java
@@ -0,0 +1,12 @@
+package com.keuin.blame.data.enums.transformer;
+
+import com.keuin.blame.data.enums.ObjectType;
+import org.bson.Transformer;
+
+public class ObjectTypeTransformer implements Transformer {
+    @Override
+    public Object transform(Object objectToTransform) {
+        ObjectType objectType = (ObjectType) objectToTransform;
+        return objectType.getValue();
+    }
+}
diff --git a/src/main/java/com/keuin/blame/util/MinecraftUtil.java b/src/main/java/com/keuin/blame/util/MinecraftUtil.java
new file mode 100644
index 0000000..ce8707e
--- /dev/null
+++ b/src/main/java/com/keuin/blame/util/MinecraftUtil.java
@@ -0,0 +1,11 @@
+package com.keuin.blame.util;
+
+import net.minecraft.world.World;
+
+public class MinecraftUtil {
+
+    public static String worldToString(World world) {
+        return world.getRegistryKey().getValue().toString();
+    }
+
+}
diff --git a/src/main/java/com/keuin/blame/util/PrintUtil.java b/src/main/java/com/keuin/blame/util/PrintUtil.java
new file mode 100644
index 0000000..fdd1ea0
--- /dev/null
+++ b/src/main/java/com/keuin/blame/util/PrintUtil.java
@@ -0,0 +1,140 @@
+package com.keuin.blame.util;
+
+import com.mojang.brigadier.context.CommandContext;
+import net.fabricmc.fabric.api.event.lifecycle.v1.ServerLifecycleEvents;
+import net.minecraft.network.MessageType;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.PlayerManager;
+import net.minecraft.server.command.ServerCommandSource;
+import net.minecraft.text.LiteralText;
+import net.minecraft.text.Style;
+import net.minecraft.util.Formatting;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.UUID;
+
+
+public final class PrintUtil implements ServerLifecycleEvents.ServerStarted {
+
+    private static final Object syncMessage = new Object();
+    private static final Object syncBroadcast = new Object();
+
+    private static final Style broadcastStyle = Style.EMPTY.withColor(Formatting.AQUA);
+    private static final Style infoStyle = Style.EMPTY.withColor(Formatting.WHITE);
+    private static final Style stressStyle = Style.EMPTY.withColor(Formatting.AQUA);
+    private static final Style warnStyle = Style.EMPTY.withColor(Formatting.YELLOW);
+    private static final Style errorStyle = Style.EMPTY.withColor(Formatting.DARK_RED);
+
+    private static final Logger LOGGER = LogManager.getLogger();
+    private static final String LOG_HEADING = "[Blame]";
+    private static PlayerManager playerManager = null;
+
+    private static final UUID UUID_NULL = UUID.fromString("00000000-0000-0000-0000-000000000000");
+
+    // Used to handle server started event, to get player manager
+    // You should put `ServerLifecycleEvents.SERVER_STARTED.register(PrintUtil.INSTANCE);` in the plugin init method
+    public static final PrintUtil INSTANCE = new PrintUtil();
+
+    private PrintUtil() {
+    }
+
+    @Override
+    public void onServerStarted(MinecraftServer minecraftServer) {
+        PrintUtil.playerManager = minecraftServer.getPlayerManager();
+    }
+
+    public static void setPlayerManager(PlayerManager playerManager) {
+        if (PrintUtil.playerManager == null)
+            PrintUtil.playerManager = playerManager;
+    }
+
+    public static void broadcast(String message) {
+        synchronized (syncBroadcast) {
+            if (playerManager != null)
+                playerManager.broadcastChatMessage(
+                        new LiteralText(message).setStyle(broadcastStyle),
+                        MessageType.SYSTEM,
+                        UUID_NULL
+                );
+        }
+    }
+
+    public static CommandContext<ServerCommandSource> msgStress(CommandContext<ServerCommandSource> context, String messageText) {
+        return msgStress(context, messageText, false);
+    }
+
+    public static CommandContext<ServerCommandSource> msgInfo(CommandContext<ServerCommandSource> context, String messageText) {
+        return msgInfo(context, messageText, false);
+    }
+
+    public static CommandContext<ServerCommandSource> msgWarn(CommandContext<ServerCommandSource> context, String messageText) {
+        return msgWarn(context, messageText, false);
+    }
+
+    public static CommandContext<ServerCommandSource> msgErr(CommandContext<ServerCommandSource> context, String messageText) {
+        return msgErr(context, messageText, false);
+    }
+
+    public static CommandContext<ServerCommandSource> msgStress(CommandContext<ServerCommandSource> context, String messageText, boolean broadcastToOps) {
+        return message(context, messageText, broadcastToOps, stressStyle);
+    }
+
+    public static CommandContext<ServerCommandSource> msgInfo(CommandContext<ServerCommandSource> context, String messageText, boolean broadcastToOps) {
+        return message(context, messageText, broadcastToOps, infoStyle);
+    }
+
+    public static CommandContext<ServerCommandSource> msgWarn(CommandContext<ServerCommandSource> context, String messageText, boolean broadcastToOps) {
+        return message(context, messageText, broadcastToOps, warnStyle);
+    }
+
+    public static CommandContext<ServerCommandSource> msgErr(CommandContext<ServerCommandSource> context, String messageText, boolean broadcastToOps) {
+        return message(context, messageText, broadcastToOps, errorStyle);
+    }
+
+    private static CommandContext<ServerCommandSource> message(CommandContext<ServerCommandSource> context, String messageText, boolean broadcastToOps, Style style) {
+        synchronized (syncMessage) {
+            LiteralText text = new LiteralText(messageText);
+            text.setStyle(style);
+            context.getSource().sendFeedback(text, broadcastToOps);
+        }
+        return context;
+    }
+
+    /**
+     * Print debug message on the server console.
+     *
+     * @param string the message.
+     */
+    public static void debug(String string) {
+        LOGGER.debug(LOG_HEADING + " " + string);
+    }
+
+    /**
+     * Print informative message on the server console.
+     *
+     * @param string the message.
+     */
+    public static void info(String string) {
+        LOGGER.info(LOG_HEADING + " " + string);
+    }
+
+    /**
+     * Print warning message on the server console.
+     *
+     * @param string the message.
+     */
+    public static void warn(String string) {
+        LOGGER.warn(LOG_HEADING + " " + string);
+    }
+
+    /**
+     * Print error message on the server console.
+     *
+     * @param string the message.
+     */
+    public static void error(String string) {
+        LOGGER.error(LOG_HEADING + " " + string);
+    }
+
+}
diff --git a/src/main/java/com/keuin/blame/util/UuidUtils.java b/src/main/java/com/keuin/blame/util/UuidUtils.java
new file mode 100644
index 0000000..b282129
--- /dev/null
+++ b/src/main/java/com/keuin/blame/util/UuidUtils.java
@@ -0,0 +1,20 @@
+package com.keuin.blame.util;
+
+import java.nio.ByteBuffer;
+import java.util.UUID;
+
+public class UuidUtils {
+    public static UUID asUuid(byte[] bytes) {
+        ByteBuffer bb = ByteBuffer.wrap(bytes);
+        long firstLong = bb.getLong();
+        long secondLong = bb.getLong();
+        return new UUID(firstLong, secondLong);
+    }
+
+    public static byte[] asBytes(UUID uuid) {
+        ByteBuffer bb = ByteBuffer.wrap(new byte[16]);
+        bb.putLong(uuid.getMostSignificantBits());
+        bb.putLong(uuid.getLeastSignificantBits());
+        return bb.array();
+    }
+}
\ No newline at end of file