commit 9380770492015453a895eb79d743c84b9d228c9f
Author: TheMode <themode@outlook.fr>
Date:   Sat Aug 3 15:25:24 2019 +0200

    Initial commit

diff --git a/build.gradle b/build.gradle
new file mode 100644
index 000000000..39c249ed7
--- /dev/null
+++ b/build.gradle
@@ -0,0 +1,18 @@
+plugins {
+    id 'java'
+}
+
+group 'fr.themode.minestom'
+version '1.0'
+
+sourceCompatibility = 1.8
+
+repositories {
+    mavenCentral()
+    maven { url 'https://jitpack.io' }
+}
+
+dependencies {
+    testCompile group: 'junit', name: 'junit', version: '4.12'
+    implementation 'com.github.Adamaq01:ozao-net:2.3.1'
+}
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 000000000..94336fcae
Binary files /dev/null and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 000000000..3ecf9801d
--- /dev/null
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+#Thu Aug 01 13:49:10 CEST 2019
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.3-all.zip
diff --git a/gradlew b/gradlew
new file mode 100644
index 000000000..cccdd3d51
--- /dev/null
+++ b/gradlew
@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
new file mode 100644
index 000000000..f9553162f
--- /dev/null
+++ b/gradlew.bat
@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/settings.gradle b/settings.gradle
new file mode 100644
index 000000000..ad69ae53c
--- /dev/null
+++ b/settings.gradle
@@ -0,0 +1,2 @@
+rootProject.name = 'Minestom'
+
diff --git a/src/main/java/fr/themode/minestom/Main.java b/src/main/java/fr/themode/minestom/Main.java
new file mode 100644
index 000000000..632f43132
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/Main.java
@@ -0,0 +1,61 @@
+package fr.themode.minestom;
+
+import fr.adamaq01.ozao.net.packet.Packet;
+import fr.adamaq01.ozao.net.server.Connection;
+import fr.adamaq01.ozao.net.server.Server;
+import fr.adamaq01.ozao.net.server.ServerHandler;
+import fr.adamaq01.ozao.net.server.backend.tcp.TCPServer;
+import fr.themode.minestom.net.ConnectionManager;
+import fr.themode.minestom.net.PacketProcessor;
+import fr.themode.minestom.net.protocol.MinecraftProtocol;
+
+import java.lang.reflect.InvocationTargetException;
+
+public class Main {
+
+    private static ConnectionManager connectionManager;
+    private static PacketProcessor packetProcessor;
+
+    public static void main(String[] args) {
+
+        connectionManager = new ConnectionManager();
+        packetProcessor = new PacketProcessor(connectionManager);
+
+        Server server = new TCPServer(new MinecraftProtocol()).addHandler(new ServerHandler() {
+            @Override
+            public void onConnect(Server server, Connection connection) {
+                System.out.println("A connection");
+            }
+
+            @Override
+            public void onDisconnect(Server server, Connection connection) {
+                System.out.println("A DISCONNECTION");
+            }
+
+            @Override
+            public void onPacketReceive(Server server, Connection connection, Packet packet) {
+                try {
+                    packetProcessor.process(connection, packet);
+                } catch (NoSuchMethodException e) {
+                    e.printStackTrace();
+                } catch (IllegalAccessException e) {
+                    e.printStackTrace();
+                } catch (InvocationTargetException e) {
+                    e.printStackTrace();
+                } catch (InstantiationException e) {
+                    e.printStackTrace();
+                }
+            }
+
+            @Override
+            public void onException(Server server, Connection connection, Throwable cause) {
+                cause.printStackTrace();
+            }
+        });
+
+        server.bind(25565);
+        System.out.println("Server started");
+
+    }
+
+}
diff --git a/src/main/java/fr/themode/minestom/entity/GameMode.java b/src/main/java/fr/themode/minestom/entity/GameMode.java
new file mode 100644
index 000000000..0665db213
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/entity/GameMode.java
@@ -0,0 +1,25 @@
+package fr.themode.minestom.entity;
+
+public enum GameMode {
+
+    SURVIVAL((byte) 0), CREATIVE((byte) 1), ADVENTURE((byte) 2), SPECTATOR((byte) 3);
+
+    private byte id;
+    private boolean hardcore;
+
+    GameMode(byte id) {
+        this.id = id;
+    }
+
+    public void setHardcore(boolean hardcore) {
+        this.hardcore = hardcore;
+    }
+
+    public byte getId() {
+        return id;
+    }
+
+    public boolean isHardcore() {
+        return hardcore;
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/entity/Player.java b/src/main/java/fr/themode/minestom/entity/Player.java
new file mode 100644
index 000000000..e490d1b21
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/entity/Player.java
@@ -0,0 +1,12 @@
+package fr.themode.minestom.entity;
+
+import fr.themode.minestom.net.player.PlayerConnection;
+
+public class Player {
+
+    private PlayerConnection playerConnection;
+
+    public PlayerConnection getPlayerConnection() {
+        return playerConnection;
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/ConnectionManager.java b/src/main/java/fr/themode/minestom/net/ConnectionManager.java
new file mode 100644
index 000000000..3e547aa4f
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/ConnectionManager.java
@@ -0,0 +1,24 @@
+package fr.themode.minestom.net;
+
+import fr.themode.minestom.entity.Player;
+import fr.themode.minestom.net.player.PlayerConnection;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+public class ConnectionManager {
+
+    private Set<PlayerConnection> connections = new HashSet<>();
+    private Map<PlayerConnection, Player> connectionPlayerMap = new HashMap<>();
+
+    public Player getPlayer(PlayerConnection connection) {
+        return connectionPlayerMap.get(connection);
+    }
+
+    // Is only used at LoginStartPacket#process
+    public void createPlayer(PlayerConnection connection) {
+        this.connectionPlayerMap.put(connection, new Player());
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/ConnectionState.java b/src/main/java/fr/themode/minestom/net/ConnectionState.java
new file mode 100644
index 000000000..0de9dce6c
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/ConnectionState.java
@@ -0,0 +1,7 @@
+package fr.themode.minestom.net;
+
+public enum ConnectionState {
+
+    UNKNOWN, STATUS, LOGIN, PLAY;
+
+}
diff --git a/src/main/java/fr/themode/minestom/net/PacketProcessor.java b/src/main/java/fr/themode/minestom/net/PacketProcessor.java
new file mode 100644
index 000000000..6a87230de
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/PacketProcessor.java
@@ -0,0 +1,80 @@
+package fr.themode.minestom.net;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.adamaq01.ozao.net.packet.Packet;
+import fr.adamaq01.ozao.net.server.Connection;
+import fr.themode.minestom.entity.Player;
+import fr.themode.minestom.net.packet.client.ClientPlayPacket;
+import fr.themode.minestom.net.packet.client.ClientPreplayPacket;
+import fr.themode.minestom.net.packet.client.handler.ClientLoginPacketsHandler;
+import fr.themode.minestom.net.packet.client.handler.ClientPlayPacketsHandler;
+import fr.themode.minestom.net.packet.client.handler.ClientStatusPacketsHandler;
+import fr.themode.minestom.net.packet.client.handshake.HandshakePacket;
+import fr.themode.minestom.net.player.PlayerConnection;
+
+import java.lang.reflect.InvocationTargetException;
+import java.util.HashMap;
+import java.util.Map;
+
+import static fr.themode.minestom.net.protocol.MinecraftProtocol.PACKET_ID_IDENTIFIER;
+
+public class PacketProcessor {
+
+    private Map<Connection, PlayerConnection> connectionPlayerConnectionMap = new HashMap<>();
+
+    private ConnectionManager connectionManager;
+
+    // Protocols
+    private ClientStatusPacketsHandler statusPacketsHandler;
+    private ClientLoginPacketsHandler loginPacketsHandler;
+    private ClientPlayPacketsHandler playPacketsHandler;
+
+    public PacketProcessor(ConnectionManager connectionManager) {
+        this.connectionManager = connectionManager;
+
+        this.statusPacketsHandler = new ClientStatusPacketsHandler();
+        this.loginPacketsHandler = new ClientLoginPacketsHandler();
+        this.playPacketsHandler = new ClientPlayPacketsHandler();
+    }
+
+    public void process(Connection connection, Packet packet) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException {
+        int id = packet.get(PACKET_ID_IDENTIFIER);
+        System.out.println("RECEIVED ID: " + id);
+        Buffer buffer = packet.getPayload();
+        connectionPlayerConnectionMap.get(connection);
+        PlayerConnection playerConnection = connectionPlayerConnectionMap.computeIfAbsent(connection, c -> new PlayerConnection(c));
+        ConnectionState connectionState = playerConnection.getConnectionState();
+
+        if (connectionState == ConnectionState.UNKNOWN) {
+            // Should be handshake packet
+            if (id == 0) {
+                HandshakePacket handshakePacket = new HandshakePacket();
+                handshakePacket.read(buffer);
+                handshakePacket.process(playerConnection, connectionManager);
+            }
+            return;
+        }
+
+        switch (connectionState) {
+            case PLAY:
+                Player player = connectionManager.getPlayer(playerConnection);
+                ClientPlayPacket playPacket = (ClientPlayPacket) playPacketsHandler.getPacketClass(id).getDeclaredConstructor().newInstance();
+                playPacket.read(buffer);
+                playPacket.process(player);
+                break;
+            case LOGIN:
+                ClientPreplayPacket loginPacket = (ClientPreplayPacket) loginPacketsHandler.getPacketClass(id).getDeclaredConstructor().newInstance();
+                loginPacket.read(buffer);
+                loginPacket.process(playerConnection, connectionManager);
+                break;
+            case STATUS:
+                ClientPreplayPacket statusPacket = (ClientPreplayPacket) statusPacketsHandler.getPacketClass(id).getDeclaredConstructor().newInstance();
+                statusPacket.read(buffer);
+                statusPacket.process(playerConnection, connectionManager);
+                break;
+            case UNKNOWN:
+                // Ignore packet (unexpected)
+                break;
+        }
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/client/ClientPacket.java b/src/main/java/fr/themode/minestom/net/packet/client/ClientPacket.java
new file mode 100644
index 000000000..a63780d92
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/client/ClientPacket.java
@@ -0,0 +1,9 @@
+package fr.themode.minestom.net.packet.client;
+
+import fr.adamaq01.ozao.net.Buffer;
+
+public interface ClientPacket {
+
+    void read(Buffer buffer);
+
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/client/ClientPlayPacket.java b/src/main/java/fr/themode/minestom/net/packet/client/ClientPlayPacket.java
new file mode 100644
index 000000000..ed0ef3485
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/client/ClientPlayPacket.java
@@ -0,0 +1,10 @@
+package fr.themode.minestom.net.packet.client;
+
+import fr.themode.minestom.entity.Player;
+import fr.themode.minestom.net.packet.client.ClientPacket;
+
+public interface ClientPlayPacket extends ClientPacket {
+
+    void process(Player player);
+
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/client/ClientPreplayPacket.java b/src/main/java/fr/themode/minestom/net/packet/client/ClientPreplayPacket.java
new file mode 100644
index 000000000..4d77055a9
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/client/ClientPreplayPacket.java
@@ -0,0 +1,9 @@
+package fr.themode.minestom.net.packet.client;
+
+import fr.themode.minestom.net.ConnectionManager;
+import fr.themode.minestom.net.player.PlayerConnection;
+
+public interface ClientPreplayPacket extends ClientPacket {
+
+    void process(PlayerConnection connection, ConnectionManager connectionManager);
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/client/handler/ClientLoginPacketsHandler.java b/src/main/java/fr/themode/minestom/net/packet/client/handler/ClientLoginPacketsHandler.java
new file mode 100644
index 000000000..f222da5c4
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/client/handler/ClientLoginPacketsHandler.java
@@ -0,0 +1,11 @@
+package fr.themode.minestom.net.packet.client.handler;
+
+import fr.themode.minestom.net.packet.client.login.LoginStartPacket;
+
+public class ClientLoginPacketsHandler extends ClientPacketsHandler {
+
+    public ClientLoginPacketsHandler() {
+        register(0, LoginStartPacket.class);
+    }
+
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/client/handler/ClientPacketsHandler.java b/src/main/java/fr/themode/minestom/net/packet/client/handler/ClientPacketsHandler.java
new file mode 100644
index 000000000..ba150ce7a
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/client/handler/ClientPacketsHandler.java
@@ -0,0 +1,20 @@
+package fr.themode.minestom.net.packet.client.handler;
+
+import fr.themode.minestom.net.packet.client.ClientPacket;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class ClientPacketsHandler {
+
+    private Map<Integer, Class<? extends ClientPacket>> idPacketMap = new HashMap<>();
+
+    public void register(int id, Class<? extends ClientPacket> packet) {
+        this.idPacketMap.put(id, packet);
+    }
+
+    public Class<? extends ClientPacket> getPacketClass(int id) {
+        return idPacketMap.get(id);
+    }
+
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/client/handler/ClientPlayPacketsHandler.java b/src/main/java/fr/themode/minestom/net/packet/client/handler/ClientPlayPacketsHandler.java
new file mode 100644
index 000000000..0238a5f83
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/client/handler/ClientPlayPacketsHandler.java
@@ -0,0 +1,13 @@
+package fr.themode.minestom.net.packet.client.handler;
+
+import fr.themode.minestom.net.packet.client.play.ClientPluginMessagePacket;
+import fr.themode.minestom.net.packet.client.play.ClientSettingsPacket;
+
+public class ClientPlayPacketsHandler extends ClientPacketsHandler {
+
+    public ClientPlayPacketsHandler() {
+        register(0x05, ClientSettingsPacket.class);
+        register(0x0B, ClientPluginMessagePacket.class);
+    }
+
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/client/handler/ClientStatusPacketsHandler.java b/src/main/java/fr/themode/minestom/net/packet/client/handler/ClientStatusPacketsHandler.java
new file mode 100644
index 000000000..241a9afcb
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/client/handler/ClientStatusPacketsHandler.java
@@ -0,0 +1,13 @@
+package fr.themode.minestom.net.packet.client.handler;
+
+import fr.themode.minestom.net.packet.client.status.PingPacket;
+import fr.themode.minestom.net.packet.client.status.StatusRequestPacket;
+
+public class ClientStatusPacketsHandler extends ClientPacketsHandler {
+
+    public ClientStatusPacketsHandler() {
+        register(0x00, StatusRequestPacket.class);
+        register(0x01, PingPacket.class);
+    }
+
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/client/handshake/HandshakePacket.java b/src/main/java/fr/themode/minestom/net/packet/client/handshake/HandshakePacket.java
new file mode 100644
index 000000000..41a396948
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/client/handshake/HandshakePacket.java
@@ -0,0 +1,38 @@
+package fr.themode.minestom.net.packet.client.handshake;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.ConnectionManager;
+import fr.themode.minestom.net.ConnectionState;
+import fr.themode.minestom.net.packet.client.ClientPreplayPacket;
+import fr.themode.minestom.net.player.PlayerConnection;
+
+import static fr.themode.minestom.utils.Utils.readString;
+import static fr.themode.minestom.utils.Utils.readVarInt;
+
+public class HandshakePacket implements ClientPreplayPacket {
+
+    private int nextState;
+
+    @Override
+    public void read(Buffer buffer) {
+        int protocolVersion = readVarInt(buffer);
+        String serverAddress = readString(buffer);
+        short serverPort = buffer.getShort();
+        this.nextState = readVarInt(buffer);
+    }
+
+    @Override
+    public void process(PlayerConnection connection, ConnectionManager connectionManager) {
+        switch (nextState) {
+            case 1:
+                connection.setConnectionState(ConnectionState.STATUS);
+                break;
+            case 2:
+                connection.setConnectionState(ConnectionState.LOGIN);
+                break;
+            default:
+                // Unexpected error
+                break;
+        }
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/client/login/LoginStartPacket.java b/src/main/java/fr/themode/minestom/net/packet/client/login/LoginStartPacket.java
new file mode 100644
index 000000000..573f0b855
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/client/login/LoginStartPacket.java
@@ -0,0 +1,58 @@
+package fr.themode.minestom.net.packet.client.login;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.entity.GameMode;
+import fr.themode.minestom.net.ConnectionManager;
+import fr.themode.minestom.net.ConnectionState;
+import fr.themode.minestom.net.packet.client.ClientPreplayPacket;
+import fr.themode.minestom.net.packet.server.login.JoinGamePacket;
+import fr.themode.minestom.net.packet.server.login.LoginSuccessPacket;
+import fr.themode.minestom.net.packet.server.play.SpawnPositionPacket;
+import fr.themode.minestom.net.player.PlayerConnection;
+import fr.themode.minestom.utils.Utils;
+import fr.themode.minestom.world.Dimension;
+
+public class LoginStartPacket implements ClientPreplayPacket {
+
+    private String username;
+
+    @Override
+    public void process(PlayerConnection connection, ConnectionManager connectionManager) {
+        // TODO send encryption request OR directly login success
+        LoginSuccessPacket successPacket = new LoginSuccessPacket(username);
+        connection.sendPacket(successPacket);
+
+        connection.setConnectionState(ConnectionState.PLAY);
+        connectionManager.createPlayer(connection);
+
+        // TODO complete login sequence with optionals packets
+        JoinGamePacket joinGamePacket = new JoinGamePacket();
+        joinGamePacket.entityId = 32;
+        joinGamePacket.gameMode = GameMode.SURVIVAL;
+        joinGamePacket.dimension = Dimension.OVERWORLD;
+        joinGamePacket.maxPlayers = 0;
+        joinGamePacket.levelType = "default";
+        joinGamePacket.reducedDebugInfo = false;
+
+        connection.sendPacket(joinGamePacket);
+
+        // TODO minecraft:brand plugin message
+
+        // TODO send server difficulty
+
+        // TODO player abilities
+
+        SpawnPositionPacket spawnPositionPacket = new SpawnPositionPacket();
+        spawnPositionPacket.x = 50;
+        spawnPositionPacket.y = 50;
+        spawnPositionPacket.z = 50;
+
+        //  connection.sendPacket(spawnPositionPacket);
+
+    }
+
+    @Override
+    public void read(Buffer buffer) {
+        this.username = Utils.readString(buffer);
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/client/play/ClientPluginMessagePacket.java b/src/main/java/fr/themode/minestom/net/packet/client/play/ClientPluginMessagePacket.java
new file mode 100644
index 000000000..840526d2c
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/client/play/ClientPluginMessagePacket.java
@@ -0,0 +1,23 @@
+package fr.themode.minestom.net.packet.client.play;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.entity.Player;
+import fr.themode.minestom.net.packet.client.ClientPlayPacket;
+import fr.themode.minestom.utils.Utils;
+
+public class ClientPluginMessagePacket implements ClientPlayPacket {
+
+    private String identifier;
+    private byte[] data;
+
+    @Override
+    public void process(Player player) {
+
+    }
+
+    @Override
+    public void read(Buffer buffer) {
+        this.identifier = Utils.readString(buffer);
+        this.data = buffer.getAllBytes();
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/client/play/ClientSettingsPacket.java b/src/main/java/fr/themode/minestom/net/packet/client/play/ClientSettingsPacket.java
new file mode 100644
index 000000000..7a65fb46e
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/client/play/ClientSettingsPacket.java
@@ -0,0 +1,31 @@
+package fr.themode.minestom.net.packet.client.play;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.entity.Player;
+import fr.themode.minestom.net.packet.client.ClientPlayPacket;
+import fr.themode.minestom.utils.Utils;
+
+public class ClientSettingsPacket implements ClientPlayPacket {
+
+    private String locale;
+    private byte viewDistance;
+    // TODO chat mode
+    private boolean chatColors;
+    private byte displayedSkinParts;
+    // TODO main hand
+
+    @Override
+    public void process(Player player) {
+
+    }
+
+    @Override
+    public void read(Buffer buffer) {
+        this.locale = Utils.readString(buffer);
+        this.viewDistance = buffer.getByte();
+        Utils.readVarInt(buffer); // chat mode
+        this.chatColors = buffer.getBoolean();
+        this.displayedSkinParts = buffer.getByte();
+        Utils.readVarInt(buffer); // main hand
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/client/play/TestPacket.java b/src/main/java/fr/themode/minestom/net/packet/client/play/TestPacket.java
new file mode 100644
index 000000000..c4ab90351
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/client/play/TestPacket.java
@@ -0,0 +1,18 @@
+package fr.themode.minestom.net.packet.client.play;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.entity.Player;
+import fr.themode.minestom.net.packet.client.ClientPlayPacket;
+
+public class TestPacket implements ClientPlayPacket {
+
+    @Override
+    public void process(Player player) {
+
+    }
+
+    @Override
+    public void read(Buffer buffer) {
+        System.out.println("Hey c'est moi");
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/client/status/PingPacket.java b/src/main/java/fr/themode/minestom/net/packet/client/status/PingPacket.java
new file mode 100644
index 000000000..04764bdc3
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/client/status/PingPacket.java
@@ -0,0 +1,24 @@
+package fr.themode.minestom.net.packet.client.status;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.ConnectionManager;
+import fr.themode.minestom.net.packet.client.ClientPreplayPacket;
+import fr.themode.minestom.net.packet.server.status.PongPacket;
+import fr.themode.minestom.net.player.PlayerConnection;
+
+public class PingPacket implements ClientPreplayPacket {
+
+    private long number;
+
+    @Override
+    public void process(PlayerConnection connection, ConnectionManager connectionManager) {
+        PongPacket pongPacket = new PongPacket(number);
+        connection.sendPacket(pongPacket);
+        connection.getConnection().close();
+    }
+
+    @Override
+    public void read(Buffer buffer) {
+        this.number = buffer.getLong();
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/client/status/StatusRequestPacket.java b/src/main/java/fr/themode/minestom/net/packet/client/status/StatusRequestPacket.java
new file mode 100644
index 000000000..656dd857a
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/client/status/StatusRequestPacket.java
@@ -0,0 +1,21 @@
+package fr.themode.minestom.net.packet.client.status;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.ConnectionManager;
+import fr.themode.minestom.net.packet.client.ClientPreplayPacket;
+import fr.themode.minestom.net.packet.server.handshake.ResponsePacket;
+import fr.themode.minestom.net.player.PlayerConnection;
+
+public class StatusRequestPacket implements ClientPreplayPacket {
+
+    @Override
+    public void process(PlayerConnection connection, ConnectionManager connectionManager) {
+        ResponsePacket responsePacket = new ResponsePacket();
+        connection.sendPacket(responsePacket);
+    }
+
+    @Override
+    public void read(Buffer buffer) {
+        // Empty
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/server/ServerPacket.java b/src/main/java/fr/themode/minestom/net/packet/server/ServerPacket.java
new file mode 100644
index 000000000..a2c9c9d93
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/server/ServerPacket.java
@@ -0,0 +1,11 @@
+package fr.themode.minestom.net.packet.server;
+
+import fr.adamaq01.ozao.net.Buffer;
+
+public interface ServerPacket {
+
+    void write(Buffer buffer);
+
+    int getId();
+
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/server/handshake/ResponsePacket.java b/src/main/java/fr/themode/minestom/net/packet/server/handshake/ResponsePacket.java
new file mode 100644
index 000000000..9fbcae91d
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/server/handshake/ResponsePacket.java
@@ -0,0 +1,39 @@
+package fr.themode.minestom.net.packet.server.handshake;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.server.ServerPacket;
+import fr.themode.minestom.utils.Utils;
+
+public class ResponsePacket implements ServerPacket {
+
+    private static final String JSON_EXAMPLE = "{\n" +
+            "    \"version\": {\n" +
+            "        \"name\": \"1.14.4\",\n" +
+            "        \"protocol\": 498\n" +
+            "    },\n" +
+            "    \"players\": {\n" +
+            "        \"max\": 100,\n" +
+            "        \"online\": 1,\n" +
+            "        \"sample\": [\n" +
+            "            {\n" +
+            "                \"name\": \"TheMode\",\n" +
+            "                \"id\": \"4566e69f-c907-48ee-8d71-d7ba5aa00d20\"\n" +
+            "            }\n" +
+            "        ]\n" +
+            "    },\t\n" +
+            "    \"description\": {\n" +
+            "        \"text\": \"Wallah les cubes\"\n" +
+            "    },\n" +
+            "    \"favicon\": \"data:image/png;base64,<data>\"\n" +
+            "}";
+
+    @Override
+    public void write(Buffer buffer) {
+        Utils.writeString(buffer, JSON_EXAMPLE);
+    }
+
+    @Override
+    public int getId() {
+        return 0x00;
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/server/login/JoinGamePacket.java b/src/main/java/fr/themode/minestom/net/packet/server/login/JoinGamePacket.java
new file mode 100644
index 000000000..506bfdb0a
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/server/login/JoinGamePacket.java
@@ -0,0 +1,37 @@
+package fr.themode.minestom.net.packet.server.login;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.entity.GameMode;
+import fr.themode.minestom.net.packet.server.ServerPacket;
+import fr.themode.minestom.utils.Utils;
+import fr.themode.minestom.world.Dimension;
+
+public class JoinGamePacket implements ServerPacket {
+
+    public int entityId;
+    public GameMode gameMode = GameMode.SURVIVAL;
+    public Dimension dimension = Dimension.OVERWORLD;
+    public byte maxPlayers = 0; // Unused
+    public String levelType = "default";
+    public boolean reducedDebugInfo = false;
+
+    @Override
+    public void write(Buffer buffer) {
+        int gameModeId = gameMode.getId();
+        if (gameMode.isHardcore())
+            gameModeId |= 8;
+
+        buffer.putInt(entityId);
+        buffer.putByte((byte) gameModeId);
+        buffer.putInt(dimension.getId());
+        buffer.putByte(maxPlayers);
+        Utils.writeString(buffer, levelType);
+        Utils.writeVarInt(buffer, 8);
+        buffer.putBoolean(reducedDebugInfo);
+    }
+
+    @Override
+    public int getId() {
+        return 0x25;
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/server/login/LoginSuccessPacket.java b/src/main/java/fr/themode/minestom/net/packet/server/login/LoginSuccessPacket.java
new file mode 100644
index 000000000..96ea98d18
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/server/login/LoginSuccessPacket.java
@@ -0,0 +1,27 @@
+package fr.themode.minestom.net.packet.server.login;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.server.ServerPacket;
+import fr.themode.minestom.utils.Utils;
+
+import java.util.UUID;
+
+public class LoginSuccessPacket implements ServerPacket {
+
+    public String username;
+
+    public LoginSuccessPacket(String username) {
+        this.username = username;
+    }
+
+    @Override
+    public void write(Buffer buffer) {
+        Utils.writeString(buffer, UUID.randomUUID().toString()); // TODO mojang auth
+        Utils.writeString(buffer, username);
+    }
+
+    @Override
+    public int getId() {
+        return 0x02;
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/server/play/SpawnPositionPacket.java b/src/main/java/fr/themode/minestom/net/packet/server/play/SpawnPositionPacket.java
new file mode 100644
index 000000000..4fa53a05c
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/server/play/SpawnPositionPacket.java
@@ -0,0 +1,20 @@
+package fr.themode.minestom.net.packet.server.play;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.server.ServerPacket;
+import fr.themode.minestom.utils.Utils;
+
+public class SpawnPositionPacket implements ServerPacket {
+
+    public int x, y, z;
+
+    @Override
+    public void write(Buffer buffer) {
+        Utils.writePosition(buffer, x, y, z);
+    }
+
+    @Override
+    public int getId() {
+        return 0x49;
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/server/play/WindowItemsPacket.java b/src/main/java/fr/themode/minestom/net/packet/server/play/WindowItemsPacket.java
new file mode 100644
index 000000000..4b255af34
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/server/play/WindowItemsPacket.java
@@ -0,0 +1,25 @@
+package fr.themode.minestom.net.packet.server.play;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.server.ServerPacket;
+
+public class WindowItemsPacket implements ServerPacket {
+
+    public byte windowId;
+    public short count;
+
+    // TODO slot data (Array of Slot)
+
+    @Override
+    public void write(Buffer buffer) {
+        buffer.putByte(windowId);
+        buffer.putShort(count);
+        // TODO replace with actual array of slot
+        buffer.putBoolean(false); // Not present
+    }
+
+    @Override
+    public int getId() {
+        return 0x15;
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/packet/server/status/PongPacket.java b/src/main/java/fr/themode/minestom/net/packet/server/status/PongPacket.java
new file mode 100644
index 000000000..dc38e489e
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/packet/server/status/PongPacket.java
@@ -0,0 +1,23 @@
+package fr.themode.minestom.net.packet.server.status;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.themode.minestom.net.packet.server.ServerPacket;
+
+public class PongPacket implements ServerPacket {
+
+    public long number;
+
+    public PongPacket(long number) {
+        this.number = number;
+    }
+
+    @Override
+    public void write(Buffer buffer) {
+        buffer.putLong(number);
+    }
+
+    @Override
+    public int getId() {
+        return 0x01;
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/player/PlayerConnection.java b/src/main/java/fr/themode/minestom/net/player/PlayerConnection.java
new file mode 100644
index 000000000..a442a06b3
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/player/PlayerConnection.java
@@ -0,0 +1,41 @@
+package fr.themode.minestom.net.player;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.adamaq01.ozao.net.packet.Packet;
+import fr.adamaq01.ozao.net.server.Connection;
+import fr.themode.minestom.net.ConnectionState;
+import fr.themode.minestom.net.packet.server.ServerPacket;
+
+import static fr.themode.minestom.net.protocol.MinecraftProtocol.PACKET_ID_IDENTIFIER;
+
+public class PlayerConnection {
+
+    private Connection connection;
+    private ConnectionState connectionState;
+
+    public PlayerConnection(Connection connection) {
+        this.connection = connection;
+        this.connectionState = ConnectionState.UNKNOWN;
+    }
+
+    public void sendPacket(ServerPacket serverPacket) {
+        Packet packet = Packet.create();
+        Buffer buffer = packet.getPayload();
+        serverPacket.write(buffer);
+        packet.put(PACKET_ID_IDENTIFIER, serverPacket.getId());
+
+        this.connection.sendPacket(packet);
+    }
+
+    public Connection getConnection() {
+        return connection;
+    }
+
+    public void setConnectionState(ConnectionState connectionState) {
+        this.connectionState = connectionState;
+    }
+
+    public ConnectionState getConnectionState() {
+        return connectionState;
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/net/protocol/MinecraftProtocol.java b/src/main/java/fr/themode/minestom/net/protocol/MinecraftProtocol.java
new file mode 100644
index 000000000..b6b4224e9
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/net/protocol/MinecraftProtocol.java
@@ -0,0 +1,67 @@
+package fr.themode.minestom.net.protocol;
+
+import fr.adamaq01.ozao.net.Buffer;
+import fr.adamaq01.ozao.net.packet.Packet;
+import fr.adamaq01.ozao.net.protocol.Protocol;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+import static fr.themode.minestom.utils.Utils.readVarInt;
+import static fr.themode.minestom.utils.Utils.writeVarInt;
+
+public class MinecraftProtocol extends Protocol {
+
+    public static final String PACKET_ID_IDENTIFIER = "id";
+
+    public MinecraftProtocol() {
+        super("minecraft");
+    }
+
+    @Override
+    public boolean verify(Buffer buffer) {
+        int length = readVarInt(buffer);
+        int realLength = buffer.slice(buffer.readerIndex()).length();
+        int id = readVarInt(buffer);
+        buffer.readerIndex(0);
+        return length == realLength && id >= 0;
+    }
+
+    @Override
+    public boolean verify(Packet packet) {
+        return packet.get("id") != null;
+    }
+
+    @Override
+    public Collection<Buffer> cut(Buffer buffer) {
+        ArrayList<Buffer> buffers = new ArrayList<>();
+        int read = 0;
+        while (read < buffer.length()) {
+            int lengthLength = buffer.readerIndex(read).readerIndex();
+            int length = readVarInt(buffer);
+            lengthLength = buffer.readerIndex() - lengthLength;
+            buffers.add(buffer.sliceCopy(read, length + lengthLength));
+            read += length + lengthLength;
+        }
+        return buffers;
+    }
+
+    @Override
+    public Packet decode(Buffer buffer) {
+        int length = readVarInt(buffer);
+        int id = readVarInt(buffer);
+        Buffer packetPayload = buffer.sliceCopy(buffer.readerIndex());
+        return Packet.create(packetPayload).put(PACKET_ID_IDENTIFIER, id);
+    }
+
+    @Override
+    public Buffer encode(Packet packet) {
+        Buffer buffer = Buffer.create();
+        Buffer idAndPayload = Buffer.create();
+        writeVarInt(idAndPayload, packet.get(PACKET_ID_IDENTIFIER));
+        idAndPayload.putBuffer(packet.getPayload());
+        writeVarInt(buffer, idAndPayload.length());
+        buffer.putBuffer(idAndPayload);
+        return buffer;
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/utils/Utils.java b/src/main/java/fr/themode/minestom/utils/Utils.java
new file mode 100644
index 000000000..99860987c
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/utils/Utils.java
@@ -0,0 +1,111 @@
+package fr.themode.minestom.utils;
+
+import fr.adamaq01.ozao.net.Buffer;
+
+import java.io.UnsupportedEncodingException;
+
+public class Utils {
+
+    public static void writeString(Buffer buffer, String value) {
+        byte[] bytes = new byte[0];
+        try {
+            bytes = value.getBytes("UTF-8");
+        } catch (UnsupportedEncodingException e) {
+            e.printStackTrace();
+        }
+        if (bytes.length > 32767) {
+            System.out.println("String too big (was " + value.length() + " bytes encoded, max " + 32767 + ")");
+        } else {
+            writeVarInt(buffer, bytes.length);
+            buffer.putBytes(bytes);
+        }
+    }
+
+    public static String readString(Buffer buffer) {
+        int length = readVarInt(buffer);
+        byte bytes[] = buffer.getBytes(length);
+        try {
+            return new String(bytes, "UTF-8");
+        } catch (UnsupportedEncodingException e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+    public static void writeVarInt(Buffer buffer, int value) {
+        do {
+            byte temp = (byte) (value & 0b01111111);
+            value >>>= 7;
+            if (value != 0) {
+                temp |= 0b10000000;
+            }
+            buffer.putByte(temp);
+        } while (value != 0);
+    }
+
+    public static int readVarInt(Buffer buffer) {
+        int numRead = 0;
+        int result = 0;
+        byte read;
+        do {
+            read = buffer.getByte();
+            int value = (read & 0b01111111);
+            result |= (value << (7 * numRead));
+
+            numRead++;
+            if (numRead > 5) {
+                throw new RuntimeException("VarInt is too big");
+            }
+        } while ((read & 0b10000000) != 0);
+
+        return result;
+    }
+
+    // ??
+    public static int lengthVarInt(int value) {
+        int i = 0;
+        do {
+            i++;
+            byte temp = (byte) (value & 0b01111111);
+            value >>>= 7;
+            if (value != 0) {
+                temp |= 0b10000000;
+            }
+        } while (value != 0);
+        return i;
+    }
+
+    public static void writeVarLong(Buffer buffer, long value) {
+        do {
+            byte temp = (byte) (value & 0b01111111);
+            value >>>= 7;
+            if (value != 0) {
+                temp |= 0b10000000;
+            }
+            buffer.putByte(temp);
+        } while (value != 0);
+    }
+
+    public static long readVarLong(Buffer buffer) {
+        int numRead = 0;
+        long result = 0;
+        byte read;
+        do {
+            read = buffer.getByte();
+            int value = (read & 0b01111111);
+            result |= (value << (7 * numRead));
+
+            numRead++;
+            if (numRead > 10) {
+                throw new RuntimeException("VarLong is too big");
+            }
+        } while ((read & 0b10000000) != 0);
+
+        return result;
+    }
+
+    public static void writePosition(Buffer buffer, int x, int y, int z) {
+        buffer.putLong(((x & 0x3FFFFFF) << 38) | ((y & 0xFFF) << 26) | (z & 0x3FFFFFF));
+    }
+
+}
diff --git a/src/main/java/fr/themode/minestom/world/Difficulty.java b/src/main/java/fr/themode/minestom/world/Difficulty.java
new file mode 100644
index 000000000..13aefba81
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/world/Difficulty.java
@@ -0,0 +1,16 @@
+package fr.themode.minestom.world;
+
+public enum Difficulty {
+
+    PEACEFUL((byte) 0), EASY((byte) 1), NORMAL((byte) 2), HARD((byte) 3);
+
+    private byte id;
+
+    Difficulty(byte id) {
+        this.id = id;
+    }
+
+    public byte getId() {
+        return id;
+    }
+}
diff --git a/src/main/java/fr/themode/minestom/world/Dimension.java b/src/main/java/fr/themode/minestom/world/Dimension.java
new file mode 100644
index 000000000..80dc05a0d
--- /dev/null
+++ b/src/main/java/fr/themode/minestom/world/Dimension.java
@@ -0,0 +1,16 @@
+package fr.themode.minestom.world;
+
+public enum Dimension {
+
+    NETHER(-1), OVERWORLD(0), END(1);
+
+    private int id;
+
+    Dimension(int id) {
+        this.id = id;
+    }
+
+    public int getId() {
+        return id;
+    }
+}