Add TexturePackSystem

VelocityCore/src/de/steamwar/velocitycore/VelocityCore.java

@@ -153,6 +153,7 @@ public class VelocityCore implements ReloadablePlugin {
         new CheckListener();
         new IPSanitizer();
         new VersionAnnouncer();
+        new TexturePackSystem();
 
         local = new Node.LocalNode();
         if(MAIN_SERVER) {

VelocityCore/src/de/steamwar/velocitycore/listeners/TexturePackSystem.java

@@ -0,0 +1,105 @@
+/*
+ * This file is a part of the SteamWar software.
+ *
+ * Copyright (C) 2020  SteamWar.de-Serverteam
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.steamwar.velocitycore.listeners;
+
+import com.velocitypowered.api.event.Subscribe;
+import com.velocitypowered.api.event.player.ServerPostConnectEvent;
+import com.velocitypowered.api.proxy.player.ResourcePackInfo;
+import de.steamwar.velocitycore.VelocityCore;
+import net.kyori.adventure.text.Component;
+
+import java.io.File;
+import java.nio.charset.StandardCharsets;
+import java.util.Map;
+import java.util.TreeMap;
+import java.util.UUID;
+import java.util.concurrent.TimeUnit;
+
+// https://jd.papermc.io/velocity/3.4.0/com/velocitypowered/api/proxy/player/ResourcePackInfo.Builder.html#setHash(byte%5B%5D)
+public class TexturePackSystem extends BasicListener {
+
+    private static final File PACKS_DIR = new File("/var/www/packs");
+    private static final String BASE_ULR = "https://packs.steamwar.de/";
+    private TreeMap<Integer, Integer> protocolVersionToPackVersion = new TreeMap<>();
+
+    public TexturePackSystem() {
+        // https://minecraft.wiki/w/Pack_format#List_of_resource_pack_formats
+        // https://minecraft.wiki/w/Minecraft_Wiki:Projects/wiki.vg_merge/Protocol_version_numbers
+        protocolVersionToPackVersion.put(759, 9);
+        protocolVersionToPackVersion.put(761, 12);
+        protocolVersionToPackVersion.put(762, 13);
+        protocolVersionToPackVersion.put(763, 15);
+        protocolVersionToPackVersion.put(764, 18);
+        protocolVersionToPackVersion.put(765, 22);
+        protocolVersionToPackVersion.put(766, 32);
+        protocolVersionToPackVersion.put(767, 34);
+        protocolVersionToPackVersion.put(768, 42);
+        protocolVersionToPackVersion.put(769, 46);
+        protocolVersionToPackVersion.put(770, 55);
+    }
+
+    @Subscribe
+    public void onLogin(ServerPostConnectEvent event) {
+        if (event.getPreviousServer() != null) {
+            return;
+        }
+        VelocityCore.schedule(() -> {
+            int playerVersion = event.getPlayer().getProtocolVersion().getProtocol();
+            File selectedPack = null;
+            while (selectedPack == null) {
+                Map.Entry<Integer, Integer> pack = protocolVersionToPackVersion.floorEntry(playerVersion);
+                if (pack == null) return;
+
+                for (File file : PACKS_DIR.listFiles()) {
+                    if (file.getName().startsWith(pack.getValue() + "_")) {
+                        selectedPack = file;
+                        break;
+                    }
+                }
+
+                playerVersion--;
+            }
+
+            String fileName = selectedPack.getName();
+            fileName = fileName.substring(fileName.indexOf('_') + 1, fileName.lastIndexOf('.'));
+            byte[] hash = hexStringToByteArray(fileName);
+
+            ResourcePackInfo resourcePackInfo = VelocityCore.getProxy().createResourcePackBuilder(BASE_ULR + selectedPack.getName())
+                    .setId(UUID.nameUUIDFromBytes(fileName.getBytes(StandardCharsets.UTF_8)))
+                    .setHash(hash)
+                    .setShouldForce(false)
+                    .setPrompt(Component.text("The SteamWar TexturePack improves GUIs!"))
+                    .build();
+            event.getPlayer().sendResourcePacks(resourcePackInfo);
+        }).delay(500, TimeUnit.MILLISECONDS).schedule();
+    }
+
+    public static byte[] hexStringToByteArray(String s) {
+        int len = s.length();
+        byte[] data = new byte[len / 2];
+
+        for (int i = 0; i < len; i += 2) {
+            data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)
+                    + Character.digit(s.charAt(i+1), 16));
+        }
+
+        return data;
+    }
+}