Some work

leaf-server/src/main/java/su/plo/matter/Globals.java

@@ -0,0 +1,95 @@
+package su.plo.matter;
+
+import com.google.common.collect.Iterables;
+import net.minecraft.server.level.ServerLevel;
+
+import java.math.BigInteger;
+import java.security.SecureRandom;
+import java.util.Optional;
+
+public class Globals {
+
+    public static final int WORLD_SEED_LONGS = 16;
+    public static final int WORLD_SEED_BITS = WORLD_SEED_LONGS * 64;
+
+    public static final long[] worldSeed = new long[WORLD_SEED_LONGS];
+    public static final ThreadLocal<Integer> dimension = ThreadLocal.withInitial(() -> 0);
+
+    public enum Salt {
+        UNDEFINED,
+        BASTION_FEATURE,
+        WOODLAND_MANSION_FEATURE,
+        MINESHAFT_FEATURE,
+        BURIED_TREASURE_FEATURE,
+        NETHER_FORTRESS_FEATURE,
+        PILLAGER_OUTPOST_FEATURE,
+        GEODE_FEATURE,
+        NETHER_FOSSIL_FEATURE,
+        OCEAN_MONUMENT_FEATURE,
+        RUINED_PORTAL_FEATURE,
+        POTENTIONAL_FEATURE,
+        GENERATE_FEATURE,
+        JIGSAW_PLACEMENT,
+        STRONGHOLDS,
+        POPULATION,
+        DECORATION,
+        SLIME_CHUNK
+    }
+
+    public static void setupGlobals(ServerLevel world) {
+        if (!org.dreeam.leaf.config.modules.misc.SecureSeed.enabled) return;
+
+        long[] seed = world.getServer().getWorldData().worldGenOptions().featureSeed();
+        System.arraycopy(seed, 0, worldSeed, 0, WORLD_SEED_LONGS);
+        int worldIndex = Iterables.indexOf(world.getServer().levelKeys(), it -> it == world.dimension());
+        if (worldIndex == -1)
+            worldIndex = world.getServer().levelKeys().size(); // if we are in world construction it may not have been added to the map yet
+        dimension.set(worldIndex);
+    }
+
+    public static long[] createRandomWorldSeed() {
+        long[] seed = new long[WORLD_SEED_LONGS];
+        SecureRandom rand = new SecureRandom();
+        for (int i = 0; i < WORLD_SEED_LONGS; i++) {
+            seed[i] = rand.nextLong();
+        }
+        return seed;
+    }
+
+    // 1024-bit string -> 16 * 64 long[]
+    public static Optional<long[]> parseSeed(String seedStr) {
+        if (seedStr.isEmpty()) return Optional.empty();
+
+        if (seedStr.length() != WORLD_SEED_BITS) {
+            throw new IllegalArgumentException("Secure seed length must be " + WORLD_SEED_BITS + "-bit but found " + seedStr.length() + "-bit.");
+        }
+
+        long[] seed = new long[WORLD_SEED_LONGS];
+
+        for (int i = 0; i < WORLD_SEED_LONGS; i++) {
+            int start = i * 64;
+            int end = start + 64;
+            String seedSection = seedStr.substring(start, end);
+
+            BigInteger seedInDecimal = new BigInteger(seedSection, 2);
+            seed[i] = seedInDecimal.longValue();
+        }
+
+        return Optional.of(seed);
+    }
+
+    // 16 * 64 long[] -> 1024-bit string
+    public static String seedToString(long[] seed) {
+        StringBuilder sb = new StringBuilder();
+
+        for (long longV : seed) {
+            // Convert to 64-bit binary string per long
+            // Use format to keep 64-bit length, and use 0 to complete space
+            String binaryStr = String.format("%64s", Long.toBinaryString(longV)).replace(' ', '0');
+
+            sb.append(binaryStr);
+        }
+
+        return sb.toString();
+    }
+}