hytale-server/com/hypixel/hytale/protocol/packets/buildertools/BuilderToolState.java

package com.hypixel.hytale.protocol.packets.buildertools;

import com.hypixel.hytale.protocol.io.PacketIO;
import com.hypixel.hytale.protocol.io.ProtocolException;
import com.hypixel.hytale.protocol.io.ValidationResult;
import com.hypixel.hytale.protocol.io.VarInt;
import io.netty.buffer.ByteBuf;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import java.util.Map.Entry;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;

public class BuilderToolState {
   public static final int NULLABLE_BIT_FIELD_SIZE = 1;
   public static final int FIXED_BLOCK_SIZE = 2;
   public static final int VARIABLE_FIELD_COUNT = 3;
   public static final int VARIABLE_BLOCK_START = 14;
   public static final int MAX_SIZE = 1677721600;
   @Nullable
   public String id;
   public boolean isBrush;
   @Nullable
   public BuilderToolBrushData brushData;
   @Nullable
   public Map<String, BuilderToolArg> args;

   public BuilderToolState() {
   }

   public BuilderToolState(@Nullable String id, boolean isBrush, @Nullable BuilderToolBrushData brushData, @Nullable Map<String, BuilderToolArg> args) {
      this.id = id;
      this.isBrush = isBrush;
      this.brushData = brushData;
      this.args = args;
   }

   public BuilderToolState(@Nonnull BuilderToolState other) {
      this.id = other.id;
      this.isBrush = other.isBrush;
      this.brushData = other.brushData;
      this.args = other.args;
   }

   @Nonnull
   public static BuilderToolState deserialize(@Nonnull ByteBuf buf, int offset) {
      BuilderToolState obj = new BuilderToolState();
      byte nullBits = buf.getByte(offset);
      obj.isBrush = buf.getByte(offset + 1) != 0;
      if ((nullBits & 1) != 0) {
         int varPos0 = offset + 14 + buf.getIntLE(offset + 2);
         int idLen = VarInt.peek(buf, varPos0);
         if (idLen < 0) {
            throw ProtocolException.negativeLength("Id", idLen);
         }

         if (idLen > 4096000) {
            throw ProtocolException.stringTooLong("Id", idLen, 4096000);
         }

         obj.id = PacketIO.readVarString(buf, varPos0, PacketIO.UTF8);
      }

      if ((nullBits & 2) != 0) {
         int varPos1 = offset + 14 + buf.getIntLE(offset + 6);
         obj.brushData = BuilderToolBrushData.deserialize(buf, varPos1);
      }

      if ((nullBits & 4) != 0) {
         int varPos2 = offset + 14 + buf.getIntLE(offset + 10);
         int argsCount = VarInt.peek(buf, varPos2);
         if (argsCount < 0) {
            throw ProtocolException.negativeLength("Args", argsCount);
         }

         if (argsCount > 4096000) {
            throw ProtocolException.dictionaryTooLarge("Args", argsCount, 4096000);
         }

         int varIntLen = VarInt.length(buf, varPos2);
         obj.args = new HashMap<>(argsCount);
         int dictPos = varPos2 + varIntLen;

         for (int i = 0; i < argsCount; i++) {
            int keyLen = VarInt.peek(buf, dictPos);
            if (keyLen < 0) {
               throw ProtocolException.negativeLength("key", keyLen);
            }

            if (keyLen > 4096000) {
               throw ProtocolException.stringTooLong("key", keyLen, 4096000);
            }

            int keyVarLen = VarInt.length(buf, dictPos);
            String key = PacketIO.readVarString(buf, dictPos);
            dictPos += keyVarLen + keyLen;
            BuilderToolArg val = BuilderToolArg.deserialize(buf, dictPos);
            dictPos += BuilderToolArg.computeBytesConsumed(buf, dictPos);
            if (obj.args.put(key, val) != null) {
               throw ProtocolException.duplicateKey("args", key);
            }
         }
      }

      return obj;
   }

   public static int computeBytesConsumed(@Nonnull ByteBuf buf, int offset) {
      byte nullBits = buf.getByte(offset);
      int maxEnd = 14;
      if ((nullBits & 1) != 0) {
         int fieldOffset0 = buf.getIntLE(offset + 2);
         int pos0 = offset + 14 + fieldOffset0;
         int sl = VarInt.peek(buf, pos0);
         pos0 += VarInt.length(buf, pos0) + sl;
         if (pos0 - offset > maxEnd) {
            maxEnd = pos0 - offset;
         }
      }

      if ((nullBits & 2) != 0) {
         int fieldOffset1 = buf.getIntLE(offset + 6);
         int pos1 = offset + 14 + fieldOffset1;
         pos1 += BuilderToolBrushData.computeBytesConsumed(buf, pos1);
         if (pos1 - offset > maxEnd) {
            maxEnd = pos1 - offset;
         }
      }

      if ((nullBits & 4) != 0) {
         int fieldOffset2 = buf.getIntLE(offset + 10);
         int pos2 = offset + 14 + fieldOffset2;
         int dictLen = VarInt.peek(buf, pos2);
         pos2 += VarInt.length(buf, pos2);

         for (int i = 0; i < dictLen; i++) {
            int sl = VarInt.peek(buf, pos2);
            pos2 += VarInt.length(buf, pos2) + sl;
            pos2 += BuilderToolArg.computeBytesConsumed(buf, pos2);
         }

         if (pos2 - offset > maxEnd) {
            maxEnd = pos2 - offset;
         }
      }

      return maxEnd;
   }

   public void serialize(@Nonnull ByteBuf buf) {
      int startPos = buf.writerIndex();
      byte nullBits = 0;
      if (this.id != null) {
         nullBits = (byte)(nullBits | 1);
      }

      if (this.brushData != null) {
         nullBits = (byte)(nullBits | 2);
      }

      if (this.args != null) {
         nullBits = (byte)(nullBits | 4);
      }

      buf.writeByte(nullBits);
      buf.writeByte(this.isBrush ? 1 : 0);
      int idOffsetSlot = buf.writerIndex();
      buf.writeIntLE(0);
      int brushDataOffsetSlot = buf.writerIndex();
      buf.writeIntLE(0);
      int argsOffsetSlot = buf.writerIndex();
      buf.writeIntLE(0);
      int varBlockStart = buf.writerIndex();
      if (this.id != null) {
         buf.setIntLE(idOffsetSlot, buf.writerIndex() - varBlockStart);
         PacketIO.writeVarString(buf, this.id, 4096000);
      } else {
         buf.setIntLE(idOffsetSlot, -1);
      }

      if (this.brushData != null) {
         buf.setIntLE(brushDataOffsetSlot, buf.writerIndex() - varBlockStart);
         this.brushData.serialize(buf);
      } else {
         buf.setIntLE(brushDataOffsetSlot, -1);
      }

      if (this.args != null) {
         buf.setIntLE(argsOffsetSlot, buf.writerIndex() - varBlockStart);
         if (this.args.size() > 4096000) {
            throw ProtocolException.dictionaryTooLarge("Args", this.args.size(), 4096000);
         }

         VarInt.write(buf, this.args.size());

         for (Entry<String, BuilderToolArg> e : this.args.entrySet()) {
            PacketIO.writeVarString(buf, e.getKey(), 4096000);
            e.getValue().serialize(buf);
         }
      } else {
         buf.setIntLE(argsOffsetSlot, -1);
      }
   }

   public int computeSize() {
      int size = 14;
      if (this.id != null) {
         size += PacketIO.stringSize(this.id);
      }

      if (this.brushData != null) {
         size += this.brushData.computeSize();
      }

      if (this.args != null) {
         int argsSize = 0;

         for (Entry<String, BuilderToolArg> kvp : this.args.entrySet()) {
            argsSize += PacketIO.stringSize(kvp.getKey()) + kvp.getValue().computeSize();
         }

         size += VarInt.size(this.args.size()) + argsSize;
      }

      return size;
   }

   public static ValidationResult validateStructure(@Nonnull ByteBuf buffer, int offset) {
      if (buffer.readableBytes() - offset < 14) {
         return ValidationResult.error("Buffer too small: expected at least 14 bytes");
      } else {
         byte nullBits = buffer.getByte(offset);
         if ((nullBits & 1) != 0) {
            int idOffset = buffer.getIntLE(offset + 2);
            if (idOffset < 0) {
               return ValidationResult.error("Invalid offset for Id");
            }

            int pos = offset + 14 + idOffset;
            if (pos >= buffer.writerIndex()) {
               return ValidationResult.error("Offset out of bounds for Id");
            }

            int idLen = VarInt.peek(buffer, pos);
            if (idLen < 0) {
               return ValidationResult.error("Invalid string length for Id");
            }

            if (idLen > 4096000) {
               return ValidationResult.error("Id exceeds max length 4096000");
            }

            pos += VarInt.length(buffer, pos);
            pos += idLen;
            if (pos > buffer.writerIndex()) {
               return ValidationResult.error("Buffer overflow reading Id");
            }
         }

         if ((nullBits & 2) != 0) {
            int brushDataOffset = buffer.getIntLE(offset + 6);
            if (brushDataOffset < 0) {
               return ValidationResult.error("Invalid offset for BrushData");
            }

            int posx = offset + 14 + brushDataOffset;
            if (posx >= buffer.writerIndex()) {
               return ValidationResult.error("Offset out of bounds for BrushData");
            }

            ValidationResult brushDataResult = BuilderToolBrushData.validateStructure(buffer, posx);
            if (!brushDataResult.isValid()) {
               return ValidationResult.error("Invalid BrushData: " + brushDataResult.error());
            }

            posx += BuilderToolBrushData.computeBytesConsumed(buffer, posx);
         }

         if ((nullBits & 4) != 0) {
            int argsOffset = buffer.getIntLE(offset + 10);
            if (argsOffset < 0) {
               return ValidationResult.error("Invalid offset for Args");
            }

            int posxx = offset + 14 + argsOffset;
            if (posxx >= buffer.writerIndex()) {
               return ValidationResult.error("Offset out of bounds for Args");
            }

            int argsCount = VarInt.peek(buffer, posxx);
            if (argsCount < 0) {
               return ValidationResult.error("Invalid dictionary count for Args");
            }

            if (argsCount > 4096000) {
               return ValidationResult.error("Args exceeds max length 4096000");
            }

            posxx += VarInt.length(buffer, posxx);

            for (int i = 0; i < argsCount; i++) {
               int keyLen = VarInt.peek(buffer, posxx);
               if (keyLen < 0) {
                  return ValidationResult.error("Invalid string length for key");
               }

               if (keyLen > 4096000) {
                  return ValidationResult.error("key exceeds max length 4096000");
               }

               posxx += VarInt.length(buffer, posxx);
               posxx += keyLen;
               if (posxx > buffer.writerIndex()) {
                  return ValidationResult.error("Buffer overflow reading key");
               }

               posxx += BuilderToolArg.computeBytesConsumed(buffer, posxx);
            }
         }

         return ValidationResult.OK;
      }
   }

   public BuilderToolState clone() {
      BuilderToolState copy = new BuilderToolState();
      copy.id = this.id;
      copy.isBrush = this.isBrush;
      copy.brushData = this.brushData != null ? this.brushData.clone() : null;
      if (this.args != null) {
         Map<String, BuilderToolArg> m = new HashMap<>();

         for (Entry<String, BuilderToolArg> e : this.args.entrySet()) {
            m.put(e.getKey(), e.getValue().clone());
         }

         copy.args = m;
      }

      return copy;
   }

   @Override
   public boolean equals(Object obj) {
      if (this == obj) {
         return true;
      } else {
         return !(obj instanceof BuilderToolState other)
            ? false
            : Objects.equals(this.id, other.id)
               && this.isBrush == other.isBrush
               && Objects.equals(this.brushData, other.brushData)
               && Objects.equals(this.args, other.args);
      }
   }

   @Override
   public int hashCode() {
      return Objects.hash(this.id, this.isBrush, this.brushData, this.args);
   }
}