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

import com.hypixel.hytale.protocol.NetworkChannel;
import com.hypixel.hytale.protocol.Packet;
import com.hypixel.hytale.protocol.ToClientPacket;
import com.hypixel.hytale.protocol.UpdateType;
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 UpdateTranslations implements Packet, ToClientPacket {
   public static final int PACKET_ID = 64;
   public static final boolean IS_COMPRESSED = true;
   public static final int NULLABLE_BIT_FIELD_SIZE = 1;
   public static final int FIXED_BLOCK_SIZE = 2;
   public static final int VARIABLE_FIELD_COUNT = 1;
   public static final int VARIABLE_BLOCK_START = 2;
   public static final int MAX_SIZE = 1677721600;
   @Nonnull
   public UpdateType type = UpdateType.Init;
   @Nullable
   public Map<String, String> translations;

   @Override
   public int getId() {
      return 64;
   }

   @Override
   public NetworkChannel getChannel() {
      return NetworkChannel.Default;
   }

   public UpdateTranslations() {
   }

   public UpdateTranslations(@Nonnull UpdateType type, @Nullable Map<String, String> translations) {
      this.type = type;
      this.translations = translations;
   }

   public UpdateTranslations(@Nonnull UpdateTranslations other) {
      this.type = other.type;
      this.translations = other.translations;
   }

   @Nonnull
   public static UpdateTranslations deserialize(@Nonnull ByteBuf buf, int offset) {
      UpdateTranslations obj = new UpdateTranslations();
      byte nullBits = buf.getByte(offset);
      obj.type = UpdateType.fromValue(buf.getByte(offset + 1));
      int pos = offset + 2;
      if ((nullBits & 1) != 0) {
         int translationsCount = VarInt.peek(buf, pos);
         if (translationsCount < 0) {
            throw ProtocolException.negativeLength("Translations", translationsCount);
         }

         if (translationsCount > 4096000) {
            throw ProtocolException.dictionaryTooLarge("Translations", translationsCount, 4096000);
         }

         pos += VarInt.size(translationsCount);
         obj.translations = new HashMap<>(translationsCount);

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

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

            int keyVarLen = VarInt.length(buf, pos);
            String key = PacketIO.readVarString(buf, pos);
            pos += keyVarLen + keyLen;
            int valLen = VarInt.peek(buf, pos);
            if (valLen < 0) {
               throw ProtocolException.negativeLength("val", valLen);
            }

            if (valLen > 4096000) {
               throw ProtocolException.stringTooLong("val", valLen, 4096000);
            }

            int valVarLen = VarInt.length(buf, pos);
            String val = PacketIO.readVarString(buf, pos);
            pos += valVarLen + valLen;
            if (obj.translations.put(key, val) != null) {
               throw ProtocolException.duplicateKey("translations", key);
            }
         }
      }

      return obj;
   }

   public static int computeBytesConsumed(@Nonnull ByteBuf buf, int offset) {
      byte nullBits = buf.getByte(offset);
      int pos = offset + 2;
      if ((nullBits & 1) != 0) {
         int dictLen = VarInt.peek(buf, pos);
         pos += VarInt.length(buf, pos);

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

      return pos - offset;
   }

   @Override
   public void serialize(@Nonnull ByteBuf buf) {
      byte nullBits = 0;
      if (this.translations != null) {
         nullBits = (byte)(nullBits | 1);
      }

      buf.writeByte(nullBits);
      buf.writeByte(this.type.getValue());
      if (this.translations != null) {
         if (this.translations.size() > 4096000) {
            throw ProtocolException.dictionaryTooLarge("Translations", this.translations.size(), 4096000);
         }

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

         for (Entry<String, String> e : this.translations.entrySet()) {
            PacketIO.writeVarString(buf, e.getKey(), 4096000);
            PacketIO.writeVarString(buf, e.getValue(), 4096000);
         }
      }
   }

   @Override
   public int computeSize() {
      int size = 2;
      if (this.translations != null) {
         int translationsSize = 0;

         for (Entry<String, String> kvp : this.translations.entrySet()) {
            translationsSize += PacketIO.stringSize(kvp.getKey()) + PacketIO.stringSize(kvp.getValue());
         }

         size += VarInt.size(this.translations.size()) + translationsSize;
      }

      return size;
   }

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

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

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

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

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

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

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

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

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

         return ValidationResult.OK;
      }
   }

   public UpdateTranslations clone() {
      UpdateTranslations copy = new UpdateTranslations();
      copy.type = this.type;
      copy.translations = this.translations != null ? new HashMap<>(this.translations) : null;
      return copy;
   }

   @Override
   public boolean equals(Object obj) {
      if (this == obj) {
         return true;
      } else {
         return !(obj instanceof UpdateTranslations other)
            ? false
            : Objects.equals(this.type, other.type) && Objects.equals(this.translations, other.translations);
      }
   }

   @Override
   public int hashCode() {
      return Objects.hash(this.type, this.translations);
   }
}
