package org.infinispan.hotrod.impl.transport.netty;

import static org.infinispan.hotrod.impl.transport.netty.HintedReplayingDecoder.REPLAY;

import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.channels.FileChannel;
import java.nio.channels.GatheringByteChannel;
import java.nio.channels.ScatteringByteChannel;
import java.nio.charset.Charset;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.buffer.SwappedByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.util.ByteProcessor;
import io.netty.util.internal.StringUtil;

/**
 * Copy-paste of {@link io.netty.handler.codec.ReplayingDecoderByteBuf} which hints {@link HintedReplayingDecoder}
 * to not try decoding until requested bytes are received.
 */
public class HintingByteBuf extends ByteBuf {
   private final HintedReplayingDecoder<?> decoder;
   private ByteBuf buffer;
   private boolean terminated;
   private SwappedByteBuf swapped;

   HintingByteBuf(HintedReplayingDecoder<?> decoder) {
      this.decoder = decoder;
   }

   void setCumulation(ByteBuf buffer) {
      this.buffer = buffer;
   }

   void terminate() {
      terminated = true;
   }

   @Override
   public int capacity() {
      if (terminated) {
         return buffer.capacity();
      } else {
         return Integer.MAX_VALUE;
      }
   }

   @Override
   public ByteBuf capacity(int newCapacity) {
      throw reject();
   }

   @Override
   public int maxCapacity() {
      return capacity();
   }

   @Override
   public ByteBufAllocator alloc() {
      return buffer.alloc();
   }

   @Override
   public boolean isReadOnly() {
      return false;
   }

   @SuppressWarnings("deprecation")
   @Override
   public ByteBuf asReadOnly() {
      return Unpooled.unmodifiableBuffer(this);
   }

   @Override
   public boolean isDirect() {
      return buffer.isDirect();
   }

   @Override
   public boolean hasArray() {
      return false;
   }

   @Override
   public byte[] array() {
      throw new UnsupportedOperationException();
   }

   @Override
   public int arrayOffset() {
      throw new UnsupportedOperationException();
   }

   @Override
   public boolean hasMemoryAddress() {
      return false;
   }

   @Override
   public long memoryAddress() {
      throw new UnsupportedOperationException();
   }

   @Override
   public ByteBuf clear() {
      throw reject();
   }

   @Override
   public boolean equals(Object obj) {
      return this == obj;
   }

   @Override
   public int compareTo(ByteBuf buffer) {
      throw reject();
   }

   @Override
   public ByteBuf copy() {
      throw reject();
   }

   @Override
   public ByteBuf copy(int index, int length) {
      checkIndex(index, length);
      return buffer.copy(index, length);
   }

   @Override
   public ByteBuf discardReadBytes() {
      throw reject();
   }

   @Override
   public ByteBuf ensureWritable(int writableBytes) {
      throw reject();
   }

   @Override
   public int ensureWritable(int minWritableBytes, boolean force) {
      throw reject();
   }

   @Override
   public ByteBuf duplicate() {
      throw reject();
   }

   @Override
   public ByteBuf retainedDuplicate() {
      throw reject();
   }

   @Override
   public boolean getBoolean(int index) {
      checkIndex(index, 1);
      return buffer.getBoolean(index);
   }

   @Override
   public byte getByte(int index) {
      checkIndex(index, 1);
      return buffer.getByte(index);
   }

   @Override
   public short getUnsignedByte(int index) {
      checkIndex(index, 1);
      return buffer.getUnsignedByte(index);
   }

   @Override
   public ByteBuf getBytes(int index, byte[] dst, int dstIndex, int length) {
      checkIndex(index, length);
      buffer.getBytes(index, dst, dstIndex, length);
      return this;
   }

   @Override
   public ByteBuf getBytes(int index, byte[] dst) {
      checkIndex(index, dst.length);
      buffer.getBytes(index, dst);
      return this;
   }

   @Override
   public ByteBuf getBytes(int index, ByteBuffer dst) {
      throw reject();
   }

   @Override
   public ByteBuf getBytes(int index, ByteBuf dst, int dstIndex, int length) {
      checkIndex(index, length);
      buffer.getBytes(index, dst, dstIndex, length);
      return this;
   }

   @Override
   public ByteBuf getBytes(int index, ByteBuf dst, int length) {
      throw reject();
   }

   @Override
   public ByteBuf getBytes(int index, ByteBuf dst) {
      throw reject();
   }

   @Override
   public int getBytes(int index, GatheringByteChannel out, int length) {
      throw reject();
   }

   @Override
   public int getBytes(int index, FileChannel out, long position, int length) {
      throw reject();
   }

   @Override
   public ByteBuf getBytes(int index, OutputStream out, int length) {
      throw reject();
   }

   @Override
   public int getInt(int index) {
      checkIndex(index, 4);
      return buffer.getInt(index);
   }

   @Override
   public int getIntLE(int index) {
      checkIndex(index, 4);
      return buffer.getIntLE(index);
   }

   @Override
   public long getUnsignedInt(int index) {
      checkIndex(index, 4);
      return buffer.getUnsignedInt(index);
   }

   @Override
   public long getUnsignedIntLE(int index) {
      checkIndex(index, 4);
      return buffer.getUnsignedIntLE(index);
   }

   @Override
   public long getLong(int index) {
      checkIndex(index, 8);
      return buffer.getLong(index);
   }

   @Override
   public long getLongLE(int index) {
      checkIndex(index, 8);
      return buffer.getLongLE(index);
   }

   @Override
   public int getMedium(int index) {
      checkIndex(index, 3);
      return buffer.getMedium(index);
   }

   @Override
   public int getMediumLE(int index) {
      checkIndex(index, 3);
      return buffer.getMediumLE(index);
   }

   @Override
   public int getUnsignedMedium(int index) {
      checkIndex(index, 3);
      return buffer.getUnsignedMedium(index);
   }

   @Override
   public int getUnsignedMediumLE(int index) {
      checkIndex(index, 3);
      return buffer.getUnsignedMediumLE(index);
   }

   @Override
   public short getShort(int index) {
      checkIndex(index, 2);
      return buffer.getShort(index);
   }

   @Override
   public short getShortLE(int index) {
      checkIndex(index, 2);
      return buffer.getShortLE(index);
   }

   @Override
   public int getUnsignedShort(int index) {
      checkIndex(index, 2);
      return buffer.getUnsignedShort(index);
   }

   @Override
   public int getUnsignedShortLE(int index) {
      checkIndex(index, 2);
      return buffer.getUnsignedShortLE(index);
   }

   @Override
   public char getChar(int index) {
      checkIndex(index, 2);
      return buffer.getChar(index);
   }

   @Override
   public float getFloat(int index) {
      checkIndex(index, 4);
      return buffer.getFloat(index);
   }

   @Override
   public double getDouble(int index) {
      checkIndex(index, 8);
      return buffer.getDouble(index);
   }

   @Override
   public CharSequence getCharSequence(int index, int length, Charset charset) {
      checkIndex(index, length);
      return buffer.getCharSequence(index, length, charset);
   }

   @Override
   public int hashCode() {
      throw reject();
   }

   @Override
   public int indexOf(int fromIndex, int toIndex, byte value) {
      if (fromIndex == toIndex) {
         return -1;
      }

      if (Math.max(fromIndex, toIndex) > buffer.writerIndex()) {
         decoder.requireWriterIndex(Math.max(fromIndex, toIndex));
         throw REPLAY;
      }

      return buffer.indexOf(fromIndex, toIndex, value);
   }

   @Override
   public int bytesBefore(byte value) {
      int bytes = buffer.bytesBefore(value);
      if (bytes < 0) {
         throw REPLAY;
      }
      return bytes;
   }

   @Override
   public int bytesBefore(int length, byte value) {
      return bytesBefore(buffer.readerIndex(), length, value);
   }

   @Override
   public int bytesBefore(int index, int length, byte value) {
      final int writerIndex = buffer.writerIndex();
      if (index >= writerIndex) {
         throw REPLAY;
      }

      if (index <= writerIndex - length) {
         return buffer.bytesBefore(index, length, value);
      }

      int res = buffer.bytesBefore(index, writerIndex - index, value);
      if (res < 0) {
         throw REPLAY;
      } else {
         return res;
      }
   }

   @Override
   public int forEachByte(ByteProcessor processor) {
      int ret = buffer.forEachByte(processor);
      if (ret < 0) {
         throw REPLAY;
      } else {
         return ret;
      }
   }

   @Override
   public int forEachByte(int index, int length, ByteProcessor processor) {
      final int writerIndex = buffer.writerIndex();
      if (index >= writerIndex) {
         decoder.requireWriterIndex(index);
         throw REPLAY;
      }

      if (index <= writerIndex - length) {
         return buffer.forEachByte(index, length, processor);
      }

      int ret = buffer.forEachByte(index, writerIndex - index, processor);
      if (ret < 0) {
         throw REPLAY;
      } else {
         return ret;
      }
   }

   @Override
   public int forEachByteDesc(ByteProcessor processor) {
      if (terminated) {
         return buffer.forEachByteDesc(processor);
      } else {
         throw reject();
      }
   }

   @Override
   public int forEachByteDesc(int index, int length, ByteProcessor processor) {
      if (index + length > buffer.writerIndex()) {
         decoder.requireWriterIndex(index + length);
         throw REPLAY;
      }

      return buffer.forEachByteDesc(index, length, processor);
   }

   @Override
   public ByteBuf markReaderIndex() {
      buffer.markReaderIndex();
      return this;
   }

   @Override
   public ByteBuf markWriterIndex() {
      throw reject();
   }

   @Override
   public ByteOrder order() {
      return buffer.order();
   }

   @Override
   public ByteBuf order(ByteOrder endianness) {
      if (endianness == null) {
         throw new NullPointerException("endianness");
      }
      if (endianness == order()) {
         return this;
      }

      SwappedByteBuf swapped = this.swapped;
      if (swapped == null) {
         this.swapped = swapped = new SwappedByteBuf(this);
      }
      return swapped;
   }

   @Override
   public boolean isReadable() {
      return buffer.isReadable(); // see readableBytes();
   }

   @Override
   public boolean isReadable(int size) {
      return buffer.isReadable(size); // see readableBytes();
   }

   @Override
   public int readableBytes() {
      // Contrary to ReplayingDecoderByteBuf we will provide the correct number.
      // If someone reads past this number we'll throw the Signal as usual, but we're not fooling anyone.
      // This is useful when injecting another handler below the decoder (as GetStreamOperation does),
      // as we can hand over the buffered bytes to be consumed immediately.
      return buffer.readableBytes();
   }

   @Override
   public boolean readBoolean() {
      checkReadableBytes(1);
      return buffer.readBoolean();
   }

   @Override
   public byte readByte() {
      checkReadableBytes(1);
      return buffer.readByte();
   }

   @Override
   public short readUnsignedByte() {
      checkReadableBytes(1);
      return buffer.readUnsignedByte();
   }

   @Override
   public ByteBuf readBytes(byte[] dst, int dstIndex, int length) {
      checkReadableBytes(length);
      buffer.readBytes(dst, dstIndex, length);
      return this;
   }

   @Override
   public ByteBuf readBytes(byte[] dst) {
      checkReadableBytes(dst.length);
      buffer.readBytes(dst);
      return this;
   }

   @Override
   public ByteBuf readBytes(ByteBuffer dst) {
      throw reject();
   }

   @Override
   public ByteBuf readBytes(ByteBuf dst, int dstIndex, int length) {
      checkReadableBytes(length);
      buffer.readBytes(dst, dstIndex, length);
      return this;
   }

   @Override
   public ByteBuf readBytes(ByteBuf dst, int length) {
      throw reject();
   }

   @Override
   public ByteBuf readBytes(ByteBuf dst) {
      checkReadableBytes(dst.writableBytes());
      buffer.readBytes(dst);
      return this;
   }

   @Override
   public int readBytes(GatheringByteChannel out, int length) {
      throw reject();
   }

   @Override
   public int readBytes(FileChannel out, long position, int length) {
      throw reject();
   }

   @Override
   public ByteBuf readBytes(int length) {
      checkReadableBytes(length);
      return buffer.readBytes(length);
   }

   @Override
   public ByteBuf readSlice(int length) {
      checkReadableBytes(length);
      return buffer.readSlice(length);
   }

   @Override
   public ByteBuf readRetainedSlice(int length) {
      checkReadableBytes(length);
      return buffer.readRetainedSlice(length);
   }

   @Override
   public ByteBuf readBytes(OutputStream out, int length) {
      throw reject();
   }

   @Override
   public int readerIndex() {
      return buffer.readerIndex();
   }

   @Override
   public ByteBuf readerIndex(int readerIndex) {
      buffer.readerIndex(readerIndex);
      return this;
   }

   @Override
   public int readInt() {
      checkReadableBytes(4);
      return buffer.readInt();
   }

   @Override
   public int readIntLE() {
      checkReadableBytes(4);
      return buffer.readIntLE();
   }

   @Override
   public long readUnsignedInt() {
      checkReadableBytes(4);
      return buffer.readUnsignedInt();
   }

   @Override
   public long readUnsignedIntLE() {
      checkReadableBytes(4);
      return buffer.readUnsignedIntLE();
   }

   @Override
   public long readLong() {
      checkReadableBytes(8);
      return buffer.readLong();
   }

   @Override
   public long readLongLE() {
      checkReadableBytes(8);
      return buffer.readLongLE();
   }

   @Override
   public int readMedium() {
      checkReadableBytes(3);
      return buffer.readMedium();
   }

   @Override
   public int readMediumLE() {
      checkReadableBytes(3);
      return buffer.readMediumLE();
   }

   @Override
   public int readUnsignedMedium() {
      checkReadableBytes(3);
      return buffer.readUnsignedMedium();
   }

   @Override
   public int readUnsignedMediumLE() {
      checkReadableBytes(3);
      return buffer.readUnsignedMediumLE();
   }

   @Override
   public short readShort() {
      checkReadableBytes(2);
      return buffer.readShort();
   }

   @Override
   public short readShortLE() {
      checkReadableBytes(2);
      return buffer.readShortLE();
   }

   @Override
   public int readUnsignedShort() {
      checkReadableBytes(2);
      return buffer.readUnsignedShort();
   }

   @Override
   public int readUnsignedShortLE() {
      checkReadableBytes(2);
      return buffer.readUnsignedShortLE();
   }

   @Override
   public char readChar() {
      checkReadableBytes(2);
      return buffer.readChar();
   }

   @Override
   public float readFloat() {
      checkReadableBytes(4);
      return buffer.readFloat();
   }

   @Override
   public double readDouble() {
      checkReadableBytes(8);
      return buffer.readDouble();
   }

   @Override
   public CharSequence readCharSequence(int length, Charset charset) {
      checkReadableBytes(length);
      return buffer.readCharSequence(length, charset);
   }

   @Override
   public ByteBuf resetReaderIndex() {
      buffer.resetReaderIndex();
      return this;
   }

   @Override
   public ByteBuf resetWriterIndex() {
      throw reject();
   }

   @Override
   public ByteBuf setBoolean(int index, boolean value) {
      throw reject();
   }

   @Override
   public ByteBuf setByte(int index, int value) {
      throw reject();
   }

   @Override
   public ByteBuf setBytes(int index, byte[] src, int srcIndex, int length) {
      throw reject();
   }

   @Override
   public ByteBuf setBytes(int index, byte[] src) {
      throw reject();
   }

   @Override
   public ByteBuf setBytes(int index, ByteBuffer src) {
      throw reject();
   }

   @Override
   public ByteBuf setBytes(int index, ByteBuf src, int srcIndex, int length) {
      throw reject();
   }

   @Override
   public ByteBuf setBytes(int index, ByteBuf src, int length) {
      throw reject();
   }

   @Override
   public ByteBuf setBytes(int index, ByteBuf src) {
      throw reject();
   }

   @Override
   public int setBytes(int index, InputStream in, int length) {
      throw reject();
   }

   @Override
   public ByteBuf setZero(int index, int length) {
      throw reject();
   }

   @Override
   public int setBytes(int index, ScatteringByteChannel in, int length) {
      throw reject();
   }

   @Override
   public int setBytes(int index, FileChannel in, long position, int length) {
      throw reject();
   }

   @Override
   public ByteBuf setIndex(int readerIndex, int writerIndex) {
      throw reject();
   }

   @Override
   public ByteBuf setInt(int index, int value) {
      throw reject();
   }

   @Override
   public ByteBuf setIntLE(int index, int value) {
      throw reject();
   }

   @Override
   public ByteBuf setLong(int index, long value) {
      throw reject();
   }

   @Override
   public ByteBuf setLongLE(int index, long value) {
      throw reject();
   }

   @Override
   public ByteBuf setMedium(int index, int value) {
      throw reject();
   }

   @Override
   public ByteBuf setMediumLE(int index, int value) {
      throw reject();
   }

   @Override
   public ByteBuf setShort(int index, int value) {
      throw reject();
   }

   @Override
   public ByteBuf setShortLE(int index, int value) {
      throw reject();
   }

   @Override
   public ByteBuf setChar(int index, int value) {
      throw reject();
   }

   @Override
   public ByteBuf setFloat(int index, float value) {
      throw reject();
   }

   @Override
   public ByteBuf setDouble(int index, double value) {
      throw reject();
   }

   @Override
   public ByteBuf skipBytes(int length) {
      checkReadableBytes(length);
      buffer.skipBytes(length);
      return this;
   }

   @Override
   public ByteBuf slice() {
      throw reject();
   }

   @Override
   public ByteBuf retainedSlice() {
      throw reject();
   }

   @Override
   public ByteBuf slice(int index, int length) {
      checkIndex(index, length);
      return buffer.slice(index, length);
   }

   @Override
   public ByteBuf retainedSlice(int index, int length) {
      checkIndex(index, length);
      return buffer.slice(index, length);
   }

   @Override
   public int nioBufferCount() {
      return buffer.nioBufferCount();
   }

   @Override
   public ByteBuffer nioBuffer() {
      throw reject();
   }

   @Override
   public ByteBuffer nioBuffer(int index, int length) {
      checkIndex(index, length);
      return buffer.nioBuffer(index, length);
   }

   @Override
   public ByteBuffer[] nioBuffers() {
      throw reject();
   }

   @Override
   public ByteBuffer[] nioBuffers(int index, int length) {
      checkIndex(index, length);
      return buffer.nioBuffers(index, length);
   }

   @Override
   public ByteBuffer internalNioBuffer(int index, int length) {
      checkIndex(index, length);
      return buffer.internalNioBuffer(index, length);
   }

   @Override
   public String toString(int index, int length, Charset charset) {
      checkIndex(index, length);
      return buffer.toString(index, length, charset);
   }

   @Override
   public String toString(Charset charsetName) {
      throw reject();
   }

   @Override
   public String toString() {
      return StringUtil.simpleClassName(this) + '(' +
            "ridx=" +
            readerIndex() +
            ", " +
            "widx=" +
            writerIndex() +
            ')';
   }

   @Override
   public boolean isWritable() {
      return false;
   }

   @Override
   public boolean isWritable(int size) {
      return false;
   }

   @Override
   public int writableBytes() {
      return 0;
   }

   @Override
   public int maxWritableBytes() {
      return 0;
   }

   @Override
   public ByteBuf writeBoolean(boolean value) {
      throw reject();
   }

   @Override
   public ByteBuf writeByte(int value) {
      throw reject();
   }

   @Override
   public ByteBuf writeBytes(byte[] src, int srcIndex, int length) {
      throw reject();
   }

   @Override
   public ByteBuf writeBytes(byte[] src) {
      throw reject();
   }

   @Override
   public ByteBuf writeBytes(ByteBuffer src) {
      throw reject();
   }

   @Override
   public ByteBuf writeBytes(ByteBuf src, int srcIndex, int length) {
      throw reject();
   }

   @Override
   public ByteBuf writeBytes(ByteBuf src, int length) {
      throw reject();
   }

   @Override
   public ByteBuf writeBytes(ByteBuf src) {
      throw reject();
   }

   @Override
   public int writeBytes(InputStream in, int length) {
      throw reject();
   }

   @Override
   public int writeBytes(ScatteringByteChannel in, int length) {
      throw reject();
   }

   @Override
   public int writeBytes(FileChannel in, long position, int length) {
      throw reject();
   }

   @Override
   public ByteBuf writeInt(int value) {
      throw reject();
   }

   @Override
   public ByteBuf writeIntLE(int value) {
      throw reject();
   }

   @Override
   public ByteBuf writeLong(long value) {
      throw reject();
   }

   @Override
   public ByteBuf writeLongLE(long value) {
      throw reject();
   }

   @Override
   public ByteBuf writeMedium(int value) {
      throw reject();
   }

   @Override
   public ByteBuf writeMediumLE(int value) {
      throw reject();
   }

   @Override
   public ByteBuf writeZero(int length) {
      throw reject();
   }

   @Override
   public int writerIndex() {
      return buffer.writerIndex();
   }

   @Override
   public ByteBuf writerIndex(int writerIndex) {
      throw reject();
   }

   @Override
   public ByteBuf writeShort(int value) {
      throw reject();
   }

   @Override
   public ByteBuf writeShortLE(int value) {
      throw reject();
   }

   @Override
   public ByteBuf writeChar(int value) {
      throw reject();
   }

   @Override
   public ByteBuf writeFloat(float value) {
      throw reject();
   }

   @Override
   public ByteBuf writeDouble(double value) {
      throw reject();
   }

   @Override
   public int setCharSequence(int index, CharSequence sequence, Charset charset) {
      throw reject();
   }

   @Override
   public int writeCharSequence(CharSequence sequence, Charset charset) {
      throw reject();
   }

   private void checkIndex(int index, int length) {
      if (index + length > buffer.writerIndex()) {
         decoder.requireWriterIndex(index + length);
         throw REPLAY;
      }
   }

   private void checkReadableBytes(int readableBytes) {
      if (buffer.readableBytes() < readableBytes) {
         decoder.requireWriterIndex(buffer.readerIndex() + readableBytes);
         throw REPLAY;
      }
   }

   @Override
   public ByteBuf discardSomeReadBytes() {
      throw reject();
   }

   @Override
   public int refCnt() {
      return buffer.refCnt();
   }

   @Override
   public ByteBuf retain() {
      throw reject();
   }

   @Override
   public ByteBuf retain(int increment) {
      throw reject();
   }

   @Override
   public ByteBuf touch() {
      buffer.touch();
      return this;
   }

   @Override
   public ByteBuf touch(Object hint) {
      buffer.touch(hint);
      return this;
   }

   @Override
   public boolean release() {
      throw reject();
   }

   @Override
   public boolean release(int decrement) {
      throw reject();
   }

   @Override
   public ByteBuf unwrap() {
      throw reject();
   }

   private static UnsupportedOperationException reject() {
      return new UnsupportedOperationException("not a replayable operation");
   }
}
