package spark.network.netty;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundByteHandlerAdapter;


abstract class FileClientHandler extends ChannelInboundByteHandlerAdapter {

  private FileHeader currentHeader = null;

  private volatile boolean handlerCalled = false;

  public boolean isComplete() {
    return handlerCalled;
  }

  public abstract void handle(ChannelHandlerContext ctx, ByteBuf in, FileHeader header);
  public abstract void handleError(String blockId);

  @Override
  public ByteBuf newInboundBuffer(ChannelHandlerContext ctx) {
    // Use direct buffer if possible.
    return ctx.alloc().ioBuffer();
  }

  @Override
  public void inboundBufferUpdated(ChannelHandlerContext ctx, ByteBuf in) {
    // get header
    if (currentHeader == null && in.readableBytes() >= FileHeader.HEADER_SIZE()) {
      currentHeader = FileHeader.create(in.readBytes(FileHeader.HEADER_SIZE()));
    }
    // get file
    if(in.readableBytes() >= currentHeader.fileLen()) {
      handle(ctx, in, currentHeader);
      handlerCalled = true;
      currentHeader = null;
      ctx.close();
    }
  }

}