package com.pingcap.ch;

import com.pingcap.common.ReadBuffer;
import com.pingcap.common.WriteBuffer;
import java.io.IOException;
import shade.com.google.common.base.Preconditions;

public class CHBlockInfo {
  public boolean is_overflows = false;
  public int bucket_num = -1;

  // Not part of this info.
  public boolean isEOF = false;

  public CHBlockInfo(boolean is_overflows, int bucket_num) {
    this.is_overflows = is_overflows;
    this.bucket_num = bucket_num;
  }

  public CHBlockInfo() {}

  public void write(WriteBuffer writer) throws IOException {
    writer.writeVarUInt64(1);
    writer.writeByte((byte) 0);
    writer.writeVarUInt64(2);
    writer.writeInt(bucket_num);
    writer.writeVarUInt64(0);
  }

  public static CHBlockInfo read(ReadBuffer reader) throws IOException {
    try {
      // Check remaining data.
      reader.ensure(1);
    } catch (IOException e) {
      if ("End of stream.".equals(e.getMessage())) {
        // Legal case. Noting to read means empty block.
        CHBlockInfo info = new CHBlockInfo();
        info.isEOF = true;
        return info;
      } else {
        throw e;
      }
    }

    Preconditions.checkState(reader.readVarUInt64() == 1);
    boolean is_overflows = reader.readByte() != 0;
    Preconditions.checkState(reader.readVarUInt64() == 2);
    int bucket_num = reader.readInt();
    long mark = reader.readVarUInt64();
    Preconditions.checkState(mark == 0);

    return new CHBlockInfo(is_overflows, bucket_num);
  }
}