package sarama

import "fmt"

type responseHeader struct {
	length        int32
	correlationID int32
}

func (r *responseHeader) decode(pd packetDecoder, version int16) (err error) {
	if version >= 1 {
		if decoder, ok := pd.(*realDecoder); ok {
			pd = &realFlexibleDecoder{decoder}
		} else {
			return PacketDecodingError{"failed to instantiate flexible decoder"}
		}
	}
	r.length, err = pd.getInt32()
	if err != nil {
		return err
	}
	if r.length <= 4 || r.length > MaxResponseSize {
		return PacketDecodingError{fmt.Sprintf("message of length %d too large or too small", r.length)}
	}

	r.correlationID, err = pd.getInt32()
	if err != nil {
		return err
	}

	_, err = pd.getEmptyTaggedFieldArray()
	return err
}