// Copyright 2024 Matthew Rich <matthewrich.conf@gmail.com>. All rights reserved.

package containerlog

import (
	"io"
	"encoding/binary"
)

func Header(r io.Reader) (s StreamType, size uint64, err error) {
	var header []byte = make([]byte, 8)
	if _, err = io.ReadFull(r, header); err == nil {
		s = StreamType(header[0])
		if err = s.Validate(); err == nil {
			header[0] = 0x0
			size = binary.BigEndian.Uint64(header)
		}
	}
	return
}

func ReadMessage(r io.Reader, size uint64) (message string, err error) {
	var messageData []byte = make([]byte, size)
	var bytesRead int
	if bytesRead, err = r.Read(messageData); err == nil && uint64(bytesRead) == size {
		message = string(messageData)
	}
	return
}

func Read(r io.Reader) (s StreamType, message string, err error) {
	var messageSize uint64
	if s, messageSize, err = Header(r); err == nil {
		if message, err = ReadMessage(r, messageSize); err == nil {
			return
		}
	}
	return
}