package network

import (
	"errors"
	"io"
	"sync"

	"git.hpds.cc/Component/network/frame"
)

// ErrStreamNil be returned if FrameStream underlying stream is nil.
var ErrStreamNil = errors.New("hpdsMq: frame stream underlying is nil")

// FrameStream is the QUIC Stream with the minimum unit Frame.
type FrameStream struct {
	// Stream is a QUIC stream.
	stream io.ReadWriter
	mu     sync.Mutex
}

// NewFrameStream creates a new FrameStream.
func NewFrameStream(s io.ReadWriter) frame.ReadWriter {
	return &FrameStream{stream: s}
}

// ReadFrame reads next frame from QUIC stream.
func (fs *FrameStream) ReadFrame() (frame.Frame, error) {
	if fs.stream == nil {
		return nil, ErrStreamNil
	}
	return ParseFrame(fs.stream)
}

// WriteFrame writes a frame into QUIC stream.
func (fs *FrameStream) WriteFrame(frm frame.Frame) error {
	if fs.stream == nil {
		return ErrStreamNil
	}
	fs.mu.Lock()
	defer fs.mu.Unlock()
	_, err := fs.stream.Write(frm.Encode())
	return err
}