cam2ip/handlers/socket.go

package handlers

import (
	"bytes"
	"context"
	"log"
	"net/http"
	"time"

	"github.com/coder/websocket"

	"github.com/gen2brain/cam2ip/image"
)

// Socket handler.
type Socket struct {
	reader  ImageReader
	delay   int
	quality int
}

// NewSocket returns new socket handler.
func NewSocket(reader ImageReader, delay, quality int) *Socket {
	return &Socket{reader, delay, quality}
}

// ServeHTTP handles requests on incoming connections.
func (s *Socket) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	conn, err := websocket.Accept(w, r, nil)
	if err != nil {
		log.Printf("socket: accept: %v", err)

		return
	}

	ctx := context.Background()

	for {
		img, err := s.reader.Read()
		if err != nil {
			log.Printf("socket: read: %v", err)
			break
		}

		w := new(bytes.Buffer)

		err = image.NewEncoder(w, s.quality).Encode(img)
		if err != nil {
			log.Printf("socket: encode: %v", err)
			continue
		}

		b64 := image.EncodeToString(w.Bytes())

		err = conn.Write(ctx, websocket.MessageText, []byte(b64))
		if err != nil {
			break
		}

		if s.delay > 0 {
			time.Sleep(time.Duration(s.delay) * time.Millisecond)
		}
	}

	_ = conn.Close(websocket.StatusNormalClosure, "")
}