Refactor gateway module to remove mqtt dependency

pkg/gateway/util_test.go

@@ -0,0 +1,168 @@
+package gateway
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"github.com/cyrilix/robocar-simulator/pkg/simulator"
+	log "github.com/sirupsen/logrus"
+	"io"
+	"net"
+	"sync"
+)
+
+type Gw2SimMock struct {
+	initMsgsOnce sync.Once
+
+	ln             net.Listener
+	notifyChan     chan *simulator.ControlMsg
+	initNotifyChan sync.Once
+}
+
+func (c *Gw2SimMock) Notify() <-chan *simulator.ControlMsg {
+	c.initNotifyChan.Do(func() { c.notifyChan = make(chan *simulator.ControlMsg) })
+	return c.notifyChan
+}
+
+func (c *Gw2SimMock) listen() error {
+	ln, err := net.Listen("tcp", "127.0.0.1:")
+	c.ln = ln
+	if err != nil {
+
+		return fmt.Errorf("unable to listen on port: %v", err)
+	}
+
+	go func() {
+		for {
+			conn, err := c.ln.Accept()
+			if err != nil {
+				log.Debugf("connection close: %v", err)
+				break
+			}
+			go c.handleConnection(conn)
+		}
+	}()
+	return nil
+}
+
+func (c *Gw2SimMock) Addr() string {
+	return c.ln.Addr().String()
+}
+
+func (c *Gw2SimMock) handleConnection(conn net.Conn) {
+	c.initNotifyChan.Do(func() { c.notifyChan = make(chan *simulator.ControlMsg) })
+	reader := bufio.NewReader(conn)
+	for {
+		rawCmd, err := reader.ReadBytes('\n')
+		if err != nil {
+			if err == io.EOF {
+				log.Debug("connection closed")
+				break
+			}
+			log.Errorf("unable to read request: %v", err)
+			return
+		}
+
+		var msg simulator.ControlMsg
+		err = json.Unmarshal(rawCmd, &msg)
+		if err != nil {
+			log.Errorf("unable to unmarchal control msg \"%v\": %v", string(rawCmd), err)
+			continue
+		}
+
+		c.notifyChan <- &msg
+	}
+}
+
+func (c *Gw2SimMock) Close() error {
+	log.Debugf("close mock server")
+	err := c.ln.Close()
+	if err != nil {
+		return fmt.Errorf("unable to close mock server: %v", err)
+	}
+	if c.notifyChan != nil {
+		close(c.notifyChan)
+	}
+	return nil
+}
+
+type Sim2GwMock struct {
+	ln            net.Listener
+	muConn        sync.Mutex
+	conn          net.Conn
+	writer        *bufio.Writer
+	newConnection chan net.Conn
+	logger        *log.Entry
+}
+
+func (c *Sim2GwMock) EmitMsg(p string) (err error) {
+	c.muConn.Lock()
+	defer c.muConn.Unlock()
+	_, err = c.writer.WriteString(p + "\n")
+	if err != nil {
+		c.logger.Errorf("unable to write response: %v", err)
+	}
+	if err == io.EOF {
+		c.logger.Info("Connection closed")
+		return err
+	}
+	err = c.writer.Flush()
+	return err
+}
+
+func (c *Sim2GwMock) WaitConnection() {
+	c.muConn.Lock()
+	defer c.muConn.Unlock()
+	c.logger.Debug("simulator waiting connection")
+	if c.conn != nil {
+		return
+	}
+	c.logger.Debug("new connection")
+	conn := <-c.newConnection
+
+	c.conn = conn
+	c.writer = bufio.NewWriter(conn)
+}
+
+func (c *Sim2GwMock) Start() error {
+	c.logger = log.WithField("simulator", "mock")
+	c.newConnection = make(chan net.Conn)
+	ln, err := net.Listen("tcp", "127.0.0.1:")
+	c.ln = ln
+	if err != nil {
+		return fmt.Errorf("unable to listen on port: %v", err)
+	}
+	go func() {
+		for {
+			conn, err := c.ln.Accept()
+			if err != nil && err == io.EOF {
+				c.logger.Errorf("connection close: %v", err)
+				break
+			}
+			if c.newConnection == nil {
+				break
+			}
+			c.newConnection <- conn
+		}
+	}()
+	return nil
+}
+
+func (c *Sim2GwMock) Addr() string {
+	return c.ln.Addr().String()
+}
+
+func (c *Sim2GwMock) Close() error {
+	c.logger.Debug("close mock server")
+
+	if c == nil {
+		return nil
+	}
+	close(c.newConnection)
+	c.newConnection = nil
+	err := c.ln.Close()
+	if err != nil {
+		return fmt.Errorf("unable to close mock server: %v", err)
+	}
+	return nil
+}