feat(gateway): added reply to the POST request with the latest measurement

Signed-off-by: Klagarge <remi@heredero.ch>

gateway/src/PublishCommand.go

@@ -3,6 +3,7 @@ package main
 import (
 	"errors"
 	_ "gateway-softweng/docs"
+	"time"
 
 	_ "github.com/eclipse/paho.mqtt.golang"
 	"github.com/gin-gonic/gin"
@@ -24,25 +25,25 @@ type Command struct {
 // @Param room query string true "Room name" example(Bedroom)
 // @Param device query string true "Device name" example(DoorSensor)
 // @Param command body main.Command true "Command to publish"
-// @Success 200 {object} map[string]string "status:ok"
+// @Success 200 {object} map[string]interface{} "response or status:ok"
 // @Failure 500 {object} gin.H
 // @Router /raclette [post]
-func (gh *Gateway) publishCommand(c *gin.Context) error {
+func (gh *Gateway) publishCommand(c *gin.Context) (string, error) {
 	// Get the user from the authenticated context
 	//userid := c.MustGet(gin.AuthUserKey).(string)
 
 	// Get user, room and device from the query parameters
 	user, ret := c.GetQuery("user")
 	if !ret {
-		return errors.New("no user found")
+		return "", errors.New("no user found")
 	}
 	room, ret := c.GetQuery("room")
 	if !ret {
-		return errors.New(`no room found`)
+		return "", errors.New(`no room found`)
 	}
 	device, ret := c.GetQuery("device")
 	if !ret {
-		return errors.New(`no device found`)
+		return "", errors.New(`no device found`)
 	}
 
 	// Define the JSON structure for the command
@@ -51,14 +52,38 @@ func (gh *Gateway) publishCommand(c *gin.Context) error {
 	// Bind the JSON payload to the structure
 	err := c.Bind(&json)
 	if err != nil {
-		return err
+		return "", err
 	}
 
+	// Set the pending request fields to track this request
+	gh.pendingUser = user
+	gh.pendingRoom = room
+	gh.pendingDevice = device
+
 	// Publish the command to the MQTT broker
-	topic := user + "/" + room + "/" + device + "/cmd/" + json.Command
-	token := gh.mqtt.Publish(topic, 1, false, "")
+	cmdTopic := user + "/" + room + "/" + device + "/cmd/" + json.Command
+	token := gh.mqtt.Publish(cmdTopic, 1, false, "")
 	if token.Wait() && token.Error() != nil {
-		return token.Error()
+		// Clear pending request fields
+		gh.pendingUser = ""
+		gh.pendingRoom = ""
+		gh.pendingDevice = ""
+		return "", token.Error()
+	}
+
+	// Wait for response with a 1-second timeout
+	select {
+	case response := <-gh.pendingChan:
+		// Clear pending request fields
+		gh.pendingUser = ""
+		gh.pendingRoom = ""
+		gh.pendingDevice = ""
+		return response, nil
+	case <-time.After(1 * time.Second):
+		// Timeout occurred, clear pending request fields
+		gh.pendingUser = ""
+		gh.pendingRoom = ""
+		gh.pendingDevice = ""
+		return "", nil
 	}
-	return nil
 }