From ba0fdc7863f2902e96166ef436b1064577268387 Mon Sep 17 00:00:00 2001
From: Sem van der Hoeven <semmer99@gmail.com>
Date: Thu, 8 Jun 2023 12:36:59 +0200
Subject: [PATCH] add timeout

---
 api/views/index.ejs                           | 21 ++++++++++---------
 .../api_communication/api_listener.py         |  5 +++++
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/api/views/index.ejs b/api/views/index.ejs
index 36f16012..17a5fefd 100644
--- a/api/views/index.ejs
+++ b/api/views/index.ejs
@@ -76,9 +76,9 @@
 
 <script>
     var ws;
+    var api_timout;
     var checked_for_connection = false;
     var connected_to_api = false;
-    // setInterval(check_ws_connection, 1000, ws);
     assign_button_callbacks();
     openSocket = () => {
 
@@ -317,22 +317,23 @@
             document.getElementById("failsafe").style.color = "white";
             document.getElementById("failsafe").style.textDecoration = "bold";
             alert("Failsafe enabled! Drone is landing. The failsafe message is:\n" + data.message);
+        } else if (data.type == "API_HEARTBEAT") {
+            clearTimeout(api_timout);
         } else {
             // decodeBase64Image(data.image, document.getElementById("result-video"));
         }
     }
 
     function check_ws_connection() {
-        if (checked_for_connection == false && connected_to_api)
-        {
+        if (checked_for_connection == false && connected_to_api) {
             console.log("Checking connection to API")
-            console.log(ws.readyState)
-            if (ws.readyState != WebSocket.OPEN) {
-                alert("Lost connection to API!")
+            ws.send(JSON.stringify({ "command": 7 }));
+            api_timout = setTimeout(function () {
+                alert("API did not respond on time!")
                 document.getElementById("connectedlabel").innerHTML = "Not connected to drone";
-                document.getElementById("connectbutton").disabled = false;                
-                checked_for_connection = true;
-            }
+                document.getElementById("connectbutton").disabled = false;
+            }, 1000);
+
         }
     }
 
@@ -345,7 +346,7 @@
             document.getElementById("connectedlabel").innerHTML = "Connected to drone";
             document.getElementById("connectbutton").disabled = true;
             connected_to_api = true;
-            setInterval(check_ws_connection, 1000);
+            setInterval(check_ws_connection, 2000);
             openSocket();
         });
 
diff --git a/src/api_communication/api_communication/api_listener.py b/src/api_communication/api_communication/api_listener.py
index 1ae1ac00..49a0f52a 100644
--- a/src/api_communication/api_communication/api_listener.py
+++ b/src/api_communication/api_communication/api_listener.py
@@ -42,6 +42,7 @@ class RequestCommand(Enum):
     MOVE_DIRECTION = 3
     TAKE_PICTURE = 5
     EMERGENCY_STOP = 6
+    API_HEARTBEAT = 7
 
 
 class ResponseMessage(Enum):
@@ -53,6 +54,7 @@ class ResponseMessage(Enum):
     IMAGE = 1
     MOVE_DIRECTION_RESULT = 2
     FAILSAFE = 3
+    API_HEARTBEAT = 4
 
 
 class ApiListener(Node):
@@ -442,6 +444,9 @@ class ApiListener(Node):
                 elif message_json['command'] == RequestCommand.EMERGENCY_STOP.value:
                     self.get_logger().info('Emergency stop command received')
                     self.emergency_stop()
+                elif message_json['command'] == RequestCommand.API_HEARTBEAT.value:
+                    self.get_logger().info('API heartbeat received')
+                    self.message_queue.append(json.dumps({"type": ResponseMessage.API_HEARTBEAT.name}))
                 else:
                     self.get_logger().error('Received unknown command ' +
                                             str(message_json['command']))