Added important admin frontend functions with error handling, the corresponding api endpoints, and the timer logic

scoreboard/public/javascripts/admin.js

@@ -1,11 +1,66 @@
+function updateFrontend(values) {
+    values.duration = moment.duration(values.duration)                  // Create moment object from ISO 8601 string
+    values.durationLeft = moment.duration(values.durationLeft)          // Create moment object from ISO 8601 string
+    document.getElementById("durationLeft").innerHTML = values.print    // Display durationLeft as prettyfied string
 
-function timerStart()
-{
-    fetch("/admin/timerStart", {
-        method: "POST",
-        headers: {'Content-Type': 'text/html'},
-        body: ""
-    }).then(res => {
-        console.log(res);
-    })
+    if(values.isPaused) {                                               // Set button state depending on timer status
+        document.getElementById("timerStartBtn").disabled = false
+        document.getElementById("timerPauseBtn").disabled = true
+    } else {
+        document.getElementById("timerStartBtn").disabled = true
+        document.getElementById("timerPauseBtn").disabled = false
+    }
+}
+
+async function initialUpdate() {
+    const response = await fetch("/admin/timerGetValues");  // Call API Endpoint /admin/timerGetValues
+    const data = await response.json();                     // Wait for asyncronous transfer to complete and parse json (which got received by backend)
+    console.log(data);                                      // Print received data
+    updateFrontend(data);                                   // Update admin frontend with received values
+}
+
+// Timerfunctions
+async function timerStart() {
+    const response = await fetch("/admin/timerStart");      // Call API Endpoint /admin/timerStart
+    if(response.status == 200) {
+        const data = await response.json();                 // Wait for asyncronous transfer to complete and parse json (which got received by backend)
+        console.log(data);                                  // Print received data
+        updateFrontend(data);                               // Update admin frontend with received values
+    } else {
+        //console.log("Error, Timer bereits abgelaufen: ", response.status);
+        const timerStartErrorToast = bootstrap.Toast.getOrCreateInstance(document.getElementById("timerStartErrorToast"));  // Create toast instance byId timerStartErrorToast
+        timerStartErrorToast.show();                        // Show error toast
+    }
+}
+
+async function timerPause() {
+    const response = await fetch("/admin/timerPause");      // Call API Endpoint /admin/timerStart
+    if(response.status == 200) {
+        const data = await response.json();                 // Wait for asyncronous transfer to complete and parse json (which got received by backend)
+        console.log(data);                                  // Print received data
+        updateFrontend(data);                               // Update admin frontend with received values
+    } else {
+        //console.log("Error, Timer bereits pausiert: ", response.status);
+        const timerPauseErrorToast = bootstrap.Toast.getOrCreateInstance(document.getElementById("timerPauseErrorToast"));  // Create toast instance byId timerStartErrorToast
+        timerPauseErrorToast.show();                        // Show error toast
+    }
+}
+
+async function timerReset() {
+    let newDuration = document.getElementById("timerSelectDuration").value;
+    const response = await fetch("/admin/timerReset", {     // Call API Endpoint /admin/timerStart with selected new duration in seconds
+        method: 'POST',
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({duration: newDuration})
+    });
+    const data = await response.json();                     // Wait for asyncronous transfer to complete and parse json (which got received by backend)
+    console.log(data);                                      // Print received data
+    updateFrontend(data);                                   // Update admin frontend with received values
+}
+
+// Scoreboardfunctions
+async function scoreSwitch() {
+    const response = await fetch("/admin/scoreSwitch");     // Call API Endpoint /admin/timerStart
+    const data = await response.json();                     // Wait for asyncronous transfer to complete and parse json (which got received by backend)
+    console.log(data);                                      // Print received data
 }