feat: enhance sync functionality with unsynced answer detection and UI updates

js/main.js

@@ -4,7 +4,7 @@ import * as viewer from "./viewer.js";
 import * as interact from "./interact.js";
 import * as config from "./config.js";
 import { db, question_db } from "./db.js";
-import { initSync, triggerImmediateSync } from "./sync.js";
+import { initSync, triggerImmediateSync, updateSyncUI } from "./sync.js";
 // const { v4: uuidv4 } = require('uuid');
 
 log.setDefaultLevel("warn")
@@ -207,6 +207,7 @@ cornerstoneTools.init();
 function putAnswer(answer) {
   answer.time_answered = new Date().toISOString();
   answer.synced = false;
+  updateSyncUI("syncing");
   db.answers.put(answer).then(() => {
     triggerImmediateSync(exam_details, URLS);
   });

js/sync.js

@@ -119,8 +119,26 @@ export function initSync(exam_details, URLS) {
     clearInterval(syncInterval);
   }
 
-  // Set initial state
+  // Check if there are unsynced answers at startup
-  updateSyncUI("saved");
+  db.answers
+    .where({
+      aid: exam_details.aid,
+      cid: exam_details.cid,
+      eid: exam_details.eid,
+    })
+    .filter(ans => ans.synced === false)
+    .toArray()
+    .then(unsynced => {
+      if (unsynced && unsynced.length > 0) {
+        updateSyncUI("failed"); // Unsynced answers exist; they aren't accepted by server yet
+        performSync(exam_details, URLS);
+      } else {
+        updateSyncUI("saved");
+      }
+    })
+    .catch(() => {
+      updateSyncUI("saved");
+    });
 
   // Run periodic sync every 15 seconds
   syncInterval = setInterval(() => {