feat: skip QSOs with unchanged confirmation data

When syncing from LoTW/DCL, only update QSOs if confirmation data
has changed. This avoids unnecessary database updates and makes it
clear which QSOs actually changed.

- LoTW: Checks if lotwQslRstatus or lotwQslRdate changed
- DCL: Checks if dclQslRstatus, dclQslRdate, DOK, or grid changed
- Frontend: Shows skipped count in sync summary

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/backend/services/dcl.service.js

@@ -192,6 +192,7 @@ export async function syncQSOs(userId, dclApiKey, sinceDate = null, jobId = null
 
     let addedCount = 0;
     let updatedCount = 0;
+    let skippedCount = 0;
     const errors = [];
     const addedQSOs = [];
     const updatedQSOs = [];
@@ -219,26 +220,41 @@ export async function syncQSOs(userId, dclApiKey, sinceDate = null, jobId = null
           .limit(1);
 
         if (existing.length > 0) {
-          // Update existing QSO with DCL confirmation and DOK data
+          const existingQSO = existing[0];
-          await db
+
-            .update(qsos)
+          // Check if DCL confirmation or DOK data has changed
-            .set({
+          const dataChanged =
-              dclQslRdate: dbQSO.dclQslRdate,
+            existingQSO.dclQslRstatus !== dbQSO.dclQslRstatus ||
-              dclQslRstatus: dbQSO.dclQslRstatus,
+            existingQSO.dclQslRdate !== dbQSO.dclQslRdate ||
-              darcDok: dbQSO.darcDok || existing[0].darcDok,
+            existingQSO.darcDok !== (dbQSO.darcDok || existingQSO.darcDok) ||
-              myDarcDok: dbQSO.myDarcDok || existing[0].myDarcDok,
+            existingQSO.myDarcDok !== (dbQSO.myDarcDok || existingQSO.myDarcDok) ||
-              grid: dbQSO.grid || existing[0].grid,
+            existingQSO.grid !== (dbQSO.grid || existingQSO.grid);
-              gridSource: dbQSO.gridSource || existing[0].gridSource,
+
-            })
+          if (dataChanged) {
-            .where(eq(qsos.id, existing[0].id));
+            // Update existing QSO with changed DCL confirmation and DOK data
-          updatedCount++;
+            await db
-          // Track updated QSO (CALL and DATE)
+              .update(qsos)
-          updatedQSOs.push({
+              .set({
-            callsign: dbQSO.callsign,
+                dclQslRdate: dbQSO.dclQslRdate,
-            date: dbQSO.qsoDate,
+                dclQslRstatus: dbQSO.dclQslRstatus,
-            band: dbQSO.band,
+                darcDok: dbQSO.darcDok || existingQSO.darcDok,
-            mode: dbQSO.mode,
+                myDarcDok: dbQSO.myDarcDok || existingQSO.myDarcDok,
-          });
+                grid: dbQSO.grid || existingQSO.grid,
+                gridSource: dbQSO.gridSource || existingQSO.gridSource,
+              })
+              .where(eq(qsos.id, existingQSO.id));
+            updatedCount++;
+            // Track updated QSO (CALL and DATE)
+            updatedQSOs.push({
+              callsign: dbQSO.callsign,
+              date: dbQSO.qsoDate,
+              band: dbQSO.band,
+              mode: dbQSO.mode,
+            });
+          } else {
+            // Skip - same data
+            skippedCount++;
+          }
         } else {
           // Insert new QSO
           await db.insert(qsos).values(dbQSO);
@@ -274,6 +290,7 @@ export async function syncQSOs(userId, dclApiKey, sinceDate = null, jobId = null
       total: adifQSOs.length,
       added: addedCount,
       updated: updatedCount,
+      skipped: skippedCount,
       addedQSOs,
       updatedQSOs,
       confirmed: adifQSOs.filter(q => q.dcl_qsl_rcvd === 'Y').length,

src/backend/services/lotw.service.js

@@ -222,6 +222,7 @@ export async function syncQSOs(userId, lotwUsername, lotwPassword, sinceDate = n
 
   let addedCount = 0;
   let updatedCount = 0;
+  let skippedCount = 0;
   const errors = [];
   const addedQSOs = [];
   const updatedQSOs = [];
@@ -247,22 +248,34 @@ export async function syncQSOs(userId, lotwUsername, lotwPassword, sinceDate = n
         .limit(1);
 
       if (existing.length > 0) {
-        await db
+        const existingQSO = existing[0];
-          .update(qsos)
+
-          .set({
+        // Check if LoTW confirmation data has changed
-            lotwQslRdate: dbQSO.lotwQslRdate,
+        const confirmationChanged =
-            lotwQslRstatus: dbQSO.lotwQslRstatus,
+          existingQSO.lotwQslRstatus !== dbQSO.lotwQslRstatus ||
-            lotwSyncedAt: dbQSO.lotwSyncedAt,
+          existingQSO.lotwQslRdate !== dbQSO.lotwQslRdate;
-          })
+
-          .where(eq(qsos.id, existing[0].id));
+        if (confirmationChanged) {
-        updatedCount++;
+          await db
-        // Track updated QSO (CALL and DATE)
+            .update(qsos)
-        updatedQSOs.push({
+            .set({
-          callsign: dbQSO.callsign,
+              lotwQslRdate: dbQSO.lotwQslRdate,
-          date: dbQSO.qsoDate,
+              lotwQslRstatus: dbQSO.lotwQslRstatus,
-          band: dbQSO.band,
+              lotwSyncedAt: dbQSO.lotwSyncedAt,
-          mode: dbQSO.mode,
+            })
-        });
+            .where(eq(qsos.id, existingQSO.id));
+          updatedCount++;
+          // Track updated QSO (CALL and DATE)
+          updatedQSOs.push({
+            callsign: dbQSO.callsign,
+            date: dbQSO.qsoDate,
+            band: dbQSO.band,
+            mode: dbQSO.mode,
+          });
+        } else {
+          // Skip - same data
+          skippedCount++;
+        }
       } else {
         await db.insert(qsos).values(dbQSO);
         addedCount++;
@@ -288,13 +301,14 @@ export async function syncQSOs(userId, lotwUsername, lotwPassword, sinceDate = n
     }
   }
 
-  logger.info('LoTW sync completed', { total: adifQSOs.length, added: addedCount, updated: updatedCount, jobId });
+  logger.info('LoTW sync completed', { total: adifQSOs.length, added: addedCount, updated: updatedCount, skipped: skippedCount, jobId });
 
   return {
     success: true,
     total: adifQSOs.length,
     added: addedCount,
     updated: updatedCount,
+    skipped: skippedCount,
     addedQSOs,
     updatedQSOs,
     errors: errors.length > 0 ? errors : undefined,

src/frontend/src/routes/qsos/+page.svelte

@@ -296,7 +296,12 @@
     <div class="alert {syncResult.success ? 'alert-success' : 'alert-error'}">
       {#if syncResult.success}
         <h3>Sync Complete!</h3>
-        <p>Total: {syncResult.total}, Added: {syncResult.added}, Updated: {syncResult.updated}</p>
+        <p>
+          Total: {syncResult.total},
+          Added: {syncResult.added},
+          Updated: {syncResult.updated || 0},
+          Skipped: {syncResult.skipped || 0}
+        </p>
         {#if syncResult.errors && syncResult.errors.length > 0}
           <p class="text-small">Some QSOs had errors</p>
         {/if}