Improve check for duplicates

apps/api/src/app/import/import.service.ts

@@ -326,7 +326,8 @@ export class ImportService {
     }
 
     if (!isDryRun && accountsWithBalancesDto?.length) {
-      const [existingAccounts, existingPlatforms] = await Promise.all([
+      const [existingAccounts, existingAccountsOfUser, existingPlatforms] =
+        await Promise.all([
           this.accountService.accounts({
             where: {
               id: {
@@ -336,6 +337,9 @@ export class ImportService {
               }
             }
           }),
+          this.accountService.accounts({
+            where: { userId: user.id }
+          }),
           this.platformService.getPlatforms()
         ]);
 
@@ -351,8 +355,28 @@ export class ImportService {
           return existingAccount.id === accountWithBalances.id;
         });
 
-        // If there is no account or if the account belongs to a different user then create a new account
+        // If there is no account or if the account belongs to a different
+        // user, then reuse an existing account of the user with the same name
+        // or create a new account
         if (!accountWithSameId || accountWithSameId.userId !== user.id) {
+          // Check if the user has an account with the same name
+          const accountWithSameNameOfUser = existingAccountsOfUser.find(
+            ({ name }) => {
+              return name === accountWithBalances.name;
+            }
+          );
+
+          if (accountWithSameNameOfUser) {
+            // Reuse the account of the user instead of creating a duplicate
+            if (
+              accountWithBalances.id &&
+              accountWithBalances.id !== accountWithSameNameOfUser.id
+            ) {
+              // Store the new to old account ID mappings for updating activities
+              accountIdMapping[accountWithBalances.id] =
+                accountWithSameNameOfUser.id;
+            }
+          } else {
             const account = omit(accountWithBalances, [
               'balances',
               'isExcluded',
@@ -420,6 +444,7 @@ export class ImportService {
           }
         }
       }
+    }
 
     if (assetProfilesWithMarketDataDto?.length) {
       const customAssetProfileNames = assetProfilesWithMarketDataDto
@@ -823,10 +848,10 @@ export class ImportService {
         unitPrice
       }) => {
         const date = parseISO(dateString);
+
         const isDuplicate = existingActivities.some((activity) => {
           return (
-            activity.accountId === accountId &&
-            activity.comment === comment &&
+            (activity.comment ?? null) === (comment ?? null) &&
             (activity.currency === currency ||
               activity.assetProfile.currency === currency) &&
             activity.assetProfile.dataSource === dataSource &&