fix(infra): don't advance account cursor unless all transactions proceed successfully

src/FiscalOS.Infra/Transactions/Plaid/PlaidAddedTransactionHandler.cs

@@ -5,50 +5,102 @@ namespace FiscalOS.Infra.Transactions.Plaid;
 
 internal interface IPlaidAddedTransactionHandler
 {
-  void Handle(Account account, IEnumerable<Going.Plaid.Entity.Transaction> added);
+  Task<int> HandleAsync(
+    Account account,
+    IEnumerable<Going.Plaid.Entity.Transaction> added,
+    CancellationToken ct
+  );
 }
 
 internal sealed class PlaidAddedTransactionHandler : IPlaidAddedTransactionHandler
 {
   private readonly ILogger<PlaidAddedTransactionHandler> _logger;
+  private readonly AppDbContext _appDbContext;
 
-  private PlaidAddedTransactionHandler(ILogger<PlaidAddedTransactionHandler> logger)
+  private PlaidAddedTransactionHandler(
+    ILogger<PlaidAddedTransactionHandler> logger,
+    AppDbContext appDbContext
+  )
   {
     _logger = logger;
+    _appDbContext = appDbContext;
   }
 
   public static PlaidAddedTransactionHandler From(IServiceProvider serviceProvider)
   {
     return new(
-      serviceProvider.GetRequiredService<ILogger<PlaidAddedTransactionHandler>>()
+      serviceProvider.GetRequiredService<ILogger<PlaidAddedTransactionHandler>>(),
+      serviceProvider.GetRequiredService<AppDbContext>()
     );
   }
 
-  public void Handle(Account account, IEnumerable<Going.Plaid.Entity.Transaction> added)
+  public async Task<int> HandleAsync(Account account, IEnumerable<Going.Plaid.Entity.Transaction> added, CancellationToken ct)
   {
+    var existingTransactionIds = added.Select(t => t.TransactionId);
+    var existingTransactions = await _appDbContext.Transactions
+      .Where(t => t.Metadata is PlaidTransactionMetadata && existingTransactionIds.Contains(((PlaidTransactionMetadata)t.Metadata).PlaidId))
+      .ToListAsync(ct)
+      .ConfigureAwait(false);
+
+    var addedCount = 0;
+
     foreach (var addedTransaction in added)
     {
-      if (addedTransaction.Pending.GetValueOrDefault())
+      try
       {
-        _logger.LogInformation(
-          "Skipping pending transaction {TransactionId} for account {AccountId} as it has not been posted yet",
-          addedTransaction.TransactionId,
-          account.Id
-        );
-        continue;
-      }
+        if (addedTransaction.Pending.GetValueOrDefault())
+        {
+          _logger.LogInformation(
+            "Skipping pending transaction {TransactionId} for account {AccountId} as it has not been posted yet",
+            addedTransaction.TransactionId,
+            account.Id
+          );
+          addedCount++;
+          continue;
+        }
 
-      var transactionMetadata = PlaidTransactionMetadata.From(addedTransaction.TransactionId);
-      var transaction = Transaction.From(
-        account.UserId,
-        account.Id,
-        addedTransaction.MerchantName,
-        addedTransaction.Description,
-        addedTransaction.Amount,
-        addedTransaction.PostedDate,
-        transactionMetadata
-      );
-      account.AddTransaction(transaction);
+        var existingTransaction = existingTransactions.FirstOrDefault(
+          t => t.Metadata is PlaidTransactionMetadata metadata && metadata.PlaidId == addedTransaction.TransactionId
+        );
+
+        if (existingTransaction is not null)
+        {
+          _logger.LogInformation(
+            "Skipping added transaction {PlaidTransactionId} for account {AccountId} as it has already been added as transaction {TransactionId}",
+            addedTransaction.TransactionId,
+            account.Id,
+            existingTransaction.Id
+          );
+          addedCount++;
+          continue;
+        }
+
+        var transactionMetadata = PlaidTransactionMetadata.From(addedTransaction.TransactionId);
+        var transaction = Transaction.From(
+          account.UserId,
+          account.Id,
+          addedTransaction.Merchant,
+          addedTransaction.Description,
+          addedTransaction.Amount,
+          addedTransaction.PostedDate,
+          transactionMetadata
+        );
+        account.AddTransaction(transaction);
+        addedCount++;
+      }
+      catch (Exception ex)
+      {
+        _logger.LogError(
+          ex,
+          "Failed to added transaction {PlaidTransactionId} to account {AccountId}",
+          account.Id,
+          addedTransaction.TransactionId
+        );
+      }
     }
+
+    _logger.LogInformation("Added {AddedCount} transactions to account {AccountId}", addedCount, account.Id);
+
+    return addedCount;
   }
 }