Added support for resubmitting the DLQ messages

Author: kyurkchyan

README.md

@@ -18,6 +18,7 @@ dotnet build
 | Command | Description |
 |---------|-------------|
 | [purge-dlq](docs/purge-dlq.md) | Purge messages from a dead letter queue |
+| [resubmit-dlq](docs/resubmit-dlq.md) | Resubmit messages from a dead letter queue back to the main queue |
 
 ## Quick Start
 
@@ -27,6 +28,12 @@ dotnet run -- purge-dlq -n mynamespace.servicebus.windows.net -q myqueue
 
 # Interactive mode - select which message categories to purge
 dotnet run -- purge-dlq -n mynamespace.servicebus.windows.net -q myqueue -i
+
+# Resubmit DLQ messages back to the main queue
+dotnet run -- resubmit-dlq -n mynamespace.servicebus.windows.net -q myqueue
+
+# Interactive mode - select which message categories to resubmit
+dotnet run -- resubmit-dlq -n mynamespace.servicebus.windows.net -q myqueue -i
 ```
 
 ## Authentication

ServiceBusToolset/Commands/PurgeDlqCommand.cs

@@ -1,18 +1,20 @@
 using Azure.Identity;
 using Azure.Messaging.ServiceBus;
+using ServiceBusToolset.Models;
 using ServiceBusToolset.Options;
 using ServiceBusToolset.Services;
 
 namespace ServiceBusToolset.Commands;
 
-public class PurgeDlqCommand(IServiceBusClientFactory clientFactory, IConsoleOutput output) : BaseCommand<PurgeDlqOptions>(clientFactory, output), ICommand<PurgeDlqOptions>
+public class PurgeDlqCommand(
+    IServiceBusClientFactory clientFactory,
+    IConsoleOutput output,
+    IDlqCategoryAnalyzer categoryAnalyzer) : BaseCommand<PurgeDlqOptions>(clientFactory, output), ICommand<PurgeDlqOptions>
 {
     private const int MaxBatchSize = 100;
     private static readonly TimeSpan MaxWaitTime = TimeSpan.FromSeconds(5);
     private const int EmptyBatchThreshold = 3;
 
-    private record DlqCategory(string Label, string DeadLetterReason, int Count);
-
     public async Task<int> ExecuteAsync(PurgeDlqOptions options, CancellationToken cancellationToken = default)
     {
         var validationError = options.Validate();
@@ -275,7 +277,13 @@ private async Task<int> ExecuteInteractivePurgeAsync(
         Output.Info($"Analyzing DLQ for {entityDescription}...");
 
         // Step 1: Peek all messages and build category dictionary
-        var categories = await BuildCategoryListAsync(client, options, cancellationToken);
+        var categories = await categoryAnalyzer.AnalyzeCategoriesAsync(
+            client,
+            options.Queue,
+            options.Topic,
+            options.Subscription,
+            Output,
+            cancellationToken);
 
         if (categories.Count == 0)
         {
@@ -323,63 +331,6 @@ private async Task<int> ExecuteInteractivePurgeAsync(
         return 0;
     }
 
-    private async Task<List<DlqCategory>> BuildCategoryListAsync(
-        ServiceBusClient client,
-        PurgeDlqOptions options,
-        CancellationToken cancellationToken)
-    {
-        await using var receiver = CreateDlqReceiver(client,
-                                                     options.Queue,
-                                                     options.Topic,
-                                                     options.Subscription,
-                                                     ServiceBusReceiveMode.PeekLock);
-
-        var categoryCounts = new Dictionary<(string Label, string Reason), int>();
-        var totalPeeked = 0;
-        long? fromSequenceNumber = null;
-
-        while (!cancellationToken.IsCancellationRequested)
-        {
-            IReadOnlyList<ServiceBusReceivedMessage> messages;
-
-            if (fromSequenceNumber.HasValue)
-            {
-                messages = await receiver.PeekMessagesAsync(MaxBatchSize, fromSequenceNumber.Value, cancellationToken);
-            }
-            else
-            {
-                messages = await receiver.PeekMessagesAsync(MaxBatchSize, cancellationToken: cancellationToken);
-            }
-
-            if (messages.Count == 0)
-            {
-                break;
-            }
-
-            foreach (var msg in messages)
-            {
-                var label = msg.Subject ?? "(none)";
-                var reason = msg.DeadLetterReason ?? "(none)";
-                var key = (label, reason);
-
-                var count = categoryCounts.GetValueOrDefault(key, 0);
-                categoryCounts[key] = count + 1;
-            }
-
-            totalPeeked += messages.Count;
-            fromSequenceNumber = messages[^1].SequenceNumber + 1;
-
-            Output.Progress($"Peeked {totalPeeked} messages...");
-        }
-
-        Console.WriteLine();
-
-        return categoryCounts
-            .OrderByDescending(kvp => kvp.Value)
-            .Select(kvp => new DlqCategory(kvp.Key.Label, kvp.Key.Reason, kvp.Value))
-            .ToList();
-    }
-
     private void DisplayCategoryTable(IReadOnlyCollection<DlqCategory> categories)
     {
         Output.Info("");