Feature: Receipt parse queue with background worker

Add ReceiptParseQueue (Channel-based singleton) and
ReceiptParseWorkerService (BackgroundService) for sequential receipt
parsing. Replaces fire-and-forget Task.Run with a proper queue.
ReceiptManager now enqueues uploaded receipts and supports bulk upload
via UploadManyUnmappedReceiptsAsync. Worker recovers pending items on
startup. Register IAIToolExecutor and IAIVisionClientResolver in DI.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

MoneyMap/Program.cs

@@ -2,6 +2,7 @@ using System.Globalization;
 using Microsoft.EntityFrameworkCore;
 using MoneyMap.Data;
 using MoneyMap.Services;
+using MoneyMap.Services.AITools;
 
 // Set default culture to en-US for currency formatting ($)
 var culture = new CultureInfo("en-US");
@@ -61,11 +62,17 @@ builder.Services.AddScoped<IReceiptManager, ReceiptManager>();
 builder.Services.AddScoped<IReceiptAutoMapper, ReceiptAutoMapper>();
 builder.Services.AddScoped<IPdfToImageConverter, PdfToImageConverter>();
 
-// AI vision clients
+// Receipt parse queue and background worker
+builder.Services.AddSingleton<IReceiptParseQueue, ReceiptParseQueue>();
+builder.Services.AddHostedService<ReceiptParseWorkerService>();
+
+// AI vision clients and tool-use support
 builder.Services.AddHttpClient<OpenAIVisionClient>();
 builder.Services.AddHttpClient<ClaudeVisionClient>();
 builder.Services.AddHttpClient<OllamaVisionClient>();
 builder.Services.AddHttpClient<LlamaCppVisionClient>();
+builder.Services.AddScoped<IAIVisionClientResolver, AIVisionClientResolver>();
+builder.Services.AddScoped<IAIToolExecutor, AIToolExecutor>();
 builder.Services.AddScoped<IReceiptParser, AIReceiptParser>();
 
 // AI categorization service

MoneyMap/Services/ReceiptManager.cs

@@ -10,6 +10,7 @@ namespace MoneyMap.Services
     {
         Task<ReceiptUploadResult> UploadReceiptAsync(long transactionId, IFormFile file);
         Task<ReceiptUploadResult> UploadUnmappedReceiptAsync(IFormFile file);
+        Task<BulkUploadResult> UploadManyUnmappedReceiptsAsync(IReadOnlyList<IFormFile> files);
         Task<bool> DeleteReceiptAsync(long receiptId);
         Task<bool> MapReceiptToTransactionAsync(long receiptId, long transactionId);
         Task<bool> UnmapReceiptAsync(long receiptId);
@@ -23,6 +24,7 @@ namespace MoneyMap.Services
         private readonly IWebHostEnvironment _environment;
         private readonly IConfiguration _configuration;
         private readonly IServiceProvider _serviceProvider;
+        private readonly IReceiptParseQueue _parseQueue;
         private readonly ILogger<ReceiptManager> _logger;
         private const long MaxFileSize = 10 * 1024 * 1024; // 10MB
         private static readonly string[] AllowedExtensions = { ".jpg", ".jpeg", ".png", ".pdf", ".gif", ".heic" };
@@ -47,12 +49,14 @@ namespace MoneyMap.Services
             IWebHostEnvironment environment,
             IConfiguration configuration,
             IServiceProvider serviceProvider,
+            IReceiptParseQueue parseQueue,
             ILogger<ReceiptManager> logger)
         {
             _db = db;
             _environment = environment;
             _configuration = configuration;
             _serviceProvider = serviceProvider;
+            _parseQueue = parseQueue;
             _logger = logger;
         }
 
@@ -147,28 +151,50 @@ namespace MoneyMap.Services
                 UploadedAtUtc = DateTime.UtcNow
             };
 
+            receipt.ParseStatus = ReceiptParseStatus.Queued;
             _db.Receipts.Add(receipt);
             await _db.SaveChangesAsync();
 
-            // Automatically parse the receipt after upload (in background, don't wait for result)
-            _ = Task.Run(async () =>
-            {
-                try
-                {
-                    using var scope = _serviceProvider.CreateScope();
-                    var parser = scope.ServiceProvider.GetRequiredService<IReceiptParser>();
-                    await parser.ParseReceiptAsync(receipt.Id);
-                    _logger.LogInformation("Background parsing completed for receipt {ReceiptId}", receipt.Id);
-                }
-                catch (Exception ex)
-                {
-                    _logger.LogError(ex, "Background parsing failed for receipt {ReceiptId}: {Message}", receipt.Id, ex.Message);
-                }
-            });
+            await _parseQueue.EnqueueAsync(receipt.Id);
+            _logger.LogInformation("Receipt {ReceiptId} enqueued for parsing", receipt.Id);
 
             return ReceiptUploadResult.Success(receipt, duplicateWarnings);
         }
 
+        public async Task<BulkUploadResult> UploadManyUnmappedReceiptsAsync(IReadOnlyList<IFormFile> files)
+        {
+            var uploaded = new List<BulkUploadItem>();
+            var failed = new List<BulkUploadFailure>();
+
+            foreach (var file in files)
+            {
+                var result = await UploadReceiptInternalAsync(file, null);
+                if (result.IsSuccess)
+                {
+                    uploaded.Add(new BulkUploadItem
+                    {
+                        ReceiptId = result.Receipt!.Id,
+                        FileName = result.Receipt.FileName,
+                        DuplicateWarnings = result.DuplicateWarnings
+                    });
+                }
+                else
+                {
+                    failed.Add(new BulkUploadFailure
+                    {
+                        FileName = file.FileName,
+                        ErrorMessage = result.ErrorMessage ?? "Unknown error"
+                    });
+                }
+            }
+
+            return new BulkUploadResult
+            {
+                Uploaded = uploaded,
+                Failed = failed
+            };
+        }
+
         private async Task<List<DuplicateWarning>> CheckForDuplicatesAsync(string fileHash, string fileName, long fileSize)
         {
             var warnings = new List<DuplicateWarning>();
@@ -361,4 +387,24 @@ namespace MoneyMap.Services
         public string? TransactionName { get; set; }
         public string Reason { get; set; } = "";
     }
+
+    public class BulkUploadResult
+    {
+        public List<BulkUploadItem> Uploaded { get; init; } = new();
+        public List<BulkUploadFailure> Failed { get; init; } = new();
+        public int TotalCount => Uploaded.Count + Failed.Count;
+    }
+
+    public class BulkUploadItem
+    {
+        public long ReceiptId { get; set; }
+        public string FileName { get; set; } = "";
+        public List<DuplicateWarning> DuplicateWarnings { get; set; } = new();
+    }
+
+    public class BulkUploadFailure
+    {
+        public string FileName { get; set; } = "";
+        public string ErrorMessage { get; set; } = "";
+    }
 }

MoneyMap/Services/ReceiptParseQueue.cs

@@ -0,0 +1,56 @@
+using System.Threading.Channels;
+
+namespace MoneyMap.Services
+{
+    public interface IReceiptParseQueue
+    {
+        ValueTask EnqueueAsync(long receiptId, CancellationToken ct = default);
+        ValueTask EnqueueManyAsync(IEnumerable<long> receiptIds, CancellationToken ct = default);
+        ValueTask<long> DequeueAsync(CancellationToken ct);
+        int QueueLength { get; }
+        long? CurrentlyProcessingId { get; }
+        void SetCurrentlyProcessing(long? receiptId);
+    }
+
+    public class ReceiptParseQueue : IReceiptParseQueue
+    {
+        private readonly Channel<long> _channel = Channel.CreateUnbounded<long>(
+            new UnboundedChannelOptions { SingleReader = true });
+
+        private long _currentlyProcessingId;
+
+        public int QueueLength => _channel.Reader.Count;
+
+        public long? CurrentlyProcessingId
+        {
+            get
+            {
+                var val = Interlocked.Read(ref _currentlyProcessingId);
+                return val == 0 ? null : val;
+            }
+        }
+
+        public void SetCurrentlyProcessing(long? receiptId)
+        {
+            Interlocked.Exchange(ref _currentlyProcessingId, receiptId ?? 0);
+        }
+
+        public async ValueTask EnqueueAsync(long receiptId, CancellationToken ct = default)
+        {
+            await _channel.Writer.WriteAsync(receiptId, ct);
+        }
+
+        public async ValueTask EnqueueManyAsync(IEnumerable<long> receiptIds, CancellationToken ct = default)
+        {
+            foreach (var id in receiptIds)
+            {
+                await _channel.Writer.WriteAsync(id, ct);
+            }
+        }
+
+        public async ValueTask<long> DequeueAsync(CancellationToken ct)
+        {
+            return await _channel.Reader.ReadAsync(ct);
+        }
+    }
+}

MoneyMap/Services/ReceiptParseWorkerService.cs

@@ -0,0 +1,129 @@
+using Microsoft.EntityFrameworkCore;
+using MoneyMap.Data;
+using MoneyMap.Models;
+
+namespace MoneyMap.Services
+{
+    public class ReceiptParseWorkerService : BackgroundService
+    {
+        private readonly IReceiptParseQueue _queue;
+        private readonly IServiceScopeFactory _scopeFactory;
+        private readonly ILogger<ReceiptParseWorkerService> _logger;
+
+        public ReceiptParseWorkerService(
+            IReceiptParseQueue queue,
+            IServiceScopeFactory scopeFactory,
+            ILogger<ReceiptParseWorkerService> logger)
+        {
+            _queue = queue;
+            _scopeFactory = scopeFactory;
+            _logger = logger;
+        }
+
+        protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+        {
+            _logger.LogInformation("ReceiptParseWorkerService starting");
+
+            await RecoverPendingItemsAsync(stoppingToken);
+
+            while (!stoppingToken.IsCancellationRequested)
+            {
+                long receiptId = 0;
+                try
+                {
+                    receiptId = await _queue.DequeueAsync(stoppingToken);
+                    _queue.SetCurrentlyProcessing(receiptId);
+
+                    await SetParseStatusAsync(receiptId, ReceiptParseStatus.Parsing);
+
+                    _logger.LogInformation("Processing receipt {ReceiptId} from parse queue", receiptId);
+
+                    using var scope = _scopeFactory.CreateScope();
+                    var parser = scope.ServiceProvider.GetRequiredService<IReceiptParser>();
+                    var result = await parser.ParseReceiptAsync(receiptId);
+
+                    var finalStatus = result.IsSuccess
+                        ? ReceiptParseStatus.Completed
+                        : ReceiptParseStatus.Failed;
+
+                    await SetParseStatusAsync(receiptId, finalStatus);
+
+                    _logger.LogInformation(
+                        "Receipt {ReceiptId} parse {Status}: {Message}",
+                        receiptId, finalStatus, result.Message);
+                }
+                catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+                {
+                    break;
+                }
+                catch (Exception ex)
+                {
+                    _logger.LogError(ex, "Error processing receipt {ReceiptId} from parse queue", receiptId);
+
+                    if (receiptId > 0)
+                    {
+                        try
+                        {
+                            await SetParseStatusAsync(receiptId, ReceiptParseStatus.Failed);
+                        }
+                        catch (Exception statusEx)
+                        {
+                            _logger.LogError(statusEx, "Failed to update ParseStatus to Failed for receipt {ReceiptId}", receiptId);
+                        }
+                    }
+                }
+                finally
+                {
+                    _queue.SetCurrentlyProcessing(null);
+                }
+            }
+
+            _logger.LogInformation("ReceiptParseWorkerService stopping");
+        }
+
+        private async Task RecoverPendingItemsAsync(CancellationToken ct)
+        {
+            try
+            {
+                using var scope = _scopeFactory.CreateScope();
+                var db = scope.ServiceProvider.GetRequiredService<MoneyMapContext>();
+
+                var pendingIds = await db.Receipts
+                    .Where(r => r.ParseStatus == ReceiptParseStatus.Queued
+                             || r.ParseStatus == ReceiptParseStatus.Parsing)
+                    .OrderBy(r => r.UploadedAtUtc)
+                    .Select(r => r.Id)
+                    .ToListAsync(ct);
+
+                if (pendingIds.Count > 0)
+                {
+                    _logger.LogInformation(
+                        "Recovering {Count} receipts with pending parse status", pendingIds.Count);
+
+                    foreach (var id in pendingIds)
+                    {
+                        await db.Receipts
+                            .Where(r => r.Id == id)
+                            .ExecuteUpdateAsync(s => s.SetProperty(r => r.ParseStatus, ReceiptParseStatus.Queued), ct);
+                    }
+
+                    await _queue.EnqueueManyAsync(pendingIds, ct);
+                }
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Error recovering pending parse items on startup");
+            }
+        }
+
+        private async Task SetParseStatusAsync(long receiptId, ReceiptParseStatus status)
+        {
+            using var scope = _scopeFactory.CreateScope();
+            var db = scope.ServiceProvider.GetRequiredService<MoneyMapContext>();
+
+            await db.Receipts
+                .Where(r => r.Id == receiptId)
+                .ExecuteUpdateAsync(s => s.SetProperty(r => r.ParseStatus, status));
+        }
+    }
+}