feat(inventory-service): add shopId filter to transactions endpoint

BFF needs to query inventory transactions by shopId. The existing
endpoint only supported inventoryItemId. Now accepts either shopId
or inventoryItemId as query parameters.

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

services/inventory-service-net/src/InventoryService.API/Application/Queries/InventoryQueries.cs

@@ -32,6 +32,15 @@ public record GetTransactionsQuery(
     int Skip = 0,
     int Take = 50) : IRequest<PagedResult<InventoryTransactionDto>>;
 
+/// <summary>
+/// EN: Query to get transactions for a shop.
+/// VI: Query lấy transactions cho một shop.
+/// </summary>
+public record GetTransactionsByShopQuery(
+    Guid ShopId,
+    int Skip = 0,
+    int Take = 50) : IRequest<PagedResult<InventoryTransactionDto>>;
+
 /// <summary>
 /// EN: Query to get low stock items.
 /// VI: Query lấy các items stock thấp.

services/inventory-service-net/src/InventoryService.API/Application/Queries/InventoryQueryHandlers.cs

@@ -95,6 +95,36 @@ public class GetTransactionsQueryHandler
     }
 }
 
+/// <summary>
+/// EN: Handler for GetTransactionsByShopQuery.
+/// VI: Handler cho GetTransactionsByShopQuery.
+/// </summary>
+public class GetTransactionsByShopQueryHandler
+    : IRequestHandler<GetTransactionsByShopQuery, PagedResult<InventoryTransactionDto>>
+{
+    private readonly IInventoryRepository _repository;
+
+    public GetTransactionsByShopQueryHandler(IInventoryRepository repository)
+    {
+        _repository = repository;
+    }
+
+    public async Task<PagedResult<InventoryTransactionDto>> Handle(
+        GetTransactionsByShopQuery request,
+        CancellationToken ct)
+    {
+        var (transactions, total) = await _repository.GetTransactionsByShopAsync(
+            request.ShopId,
+            request.Skip,
+            request.Take,
+            ct);
+
+        var dtos = transactions.Select(t => t.ToDto()).ToList();
+
+        return new PagedResult<InventoryTransactionDto>(dtos, total);
+    }
+}
+
 /// <summary>
 /// EN: Handler for GetLowStockItemsQuery.
 /// VI: Handler cho GetLowStockItemsQuery.

services/inventory-service-net/src/InventoryService.API/Controllers/InventoryController.cs

@@ -251,23 +251,31 @@ public class InventoryController : ControllerBase
     }
 
     /// <summary>
-    /// EN: Get transaction history for inventory item.
-    /// VI: Lấy lịch sử transactions cho inventory item.
+    /// EN: Get transaction history by inventory item ID or shop ID.
+    /// VI: Lấy lịch sử transactions theo inventory item ID hoặc shop ID.
     /// </summary>
     [HttpGet("transactions")]
-    [SwaggerOperation(Summary = "Get transaction history")]
+    [SwaggerOperation(Summary = "Get transaction history by item or shop")]
     [SwaggerResponse(200, "Transactions retrieved successfully")]
     [SwaggerResponse(400, "Invalid request")]
     public async Task<ActionResult<ApiResponse<PagedResult<InventoryTransactionDto>>>> GetTransactions(
-        [FromQuery] Guid inventoryItemId,
+        [FromQuery] Guid? inventoryItemId = null,
+        [FromQuery] Guid? shopId = null,
         [FromQuery] int skip = 0,
         [FromQuery] int take = 50,
         CancellationToken ct = default)
     {
-        if (inventoryItemId == Guid.Empty)
-            return BadRequest(ApiResponse<PagedResult<InventoryTransactionDto>>.Fail("Inventory item ID is required"));
+        if (shopId.HasValue && shopId.Value != Guid.Empty)
+        {
+            var shopQuery = new GetTransactionsByShopQuery(shopId.Value, skip, take);
+            var shopResult = await _mediator.Send(shopQuery, ct);
+            return Ok(ApiResponse<PagedResult<InventoryTransactionDto>>.Ok(shopResult));
+        }
 
-        var query = new GetTransactionsQuery(inventoryItemId, skip, take);
+        if (!inventoryItemId.HasValue || inventoryItemId.Value == Guid.Empty)
+            return BadRequest(ApiResponse<PagedResult<InventoryTransactionDto>>.Fail("Either shopId or inventoryItemId is required"));
+
+        var query = new GetTransactionsQuery(inventoryItemId.Value, skip, take);
         var result = await _mediator.Send(query, ct);
 
         return Ok(ApiResponse<PagedResult<InventoryTransactionDto>>.Ok(result));

services/inventory-service-net/src/InventoryService.Domain/AggregatesModel/InventoryAggregate/IInventoryRepository.cs

@@ -77,6 +77,16 @@ public interface IInventoryRepository : IRepository<InventoryItem>
         int take = 50, 
         CancellationToken cancellationToken = default);
 
+    /// <summary>
+    /// EN: Get all transactions for a shop with pagination.
+    /// VI: Lấy tất cả transactions cho một shop với phân trang.
+    /// </summary>
+    Task<(IReadOnlyList<InventoryTransaction> Transactions, int Total)> GetTransactionsByShopAsync(
+        Guid shopId,
+        int skip = 0,
+        int take = 50,
+        CancellationToken cancellationToken = default);
+
     /// <summary>
     /// EN: Add inventory item asynchronously.
     /// VI: Thêm inventory item bất đồng bộ.

services/inventory-service-net/src/InventoryService.Infrastructure/Repositories/InventoryRepository.cs

@@ -110,6 +110,28 @@ public class InventoryRepository : IInventoryRepository
         return (items, total);
     }
 
+    public async Task<(IReadOnlyList<InventoryTransaction> Transactions, int Total)> GetTransactionsByShopAsync(
+        Guid shopId,
+        int skip = 0,
+        int take = 50,
+        CancellationToken cancellationToken = default)
+    {
+        var items = await _context.InventoryItems
+            .Include(i => i.Transactions)
+            .Where(i => i.ShopId == shopId)
+            .ToListAsync(cancellationToken);
+
+        var allTransactions = items
+            .SelectMany(i => i.Transactions)
+            .OrderByDescending(t => t.CreatedAt)
+            .ToList();
+
+        var total = allTransactions.Count;
+        var paged = allTransactions.Skip(skip).Take(take).ToList();
+
+        return (paged, total);
+    }
+
     public async Task<InventoryItem> AddAsync(InventoryItem item, CancellationToken cancellationToken = default)
     {
         var entity = await _context.InventoryItems.AddAsync(item, cancellationToken);