Fix product repo not returning a valid object, add query

src/Printbase.WebApi/Controllers/ProductVariantsController.cs

@@ -2,6 +2,7 @@ using MediatR;
 using Microsoft.AspNetCore.Mvc;
 using Printbase.Application.Products.Commands;
 using Printbase.Application.Products.Dtos;
+using Printbase.Application.Products.Queries;
 
 namespace Printbase.WebApi.Controllers;
 
@@ -9,6 +10,23 @@ namespace Printbase.WebApi.Controllers;
 [Route("api/[controller]")]
 public class ProductVariantsController(IMediator mediator) : ControllerBase
 {
+    [HttpGet]
+    public async Task<ActionResult<IEnumerable<ProductVariantDto>>> GetProductVariants(
+        [FromQuery] Guid? productId = null,
+        [FromQuery] bool? isActive = null,
+        [FromQuery] bool inStockOnly = false)
+    {
+        var query = new GetProductVariantsQuery
+        {
+            ProductId = productId,
+            IsActive = isActive,
+            InStockOnly = inStockOnly
+        };
+        
+        var result = await mediator.Send(query);
+        return Ok(result);
+    }
+    
     [HttpPost]
     public async Task<ActionResult<ProductVariantDto>> CreateProductVariant([FromBody] CreateProductVariantCommand command)
     {
@@ -16,7 +34,7 @@ public class ProductVariantsController(IMediator mediator) : ControllerBase
         return CreatedAtAction(nameof(CreateProductVariant), new { id = result.Id }, result);
     }
 
-    [HttpDelete("{id}")]
+    [HttpDelete("{id:guid}")]
     public async Task<ActionResult> DeleteProductVariant(Guid id)
     {
         var command = new DeleteProductVariantCommand { Id = id };