Add two basic CQRS commands/queries

src/Printbase.WebApi/Controllers/ProductsController.cs

@@ -0,0 +1,50 @@
+using MediatR;
+using Microsoft.AspNetCore.Mvc;
+using Printbase.Application.Products.Commands.CreateProduct;
+using Printbase.Application.Products.Queries;
+
+namespace Printbase.WebApi.Controllers;
+
+[ApiController]
+[Route("api/[controller]")]
+public class ProductsController(IMediator mediator) : ControllerBase
+{
+    private readonly IMediator _mediator = mediator ?? throw new ArgumentNullException(nameof(mediator));
+
+    [HttpGet("{id}")]
+    [ProducesResponseType(StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    public async Task<IActionResult> GetProductById(Guid id, [FromQuery] bool includeVariants = true)
+    {
+        var query = new GetProductByIdQuery(id, includeVariants);
+        var result = await _mediator.Send(query);
+
+        if (result == null)
+        {
+            return NotFound();
+        }
+
+        return Ok(result);
+    }
+
+    [HttpPost]
+    [ProducesResponseType(StatusCodes.Status201Created)]
+    [ProducesResponseType(StatusCodes.Status400BadRequest)]
+    public async Task<IActionResult> CreateProduct([FromBody] CreateProductCommand command)
+    {
+        if (!ModelState.IsValid)
+        {
+            return BadRequest(ModelState);
+        }
+
+        try
+        {
+            var result = await _mediator.Send(command);
+            return CreatedAtAction(nameof(GetProductById), new { id = result.Id }, result);
+        }
+        catch (ArgumentException ex)
+        {
+            return BadRequest(ex.Message);
+        }
+    }
+}