Controllers – Get

[Route("api/[controller]")]
[ApiController]
public class ProductsController : ControllerBase
{
    private readonly IProductsRepository _productRepository;

    public ProductsController(IProductsRepository productRepository) {
        _productRepository = productRepository;
    }

    [HttpGet]
    public async Task<ActionResult<List<Product>>> Get() {
        var result = await _productRepository.GetAllProducts();
        return Ok(result);
    }
}

public interface IProductsRepository
{
    Task<List<Product>> GetAllProducts();
    Task<Product> GetProductById(int id);
}

[HttpGet("{id}")]
[ProducesResponseType(200, Type = typeof(Product))]
[ProducesResponseType(404)]
public async Task<ActionResult<Product>> GetById(int id) {
    var result = await _productRepository.GetProductById(id);
    return Ok(result);
}

Task<Product?> GetProductById(int id);

[HttpGet("{id}")]
[ProducesResponseType(200, Type = typeof(Product))]
[ProducesResponseType(404)]
public async Task<ActionResult<Product>> GetById(int id) {
    var result = await _productRepository.GetProductById(id);
    if(result == null) {
        return NotFound();
    } else {
        return Ok(result);
    }  
}

public class ProductsRepository : IProductsRepository
{
    private readonly List<Product> _products = new List<Product>();
    public ProductsRepository() {
        _products.Add(new Product 
        {
                id = 1,
                name = "ASUS Computer",
                description = "Best computer",
                price = 2400,
                amount = 4,
                producer = "Asus"
        });
    }
    public async Task<List<Product>> GetAllProducts() {
        await Task.Delay(1000);
        return _products;
    }

    public async Task<Product?> GetProductById(int id) {
        await Task.Delay(500);
        var item = this._products.FirstOrDefault(x => x.id == id);
        if(item == null) {
            return null;
        }
        return item;
    }
}