OrdersController.cs

namespace Comanda.Orchestrator.WebApi.Controllers;

[ApiController]
[Route("api/v1/orders")]
public sealed class OrdersController(IDispatcher dispatcher) : ControllerBase
{
    [HttpGet]
    [Authorize(Roles = Permissions.ViewOrders)]
    public async Task<IActionResult> GetOrdersAsync([FromQuery] OrdersFetchParameters request, CancellationToken cancellation)
    {
        var result = await dispatcher.DispatchAsync(request, cancellation);

        /* applies pagination navigation links according to RFC 8288 (web linking) */
        /* https://datatracker.ietf.org/doc/html/rfc8288 */
        if (result.IsSuccess && result.Data is not null)
        {
            Response.WithPagination(result.Data);
            Response.WithWebLinking(result.Data, Request);
        }

        return result switch
        {
            { IsSuccess: true } when result.Data is not null =>
                StatusCode(StatusCodes.Status200OK, result.Data.Items),

            { IsFailure: true } when result.Error == CommonErrors.OperationFailed =>
                StatusCode(StatusCodes.Status500InternalServerError, result.Error),

            { IsFailure: true } when result.Error == CommonErrors.RateLimitExceeded =>
                StatusCode(StatusCodes.Status429TooManyRequests, result.Error),
        };
    }

    [HttpPost]
    [Idempotent] // https://developer.mozilla.org/en-US/docs/Glossary/Idempotent
    [Authorize(Roles = Permissions.CreateOrder)]
    public async Task<IActionResult> CreateOrderAsync([FromBody] OrderCreationScheme request, CancellationToken cancellation)
    {
        var result = await dispatcher.DispatchAsync(request, cancellation);

        /* appends resource location header according to RFC 9110 (HTTP Semantics) */
        /* https://www.rfc-editor.org/rfc/rfc9110.html */
        if (result.IsSuccess && result.Data is not null)
        {
            Response.WithResourceLocation(Request, result.Data.Identifier);
        }

        return result switch
        {
            { IsSuccess: true } when result.Data is not null =>
                StatusCode(StatusCodes.Status201Created, result.Data),

            { IsFailure: true } when result.Error == CommonErrors.OperationFailed =>
                StatusCode(StatusCodes.Status500InternalServerError, result.Error),

            { IsFailure: true } when result.Error == CommonErrors.RateLimitExceeded =>
                StatusCode(StatusCodes.Status429TooManyRequests, result.Error),
        };
    }

    [HttpPut("{id}")]
    [Authorize(Roles = Permissions.UpdateOrder)]
    public async Task<IActionResult> UpdateOrderAsync([FromBody] OrderModificationScheme request, [FromRoute] string id, CancellationToken cancellation)
    {
        var result = await dispatcher.DispatchAsync(request with { Id = id }, cancellation);

        return result switch
        {
            { IsSuccess: true } when result.Data is not null =>
                StatusCode(StatusCodes.Status200OK, result.Data),

            { IsFailure: true } when result.Error == OrderErrors.OrderDoesNotExist =>
                StatusCode(StatusCodes.Status404NotFound, result.Error),

            { IsFailure: true } when result.Error == CommonErrors.OperationFailed =>
                StatusCode(StatusCodes.Status500InternalServerError, result.Error),

            { IsFailure: true } when result.Error == CommonErrors.RateLimitExceeded =>
                StatusCode(StatusCodes.Status429TooManyRequests, result.Error),
        };
    }
}