hrynco-notification-service/HrynCo.NotificationService.Api/Controllers/ApiControllerBase.cs

using HrynCo.NotificationService.Api.Infrastructure;
using HrynCo.NotificationService.Services.Core;
using MediatR;
using Microsoft.AspNetCore.Mvc;

namespace HrynCo.NotificationService.Api.Controllers;

[Route("api/v1/[controller]")]
[ApiController]
public abstract class ApiControllerBase : ControllerBase
{
    protected ApiControllerBase(IMediator mediator)
    {
        Mediator = mediator;
    }

    protected IMediator Mediator { get; }

    protected IActionResult FromServiceResult<T>(ServiceResult<T> result) =>
        result.IsSuccess
            ? Ok(new ApiResponse<T> { Success = true, Data = result.Result })
            : MapServiceError(result.Error!);

    protected IActionResult CreatedFromServiceResult<T>(ServiceResult<Guid> result, string actionName, Func<Guid, T> routeValues) =>
        result.IsSuccess
            ? CreatedAtAction(actionName, routeValues(result.Result), new ApiResponse<Guid> { Success = true, Data = result.Result })
            : MapServiceError(result.Error!);

    protected IActionResult MapServiceError(ServiceError error)
    {
        string code = error.Code?.ToString() ?? "Unknown";

        return error.Code switch
        {
            ServiceErrorCode.NotFound => NotFound(ErrorResponse(code, error.Message)),
            ServiceErrorCode.Conflict => Conflict(ErrorResponse(code, error.Message)),
            ServiceErrorCode.InvalidRequest => BadRequest(ErrorResponse(code, error.Message)),
            null => throw new InvalidOperationException("Error code was null for failed result."),
            _ => throw new ArgumentOutOfRangeException(nameof(error), error, "Unexpected error code.")
        };
    }

    private static ApiResponse<object> ErrorResponse(string code, string message) =>
        new() { Success = false, Error = new ApiError { Code = code, Message = message } };
}