vita_asistente/Controllers/RolesController.cs

using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using System.Threading.Tasks;
using System.Linq;

namespace vita_asistente.Controllers
{
    [Authorize(Roles = "Admin")]
    public class RolesController : Controller
    {
        private readonly RoleManager<IdentityRole> _roleManager;

        public RolesController(RoleManager<IdentityRole> roleManager)
        {
            _roleManager = roleManager;
        }

        // GET: Roles
        public async Task<IActionResult> Index()
        {
            var roles = await _roleManager.Roles.ToListAsync();
            return View(roles);
        }

        // GET: Roles/Create
        public IActionResult Create()
        {
            return View();
        }

        // POST: Roles/Create
        [HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> Create(string roleName)
        {
            if (string.IsNullOrEmpty(roleName))
            {
                ModelState.AddModelError("", "El nombre del rol no puede estar vacío.");
                return View();
            }

            var roleExists = await _roleManager.RoleExistsAsync(roleName);
            if (!roleExists)
            {
                var result = await _roleManager.CreateAsync(new IdentityRole(roleName));
                if (result.Succeeded)
                {
                    return RedirectToAction(nameof(Index));
                }
                foreach (var error in result.Errors)
                {
                    ModelState.AddModelError("", error.Description);
                }
            }
            else
            {
                ModelState.AddModelError("", "El rol ya existe.");
            }
            return View();
        }

        // GET: Roles/Delete/5
        public async Task<IActionResult> Delete(string id)
        {
            if (id == null) return NotFound();
            var rol = await _roleManager.FindByIdAsync(id);
            if (rol == null) return NotFound();
            return View(rol);
        }

        // POST: Roles/Delete/5
        [HttpPost, ActionName("Delete")]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> DeleteConfirmed(string id)
        {
            var rol = await _roleManager.FindByIdAsync(id);
            if (rol != null)
            {
                await _roleManager.DeleteAsync(rol);
            }
            return RedirectToAction(nameof(Index));
        }
    }
}