Assistant/backend/Auth/AuthEndpoints.cs

using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;

namespace backend.Auth;

public record RegisterRequest(string Email, string Password);
public record LoginRequest(string Email, string Password);

public static class AuthEndpoints
{
    public static IEndpointRouteBuilder MapAuthEndpoints(this IEndpointRouteBuilder app)
    {
        var grp = app.MapGroup("/api/auth");

        grp.MapPost("/register", async (
            [FromBody] RegisterRequest req,
            UserManager<ApplicationUser> users) =>
        {
            var user = new ApplicationUser { UserName = req.Email, Email = req.Email };
            var create = await users.CreateAsync(user, req.Password);
            if (!create.Succeeded)
                return Results.BadRequest(new { errors = create.Errors.Select(e => e.Description) });

            var anyAdmin = await users.GetUsersInRoleAsync(Roles.Admin);
            var role = anyAdmin.Count == 0 ? Roles.Admin : Roles.User;
            await users.AddToRoleAsync(user, role);
            return Results.Ok(new { id = user.Id, email = user.Email, role });
        });

        grp.MapPost("/login", async (
            [FromBody] LoginRequest req,
            SignInManager<ApplicationUser> signIn) =>
        {
            var res = await signIn.PasswordSignInAsync(req.Email, req.Password,
                isPersistent: true, lockoutOnFailure: false);
            return res.Succeeded ? Results.Ok() : Results.Unauthorized();
        });

        grp.MapPost("/logout", async (SignInManager<ApplicationUser> signIn) =>
        {
            await signIn.SignOutAsync();
            return Results.Ok();
        }).RequireAuthorization();

        grp.MapGet("/me", async (
            UserManager<ApplicationUser> users,
            HttpContext http) =>
        {
            var user = await users.GetUserAsync(http.User);
            if (user is null) return Results.Unauthorized();
            var rolesList = await users.GetRolesAsync(user);
            return Results.Ok(new
            {
                id = user.Id,
                email = user.Email,
                isAdmin = rolesList.Contains(Roles.Admin),
            });
        }).RequireAuthorization();

        return app;
    }
}