drinkrate/DrinkRateAPI/AuthorizationPolicies/AdminOnlyRequirement.cs

using DrinkRateAPI.DbEntities;
using DrinkRateAPI.Services;

namespace DrinkRateAPI.AuthorizationPolicies;
using Microsoft.AspNetCore.Authorization;

public class AdminOnlyRequirement : IAuthorizationRequirement
{
}

public class AdminOnlyHandler : AuthorizationHandler<AdminOnlyRequirement>
{
    private readonly ApplicationUserService _applicationUserService;
    private readonly UserProfileService _userProfileService;

    public AdminOnlyHandler(
        ApplicationUserService applicationUserService,
        UserProfileService userProfileService)
    {
        _applicationUserService = applicationUserService;
        _userProfileService = userProfileService;
    }

    protected override async Task HandleRequirementAsync(
        AuthorizationHandlerContext context, 
        AdminOnlyRequirement requirement)
    {
        DbUserProfile userProfile;
        
        try
        {
            userProfile = await _applicationUserService.UserProfileByApplicationUserAsync(context.User);
        }
        catch (Exception _)
        {
            context.Fail();
            return;
        }

        if (_userProfileService.IsUserProfileAdmin(userProfile))
        {
            context.Succeed(requirement);
        }
        else
        {
            context.Fail();
        }
    }
}