using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.Extensions.Logging;
using IdentitySample.Mvc.Data;

namespace IdentitySample.Mvc.Pages.Account.Manage
{
    public class GenerateRecoveryCodesModel : PageModel
    {
        private readonly UserManager<ApplicationUser> _userManager;
        private readonly ILogger<GenerateRecoveryCodesModel> _logger;

        public GenerateRecoveryCodesModel(
            UserManager<ApplicationUser> userManager,
            ILogger<GenerateRecoveryCodesModel> logger)
        {
            _userManager = userManager;
            _logger = logger;
        }

        public string[] RecoveryCodes { get; set; }

        public async Task<IActionResult> OnGetAsync()
        {
            var user = await _userManager.GetUserAsync(User);
            if (user == null)
            {
                throw new ApplicationException($"Unable to load user with ID '{_userManager.GetUserId(User)}'.");
            }

            if (!user.TwoFactorEnabled)
            {
                throw new ApplicationException($"Cannot generate recovery codes for user with ID '{user.Id}' as they do not have 2FA enabled.");
            }

            var recoveryCodes = await _userManager.GenerateNewTwoFactorRecoveryCodesAsync(user, 10);
            RecoveryCodes = recoveryCodes.ToArray();

            _logger.LogInformation("User with ID '{UserId}' has generated new 2FA recovery codes.", user.Id);

            return Page();
        }
    }
}