// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Linq;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.Extensions.Logging;

namespace Microsoft.AspNetCore.Identity.UI.V4.Pages.Account.Manage.Internal;

/// <summary>
///     This API supports the ASP.NET Core Identity default UI infrastructure and is not intended to be used
///     directly from your code. This API may change or be removed in future releases.
/// </summary>
[IdentityDefaultUI(typeof(GenerateRecoveryCodesModel<>))]
public abstract class GenerateRecoveryCodesModel : PageModel
{
    /// <summary>
    ///     This API supports the ASP.NET Core Identity default UI infrastructure and is not intended to be used
    ///     directly from your code. This API may change or be removed in future releases.
    /// </summary>
    [TempData]
    public string[]? RecoveryCodes { get; set; }

    /// <summary>
    ///     This API supports the ASP.NET Core Identity default UI infrastructure and is not intended to be used
    ///     directly from your code. This API may change or be removed in future releases.
    /// </summary>
    [TempData]
    public string? StatusMessage { get; set; }

    /// <summary>
    ///     This API supports the ASP.NET Core Identity default UI infrastructure and is not intended to be used
    ///     directly from your code. This API may change or be removed in future releases.
    /// </summary>
    public virtual Task<IActionResult> OnGetAsync() => throw new NotImplementedException();

    /// <summary>
    ///     This API supports the ASP.NET Core Identity default UI infrastructure and is not intended to be used
    ///     directly from your code. This API may change or be removed in future releases.
    /// </summary>
    public virtual Task<IActionResult> OnPostAsync() => throw new NotImplementedException();
}

internal sealed class GenerateRecoveryCodesModel<TUser> : GenerateRecoveryCodesModel where TUser : class
{
    private readonly UserManager<TUser> _userManager;
    private readonly ILogger<GenerateRecoveryCodesModel> _logger;

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

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

        var isTwoFactorEnabled = await _userManager.GetTwoFactorEnabledAsync(user);
        if (!isTwoFactorEnabled)
        {
            throw new InvalidOperationException($"Cannot generate recovery codes for user because they do not have 2FA enabled.");
        }

        return Page();
    }

    public override async Task<IActionResult> OnPostAsync()
    {
        var user = await _userManager.GetUserAsync(User);
        if (user == null)
        {
            return NotFound($"Unable to load user with ID '{_userManager.GetUserId(User)}'.");
        }

        var isTwoFactorEnabled = await _userManager.GetTwoFactorEnabledAsync(user);
        if (!isTwoFactorEnabled)
        {
            throw new InvalidOperationException("Cannot generate recovery codes for user as they do not have 2FA enabled.");
        }

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

        _logger.LogInformation(LoggerEventIds.TwoFARecoveryGenerated, "User has generated new 2FA recovery codes.");
        StatusMessage = "You have generated new recovery codes.";
        return RedirectToPage("./ShowRecoveryCodes");
    }
}
