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

using System.ComponentModel.DataAnnotations;
using System.Text;
using System.Text.Encodings.Web;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.AspNetCore.WebUtilities;

namespace Microsoft.AspNetCore.Identity.UI.V5.Pages.Account.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>
[AllowAnonymous]
[IdentityDefaultUI(typeof(ForgotPasswordModel<>))]
public abstract class ForgotPasswordModel : 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>
    [BindProperty]
    public InputModel Input { get; set; } = default!;

    /// <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 class InputModel
    {
        /// <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>
        [Required]
        [EmailAddress]
        public string Email { get; set; } = default!;
    }

    /// <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 ForgotPasswordModel<TUser> : ForgotPasswordModel where TUser : class
{
    private readonly UserManager<TUser> _userManager;
    private readonly IEmailSender<TUser> _emailSender;

    public ForgotPasswordModel(UserManager<TUser> userManager, IEmailSender<TUser> emailSender)
    {
        _userManager = userManager;
        _emailSender = emailSender;
    }

    public override async Task<IActionResult> OnPostAsync()
    {
        if (ModelState.IsValid)
        {
            var user = await _userManager.FindByEmailAsync(Input.Email);
            if (user == null || !(await _userManager.IsEmailConfirmedAsync(user)))
            {
                // Don't reveal that the user does not exist or is not confirmed
                return RedirectToPage("./ForgotPasswordConfirmation");
            }

            // For more information on how to enable account confirmation and password reset please
            // visit https://go.microsoft.com/fwlink/?LinkID=532713
            var code = await _userManager.GeneratePasswordResetTokenAsync(user);
            code = WebEncoders.Base64UrlEncode(Encoding.UTF8.GetBytes(code));
            var callbackUrl = Url.Page(
                "/Account/ResetPassword",
                pageHandler: null,
                values: new { area = "Identity", code },
                protocol: Request.Scheme)!;

            await _emailSender.SendPasswordResetLinkAsync(user, Input.Email, HtmlEncoder.Default.Encode(callbackUrl));

            return RedirectToPage("./ForgotPasswordConfirmation");
        }

        return Page();
    }
}
