chapter-organizer/WebApp/Components/Features/Authentication/Login.razor

@page "/login"
@layout EmptyLayout
@using System.ComponentModel.DataAnnotations
@using WebApp.Authentication
@using Microsoft.AspNetCore.Antiforgery
@using Microsoft.AspNetCore.Components.Web
@using MudInputType = MudBlazor.InputType
@using Microsoft.JSInterop
@using Microsoft.AspNetCore.WebUtilities
@inject NavigationManager Navigation
@inject LoginRateLimitService RateLimitService
@inject IHttpContextAccessor HttpContextAccessor
@inject IAntiforgery Antiforgery
@inject IJSRuntime JS

<div class="d-flex justify-center align-center" style="min-height: 100vh;">
    <MudPaper Elevation="3" Class="pa-8" MaxWidth="400px" Style="width: 100%;">
        <MudText Typo="Typo.h4" Align="Align.Center" GutterBottom="true">
            TSA Chapter Organizer
        </MudText>
        <MudText Typo="Typo.h6" Align="Align.Center" GutterBottom="true" Class="mb-6">
            Sign In
        </MudText>

        @if (!string.IsNullOrEmpty(_errorMessage))
        {
            <MudAlert Severity="Severity.Error" Class="mb-4">@_errorMessage</MudAlert>
        }

        <form id="loginForm" method="post" action="/Auth/CookieLogin" @onkeydown="HandleKeyDown">
            <input type="hidden" name="__RequestVerificationToken" value="@_antiforgeryToken" />
            <input type="hidden" id="emailInput" name="email" value="" />
            <input type="hidden" id="passwordInput" name="password" value="" />
            <input type="hidden" id="rememberMeInput" name="rememberMe" value="" />

            <MudTextField @bind-Value="_loginModel.Email"
                          Label="Email"
                          Variant="Variant.Outlined"
                          InputType="MudInputType.Email"
                          Required="true"
                          Class="mb-4" />

            <MudTextField @bind-Value="_loginModel.Password"
                          Label="Password"
                          Variant="Variant.Outlined"
                          InputType="@_passwordInput"
                          Required="true"
                          Class="mb-4"
                          Adornment="Adornment.End"
                          AdornmentIcon="@_passwordInputIcon"
                          OnAdornmentClick="TogglePasswordVisibility" />

            <div class="d-flex justify-space-between align-center mb-4">
                <MudCheckBox @bind-Value="_loginModel.RememberMe"
                             Label="Remember me?"
                             Color="Color.Primary" />
            </div>

            <MudButton ButtonType="ButtonType.Button"
                       Variant="Variant.Filled"
                       Color="Color.Primary"
                       Size="Size.Large"
                       FullWidth="true"
                       OnClick="HandleFormSubmit">
                <span>Sign In</span>
            </MudButton>
        </form>
    </MudPaper>
</div>

@code {
    private LoginModel _loginModel = new();
    private string? _errorMessage;
    private bool _passwordVisibility;
    private MudInputType _passwordInput = MudInputType.Password;
    private string _passwordInputIcon = Icons.Material.Filled.VisibilityOff;
    private string _antiforgeryToken = string.Empty;

    protected override void OnInitialized()
    {
        // Generate antiforgery token
        var httpContext = HttpContextAccessor.HttpContext;
        if (httpContext != null)
        {
            var tokenSet = Antiforgery.GetAndStoreTokens(httpContext);
            _antiforgeryToken = tokenSet.RequestToken ?? string.Empty;
        }

        // Check for error message from query parameter (set by controller on failed login)
        var uri = new Uri(Navigation.Uri);
        var queryParams = QueryHelpers.ParseQuery(uri.Query);
        if (queryParams.TryGetValue("error", out var errorValue))
        {
            _errorMessage = errorValue.ToString();
        }
    }

    private class LoginModel
    {
        [Required(ErrorMessage = "Email is required")]
        [EmailAddress(ErrorMessage = "Invalid email format")]
        [MaxLength(100, ErrorMessage = "Email must be less than 100 characters")]
        [RegularExpression(@"^[^@\s]+@[^@\s]+\.[^@\s]+$", ErrorMessage = "Please enter a valid email address")]
        public string Email { get; set; } = string.Empty;

        [Required(ErrorMessage = "Password is required")]
        [MinLength(8, ErrorMessage = "Password must be at least 8 characters")]
        [MaxLength(100, ErrorMessage = "Password must be less than 100 characters")]
        [DataType(DataType.Password)]
        public string Password { get; set; } = string.Empty;

        public bool RememberMe { get; set; }
    }

    private void TogglePasswordVisibility()
    {
        _passwordVisibility = !_passwordVisibility;
        _passwordInputIcon = _passwordVisibility
            ? Icons.Material.Filled.Visibility
            : Icons.Material.Filled.VisibilityOff;
        _passwordInput = _passwordVisibility
            ? MudInputType.Text
            : MudInputType.Password;
    }

    private async Task HandleKeyDown(KeyboardEventArgs e)
    {
        if (e.Key == "Enter")
        {
            // Blur the active element to ensure MudTextField bindings update
            await JS.InvokeVoidAsync("eval", "document.activeElement.blur()");

            // Small delay to allow bindings to process
            await Task.Delay(50);

            // Now submit the form
            await HandleFormSubmit();
        }
    }

    private async Task HandleFormSubmit()
    {
        // Update hidden inputs with current model values, then submit the form
        await JS.InvokeVoidAsync("eval", $@"
            document.getElementById('emailInput').value = {System.Text.Json.JsonSerializer.Serialize(_loginModel.Email)};
            document.getElementById('passwordInput').value = {System.Text.Json.JsonSerializer.Serialize(_loginModel.Password)};
            document.getElementById('rememberMeInput').value = '{_loginModel.RememberMe.ToString().ToLower()}';
            document.getElementById('loginForm').submit();
        ");
    }
}