AuthorBuddy/Components/Pages/Login.razor

@page "/login"
@inject IAuthService AuthService
@inject CustomAuthStateProvider AuthStateProvider
@inject NavigationManager Navigation
@inject ISettingsService SettingsService
@inject ILocalizationService Loc

@rendermode InteractiveServer

<PageTitle>@Loc["page.title.login"]</PageTitle>

<div class="auth-page">
    <div class="auth-card">
        <div class="auth-logo">
            <img src="/Assets/logo.jpg" alt="Author Buddy" />
        </div>
        <h2>@Loc["login.heading"]</h2>

        @if (!show2FA)
        {
            <div class="form-group">
                <label for="username">@Loc["login.label.username"]</label>
                <input id="username" @bind="username" @onkeydown="HandleKeyDown" />
            </div>
            <div class="form-group">
                <label for="password">@Loc["login.label.password"]</label>
                <input id="password" type="password" @bind="password" @onkeydown="HandleKeyDown" />
            </div>
            <div class="auth-actions">
                <button @onclick="DoLogin" disabled="@isBusy">@Loc["login.button.submit"]</button>
                <a href="/register">@Loc["login.link.register"]</a>
            </div>
        }
        else
        {
            <p>@Loc["login.2fa.instruction"]</p>
            <div class="form-group">
                <label for="code">@Loc["login.2fa.label.code"]</label>
                <input id="code" @bind="twoFactorCode" maxlength="6" @onkeydown="HandleKeyDown" />
            </div>
            <div class="auth-actions">
                <button @onclick="Verify2FA" disabled="@isBusy">@Loc["login.2fa.button.verify"]</button>
            </div>
        }

        @if (!string.IsNullOrEmpty(errorMessage))
        {
            <div class="auth-error">@errorMessage</div>
        }
    </div>
</div>

@code {
    private string username = string.Empty;
    private string password = string.Empty;
    private string twoFactorCode = string.Empty;
    private string errorMessage = string.Empty;
    private bool isBusy;
    private bool show2FA;

    protected override async Task OnInitializedAsync()
    {
        if (AuthService.IsLoggedIn)
        {
            Navigation.NavigateTo("/");
            return;
        }

        var users = await SettingsService.GetUsersAsync();
        if (users.Count == 0)
        {
            Navigation.NavigateTo("/register");
        }
    }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender && AuthService.IsLoggedIn)
            Navigation.NavigateTo("/");
    }

    private async Task HandleKeyDown(KeyboardEventArgs e)
    {
        if (e.Key == "Enter")
        {
            if (show2FA)
                await Verify2FA();
            else
                await DoLogin();
        }
    }

    private async Task DoLogin()
    {
        if (string.IsNullOrWhiteSpace(username) || string.IsNullOrWhiteSpace(password))
        {
            errorMessage = Loc["login.error.empty_fields"];
            return;
        }

        isBusy = true;
        errorMessage = string.Empty;

        try
        {
            var result = await AuthService.LoginAsync(username, password);
            if (AuthService.Is2FARequired)
            {
                show2FA = true;
                password = string.Empty;
            }
            else if (result)
            {
                AuthStateProvider.NotifyStateChanged();
                Navigation.NavigateTo("/");
            }
            else
            {
                errorMessage = Loc["login.error.invalid_credentials"];
            }
        }
        catch (Exception ex)
        {
            errorMessage = $"{Loc["common.error"]} {ex.Message}";
        }
        finally
        {
            isBusy = false;
        }
    }

    private async Task Verify2FA()
    {
        if (string.IsNullOrWhiteSpace(twoFactorCode) || twoFactorCode.Length != 6)
        {
            errorMessage = Loc["login.2fa.error.invalid_code"];
            return;
        }

        isBusy = true;
        errorMessage = string.Empty;

        try
        {
            var result = await AuthService.Verify2FAAsync(twoFactorCode);
            if (result)
            {
                AuthStateProvider.NotifyStateChanged();
                Navigation.NavigateTo("/");
            }
            else
            {
                errorMessage = Loc["login.2fa.error.code_failed"];
            }
        }
        catch (Exception ex)
        {
            errorMessage = $"{Loc["common.error"]} {ex.Message}";
        }
        finally
        {
            isBusy = false;
        }
    }
}