AuthorBuddy/Components/Pages/Login.razor

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

@rendermode InteractiveServer

<PageTitle>@T("Anmelden - Author Buddy", "Login - Author Buddy")</PageTitle>

<div class="auth-page">
    <div class="auth-card">
        <h2>@T("Anmelden", "Login")</h2>

        @if (!show2FA)
        {
            <div class="form-group">
                <label for="username">@T("Benutzername:", "Username:")</label>
                <input id="username" @bind="username" @onkeydown="HandleKeyDown" />
            </div>
            <div class="form-group">
                <label for="password">@T("Passwort:", "Password:")</label>
                <input id="password" type="password" @bind="password" @onkeydown="HandleKeyDown" />
            </div>
            <div class="auth-actions">
                <button @onclick="DoLogin" disabled="@isBusy">@T("Anmelden", "Login")</button>
                <a href="/register">@T("Registrieren", "Register")</a>
            </div>
        }
        else
        {
            <p>@T("Gib den 6-stelligen Code aus deiner Authenticator-App ein:", "Enter the 6-digit code from your authenticator app:")</p>
            <div class="form-group">
                <label for="code">@T("2FA-Code:", "2FA code:")</label>
                <input id="code" @bind="twoFactorCode" maxlength="6" @onkeydown="HandleKeyDown" />
            </div>
            <div class="auth-actions">
                <button @onclick="Verify2FA" disabled="@isBusy">@T("Bestätigen", "Verify")</button>
            </div>
        }

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

@code {
    private string _language = "de";
    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;

    private string T(string de, string en) => _language == "en" ? en : de;

    protected override async Task OnInitializedAsync()
    {
        _language = await SettingsService.GetLanguageAsync() ?? "de";

        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 = T("Bitte Benutzername und Passwort eingeben.", "Please enter username and password.");
            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 = T("Benutzername oder Passwort falsch.", "Invalid username or password.");
            }
        }
        catch (Exception ex)
        {
            errorMessage = $"{T("Fehler:", "Error:")} {ex.Message}";
        }
        finally
        {
            isBusy = false;
        }
    }

    private async Task Verify2FA()
    {
        if (string.IsNullOrWhiteSpace(twoFactorCode) || twoFactorCode.Length != 6)
        {
            errorMessage = T("Bitte gib einen gültigen 6-stelligen Code ein.", "Please enter a valid 6-digit code.");
            return;
        }

        isBusy = true;
        errorMessage = string.Empty;

        try
        {
            var result = await AuthService.Verify2FAAsync(twoFactorCode);
            if (result)
            {
                AuthStateProvider.NotifyStateChanged();
                Navigation.NavigateTo("/");
            }
            else
            {
                errorMessage = T("Ungültiger Code. Bitte versuche es erneut.", "Invalid code. Please try again.");
            }
        }
        catch (Exception ex)
        {
            errorMessage = $"{T("Fehler:", "Error:")} {ex.Message}";
        }
        finally
        {
            isBusy = false;
        }
    }
}