ChronoCCG/Chrono/Server/Components/Pages/Login.razor

@page "/login"
@rendermode InteractiveServer
@attribute [Microsoft.AspNetCore.Authorization.AllowAnonymous]
@using Microsoft.AspNetCore.Components.Authorization
@inject IJSRuntime JS
@inject NavigationManager Nav
@inject AuthenticationStateProvider AuthStateProvider

<PageTitle>Sign In — Chrono CCG</PageTitle>

<div class="login-container">
    <div class="login-card">
        <h1 class="login-title">Chrono CCG</h1>

        @if (_error is not null)
        {
            <div class="alert alert-danger">@_error</div>
        }

        @if (_enrolled)
        {
            <p class="login-hint">Use your registered passkey to sign in.</p>
            <button class="btn btn-primary btn-lg w-100" @onclick="SignIn" disabled="@_busy">
                @if (_busy)
                {
                    <span class="spinner-border spinner-border-sm me-2" role="status"></span>
                }
                Sign in with Passkey
            </button>
        }
        else
        {
            <p class="login-hint">No passkey enrolled yet. Register your device to get started.</p>
            <button class="btn btn-success btn-lg w-100" @onclick="Enroll" disabled="@_busy">
                @if (_busy)
                {
                    <span class="spinner-border spinner-border-sm me-2" role="status"></span>
                }
                Enroll Passkey
            </button>
        }
    </div>
</div>

@code {
    private bool _enrolled;
    private bool _busy;
    private string? _error;

    protected override async Task OnInitializedAsync()
    {
        var authState = await AuthStateProvider.GetAuthenticationStateAsync();
        if (authState.User.Identity?.IsAuthenticated == true)
        {
            Nav.NavigateTo("/", replace: true);
            return;
        }

        try
        {
            using var http = new HttpClient { BaseAddress = new Uri(Nav.BaseUri) };
            var status = await http.GetFromJsonAsync<StatusResponse>("/api/auth/status");
            _enrolled = status?.Enrolled ?? false;
        }
        catch
        {
            _enrolled = false;
        }
    }

    private async Task SignIn()
    {
        _busy = true;
        _error = null;
        try
        {
            await JS.InvokeVoidAsync("passkeyLogin");
            Nav.NavigateTo("/", forceLoad: true);
        }
        catch (Exception ex)
        {
            _error = ex.Message;
        }
        finally
        {
            _busy = false;
        }
    }

    private async Task Enroll()
    {
        _busy = true;
        _error = null;
        try
        {
            await JS.InvokeVoidAsync("passkeyEnroll");
            Nav.NavigateTo("/", forceLoad: true);
        }
        catch (Exception ex)
        {
            _error = ex.Message;
        }
        finally
        {
            _busy = false;
        }
    }

    private record StatusResponse(bool Enrolled, bool Authenticated);
}