taxbaik/TaxBaik.Web/Components/Admin/Pages/Login.razor

@page "/admin/login"
@using Microsoft.FluentUI.AspNetCore.Components
@using System.ComponentModel.DataAnnotations
@layout TaxBaik.Web.Components.Admin.Layout.BlankLayout
@attribute [AllowAnonymous]
@inject IApiClient ApiClient
@inject NavigationManager NavigationManager
@inject CustomAuthenticationStateProvider AuthStateProvider
@inject IJSRuntime Js
@inject ILocalStorageService LocalStorageService

<PageTitle>로그인</PageTitle>

<div class="admin-login-page">
    <div class="admin-login-card admin-surface">
        <div class="admin-login-brand">
            <span class="admin-brand-mark">T</span>
            <div>
                <div class="admin-brand-title">TaxBaik</div>
                <div class="admin-brand-subtitle">관리자 로그인</div>
            </div>
        </div>

        <form class="admin-login-form" @onsubmit="HandleLogin" @onsubmit:preventDefault>
            <label class="admin-field">
                <span class="admin-field-label">사용자명</span>
                <input class="admin-input" type="text" placeholder="사용자명" @bind="model.Username" autocomplete="username" />
            </label>

            <label class="admin-field">
                <span class="admin-field-label">비밀번호</span>
                <input class="admin-input" type="password" placeholder="비밀번호" @bind="model.Password" autocomplete="current-password" />
            </label>

            <label class="admin-login-remember">
                <input type="checkbox" @bind="model.RememberMe" />
                <span>아이디 저장</span>
            </label>

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

            <button type="submit" class="site-button primary admin-login-submit" disabled="@isLoading">
                @if (isLoading)
                {
                    <span>로그인 중...</span>
                }
                else
                {
                    <span>로그인</span>
                }
            </button>
        </form>
    </div>
</div>

@code {
    private bool isLoading = false;
    private string errorMessage = "";
    private LoginModel model = new();
    private const string RememberedUsernameKey = "admin-remembered-username";

    protected override async Task OnInitializedAsync()
    {
        try
        {
            var remembered = await LocalStorageService.GetItemAsStringAsync(RememberedUsernameKey);
            if (!string.IsNullOrEmpty(remembered))
            {
                model.Username = remembered;
                model.RememberMe = true;
            }
        }
        catch
        {
            // LocalStorage not available in pre-render
        }
    }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender)
            await Js.InvokeVoidAsync("taxbaikAdminSession.syncRouteClass");
    }

    private async Task HandleLogin()
    {
        if (isLoading)
            return;

        isLoading = true;
        errorMessage = "";

        try
        {
            var request = new { model.Username, model.Password };
            var response = await ApiClient.PostAsync<LoginResponse>("auth/login", request);

            if (response?.AccessToken == null || response?.RefreshToken == null)
            {
                errorMessage = "사용자명 또는 비밀번호가 올바르지 않습니다.";
                isLoading = false;
                return;
            }

            if (model.RememberMe)
            {
                await LocalStorageService.SetItemAsStringAsync(RememberedUsernameKey, model.Username);
            }
            else
            {
                await LocalStorageService.RemoveItemAsync(RememberedUsernameKey);
            }

            await ApiClient.SetAuthToken(response.AccessToken);
            await AuthStateProvider.LoginAsync(response.AccessToken, response.RefreshToken, response.ExpiresIn);
            NavigationManager.NavigateTo(GetReturnUrl(), forceLoad: false);
        }
        catch
        {
            errorMessage = "로그인 중 오류가 발생했습니다.";
            isLoading = false;
        }
    }

    private class LoginResponse
    {
        public string AccessToken { get; set; } = "";
        public string RefreshToken { get; set; } = "";
        public int ExpiresIn { get; set; }
    }

    private class LoginModel
    {
        public string Username { get; set; } = "";
        public string Password { get; set; } = "";
        public bool RememberMe { get; set; }
    }

    private string GetReturnUrl()
    {
        var uri = NavigationManager.ToAbsoluteUri(NavigationManager.Uri);
        if (!Microsoft.AspNetCore.WebUtilities.QueryHelpers.ParseQuery(uri.Query).TryGetValue("returnUrl", out var returnUrl)
            || string.IsNullOrWhiteSpace(returnUrl))
        {
            return "/taxbaik/admin/dashboard";
        }

        var value = returnUrl.ToString();
        if (!value.StartsWith("admin", StringComparison.OrdinalIgnoreCase))
        {
            return "/taxbaik/admin/dashboard";
        }

        return $"/taxbaik/{value.TrimStart('/')}";
    }
}