Refine admin login flow and verification harness

src/TaxBaik.Web/Pages/Admin/Login.cshtml

@@ -0,0 +1,85 @@
+@page "/admin/login"
+@model TaxBaik.Web.Pages.Admin.LoginModel
+@{
+    ViewData["Title"] = "관리자 로그인";
+    ViewData["Description"] = "관리자 로그인 페이지입니다.";
+    ViewData["CanonicalUrl"] = $"{Request.Scheme}://{Request.Host}/taxbaik/admin/login";
+}
+
+<section class="container py-5" style="max-width: 560px;">
+    <div class="card shadow-sm border-0">
+        <div class="card-body p-4 p-md-5">
+            <div class="mb-4">
+                <p class="text-uppercase text-muted small mb-1">TaxBaik Admin</p>
+                <h1 class="h3 fw-bold mb-2">관리자 로그인</h1>
+                <p class="text-muted mb-0">로그인 후 대시보드와 관리자 기능을 이용할 수 있습니다.</p>
+            </div>
+
+            @if (!string.IsNullOrWhiteSpace(Model.ErrorMessage))
+            {
+                <div class="alert alert-danger" role="alert">@Model.ErrorMessage</div>
+            }
+
+            <form id="admin-login-form" method="post" class="vstack gap-3">
+                @Html.AntiForgeryToken()
+                <input type="hidden" id="ReturnUrl" name="ReturnUrl" value="@Model.ReturnUrl" />
+
+                <div>
+                    <label class="form-label" for="Username">사용자명</label>
+                    <input class="form-control" id="Username" name="Username" value="@Model.Username" autocomplete="username" />
+                    <span class="text-danger small">@(!string.IsNullOrWhiteSpace(ModelState["Username"]?.Errors.FirstOrDefault()?.ErrorMessage) ? ModelState["Username"]?.Errors.FirstOrDefault()?.ErrorMessage : "")</span>
+                </div>
+
+                <div>
+                    <label class="form-label" for="Password">비밀번호</label>
+                    <input class="form-control" id="Password" name="Password" type="password" autocomplete="current-password" />
+                    <span class="text-danger small">@(!string.IsNullOrWhiteSpace(ModelState["Password"]?.Errors.FirstOrDefault()?.ErrorMessage) ? ModelState["Password"]?.Errors.FirstOrDefault()?.ErrorMessage : "")</span>
+                </div>
+
+                <div class="form-check">
+                    <input class="form-check-input" id="RememberMe" name="RememberMe" type="checkbox" value="true" checked="@(Model.RememberMe ? "checked" : null)" />
+                    <label class="form-check-label" for="RememberMe">로그인 상태 유지</label>
+                </div>
+
+                <button class="btn btn-dark w-100" id="admin-login-submit" type="submit">
+                    <span>로그인</span>
+                </button>
+            </form>
+
+            <p class="text-muted small mt-4 mb-0">
+                이 페이지는 서버 렌더링 기반입니다. 로그인 성공 후 관리자 웹앱으로 이동합니다.
+            </p>
+        </div>
+    </div>
+</section>
+
+@if (Model.LoginSucceeded && Model.TokenPair is not null)
+{
+    <script>
+        (function () {
+            const tokenPair = @Html.Raw(System.Text.Json.JsonSerializer.Serialize(
+                Model.TokenPair,
+                new System.Text.Json.JsonSerializerOptions { PropertyNamingPolicy = System.Text.Json.JsonNamingPolicy.CamelCase }));
+            const expiryTicks = 621355968000000000 + ((Date.now() + (tokenPair.expiresIn || 3600) * 1000) * 10000);
+            localStorage.setItem('accessToken', tokenPair.accessToken || '');
+            localStorage.setItem('refreshToken', tokenPair.refreshToken || '');
+            localStorage.setItem('tokenExpiry', String(expiryTicks));
+            @if (Model.RememberMe)
+            {
+                <text>
+                localStorage.setItem('admin-remembered-username', @Html.Raw(System.Text.Json.JsonSerializer.Serialize(Model.Username)));
+                localStorage.setItem('admin-remember-checkbox', 'true');
+                </text>
+            }
+            else
+            {
+                <text>
+                localStorage.removeItem('admin-remembered-username');
+                localStorage.removeItem('admin-remember-checkbox');
+                </text>
+            }
+
+            window.location.replace(@Html.Raw(System.Text.Json.JsonSerializer.Serialize(Model.RedirectUrl)));
+        })();
+    </script>
+}

src/TaxBaik.Web/Pages/Admin/Login.cshtml.cs

@@ -0,0 +1,97 @@
+using System.ComponentModel.DataAnnotations;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.RazorPages;
+using TaxBaik.Web.Endpoints.Auth;
+using TaxBaik.Web.Services;
+
+namespace TaxBaik.Web.Pages.Admin;
+
+public class LoginModel(AuthService authService) : PageModel
+{
+    [BindProperty]
+    [Display(Name = "사용자명")]
+    [Required(ErrorMessage = "사용자명을 입력하세요.")]
+    public string Username { get; set; } = string.Empty;
+
+    [BindProperty]
+    [Display(Name = "비밀번호")]
+    [DataType(DataType.Password)]
+    [Required(ErrorMessage = "비밀번호를 입력하세요.")]
+    public string Password { get; set; } = string.Empty;
+
+    [BindProperty]
+    [Display(Name = "로그인 상태 유지")]
+    public bool RememberMe { get; set; } = true;
+
+    [BindProperty(SupportsGet = true)]
+    public string? ReturnUrl { get; set; }
+
+    public string? ErrorMessage { get; set; }
+
+    public bool LoginSucceeded { get; set; }
+
+    public TokenPairResponse? TokenPair { get; set; }
+
+    public string RedirectUrl { get; set; } = "/taxbaik/admin/dashboard";
+
+    public void OnGet()
+    {
+        if (!string.IsNullOrWhiteSpace(ReturnUrl))
+        {
+            RedirectUrl = NormalizeRedirectUrl(ReturnUrl);
+        }
+    }
+
+    public async Task<IActionResult> OnPostAsync(CancellationToken ct)
+    {
+        if (!ModelState.IsValid)
+        {
+            return Page();
+        }
+
+        var tokenPair = await authService.AuthenticateAndGenerateTokenPairAsync(Username, Password);
+        if (tokenPair is null)
+        {
+            ErrorMessage = "아이디 또는 비밀번호가 올바르지 않습니다.";
+            return Page();
+        }
+
+        LoginSucceeded = true;
+        RedirectUrl = NormalizeRedirectUrl(ReturnUrl);
+        TokenPair = new TokenPairResponse
+        {
+            AccessToken = tokenPair.AccessToken,
+            RefreshToken = tokenPair.RefreshToken,
+            ExpiresIn = tokenPair.ExpiresIn,
+            Token = tokenPair.AccessToken
+        };
+
+        return Page();
+    }
+
+    private static string NormalizeRedirectUrl(string? returnUrl)
+    {
+        if (string.IsNullOrWhiteSpace(returnUrl))
+            return "/taxbaik/admin/dashboard";
+
+        if (Uri.TryCreate(returnUrl, UriKind.Relative, out var relative))
+        {
+            var value = relative.ToString();
+            if (value.StartsWith('/'))
+                return value.StartsWith("/taxbaik/", StringComparison.OrdinalIgnoreCase) ? value : $"/taxbaik{value}";
+            return $"/taxbaik/{value}";
+        }
+
+        if (Uri.TryCreate(returnUrl, UriKind.Absolute, out var absolute))
+        {
+            if (string.Equals(absolute.Host, "www.taxbaik.com", StringComparison.OrdinalIgnoreCase) ||
+                string.Equals(absolute.Host, "taxbaik.com", StringComparison.OrdinalIgnoreCase))
+            {
+                var path = absolute.PathAndQuery;
+                return path.StartsWith("/taxbaik/", StringComparison.OrdinalIgnoreCase) ? path : $"/taxbaik{path}";
+            }
+        }
+
+        return "/taxbaik/admin/dashboard";
+    }
+}