feat: add MVC Razor admin UI for email templates

- GetAllEmailTemplatesQuery + handler (new GetAll use case)
- IEmailTemplateRepository.GetAllAsync + EF implementation
- AdminTemplatesController: Index, Create, Edit, Save, Delete
- EmailTemplateEditViewModel with IsNew/PageTitle helpers
- Views/_ViewStart, _ViewImports, Shared/_Layout (Bootstrap 5)
- Shared/_EditorLayout (chained layout for all edit screens)
- Views/AdminTemplates/Index (table with edit/delete actions)
- Views/AdminTemplates/Edit (card form, readonly composite key on edit)
- Program.cs: AddControllersWithViews, UseStaticFiles, MapDefaultControllerRoute

Ref: IT-634

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

HrynCo.NotificationService.DAL.Abstract/Repositories/IEmailTemplateRepository.cs

@@ -4,6 +4,7 @@ namespace HrynCo.NotificationService.DAL.Abstract.Repositories;
 
 public interface IEmailTemplateRepository
 {
+    Task<IReadOnlyList<EmailTemplate>> GetAllAsync(CancellationToken ct = default);
     Task<IReadOnlyList<EmailTemplate>> GetByServiceAsync(string serviceName, CancellationToken ct = default);
     Task<EmailTemplate?> GetAsync(string serviceName, string key, string languageCode, CancellationToken ct = default);
     Task AddAsync(EmailTemplate template, CancellationToken ct = default);

HrynCo.NotificationService.DAL.EF/Repositories/EmailTemplateRepository.cs

@@ -12,6 +12,12 @@ internal sealed class EmailTemplateRepository : EfRepository<EmailTemplateEntity
     {
     }
 
+    public async Task<IReadOnlyList<EmailTemplate>> GetAllAsync(CancellationToken ct = default)
+    {
+        List<EmailTemplateEntity> entities = await DbSet.ToListAsync(ct);
+        return entities.Select(MapToDomain).ToList();
+    }
+
     public async Task<IReadOnlyList<EmailTemplate>> GetByServiceAsync(string serviceName, CancellationToken ct = default)
     {
         List<EmailTemplateEntity> entities = await DbSet

HrynCo.NotificationService.Services/EmailTemplates/GetAll/GetAllEmailTemplatesHandler.cs

@@ -0,0 +1,30 @@
+using HrynCo.NotificationService.DAL.Abstract;
+using HrynCo.NotificationService.DAL.Abstract.Repositories;
+using HrynCo.NotificationService.DAL.Abstract.Templates;
+using HrynCo.NotificationService.Services.Core;
+using HrynCo.NotificationService.Services.Logging;
+using static HrynCo.NotificationService.Services.Core.ServiceResultHelper;
+
+namespace HrynCo.NotificationService.Services.EmailTemplates.GetAll;
+
+internal sealed class GetAllEmailTemplatesHandler
+    : RequestHandler<GetAllEmailTemplatesQuery, ServiceResult<IReadOnlyList<EmailTemplate>>>
+{
+    private readonly IEmailTemplateRepository _templates;
+
+    public GetAllEmailTemplatesHandler(
+        IContextualSerilogLogger<GetAllEmailTemplatesQuery> logger,
+        IUnitOfWork unitOfWork,
+        IEmailTemplateRepository templates)
+        : base(logger, unitOfWork)
+    {
+        _templates = templates;
+    }
+
+    protected override async Task<ServiceResult<IReadOnlyList<EmailTemplate>>> DoOnHandle(
+        GetAllEmailTemplatesQuery request, CancellationToken cancellationToken)
+    {
+        var templates = await _templates.GetAllAsync(cancellationToken);
+        return Success(templates);
+    }
+}

HrynCo.NotificationService.Services/EmailTemplates/GetAll/GetAllEmailTemplatesQuery.cs

@@ -0,0 +1,7 @@
+using HrynCo.NotificationService.DAL.Abstract.Templates;
+using MediatR;
+using HrynCo.NotificationService.Services.Core;
+
+namespace HrynCo.NotificationService.Services.EmailTemplates.GetAll;
+
+public sealed record GetAllEmailTemplatesQuery : IRequest<ServiceResult<IReadOnlyList<EmailTemplate>>>;

HrynCo.NotificationService.Web/Controllers/Admin/AdminTemplatesController.cs

@@ -0,0 +1,138 @@
+using System.Text.Json;
+using HrynCo.NotificationService.DAL.Abstract.Templates;
+using HrynCo.NotificationService.Services.EmailTemplates.Create;
+using HrynCo.NotificationService.Services.EmailTemplates.Delete;
+using HrynCo.NotificationService.Services.EmailTemplates.Get;
+using HrynCo.NotificationService.Services.EmailTemplates.GetAll;
+using HrynCo.NotificationService.Services.EmailTemplates.Update;
+using HrynCo.NotificationService.Web.Controllers.Admin.ViewModels;
+using MediatR;
+using Microsoft.AspNetCore.Mvc;
+
+namespace HrynCo.NotificationService.Web.Controllers.Admin;
+
+[Route("admin/templates")]
+public class AdminTemplatesController : Controller
+{
+    private readonly IMediator _mediator;
+
+    public AdminTemplatesController(IMediator mediator)
+    {
+        _mediator = mediator;
+    }
+
+    // GET /admin/templates
+    [HttpGet("")]
+    public async Task<IActionResult> Index(CancellationToken ct)
+    {
+        var result = await _mediator.Send(new GetAllEmailTemplatesQuery(), ct);
+        if (!result.IsSuccess)
+        {
+            ModelState.AddModelError("", result.Error?.Message ?? "Failed to load templates.");
+            return View(Array.Empty<EmailTemplate>());
+        }
+
+        return View(result.Result);
+    }
+
+    // GET /admin/templates/create
+    [HttpGet("create")]
+    public IActionResult Create()
+    {
+        return View("Edit", new EmailTemplateEditViewModel());
+    }
+
+    // GET /admin/templates/{serviceName}/{key}/{languageCode}
+    [HttpGet("{serviceName}/{key}/{languageCode}")]
+    public async Task<IActionResult> Edit(string serviceName, string key, string languageCode, CancellationToken ct)
+    {
+        var result = await _mediator.Send(new GetEmailTemplateQuery(serviceName, key, languageCode), ct);
+        if (!result.IsSuccess || result.Result is null)
+            return NotFound();
+
+        var template = result.Result;
+        var vm = new EmailTemplateEditViewModel
+        {
+            Id = template.Id,
+            ServiceName = template.ServiceName,
+            Key = template.Key,
+            LanguageCode = template.LanguageCode,
+            Subject = template.Subject,
+            HtmlBody = template.HtmlBody,
+            TextBody = template.TextBody,
+            VariablesJson = JsonSerializer.Serialize(template.Variables)
+        };
+
+        return View(vm);
+    }
+
+    // POST /admin/templates/save
+    [HttpPost("save")]
+    [ValidateAntiForgeryToken]
+    public async Task<IActionResult> Save(EmailTemplateEditViewModel model, CancellationToken ct)
+    {
+        if (!ModelState.IsValid)
+            return View("Edit", model);
+
+        List<EmailTemplateVariable> variables;
+        try
+        {
+            variables = JsonSerializer.Deserialize<List<EmailTemplateVariable>>(model.VariablesJson,
+                new JsonSerializerOptions { PropertyNameCaseInsensitive = true })
+                ?? [];
+        }
+        catch (JsonException)
+        {
+            ModelState.AddModelError(nameof(model.VariablesJson), "Invalid JSON format for variables.");
+            return View("Edit", model);
+        }
+
+        if (model.IsNew)
+        {
+            var command = new CreateEmailTemplateCommand(
+                model.ServiceName,
+                model.Key,
+                model.LanguageCode,
+                model.Subject,
+                model.HtmlBody,
+                model.TextBody,
+                variables);
+
+            var result = await _mediator.Send(command, ct);
+            if (!result.IsSuccess)
+            {
+                ModelState.AddModelError("", result.Error?.Message ?? "Failed to create template.");
+                return View("Edit", model);
+            }
+        }
+        else
+        {
+            var command = new UpdateEmailTemplateCommand(
+                model.ServiceName,
+                model.Key,
+                model.LanguageCode,
+                model.Subject,
+                model.HtmlBody,
+                model.TextBody,
+                variables);
+
+            var result = await _mediator.Send(command, ct);
+            if (!result.IsSuccess)
+            {
+                ModelState.AddModelError("", result.Error?.Message ?? "Failed to update template.");
+                return View("Edit", model);
+            }
+        }
+
+        return RedirectToAction(nameof(Index));
+    }
+
+    // POST /admin/templates/{serviceName}/{key}/{languageCode}/delete
+    [HttpPost("{serviceName}/{key}/{languageCode}/delete")]
+    [ValidateAntiForgeryToken]
+    public async Task<IActionResult> Delete(string serviceName, string key, string languageCode, CancellationToken ct)
+    {
+        await _mediator.Send(new DeleteEmailTemplateCommand(serviceName, key, languageCode), ct);
+        return RedirectToAction(nameof(Index));
+    }
+}

HrynCo.NotificationService.Web/Controllers/Admin/ViewModels/EmailTemplateEditViewModel.cs

@@ -0,0 +1,31 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace HrynCo.NotificationService.Web.Controllers.Admin.ViewModels;
+
+public class EmailTemplateEditViewModel
+{
+    public Guid? Id { get; set; }
+
+    [Required]
+    public string ServiceName { get; set; } = "";
+
+    [Required]
+    public string Key { get; set; } = "";
+
+    [Required]
+    public string LanguageCode { get; set; } = "";
+
+    [Required]
+    public string Subject { get; set; } = "";
+
+    [Required]
+    public string HtmlBody { get; set; } = "";
+
+    public string TextBody { get; set; } = "";
+
+    // JSON array: [{"name":"UserName","required":true}, ...]
+    public string VariablesJson { get; set; } = "[]";
+
+    public bool IsNew => Id == null;
+    public string PageTitle => IsNew ? "Create Email Template" : "Edit Email Template";
+}

HrynCo.NotificationService.Web/Program.cs

@@ -13,7 +13,7 @@ var appSettings = builder.Configuration
 
 builder.Services.AddSingleton(appSettings);
 builder.Services.AddOpenApi();
-builder.Services.AddControllers();
+builder.Services.AddControllersWithViews();
 builder.Services.AddNotificationDataAccess(appSettings.ConnectionString);
 builder.Services.AddNotificationServices();
 
@@ -29,6 +29,8 @@ if (app.Environment.IsDevelopment())
     });
 }
 
+app.UseStaticFiles();
 app.UseHttpsRedirection();
 app.MapControllers();
+app.MapDefaultControllerRoute();
 app.Run();

HrynCo.NotificationService.Web/Views/AdminTemplates/Edit.cshtml

@@ -0,0 +1,71 @@
+@using HrynCo.NotificationService.Web.Controllers.Admin.ViewModels
+@model EmailTemplateEditViewModel
+@{
+    Layout = "~/Views/Shared/_EditorLayout.cshtml";
+    ViewData["Title"] = Model.PageTitle;
+    ViewData["EditorTitle"] = Model.PageTitle;
+}
+
+<form asp-action="Save" asp-controller="AdminTemplates" method="post">
+    @Html.AntiForgeryToken()
+    <input asp-for="Id" type="hidden" />
+    <input type="hidden" name="IsNew" value="@Model.IsNew" />
+
+    @if (!ViewData.ModelState.IsValid)
+    {
+        <div class="alert alert-danger mb-3">
+            @foreach (var error in ViewData.ModelState.Values.SelectMany(v => v.Errors))
+            {
+                <div>@error.ErrorMessage</div>
+            }
+        </div>
+    }
+
+    <div class="mb-3">
+        <label asp-for="ServiceName" class="form-label fw-semibold">Service Name</label>
+        <input asp-for="ServiceName" class="form-control" readonly="@(!Model.IsNew)" />
+        <span asp-validation-for="ServiceName" class="text-danger small"></span>
+    </div>
+
+    <div class="mb-3">
+        <label asp-for="Key" class="form-label fw-semibold">Key</label>
+        <input asp-for="Key" class="form-control" readonly="@(!Model.IsNew)" />
+        <span asp-validation-for="Key" class="text-danger small"></span>
+    </div>
+
+    <div class="mb-3">
+        <label asp-for="LanguageCode" class="form-label fw-semibold">Language Code</label>
+        <input asp-for="LanguageCode" class="form-control" readonly="@(!Model.IsNew)" />
+        <span asp-validation-for="LanguageCode" class="text-danger small"></span>
+    </div>
+
+    <div class="mb-3">
+        <label asp-for="Subject" class="form-label fw-semibold">Subject</label>
+        <input asp-for="Subject" class="form-control" />
+        <span asp-validation-for="Subject" class="text-danger small"></span>
+    </div>
+
+    <div class="mb-3">
+        <label asp-for="HtmlBody" class="form-label fw-semibold">HTML Body</label>
+        <textarea asp-for="HtmlBody" class="form-control font-monospace" rows="10"></textarea>
+        <span asp-validation-for="HtmlBody" class="text-danger small"></span>
+    </div>
+
+    <div class="mb-3">
+        <label asp-for="TextBody" class="form-label fw-semibold">Text Body</label>
+        <textarea asp-for="TextBody" class="form-control font-monospace" rows="5"></textarea>
+    </div>
+
+    <div class="mb-3">
+        <label asp-for="VariablesJson" class="form-label fw-semibold">Variables (JSON)</label>
+        <textarea asp-for="VariablesJson" class="form-control font-monospace" rows="4"
+                  placeholder='[{"name":"UserName","required":true}]'></textarea>
+        <span asp-validation-for="VariablesJson" class="text-danger small"></span>
+        <div class="form-text">JSON array of <code>{"name":"...", "required":true|false}</code></div>
+    </div>
+
+    @section FormActions {
+        <button type="submit" class="btn btn-primary">💾 Save</button>
+        <a href="/admin/templates" class="btn btn-secondary">✖ Cancel</a>
+    }
+</form>

HrynCo.NotificationService.Web/Views/AdminTemplates/Index.cshtml

@@ -0,0 +1,68 @@
+@using HrynCo.NotificationService.DAL.Abstract.Templates
+@model IReadOnlyList<EmailTemplate>
+@{
+    ViewData["Title"] = "Email Templates";
+}
+
+<div class="d-flex justify-content-between align-items-center mb-4">
+    <h2 class="mb-0">📋 Email Templates</h2>
+    <a href="/admin/templates/create" class="btn btn-primary">+ Create New Template</a>
+</div>
+
+@if (!ViewData.ModelState.IsValid)
+{
+    <div class="alert alert-danger">
+        @foreach (var error in ViewData.ModelState.Values.SelectMany(v => v.Errors))
+        {
+            <div>@error.ErrorMessage</div>
+        }
+    </div>
+}
+
+@if (Model is null || Model.Count == 0)
+{
+    <div class="alert alert-info">No email templates found.</div>
+}
+else
+{
+    <div class="card shadow-sm">
+        <div class="table-responsive">
+            <table class="table table-hover mb-0">
+                <thead class="table-dark">
+                    <tr>
+                        <th>Service Name</th>
+                        <th>Key</th>
+                        <th>Language</th>
+                        <th>Subject</th>
+                        <th class="text-end">Actions</th>
+                    </tr>
+                </thead>
+                <tbody>
+                    @foreach (var t in Model)
+                    {
+                        <tr>
+                            <td>@t.ServiceName</td>
+                            <td>@t.Key</td>
+                            <td>@t.LanguageCode</td>
+                            <td>@t.Subject</td>
+                            <td class="text-end">
+                                <a href="/admin/templates/@t.ServiceName/@t.Key/@t.LanguageCode"
+                                   class="btn btn-sm btn-outline-primary me-1">✏️ Edit</a>
+                                <form method="post"
+                                      action="/admin/templates/@t.ServiceName/@t.Key/@t.LanguageCode/delete"
+                                      class="d-inline">
+                                    @Html.AntiForgeryToken()
+                                    <button type="submit"
+                                            class="btn btn-sm btn-outline-danger"
+                                            onclick="return confirm('Delete this template?')">
+                                        🗑️ Delete
+                                    </button>
+                                </form>
+                            </td>
+                        </tr>
+                    }
+                </tbody>
+            </table>
+        </div>
+    </div>
+}

HrynCo.NotificationService.Web/Views/Shared/_EditorLayout.cshtml

@@ -0,0 +1,14 @@
+@{
+    Layout = "~/Views/Shared/_Layout.cshtml";
+}
+<div class="card shadow-sm">
+    <div class="card-header bg-primary text-white">
+        <h5 class="mb-0">@ViewData["EditorTitle"]</h5>
+    </div>
+    <div class="card-body">
+        @RenderBody()
+    </div>
+    <div class="card-footer d-flex gap-2">
+        @RenderSection("FormActions", required: false)
+    </div>
+</div>

HrynCo.NotificationService.Web/Views/Shared/_Layout.cshtml

@@ -0,0 +1,57 @@
+@{
+    var currentController = ViewContext.RouteData.Values["controller"]?.ToString() ?? "";
+    bool isTemplates = currentController.Equals("AdminTemplates", StringComparison.OrdinalIgnoreCase);
+    bool isChannels  = currentController.Equals("AdminChannels",  StringComparison.OrdinalIgnoreCase);
+}
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <title>@ViewData["Title"] – Notification Service</title>
+    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/css/bootstrap.min.css"
+          rel="stylesheet"
+          integrity="sha384-QWTKZyjpPEjISv5WaRU9OFeRpok6YctnYmDr5pNlyT2bRjXh0JMhjY6hW+ALEwIH"
+          crossorigin="anonymous" />
+    <style>
+        body { background-color: #f8f9fa; }
+        .sidebar { min-height: calc(100vh - 56px); background-color: #212529; padding-top: 1rem; }
+        .sidebar .nav-link { color: #adb5bd; border-radius: .375rem; margin-bottom: .25rem; }
+        .sidebar .nav-link:hover { color: #fff; background-color: #343a40; }
+        .sidebar .nav-link.active { color: #fff; background-color: #0d6efd; }
+        .main-content { padding: 2rem; }
+    </style>
+</head>
+<body>
+    <nav class="navbar navbar-dark bg-dark px-3">
+        <a class="navbar-brand fw-bold" href="/">📧 Notification Service</a>
+    </nav>
+
+    <div class="container-fluid">
+        <div class="row">
+            <nav class="col-md-2 d-none d-md-block sidebar py-3">
+                <ul class="nav flex-column px-2">
+                    <li class="nav-item">
+                        <a class="nav-link @(isTemplates ? "active" : "")" href="/admin/templates">
+                            📋 Email Templates
+                        </a>
+                    </li>
+                    <li class="nav-item">
+                        <a class="nav-link @(isChannels ? "active" : "")" href="/admin/channels">
+                            📡 Email Channels
+                        </a>
+                    </li>
+                </ul>
+            </nav>
+
+            <main class="col-md-10 ms-sm-auto main-content">
+                @RenderBody()
+            </main>
+        </div>
+    </div>
+
+    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/js/bootstrap.bundle.min.js"
+            integrity="sha384-YvpcrYf0tY3lHB60NNkmXc4s9bIOgUxi8T/jzmGBE+rYG8O9HP+CyEb1BQGE8B8Z"
+            crossorigin="anonymous"></script>
+</body>
+</html>

HrynCo.NotificationService.Web/Views/_ViewImports.cshtml

@@ -0,0 +1,3 @@
+@using HrynCo.NotificationService.Web
+@using HrynCo.NotificationService.Web.Controllers.Admin
+@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers

HrynCo.NotificationService.Web/Views/_ViewStart.cshtml

@@ -0,0 +1,3 @@
+@{
+    Layout = "~/Views/Shared/_Layout.cshtml";
+}