前端支持cms

docs/cms-setup.md

@@ -10,6 +10,14 @@
 
 初始化完成后，在 **Configuration → Features** 启用 `ElectionSystem.Cms.PublicContent`。该模块的数据迁移会自动创建下列固定公开栏目和公共元数据字段；停用模块不会删除已有公开内容。
 
+## 公开前台接入
+
+选举主程序的 Razor Pages 通过 CMS 主机的只读 `GET /api/public-content` 接口读取内容，绝不直连 CMS 数据库。该接口只允许固定公开内容类型，并且只返回已发布版本的标题、正文、发布时间和公开元数据；草稿、历史版本、选民资料、投票状态、线下计票和内部审计记录均不会返回。
+
+开发环境中主程序默认读取 `http://localhost:5065`。如 CMS 使用其他地址，配置主程序的 `Cms:PublicContentBaseUrl`（部署时使用环境变量 `Cms__PublicContentBaseUrl`）。CMS 未初始化、模块未启用或短暂不可用时，公开前台显示可恢复的“内容服务暂不可用”提示，选举业务不受影响。
+
+内容编辑完成后必须先发布，才会出现在公开首页和 `/content` 各固定栏目中；前台内容详情固定为 `/content/item/{内容 ID}`，不接受 CMS 编辑器自定义路由来覆盖选举系统路由。
+
 ## 首批内容类型
 
 在 CMS 的 Content Definition 中创建以下类型，并统一启用 Title、HTML/Markdown 正文、SEO、Taxonomy、Autoroute、Publish Later、Archive Later 和版本历史：

src/ElectionSystem.Api/Modules/Cms/PublicContentClient.cs

@@ -0,0 +1,93 @@
+using System.Net;
+using System.Net.Http.Json;
+
+namespace ElectionSystem.Api.Modules.Cms;
+
+/// <summary>
+/// Uses the CMS's deliberately small, read-only public contract. It never connects to the CMS database.
+/// </summary>
+public sealed class PublicContentClient(HttpClient httpClient, ILogger<PublicContentClient> logger)
+{
+    public async Task<PublicContentFetch<IReadOnlyList<PublicContentSummary>>> ListAsync(
+        string? contentType,
+        int take,
+        CancellationToken cancellationToken)
+    {
+        var requestUri = contentType is null
+            ? $"api/public-content?take={take}"
+            : $"api/public-content?contentType={Uri.EscapeDataString(contentType)}&take={take}";
+
+        try
+        {
+            using var response = await httpClient.GetAsync(requestUri, cancellationToken);
+            if (response.StatusCode == HttpStatusCode.NotFound)
+            {
+                return PublicContentFetch<IReadOnlyList<PublicContentSummary>>.Unavailable;
+            }
+
+            response.EnsureSuccessStatusCode();
+            var content = await response.Content.ReadFromJsonAsync<List<PublicContentSummary>>(cancellationToken);
+            return new PublicContentFetch<IReadOnlyList<PublicContentSummary>>(content ?? [], true);
+        }
+        catch (HttpRequestException exception)
+        {
+            logger.LogWarning(exception, "The CMS public-content endpoint is unavailable.");
+            return PublicContentFetch<IReadOnlyList<PublicContentSummary>>.Unavailable;
+        }
+        catch (TaskCanceledException) when (!cancellationToken.IsCancellationRequested)
+        {
+            logger.LogWarning("The CMS public-content endpoint timed out.");
+            return PublicContentFetch<IReadOnlyList<PublicContentSummary>>.Unavailable;
+        }
+    }
+
+    public async Task<PublicContentFetch<PublicContentDetail?>> GetAsync(string contentItemId, CancellationToken cancellationToken)
+    {
+        try
+        {
+            using var response = await httpClient.GetAsync($"api/public-content/{Uri.EscapeDataString(contentItemId)}", cancellationToken);
+            if (response.StatusCode == HttpStatusCode.NotFound)
+            {
+                return new PublicContentFetch<PublicContentDetail?>(null, true);
+            }
+
+            response.EnsureSuccessStatusCode();
+            return new PublicContentFetch<PublicContentDetail?>(
+                await response.Content.ReadFromJsonAsync<PublicContentDetail>(cancellationToken),
+                true);
+        }
+        catch (HttpRequestException exception)
+        {
+            logger.LogWarning(exception, "The CMS public-content endpoint is unavailable.");
+            return PublicContentFetch<PublicContentDetail?>.Unavailable;
+        }
+        catch (TaskCanceledException) when (!cancellationToken.IsCancellationRequested)
+        {
+            logger.LogWarning("The CMS public-content endpoint timed out.");
+            return PublicContentFetch<PublicContentDetail?>.Unavailable;
+        }
+    }
+}
+
+public sealed record PublicContentFetch<T>(T? Value, bool IsAvailable)
+{
+    public static PublicContentFetch<T> Unavailable { get; } = new(default, false);
+}
+
+public sealed record PublicContentSummary(
+    string ContentItemId,
+    string ContentType,
+    string Title,
+    string? RoutePath,
+    DateTime? PublishedUtc);
+
+public sealed record PublicContentDetail(
+    string ContentItemId,
+    string ContentType,
+    string Title,
+    string? RoutePath,
+    string Html,
+    DateTime? PublishedUtc,
+    string? ElectionReference,
+    string? EffectiveFromUtc,
+    string? EffectiveToUtc);

src/ElectionSystem.Api/Pages/Content/Detail.cshtml

@@ -0,0 +1,34 @@
+@page "/content/item/{contentItemId}"
+@model ElectionSystem.Api.Pages.Content.DetailModel
+@{
+    ViewData["Title"] = Model.Item?.Title ?? "公开内容";
+}
+<!DOCTYPE html>
+<html lang="zh-CN">
+<head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>@ViewData["Title"] - 选举与投票信息系统</title>
+    <link rel="stylesheet" href="~/css/site.css" />
+</head>
+<body>
+    <header class="site-header"><a class="brand" href="/">选举与投票信息系统</a><nav aria-label="主导航"><a href="/content">信息公开</a></nav></header>
+    <main class="container article">
+        @if (!Model.CmsAvailable)
+        {
+            <p class="status-note">信息公开服务暂不可用，请稍后刷新页面。</p>
+        }
+        else if (Model.Item is { } item)
+        {
+            <p class="eyebrow">@item.ContentType</p>
+            <h1>@item.Title</h1>
+            @if (item.PublishedUtc is { } publishedUtc)
+            {
+                <p class="published-at">发布时间：<time datetime="@publishedUtc.ToString("O")">@publishedUtc.ToLocalTime().ToString("yyyy-MM-dd HH:mm")</time></p>
+            }
+            <div class="cms-body">@Html.Raw(item.Html)</div>
+        }
+    </main>
+    <footer class="site-footer">所有时间和结果以活动正式公告为准。</footer>
+</body>
+</html>