feat: add blog feed (#3)

* chore: begin working on post service

* chore: add debug assets

* chore: add whitelist words

* feat: add prism for syntax highlighting

* feat: updated favicon

* feat: add blog feed

* fix: add link to written by image

* feat: add custom error pages

* fix: focus on h2 since h1 is always the journal site title

* feat: use status code pages with redirects

* fix: add discernible text to link

* feat: add support for light and dark theme

* fix: wrap body with main tag

* fix: style main element in pages to take up full width of container

* fix: add heading to home page

* feat: add not-found-corgi image

* chore: add robots.txt file

* chore: clean up place holder posts

* fix: namespace header in layouts

* fix: use logger instead of console

* fix: use new text context in each test when registering services

* chore: update workflow to debug failing tests

* chore: install playwright deps

* fix: extend expect timeout

* fix: extend expect timeout

* fix: capture traces

* fix: capture traces

* fix: index file name

src/Blog/Posts/FilePostService.cs

@@ -0,0 +1,108 @@
+namespace Blog.Posts;
+
+class FilePostService(
+  IOptions<FilePostServiceOptions> options,
+  IFileSystem fileSystem,
+  ILogger<FilePostService> logger
+) : IPostService
+{
+  private static readonly JsonSerializerOptions JsonSerializerOptions = new()
+  {
+    PropertyNameCaseInsensitive = true,
+    AllowTrailingCommas = true,
+  };
+
+  private static readonly MarkdownPipeline MarkdownPipeline = new MarkdownPipelineBuilder()
+    .UseAdvancedExtensions()
+    .UsePrism()
+    .Build();
+  
+  private const string MetaFence = "meta";
+  private const string IndexFile = "index.md";
+
+  private readonly FilePostServiceOptions _options = options.Value;
+  private readonly IFileSystem _fileSystem = fileSystem;
+  private readonly ILogger<FilePostService> _logger = logger;
+
+  private static (string? metadata, MarkdownDocument document) ParsePost(string postText)
+  {
+    var markDoc = Markdown.Parse(postText, MarkdownPipeline);
+    var postMetadata = markDoc
+      .Where(
+        x =>
+          x is FencedCodeBlock fencedCodeBlock &&
+          fencedCodeBlock.Arguments is not null &&
+          fencedCodeBlock.Arguments.Contains(MetaFence)
+      )
+      .Select(x => x as FencedCodeBlock)
+      .FirstOrDefault();
+
+    if (postMetadata is not null)
+    {
+      markDoc.Remove(postMetadata);
+    }
+
+    var metaContent = postMetadata?.Lines.ToString();
+
+    return (metaContent, markDoc);
+  }
+
+  public async Task<List<Post>> GetPostsAsync()
+  {
+    var posts = new List<Post>();
+
+    if (_fileSystem.Directory.Exists(_options.PostsDirectory) is false)
+    {
+      return posts;
+    }
+
+    var subDirectories = _fileSystem.Directory.GetDirectories(_options.PostsDirectory);
+
+    if (subDirectories.Length is 0)
+    {
+      return posts;
+    }
+
+    foreach (var subDirectory in subDirectories)
+    {
+      try
+      {
+        var indexFilePath = _fileSystem.Path.Combine(subDirectory, IndexFile);
+        
+        if (_fileSystem.File.Exists(indexFilePath) is false)
+        {
+          continue;
+        }
+        
+        var postText = await _fileSystem.File.ReadAllTextAsync(indexFilePath);
+
+        var (metaContent, document) = ParsePost(postText);
+
+        if (metaContent is null || document.Count is 0)
+        {
+          continue;
+        }
+
+        var post = JsonSerializer.Deserialize<Post>(metaContent, JsonSerializerOptions);
+
+        if (post is null || post.IsPublished is false)
+        {
+          continue;
+        }
+
+        var finalPost = post with
+        {
+          Slug = _fileSystem.Path.GetFileName(subDirectory),
+        };
+
+        posts.Add(finalPost);
+      }
+      catch (Exception ex)
+      {
+        _logger.LogError(ex, "Error while processing post in {SubDirectory}", subDirectory);
+      }
+    }
+
+    return [.. posts.OrderByDescending(x => x.PublishedAt)];
+  }
+}

src/Blog/Posts/FilePostServiceOptions.cs

@@ -0,0 +1,17 @@
+namespace Blog.Posts;
+
+class FilePostServiceOptions
+{
+  public string PostsDirectory { get; set; } = string.Empty;
+}
+
+class FilePostServiceOptionsSetup(IConfiguration configuration) : IConfigureOptions<FilePostServiceOptions>
+{
+  private const string SectionName = nameof(FilePostServiceOptions);
+  private readonly IConfiguration _configuration = configuration;
+
+  public void Configure(FilePostServiceOptions options)
+  {
+    _configuration.GetSection(SectionName).Bind(options);
+  }
+}

src/Blog/Posts/IPostService.cs

@@ -0,0 +1,6 @@
+namespace Blog.Posts;
+
+interface IPostService
+{
+  Task<List<Post>> GetPostsAsync();
+}

src/Blog/Posts/Post.cs

@@ -0,0 +1,15 @@
+namespace Blog.Posts;
+
+record Post
+{
+  public string Title { get; init; } = string.Empty;
+  public string Lead { get; init; } = string.Empty;
+  public bool IsPublished { get; init; } = false;
+  public DateTime PublishedAt { get; init; }
+  public string Slug { get; init; } = string.Empty;
+}
+
+record PostWithContent : Post
+{
+  public string Content { get; init; } = string.Empty;
+}