Centralize summary frontmatter metadata

MeetingAssistant/Summary/MeetingSummaryFailureWriter.cs

@@ -52,11 +52,11 @@ public sealed class MeetingSummaryFailureWriter : IMeetingSummaryFailureWriter
         var meetingNote = File.Exists(artifacts.MeetingNotePath)
             ? await meetingNoteStore.ReadAsync(artifacts.MeetingNotePath, cancellationToken)
             : new MeetingNote("", new MeetingNoteFrontmatter(), "");
-        var frontmatter = MeetingArtifactFrontmatterRenderer.Create(
+        var frontmatter = await MeetingSummaryFrontmatterFactory.CreateAsync(
             artifacts,
             meetingNote,
             MeetingArtifactFrontmatterRenderer.DefaultTitle(meetingNote, "Meeting Summary"),
-            artifacts.SummaryPath);
+            cancellationToken);
         await File.WriteAllTextAsync(
             artifacts.SummaryPath,
             MeetingArtifactFrontmatterRenderer.Render(

MeetingAssistant/Summary/MeetingSummaryFrontmatterFactory.cs

@@ -0,0 +1,70 @@
+using MeetingAssistant.MeetingNotes;
+using YamlDotNet.Serialization;
+
+namespace MeetingAssistant.Summary;
+
+internal static class MeetingSummaryFrontmatterFactory
+{
+    private static readonly IDeserializer YamlDeserializer = new DeserializerBuilder()
+        .IgnoreUnmatchedProperties()
+        .Build();
+
+    public static async Task<MeetingArtifactFrontmatter> CreateAsync(
+        MeetingSessionArtifacts artifacts,
+        MeetingNote meetingNote,
+        string title,
+        CancellationToken cancellationToken)
+    {
+        var frontmatter = MeetingArtifactFrontmatterRenderer.Create(
+            artifacts,
+            meetingNote,
+            title,
+            artifacts.SummaryPath);
+        frontmatter.Attendees = await ResolveSummaryAttendeesAsync(
+            artifacts.SummaryPath,
+            meetingNote,
+            cancellationToken);
+        frontmatter.Projects = CopyNonEmptyList(meetingNote.Frontmatter.Projects);
+        return frontmatter;
+    }
+
+    private static async Task<List<string>?> ResolveSummaryAttendeesAsync(
+        string summaryPath,
+        MeetingNote meetingNote,
+        CancellationToken cancellationToken)
+    {
+        var existingAttendees = await ReadExistingSummaryAttendeesAsync(summaryPath, cancellationToken);
+        return existingAttendees ?? CopyNonEmptyList(meetingNote.Frontmatter.Attendees);
+    }
+
+    private static List<string>? CopyNonEmptyList(IReadOnlyCollection<string> values)
+    {
+        return values.Count == 0 ? null : values.ToList();
+    }
+
+    private static async Task<List<string>?> ReadExistingSummaryAttendeesAsync(
+        string summaryPath,
+        CancellationToken cancellationToken)
+    {
+        if (!File.Exists(summaryPath))
+        {
+            return null;
+        }
+
+        var content = await File.ReadAllTextAsync(summaryPath, cancellationToken);
+        var document = MarkdownDocumentParser.SplitOptional(content);
+        if (!document.HasFrontmatter)
+        {
+            return null;
+        }
+
+        var yaml = YamlDeserializer.Deserialize<SummaryFrontmatterYaml>(document.Frontmatter);
+        return yaml?.Attendees;
+    }
+
+    private sealed class SummaryFrontmatterYaml
+    {
+        [YamlMember(Alias = "attendees")]
+        public List<string>? Attendees { get; set; }
+    }
+}

MeetingAssistant/Summary/MeetingSummaryTools.cs

@@ -101,13 +101,11 @@ public sealed class MeetingSummaryTools
         var summaryTitle = string.IsNullOrWhiteSpace(meetingNote.Frontmatter.Title)
             ? title
             : meetingNote.Frontmatter.Title;
-        var frontmatter = MeetingArtifactFrontmatterRenderer.Create(
+        var frontmatter = await MeetingSummaryFrontmatterFactory.CreateAsync(
             artifacts,
             meetingNote,
             string.IsNullOrWhiteSpace(summaryTitle) ? "Meeting Summary" : summaryTitle,
-            artifacts.SummaryPath);
-        frontmatter.Attendees = await ResolveSummaryAttendeesAsync(meetingNote);
-        frontmatter.Projects = ResolveSummaryProjects(meetingNote);
+            CancellationToken.None);
         await File.WriteAllTextAsync(
             artifacts.SummaryPath,
             MeetingArtifactFrontmatterRenderer.Render(frontmatter, markdown));
@@ -579,44 +577,6 @@ public sealed class MeetingSummaryTools
             .Replace(Path.AltDirectorySeparatorChar.ToString(), "/", StringComparison.Ordinal);
     }
 
-    private async Task<List<string>?> ResolveSummaryAttendeesAsync(MeetingNote meetingNote)
-    {
-        var existingAttendees = await ReadExistingSummaryAttendeesAsync();
-        if (existingAttendees is not null)
-        {
-            return existingAttendees;
-        }
-
-        return meetingNote.Frontmatter.Attendees.Count == 0
-            ? null
-            : meetingNote.Frontmatter.Attendees.ToList();
-    }
-
-    private static List<string>? ResolveSummaryProjects(MeetingNote meetingNote)
-    {
-        return meetingNote.Frontmatter.Projects.Count == 0
-            ? null
-            : meetingNote.Frontmatter.Projects.ToList();
-    }
-
-    private async Task<List<string>?> ReadExistingSummaryAttendeesAsync()
-    {
-        if (!File.Exists(artifacts.SummaryPath))
-        {
-            return null;
-        }
-
-        var content = await File.ReadAllTextAsync(artifacts.SummaryPath);
-        var document = MarkdownDocumentParser.SplitOptional(content);
-        if (!document.HasFrontmatter)
-        {
-            return null;
-        }
-
-        var yaml = YamlDeserializer.Deserialize<SummaryFrontmatterYaml>(document.Frontmatter);
-        return yaml?.Attendees;
-    }
-
     private sealed record ProjectFileTarget(BoundMeetingProject Project, string Path);
 
     private sealed record FileLineEditMode(
@@ -679,12 +639,6 @@ public sealed class MeetingSummaryTools
         public string? Summary { get; set; }
     }
 
-    private sealed class SummaryFrontmatterYaml
-    {
-        [YamlDotNet.Serialization.YamlMember(Alias = "attendees")]
-        public List<string>? Attendees { get; set; }
-    }
-
     private static DateTimeOffset? ParseDateTime(string? value)
     {
         return DateTimeOffset.TryParse(value, out var parsed)