Let the sources of your own documents open at the page they were found on (#974)

app/MindWork AI Studio/Tools/RAG/IRetrievalContextExtensions.cs

@@ -8,7 +8,36 @@ namespace AIStudio.Tools.RAG;
 public static class IRetrievalContextExtensions
 {
     private static readonly ILogger<IRetrievalContext> LOGGER = Program.LOGGER_FACTORY.CreateLogger<IRetrievalContext>();
-    
+
+    /// <summary>
+    /// Writes what the AI is told about a retrieval context, before its content follows.
+    /// </summary>
+    /// <remarks>
+    /// The location is what lets the AI say where an answer comes from. Naming only the file is
+    /// not enough in a document of two hundred pages, and we know the page: it travels from the
+    /// runtime through the index into the context. A slide or a sheet has no page, and then
+    /// nothing is claimed rather than something made up.
+    /// </remarks>
+    /// <param name="contextBuilder">The builder to write into.</param>
+    /// <param name="retrievalContext">The context to describe.</param>
+    internal static void AppendContextDescription(StringBuilder contextBuilder, IRetrievalContext retrievalContext)
+    {
+        contextBuilder.AppendLine($"Data source name: {retrievalContext.DataSourceName}");
+        contextBuilder.AppendLine($"Content category: {retrievalContext.Category}");
+        contextBuilder.AppendLine($"Content type: {retrievalContext.Type}");
+        contextBuilder.AppendLine($"Content path: {retrievalContext.Path}");
+
+        if(retrievalContext is RetrievalTextContext { PageNumber: > 0 } locatedContext)
+            contextBuilder.AppendLine($"Content location: page {locatedContext.PageNumber}");
+
+        if(retrievalContext.Links.Count is 0)
+            return;
+
+        contextBuilder.AppendLine("Additional links:");
+        foreach(var link in retrievalContext.Links)
+            contextBuilder.AppendLine($"- {link}");
+    }
+
     public static async Task<string> AsMarkdown(this IReadOnlyList<IRetrievalContext> retrievalContexts, StringBuilder? sb = null, CancellationToken token = default)
     {
         sb ??= new StringBuilder();
@@ -49,17 +78,7 @@ public static class IRetrievalContextExtensions
                 break;
         }
         
-        contextBuilder.AppendLine($"Data source name: {retrievalContext.DataSourceName}");
-        contextBuilder.AppendLine($"Content category: {retrievalContext.Category}");
-        contextBuilder.AppendLine($"Content type: {retrievalContext.Type}");
-        contextBuilder.AppendLine($"Content path: {retrievalContext.Path}");
-            
-        if(retrievalContext.Links.Count > 0)
-        {
-            contextBuilder.AppendLine("Additional links:");
-            foreach(var link in retrievalContext.Links)
-                contextBuilder.AppendLine($"- {link}");
-        }
+        AppendContextDescription(contextBuilder, retrievalContext);
 
         var guardService = Program.SERVICE_PROVIDER.GetRequiredService<PromptInjectionGuardService>();
         var source = PromptInjectionSource.RetrievalContext(retrievalContext.DataSourceName, retrievalContext.Path);

app/MindWork AI Studio/Tools/RAG/RetrievalTextContext.cs

@@ -50,4 +50,14 @@ public sealed class RetrievalTextContext : IRetrievalContext
     /// Optional link used when this context is displayed as a source reference.
     /// </summary>
     public string ReferenceLink { get; init; } = string.Empty;
+
+    /// <summary>
+    /// The page this passage was found on, or null when it has none.
+    /// </summary>
+    /// <remarks>
+    /// Kept as a number rather than only inside the reference title: the AI is told the page so it
+    /// can say where an answer comes from, and a source has to name a page a program can be sent
+    /// to. A slide or a sheet has no page and leaves this empty.
+    /// </remarks>
+    public int? PageNumber { get; init; }
 }