Added the visual briefing assistant (#893)

app/MindWork AI Studio/Assistants/VisualBriefing/VisualBriefingData.cs

@@ -0,0 +1,104 @@
+using System.Text.Json;
+
+namespace AIStudio.Assistants.VisualBriefing;
+
+/// <summary>
+/// Centralizes protected-data and embedded-asset transformations.
+/// </summary>
+internal static class VisualBriefingData
+{
+    /// <summary>
+    /// Removes the app-owned protected block from artifact data.
+    /// </summary>
+    /// <param name="data">Artifact data.</param>
+    /// <returns>Canonical business data.</returns>
+    internal static JsonElement RemoveProtectedData(JsonElement data)
+    {
+        var dictionary = data.EnumerateObject()
+            .Where(property => property.Name is not "_mwai")
+            .ToDictionary(property => property.Name, property => property.Value.Clone(), StringComparer.Ordinal);
+        return JsonSerializer.SerializeToElement(dictionary, VisualBriefingJson.Canonical);
+    }
+
+    /// <summary>
+    /// Extracts the single protected embedded-asset map.
+    /// </summary>
+    /// <param name="data">Artifact data.</param>
+    /// <returns>Stable asset IDs mapped to Data URLs.</returns>
+    internal static Dictionary<string, string> ExtractAssets(JsonElement data)
+    {
+        if (!data.TryGetProperty("_mwai", out var protectedData) ||
+            protectedData.ValueKind is not JsonValueKind.Object ||
+            !protectedData.TryGetProperty("assets", out var assets) ||
+            assets.ValueKind is not JsonValueKind.Object)
+            return [];
+
+        return assets.EnumerateObject()
+            .Where(property => property.Value.ValueKind is JsonValueKind.String)
+            .ToDictionary(
+                property => property.Name,
+                property => property.Value.GetString() ?? string.Empty,
+            StringComparer.Ordinal);
+    }
+
+    /// <summary>
+    /// Extracts protected visual asset descriptions and text alternatives.
+    /// </summary>
+    /// <param name="data">Artifact data.</param>
+    /// <returns>The extracted asset plan.</returns>
+    internal static List<VisualBriefingAssetPlanItem> ExtractAssetPlan(JsonElement data)
+    {
+        if (!data.TryGetProperty("_mwai", out var protectedData) ||
+            protectedData.ValueKind is not JsonValueKind.Object ||
+            !protectedData.TryGetProperty("assetMetadata", out var metadata) ||
+            metadata.ValueKind is not JsonValueKind.Object)
+            return [];
+
+        List<VisualBriefingAssetPlanItem> result = [];
+        foreach (var property in metadata.EnumerateObject())
+        {
+            if (property.Value.ValueKind is not JsonValueKind.Object ||
+                !property.Value.TryGetProperty("description", out var description) ||
+                description.ValueKind is not JsonValueKind.String ||
+                !property.Value.TryGetProperty("altText", out var altText) ||
+                altText.ValueKind is not JsonValueKind.String)
+                continue;
+            result.Add(new()
+            {
+                AssetId = property.Name,
+                Description = description.GetString() ?? string.Empty,
+                AltText = altText.GetString() ?? string.Empty,
+            });
+        }
+        return result;
+    }
+
+    /// <summary>
+    /// Rejects Data URLs and the protected namespace in model-owned business data.
+    /// </summary>
+    /// <param name="data">The model-owned data.</param>
+    /// <returns>An empty string on success or a safe validation issue.</returns>
+    internal static string ValidateBusinessData(JsonElement data)
+    {
+        if (data.ValueKind is not JsonValueKind.Object)
+            return "The canonical content data must be one JSON object.";
+        if (data.TryGetProperty("_mwai", out _))
+            return "The canonical content data uses the reserved _mwai property.";
+        if (ContainsDataUrl(data))
+            return "The canonical content data must reference assets by stable ID and cannot contain Data URLs.";
+        return string.Empty;
+    }
+
+    /// <summary>
+    /// Detects embedded Data URLs recursively.
+    /// </summary>
+    /// <param name="value">The JSON value to inspect.</param>
+    /// <returns>Whether a Data URL is present.</returns>
+    private static bool ContainsDataUrl(JsonElement value) => value.ValueKind switch
+    {
+        JsonValueKind.Array => value.EnumerateArray().Any(ContainsDataUrl),
+        JsonValueKind.Object => value.EnumerateObject().Any(property => ContainsDataUrl(property.Value)),
+        JsonValueKind.String => value.GetString()?.StartsWith("data:", StringComparison.OrdinalIgnoreCase) == true,
+        _ => false,
+    };
+}