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Inspectron.PrintServer.TemplateEditor/Services/JsonPathExtractor.cs

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+using System.Text.Json;
+
+namespace Inspectron.PrintServer.TemplateEditor.Services;
+
+public record JsonPropertyInfo(string Path, string Type, bool IsArray);
+
+public static class JsonPathExtractor
+{
+    public static List<JsonPropertyInfo> Extract(string json)
+    {
+        var results = new List<JsonPropertyInfo>();
+
+        try
+        {
+            using var doc = JsonDocument.Parse(json);
+            WalkElement(doc.RootElement, "", results);
+        }
+        catch (JsonException)
+        {
+            // Invalid JSON - return empty list
+        }
+
+        return results;
+    }
+
+    private static void WalkElement(JsonElement element, string prefix, List<JsonPropertyInfo> results)
+    {
+        switch (element.ValueKind)
+        {
+            case JsonValueKind.Object:
+                foreach (var prop in element.EnumerateObject())
+                {
+                    var path = string.IsNullOrEmpty(prefix) ? prop.Name : $"{prefix}.{prop.Name}";
+
+                    var type = GetTypeName(prop.Value.ValueKind);
+                    var isArray = prop.Value.ValueKind == JsonValueKind.Array;
+
+                    results.Add(new JsonPropertyInfo(path, type, isArray));
+
+                    if (prop.Value.ValueKind == JsonValueKind.Object)
+                    {
+                        WalkElement(prop.Value, path, results);
+                    }
+                    else if (prop.Value.ValueKind == JsonValueKind.Array)
+                    {
+                        WalkArrayElement(prop.Value, path, results);
+                    }
+                }
+                break;
+        }
+    }
+
+    private static void WalkArrayElement(JsonElement array, string arrayPath, List<JsonPropertyInfo> results)
+    {
+        // Inspect first element to discover item property paths
+        foreach (var item in array.EnumerateArray())
+        {
+            if (item.ValueKind == JsonValueKind.Object)
+            {
+                // Use "[item]" prefix to indicate these are array item properties
+                foreach (var prop in item.EnumerateObject())
+                {
+                    var itemPath = $"{arrayPath}[].{prop.Name}";
+                    var type = GetTypeName(prop.Value.ValueKind);
+                    var isArray = prop.Value.ValueKind == JsonValueKind.Array;
+
+                    results.Add(new JsonPropertyInfo(itemPath, type, isArray));
+
+                    if (prop.Value.ValueKind == JsonValueKind.Object)
+                    {
+                        WalkElement(prop.Value, itemPath, results);
+                    }
+                    else if (prop.Value.ValueKind == JsonValueKind.Array)
+                    {
+                        WalkArrayElement(prop.Value, itemPath, results);
+                    }
+                }
+            }
+
+            break; // Only inspect the first element
+        }
+    }
+
+    private static string GetTypeName(JsonValueKind kind) => kind switch
+    {
+        JsonValueKind.String => "string",
+        JsonValueKind.Number => "number",
+        JsonValueKind.True or JsonValueKind.False => "boolean",
+        JsonValueKind.Array => "array",
+        JsonValueKind.Object => "object",
+        JsonValueKind.Null => "null",
+        _ => "unknown"
+    };
+}