Add a rules controller

app/controllers/api/rules_controller.rb

@@ -9,15 +9,18 @@ module Api
     # GET /api/:public_key/rules/version
     # Quick version check - returns latest updated_at timestamp
     def version
+      current_sampling = HubLoad.current_sampling
+      response.headers['X-Sample-Rate'] = current_sampling[:allowed_requests].to_s
+
       render json: {
         version: Rule.latest_version,
         count: Rule.active.count,
-        sampling: HubLoad.current_sampling
+        sampling: current_sampling
       }
     end
 
-    # GET /api/:public_key/rules?since=2024-11-03T12:00:00.000Z
-    # Incremental sync - returns rules updated since timestamp
+    # GET /api/:public_key/rules?since=1730646186272060
+    # Incremental sync - returns rules updated since timestamp (microsecond Unix timestamp)
     # GET /api/:public_key/rules
     # Full sync - returns all active rules
     def index
@@ -30,9 +33,12 @@ module Api
         Rule.active.sync_order
       end
 
+      current_sampling = HubLoad.current_sampling
+      response.headers['X-Sample-Rate'] = current_sampling[:allowed_requests].to_s
+
       render json: {
         version: Rule.latest_version,
-        sampling: HubLoad.current_sampling,
+        sampling: current_sampling,
         rules: rules.map(&:to_agent_format)
       }
     rescue ArgumentError => e
@@ -59,9 +65,17 @@ module Api
     end
 
     def parse_timestamp(timestamp_str)
-      Time.parse(timestamp_str)
+      # Parse microsecond Unix timestamp
+      unless timestamp_str.match?(/^\d+$/)
+        raise ArgumentError, "Invalid timestamp format. Expected microsecond Unix timestamp (e.g., 1730646186272060)"
+      end
+
+      total_microseconds = timestamp_str.to_i
+      seconds = total_microseconds / 1_000_000
+      microseconds = total_microseconds % 1_000_000
+      Time.at(seconds, microseconds)
     rescue ArgumentError => e
-      raise ArgumentError, "Invalid timestamp format. Expected ISO8601 format (e.g., 2024-11-03T12:00:00.000Z)"
+      raise ArgumentError, "Invalid timestamp format: #{e.message}. Use microsecond Unix timestamp (e.g., 1730646186272060)"
     end
   end
 end