Strip weather data, RNG, and negative altitudes from packet comments

Weather packets had raw data strings (e.g. 007/000g000t054...)
stored as the comment instead of the trailing human-readable text.
Now iteratively strips fixed-width APRS weather fields in any order,
handling both position-included (XXX/XXX) and positionless (cXXXsXXX)
formats. Also strips RNG data and fixes altitude regex to handle
negative values. Empty comments after cleaning return nil.

lib/aprsme/packet.ex

@@ -750,15 +750,66 @@ defmodule Aprsme.Packet do
 
   defp clean_comment(comment) when is_binary(comment) do
     comment
+    |> strip_weather_data()
     # Remove altitude
-    |> String.replace(~r/\s*\/A=\d{6}/, "")
+    |> String.replace(~r/\s*\/A=-?\d{5,6}/, "")
     # Remove PHG
     |> String.replace(~r/PHG\d{4}\s*/, "")
+    # Remove RNG
+    |> String.replace(~r/RNG\d{4}\s*/, "")
     |> String.trim()
+    |> case do
+      "" -> nil
+      cleaned -> cleaned
+    end
   end
 
   defp clean_comment(comment), do: comment
 
+  # APRS weather fields: each is a letter prefix + fixed number of digits/spaces
+  @wx_field_patterns [
+    ~r/^g[\d .]{3}/,
+    ~r/^t[\d .-]{3}/,
+    ~r/^r[\d .]{3}/,
+    ~r/^p[\d .]{3}/,
+    ~r/^P[\d .]{3}/,
+    ~r/^h[\d .]{2}/,
+    ~r/^b[\d .]{5}/,
+    ~r/^s[\d .]{3}/,
+    ~r/^[Ll][\d .]{3}/
+  ]
+
+  # Matches position-included format (XXX/XXX) and positionless format (cXXXsXXX)
+  @wx_preamble_pattern ~r/^_?(?:[\d .]{3}\/[\d .]{3}|c[\d .]{3}s[\d .]{3})/
+
+  defp strip_weather_data(comment) do
+    case Regex.run(@wx_preamble_pattern, comment) do
+      [match] ->
+        comment
+        |> String.slice(String.length(match)..-1//1)
+        |> strip_wx_fields()
+
+      nil ->
+        comment
+    end
+  end
+
+  defp strip_wx_fields(str) do
+    case match_wx_field(str) do
+      nil -> str
+      match -> str |> String.slice(String.length(match)..-1//1) |> strip_wx_fields()
+    end
+  end
+
+  defp match_wx_field(str) do
+    Enum.find_value(@wx_field_patterns, fn pat ->
+      case Regex.run(pat, str) do
+        [match] -> match
+        nil -> nil
+      end
+    end)
+  end
+
   # Extract altitude from APRS comment field (e.g., "/A=000680" means 680 feet)
   defp extract_altitude_from_comment(nil), do: nil
 

test/aprsme/packet_test.exs

@@ -91,4 +91,122 @@ defmodule Aprsme.PacketTest do
       assert get_in(result, [:data, "telemetry_bits"]) == nil
     end
   end
+
+  describe "comment cleaning" do
+    test "strips weather data from weather packet comments" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "weather",
+        data_extended: %{
+          comment: "007/000g000t054r000p001P001b10052h90eMB61",
+          data_type: :weather,
+          wx: %{temperature: 54, humidity: 90, wind_speed: 0},
+          latitude: 36.124,
+          longitude: -75.723
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+      assert result[:comment] == "eMB61"
+    end
+
+    test "strips weather data with luminosity and preserves trailing comment" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "weather",
+        data_extended: %{
+          comment: "225/004g009t075r000p000h61b10206Plano, TX weather",
+          data_type: :weather,
+          wx: %{temperature: 75, humidity: 61, wind_speed: 4},
+          latitude: 32.0,
+          longitude: -96.0
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+      assert result[:comment] == "Plano, TX weather"
+    end
+
+    test "strips weather data with snow and luminosity fields" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "weather",
+        data_extended: %{
+          comment: "082/002g005t074r000p000P000b10099h58L708eMB63",
+          data_type: :weather,
+          wx: %{temperature: 74, humidity: 58, wind_speed: 2},
+          latitude: 30.0,
+          longitude: -90.0
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+      assert result[:comment] == "eMB63"
+    end
+
+    test "handles weather comment that is all weather data" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "weather",
+        data_extended: %{
+          comment: "_180/010g015t072r000p000h45b10132s005",
+          data_type: :weather,
+          wx: %{temperature: 72, humidity: 45, wind_speed: 10},
+          latitude: 32.0,
+          longitude: -96.0
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+      assert result[:comment] in [nil, ""]
+    end
+
+    test "strips positionless weather format (cXXXsXXX)" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "weather",
+        data_extended: %{
+          comment: "c011s000g000t077r000P000L000h95b10080GW2000C MaxGust:1.1mph",
+          data_type: :weather,
+          wx: %{temperature: 77, humidity: 95},
+          latitude: 6.0,
+          longitude: 79.0
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+      assert result[:comment] == "GW2000C MaxGust:1.1mph"
+    end
+
+    test "strips RNG data from comments" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "position",
+        data_extended: %{
+          comment: "RNG0050 2m Voice 145.57500MHz",
+          latitude: 61.0,
+          longitude: 14.0,
+          radiorange: "0050"
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+      assert result[:comment] == "2m Voice 145.57500MHz"
+    end
+
+    test "does not modify non-weather, non-RNG comments" do
+      attrs = %{
+        sender: "TEST",
+        data_type: "position",
+        data_extended: %{
+          comment: "70cm Voice (D-Star) 447.12500MHz -3.0000MHz",
+          latitude: 46.0,
+          longitude: -94.0
+        }
+      }
+
+      result = Packet.extract_additional_data(attrs, "test_packet")
+      assert result[:comment] == "70cm Voice (D-Star) 447.12500MHz -3.0000MHz"
+    end
+  end
 end