feat: add support for ais msg type 16

src/messages/assignment_mode_command.rs

@@ -0,0 +1,140 @@
+//! Assignment Mode Command (type 16)
+
+use super::parsers::*;
+use super::AisMessageType;
+use crate::errors::Result;
+use nom::bits::{bits, complete::take as take_bits};
+use nom::IResult;
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct AssignmentModeCommand {
+    pub message_type: u8,
+    pub repeat_indicator: u8,
+    pub mmsi: u32,
+    pub mmsi1: u32,
+    pub offset1: u16,
+    pub increment1: u16,
+    pub mmsi2: Option<u32>,
+    pub offset2: Option<u16>,
+    pub increment2: Option<u16>,
+}
+
+impl<'a> AisMessageType<'a> for AssignmentModeCommand {
+    fn name(&self) -> &'static str {
+        "Assignment Mode Command"
+    }
+
+    fn parse(data: &'a [u8]) -> Result<Self> {
+        let (_, report) = parse_base(data)?;
+        Ok(report)
+    }
+}
+
+fn parse_base(data: &[u8]) -> IResult<&[u8], AssignmentModeCommand> {
+    bits(move |data| -> IResult<_, _> {
+        let (data, message_type) = take_bits(6u8)(data)?;
+        let (data, repeat_indicator) = take_bits(2u8)(data)?;
+        let (data, mmsi) = take_bits(30u32)(data)?;
+        let (data, _spare) = take_bits::<_, u8, _, _>(2u8)(data)?;
+
+        let (data, mmsi1) = take_bits(30u32)(data)?;
+        let (data, offset1) = take_bits(12u16)(data)?;
+        let (data, increment1) = take_bits(10u16)(data)?;
+
+        // Check for remaining bits, if there are enough bits for the second station
+        let remaining_bits = remaining_bits(data);
+
+        if remaining_bits >= 52 {
+            let (data, mmsi2) = take_bits(30u32)(data)?;
+            let (data, offset2) = take_bits(12u16)(data)?;
+            let (data, increment2) = take_bits(10u16)(data)?;
+
+            Ok((
+                data,
+                AssignmentModeCommand {
+                    message_type,
+                    repeat_indicator,
+                    mmsi,
+                    mmsi1,
+                    offset1,
+                    increment1,
+                    mmsi2: Some(mmsi2),
+                    offset2: Some(offset2),
+                    increment2: Some(increment2),
+                },
+            ))
+        } else {
+            // Only one station assignment
+            Ok((
+                data,
+                AssignmentModeCommand {
+                    message_type,
+                    repeat_indicator,
+                    mmsi,
+                    mmsi1,
+                    offset1,
+                    increment1,
+                    mmsi2: None,
+                    offset2: None,
+                    increment2: None,
+                },
+            ))
+        }
+    })(data)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_type16_example_1_single_station() {
+        let bytestream = b"@01uEO@mMk7P<P00";
+        let bitstream = crate::messages::unarmor(bytestream, 0).unwrap();
+        let report = AssignmentModeCommand::parse(bitstream.as_ref()).unwrap();
+
+        assert_eq!(report.message_type, 16);
+        assert_eq!(report.repeat_indicator, 0);
+        assert_eq!(report.mmsi, 2053501);
+        assert_eq!(report.mmsi1, 224251000);
+        assert_eq!(report.offset1, 200);
+        assert_eq!(report.increment1, 0);
+        assert_eq!(report.mmsi2, None);
+        assert_eq!(report.offset2, None);
+        assert_eq!(report.increment2, None);
+    }
+
+    #[test]
+    fn test_type16_example_2_single_station() {
+        let bytestream = b"@01uEO@hsqJ0<P00";
+        let bitstream = crate::messages::unarmor(bytestream, 0).unwrap();
+        let report = AssignmentModeCommand::parse(bitstream.as_ref()).unwrap();
+
+        assert_eq!(report.message_type, 16);
+        assert_eq!(report.repeat_indicator, 0);
+        assert_eq!(report.mmsi, 2053501);
+        assert_eq!(report.mmsi1, 205252000);
+        assert_eq!(report.offset1, 200);
+        assert_eq!(report.increment1, 0);
+        assert_eq!(report.mmsi2, None);
+        assert_eq!(report.offset2, None);
+        assert_eq!(report.increment2, None);
+    }
+
+    #[test]
+    fn test_type16_example_with_two_stations() {
+        let bytestream = b"@6STUk004lQ206bCKNOBAb6SJ@5s";
+        let bitstream = crate::messages::unarmor(bytestream, 0).unwrap();
+        let report = AssignmentModeCommand::parse(bitstream.as_ref()).unwrap();
+
+        assert_eq!(report.message_type, 16);
+        assert_eq!(report.repeat_indicator, 0);
+        assert_eq!(report.mmsi, 439952844);
+        assert_eq!(report.mmsi1, 315920);
+        assert_eq!(report.offset1, 2049);
+        assert_eq!(report.increment1, 681);
+        assert_eq!(report.mmsi2, Some(230137673));
+        assert_eq!(report.offset2, Some(424));
+        assert_eq!(report.increment2, Some(419));
+    }
+}

src/messages/mod.rs

@@ -5,6 +5,7 @@ use crate::sentence::AisRawData;
 
 pub mod addressed_safety_related;
 pub mod aid_to_navigation_report;
+pub mod assignment_mode_command;
 pub mod base_station_report;
 pub mod binary_addressed;
 pub mod binary_broadcast_message;
@@ -58,6 +59,7 @@ pub enum AisMessage {
     SafetyRelatedAcknowledgment(safety_related_acknowledgment::SafetyRelatedAcknowledge),
     LongRangeAisBroadcastMessage(long_range_ais_broadcast::LongRangeAisBroadcastMessage),
     BinaryAddressedMessage(binary_addressed::BinaryAddressedMessage),
+    AssignmentModeCommand(assignment_mode_command::AssignmentModeCommand),
 }
 
 /// Trait that describes specific types of AIS messages
@@ -114,6 +116,9 @@ pub fn parse(unarmored: &[u8]) -> Result<AisMessage> {
         15 => Ok(AisMessage::Interrogation(
             interrogation::Interrogation::parse(unarmored)?,
         )),
+        16 => Ok(AisMessage::AssignmentModeCommand(
+            assignment_mode_command::AssignmentModeCommand::parse(unarmored)?,
+        )),
         17 => Ok(AisMessage::DgnssBroadcastBinaryMessage(
             dgnss_broadcast_binary_message::DgnssBroadcastBinaryMessage::parse(unarmored)?,
         )),