Merge pull request #20 from salsabiljb/Binary_Acknowledge_Message_Type_7

feat: add support for msg type 7

src/messages/binary_acknowledge.rs

@@ -0,0 +1,113 @@
+//! Binary Acknowledge (type 7)
+#[cfg(all(not(feature = "std"), not(feature = "alloc")))] 
+ use super::nom_noalloc::many_m_n; 
+use super::AisMessageType;
+use crate::errors::Result;
+use crate::lib;
+use nom::bits::{bits, complete::take as take_bits};
+#[cfg(any(feature = "std", feature = "alloc"))] 
+use nom::multi::many_m_n;
+use nom::IResult;
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct Acknowledgement {
+    pub mmsi: u32,
+    pub seq_num: u8,
+}
+
+impl Acknowledgement {
+    pub fn parse(data: (&[u8], usize)) -> IResult<(&[u8], usize), Self> {
+        let (data, mmsi) = take_bits(30u32)(data)?;
+        let (data, seq_num) = take_bits(2u8)(data)?;
+        Ok((data, Self { mmsi, seq_num }))
+    }
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+pub type AcknowledgementList = lib::std::vec::Vec<Acknowledgement>;
+#[cfg(all(not(feature = "std"), not(feature = "alloc")))]
+pub type AcknowledgementList = lib::std::vec::Vec<Acknowledgement, 4>;
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct BinaryAcknowledge {
+    pub message_type: u8,
+    pub repeat_indicator: u8,
+    pub mmsi: u32,
+    pub acks: AcknowledgementList,
+}
+
+impl<'a> AisMessageType<'a> for BinaryAcknowledge {
+    fn name(&self) -> &'static str {
+        "Binary Acknowledge"
+    }
+
+    fn parse(data: &'a [u8]) -> Result<Self> {
+        let (_, report) = parse_base(data)?;
+        Ok(report)
+    }
+}
+
+fn parse_base<'a>(data: &'a [u8]) -> IResult<&'a [u8], BinaryAcknowledge> {
+    bits(move |data: (&'a [u8], usize)| -> 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)?;
+
+        #[cfg(any(feature = "std", feature = "alloc"))]
+        let (data, acks) = many_m_n(1, 4, Acknowledgement::parse)(data)?;
+        #[cfg(all(not(feature = "std"), not(feature = "alloc")))]
+        let (data, acks) = many_m_n::<_, _, _, _, 4>(1, Acknowledgement::parse)(data)?;
+
+        Ok((
+            data,
+            BinaryAcknowledge {
+                message_type,
+                repeat_indicator,
+                mmsi,
+                acks,
+            },
+        ))
+    })(data)
+}
+
+#[cfg(test)]
+mod tests {
+    #![allow(clippy::unreadable_literal)]
+    use super::*;
+
+    #[test]
+    fn test_type7_example_1() {
+        let bytestream = b"702R5`hwCt40";
+        let bitstream = crate::messages::unarmor(bytestream, 0).unwrap();
+        let report = BinaryAcknowledge::parse(bitstream.as_ref()).unwrap();
+
+        assert_eq!(report.message_type, 7);
+        assert_eq!(report.repeat_indicator, 0);
+        assert_eq!(report.mmsi, 2655651);
+        assert_eq!(report.acks.len(), 1);
+        let ack = &report.acks[0];
+        assert_eq!(ack.mmsi, 265547840);
+        assert_eq!(ack.seq_num, 0);
+    }
+
+    #[test]
+    fn test_type7_example_2() {
+        let bytestream = b"702R5`hwCjq8";
+        let bitstream = crate::messages::unarmor(bytestream, 0).unwrap();
+        let report = BinaryAcknowledge::parse(bitstream.as_ref()).unwrap();
+
+        assert_eq!(report.message_type, 7);
+        assert_eq!(report.repeat_indicator, 0);
+        assert_eq!(report.mmsi, 2655651);
+        assert_eq!(report.acks.len(), 1);
+        let ack = &report.acks[0];
+        assert_eq!(ack.mmsi, 265538450);
+        assert_eq!(ack.seq_num, 0);
+
+        // Ensure other MMSIs are not present
+        assert!(report.acks.get(1).is_none());
+        assert!(report.acks.get(2).is_none());
+        assert!(report.acks.get(3).is_none());
+    }
+}

src/messages/mod.rs

@@ -22,7 +22,7 @@ pub mod static_data_report;
 pub mod types;
 pub mod utc_date_response;
 pub mod standard_aircraft_position_report;
-
+pub mod binary_acknowledge;
 pub use parsers::message_type;
 
 #[cfg(feature = "alloc")]
@@ -44,6 +44,7 @@ pub enum AisMessage {
     StaticDataReport(static_data_report::StaticDataReport),
     UtcDateResponse(utc_date_response::UtcDateResponse),
     StandardAircraftPositionReport(standard_aircraft_position_report::SARPositionReport),
+    BinaryAcknowledgeMessage(binary_acknowledge::BinaryAcknowledge),
 }
 
 /// Trait that describes specific types of AIS messages
@@ -70,6 +71,9 @@ pub fn parse(unarmored: &[u8]) -> Result<AisMessage> {
         5 => Ok(AisMessage::StaticAndVoyageRelatedData(
             static_and_voyage_related_data::StaticAndVoyageRelatedData::parse(unarmored)?,
         )),
+        7 => Ok(AisMessage::BinaryAcknowledgeMessage(
+            binary_acknowledge::BinaryAcknowledge::parse(unarmored)?,
+        )),
         8 => Ok(AisMessage::BinaryBroadcastMessage(
             binary_broadcast_message::BinaryBroadcastMessage::parse(unarmored)?,
         )),