add ECSS TC scheduling helper API

src/ecss/scheduling.rs

@@ -1,8 +1,18 @@
 //! PUS Service 11 Scheduling
+use core::fmt::Display;
+
 use num_enum::{IntoPrimitive, TryFromPrimitive};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
+use crate::{
+    time::{TimeWriter, TimestampError},
+    util::ToBeBytes,
+    ByteConversionError,
+};
+
+use super::{PusError, WritablePusPacket};
+
 #[derive(Debug, PartialEq, Eq, Copy, Clone, IntoPrimitive, TryFromPrimitive)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[repr(u8)]
@@ -73,11 +83,103 @@ pub enum TimeWindowType {
     ToTimeTag = 3,
 }
 
+#[derive(Debug, PartialEq, Eq, Copy, Clone)]
+pub enum ScheduleTcGenerationError {
+    ByteConversionError(ByteConversionError),
+    TimestampError(TimestampError),
+    PusError(PusError),
+}
+
+impl From<ByteConversionError> for ScheduleTcGenerationError {
+    fn from(error: ByteConversionError) -> Self {
+        Self::ByteConversionError(error)
+    }
+}
+
+impl From<TimestampError> for ScheduleTcGenerationError {
+    fn from(error: TimestampError) -> Self {
+        Self::TimestampError(error)
+    }
+}
+
+impl From<PusError> for ScheduleTcGenerationError {
+    fn from(error: PusError) -> Self {
+        Self::PusError(error)
+    }
+}
+
+impl Display for ScheduleTcGenerationError {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        let const_str = "pus schedule tc generation:";
+        match self {
+            Self::PusError(e) => {
+                write!(f, "{const_str} {e}")
+            }
+            Self::ByteConversionError(e) => {
+                write!(f, "{const_str} {e}")
+            }
+            Self::TimestampError(e) => {
+                write!(f, "{const_str} {e}")
+            }
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+impl std::error::Error for ScheduleTcGenerationError {}
+
+/// Helper function to generate the application data for a PUS telecommand to insert an
+/// activity into a time-based schedule according to ECSS-E-ST-70-41C 8.11.2.4
+///
+/// Please note that the N field is set to a [u16] unsigned bytefield with the value 1.
+pub fn generate_insert_telecommand_app_data(
+    buf: &mut [u8],
+    release_time: &impl TimeWriter,
+    request: &impl WritablePusPacket,
+) -> Result<usize, ScheduleTcGenerationError> {
+    let required_len = 2 + release_time.len_written() + request.len_written();
+    if required_len > buf.len() {
+        return Err(ByteConversionError::ToSliceTooSmall {
+            found: buf.len(),
+            expected: required_len,
+        }
+        .into());
+    }
+    let mut current_len = 0;
+    let n = 1_u16;
+    buf[current_len..current_len + 2].copy_from_slice(&n.to_be_bytes());
+    current_len += 2;
+    current_len += release_time
+        .write_to_bytes(&mut buf[current_len..current_len + release_time.len_written()])?;
+    current_len +=
+        request.write_to_bytes(&mut buf[current_len..current_len + request.len_written()])?;
+    Ok(current_len)
+}
+
+/// This function is similar to [generate_insert_telecommand_app_data] but returns the application
+/// data as a [alloc::vec::Vec].
+#[cfg(feature = "alloc")]
+pub fn generate_insert_telecommand_app_data_as_vec(
+    release_time: &impl TimeWriter,
+    request: &impl WritablePusPacket,
+) -> Result<alloc::vec::Vec<u8>, ScheduleTcGenerationError> {
+    let mut vec = alloc::vec::Vec::new();
+    vec.extend_from_slice(&1_u16.to_be_bytes());
+    vec.append(&mut release_time.to_vec()?);
+    vec.append(&mut request.to_vec()?);
+    Ok(vec)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
     #[cfg(feature = "serde")]
     use crate::tests::generic_serde_test;
+    use crate::{
+        ecss::tc::{PusTcCreator, PusTcReader, PusTcSecondaryHeader},
+        time::cds,
+        PacketId, PacketSequenceCtrl, PacketType, SpHeader,
+    };
 
     #[test]
     fn test_bool_conv_0() {
@@ -122,4 +224,43 @@ mod tests {
     fn test_serde_time_window_type() {
         generic_serde_test(TimeWindowType::SelectAll);
     }
+
+    #[test]
+    fn test_generic_insert_app_data_test() {
+        let time_writer = cds::TimeProvider::new_with_u16_days(1, 1);
+        let mut sph = SpHeader::new(
+            PacketId::const_new(PacketType::Tc, true, 0x002),
+            PacketSequenceCtrl::const_new(crate::SequenceFlags::Unsegmented, 5),
+            0,
+        );
+        let sec_header = PusTcSecondaryHeader::new_simple(17, 1);
+        let ping_tc = PusTcCreator::new_no_app_data(&mut sph, sec_header, true);
+        let mut buf: [u8; 64] = [0; 64];
+        let result = generate_insert_telecommand_app_data(&mut buf, &time_writer, &ping_tc);
+        assert!(result.is_ok());
+        assert_eq!(result.unwrap(), 2 + 7 + ping_tc.len_written());
+        let n = u16::from_be_bytes(buf[0..2].try_into().unwrap());
+        assert_eq!(n, 1);
+        let time_reader = cds::TimeProvider::from_bytes_with_u16_days(&buf[2..2 + 7]).unwrap();
+        assert_eq!(time_reader, time_writer);
+        let pus_tc_reader = PusTcReader::new(&buf[9..]).unwrap().0;
+        assert_eq!(pus_tc_reader, ping_tc);
+    }
+
+    #[test]
+    fn test_generic_insert_app_data_test_as_vec() {
+        let time_writer = cds::TimeProvider::new_with_u16_days(1, 1);
+        let mut sph = SpHeader::new(
+            PacketId::const_new(PacketType::Tc, true, 0x002),
+            PacketSequenceCtrl::const_new(crate::SequenceFlags::Unsegmented, 5),
+            0,
+        );
+        let sec_header = PusTcSecondaryHeader::new_simple(17, 1);
+        let ping_tc = PusTcCreator::new_no_app_data(&mut sph, sec_header, true);
+        let mut buf: [u8; 64] = [0; 64];
+        generate_insert_telecommand_app_data(&mut buf, &time_writer, &ping_tc).unwrap();
+        let vec = generate_insert_telecommand_app_data_as_vec(&time_writer, &ping_tc)
+            .expect("vec generation failed");
+        assert_eq!(&buf[..vec.len()], vec);
+    }
 }