From 4f7a0785f1f40f30e37ddb5eaaf7a9d8b4d06185 Mon Sep 17 00:00:00 2001
From: Robin Mueller <robin.mueller.m@gmail.com>
Date: Fri, 27 Jan 2023 00:25:51 +0100
Subject: [PATCH] add Error impls for tmtc Error enums

---
 satrs-core/src/tmtc/ccsds_distrib.rs | 28 +++++++++++++++++++++++++---
 satrs-core/src/tmtc/pus_distrib.rs   | 22 ++++++++++++++++++++++
 satrs-example/src/tmtc.rs            |  2 +-
 3 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/satrs-core/src/tmtc/ccsds_distrib.rs b/satrs-core/src/tmtc/ccsds_distrib.rs
index 79b7b63..1e45680 100644
--- a/satrs-core/src/tmtc/ccsds_distrib.rs
+++ b/satrs-core/src/tmtc/ccsds_distrib.rs
@@ -86,8 +86,11 @@
 //! ```
 use crate::tmtc::{ReceivesCcsdsTc, ReceivesTcCore};
 use alloc::boxed::Box;
+use core::fmt::{Display, Formatter};
 use downcast_rs::Downcast;
 use spacepackets::{ByteConversionError, CcsdsPacket, SizeMissmatch, SpHeader};
+#[cfg(feature = "std")]
+use std::error::Error;
 
 /// Generic trait for a handler or dispatcher object handling CCSDS packets.
 ///
@@ -134,7 +137,26 @@ pub struct CcsdsDistributor<E> {
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub enum CcsdsError<E> {
     CustomError(E),
-    PacketError(ByteConversionError),
+    ByteConversionError(ByteConversionError),
+}
+
+impl<E: Display> Display for CcsdsError<E> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
+        match self {
+            Self::CustomError(e) => write!(f, "{e}"),
+            Self::ByteConversionError(e) => write!(f, "{e}"),
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+impl<E: Error> Error for CcsdsError<E> {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        match self {
+            Self::CustomError(e) => e.source(),
+            Self::ByteConversionError(e) => e.source(),
+        }
+    }
 }
 
 impl<E: 'static> ReceivesCcsdsTc for CcsdsDistributor<E> {
@@ -150,7 +172,7 @@ impl<E: 'static> ReceivesTcCore for CcsdsDistributor<E> {
 
     fn pass_tc(&mut self, tc_raw: &[u8]) -> Result<(), Self::Error> {
         if tc_raw.len() < 7 {
-            return Err(CcsdsError::PacketError(
+            return Err(CcsdsError::ByteConversionError(
                 ByteConversionError::FromSliceTooSmall(SizeMissmatch {
                     found: tc_raw.len(),
                     expected: 7,
@@ -158,7 +180,7 @@ impl<E: 'static> ReceivesTcCore for CcsdsDistributor<E> {
             ));
         }
         let (sp_header, _) =
-            SpHeader::from_be_bytes(tc_raw).map_err(|e| CcsdsError::PacketError(e))?;
+            SpHeader::from_be_bytes(tc_raw).map_err(|e| CcsdsError::ByteConversionError(e))?;
         self.dispatch_ccsds(&sp_header, tc_raw)
     }
 }
diff --git a/satrs-core/src/tmtc/pus_distrib.rs b/satrs-core/src/tmtc/pus_distrib.rs
index 9420b4c..9d2290e 100644
--- a/satrs-core/src/tmtc/pus_distrib.rs
+++ b/satrs-core/src/tmtc/pus_distrib.rs
@@ -62,10 +62,13 @@
 //! ```
 use crate::tmtc::{ReceivesCcsdsTc, ReceivesEcssPusTc, ReceivesTcCore};
 use alloc::boxed::Box;
+use core::fmt::{Display, Formatter};
 use downcast_rs::Downcast;
 use spacepackets::ecss::{PusError, PusPacket};
 use spacepackets::tc::PusTc;
 use spacepackets::SpHeader;
+#[cfg(feature = "std")]
+use std::error::Error;
 
 pub trait PusServiceProvider: Downcast {
     type Error;
@@ -104,6 +107,25 @@ pub enum PusDistribError<E> {
     PusError(PusError),
 }
 
+impl<E: Display> Display for PusDistribError<E> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
+        match self {
+            PusDistribError::CustomError(e) => write!(f, "{e}"),
+            PusDistribError::PusError(e) => write!(f, "{e}"),
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+impl<E: Error> Error for PusDistribError<E> {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        match self {
+            Self::CustomError(e) => e.source(),
+            Self::PusError(e) => e.source(),
+        }
+    }
+}
+
 impl<E: 'static> ReceivesTcCore for PusDistributor<E> {
     type Error = PusDistribError<E>;
     fn pass_tc(&mut self, tm_raw: &[u8]) -> Result<(), Self::Error> {
diff --git a/satrs-example/src/tmtc.rs b/satrs-example/src/tmtc.rs
index 34d91a8..fc9aeba 100644
--- a/satrs-example/src/tmtc.rs
+++ b/satrs-example/src/tmtc.rs
@@ -222,7 +222,7 @@ fn poll_tc_server(udp_tmtc_server: &mut UdpTmtcServer) -> bool {
         Ok(_) => true,
         Err(e) => match e {
             ReceiveResult::ReceiverError(e) => match e {
-                CcsdsError::PacketError(e) => {
+                CcsdsError::ByteConversionError(e) => {
                     println!("Got packet error: {e:?}");
                     true
                 }