tests for time stamp provider

Cargo.toml

@@ -17,6 +17,7 @@ serde = "1.0.137"
 zerocopy = "0.6.1"
 crc = "3.0.0"
 delegate = "0.7.0"
+chrono = "0.4.19"
 
 [dependencies.heapless]
 version = "0.7.14"

src/tc.rs

@@ -474,6 +474,7 @@ impl PusTcSecondaryHeader for PusTc<'_> {
         fn ack_flags(&self) -> u8;
     });
 }
+
 #[cfg(test)]
 mod tests {
     use crate::ecss::{PusError, PusPacket};

src/time.rs

@@ -1,4 +1,6 @@
 use crate::PacketError;
+use chrono::{DateTime, TimeZone, Utc};
+
 #[cfg(feature = "std")]
 use std::time::SystemTime;
 
@@ -34,8 +36,8 @@ pub const fn unix_to_ccsds_days(unix_days: i32) -> i32 {
 ///
 ///  - CCSDS epoch: 1958 January 1
 ///  - UNIX Epoch: 1970 January 1
-pub const fn ccsds_to_unix_days(unix_days: i32) -> i32 {
-    unix_days + DAYS_CCSDS_TO_UNIX
+pub const fn ccsds_to_unix_days(ccsds_days: i32) -> i32 {
+    ccsds_days + DAYS_CCSDS_TO_UNIX
 }
 
 /// Trait for generic CCSDS time providers
@@ -48,26 +50,55 @@ trait CcsdsTimeProvider {
     /// in big endian format.
     fn p_field(&self) -> (usize, [u8; 2]);
     fn ccdsd_time_code(&self) -> CcsdsTimeCodes;
-    fn as_unix_seconds(&self) -> u64;
+    fn unix_seconds(&self) -> i64;
+    fn date_time(&self) -> DateTime<Utc>;
 }
 
+#[derive(Debug, Copy, Clone)]
 pub struct CdsShortTimeProvider {
     pfield: u8,
     ccsds_days: u16,
     ms_of_day: u32,
-    unix_seconds: u64,
+    unix_seconds: i64,
+    date_time: Option<DateTime<Utc>>,
 }
 
 impl CdsShortTimeProvider {
     pub fn new(ccsds_days: u16, ms_of_day: u32) -> Self {
-        let mut provider = Self {
+        let provider = Self {
             pfield: (CcsdsTimeCodes::Cds as u8) << 4,
             ccsds_days,
             ms_of_day,
             unix_seconds: 0,
+            date_time: None,
         };
-        provider.calc_unix_seconds();
-        provider
+        let unix_days_seconds = ccsds_to_unix_days(ccsds_days as i32) as i64 * (24 * 60 * 60);
+        provider.setup(unix_days_seconds as i64, ms_of_day.into())
+    }
+
+    #[cfg(feature = "std")]
+    pub fn from_now() -> Self {
+        let now = SystemTime::now()
+            .duration_since(SystemTime::UNIX_EPOCH)
+            .expect("Error retrieving UNIX epoch");
+        let epoch = now.as_secs();
+        let secs_of_day = epoch % SECONDS_PER_DAY as u64;
+        let unix_days_seconds = epoch - secs_of_day;
+        let ms_of_day = secs_of_day * 1000 + now.subsec_millis() as u64;
+        let provider = Self {
+            pfield: (CcsdsTimeCodes::Cds as u8) << 4,
+            ccsds_days: unix_to_ccsds_days((unix_days_seconds / SECONDS_PER_DAY as u64) as i32) as u16,
+            ms_of_day: ms_of_day as u32,
+            unix_seconds: 0,
+            date_time: None,
+        };
+        provider.setup(unix_days_seconds as i64, ms_of_day.into())
+    }
+
+    fn setup(mut self, unix_days_seconds: i64, ms_of_day: u64) -> Self {
+        self.calc_unix_seconds(unix_days_seconds, ms_of_day);
+        self.calc_date_time(unix_days_seconds, (ms_of_day % 1000) as u32);
+        self
     }
 
     #[cfg(feature = "std")]
@@ -83,13 +114,23 @@ impl CdsShortTimeProvider {
         ms_of_day
     }
 
-    fn calc_unix_seconds(&mut self) {
-        let unix_days = ccsds_to_unix_days(self.ccsds_days as i32);
-        self.unix_seconds = unix_days as u64 * (24 * 60 * 60);
-        let seconds_of_day = (self.ms_of_day as f32 / 1000.0).floor() as u64;
+    fn calc_unix_seconds(&mut self, unix_days_seconds: i64, ms_of_day: u64) {
+        self.unix_seconds = unix_days_seconds;
+        let seconds_of_day = (ms_of_day / 1000) as i64;
+        if self.unix_seconds < 0 {
+            self.unix_seconds -= seconds_of_day;
+        } else {
             self.unix_seconds += seconds_of_day;
         }
     }
+
+    fn calc_date_time(&mut self, unix_days_seconds: i64, ms_since_last_second: u32) {
+        assert!(ms_since_last_second < 1000, "Invalid MS since last second");
+        let ns_since_last_sec = ms_since_last_second * 1e6 as u32;
+        self.date_time = Some(Utc.timestamp(unix_days_seconds, ns_since_last_sec));
+    }
+}
+
 impl CcsdsTimeProvider for CdsShortTimeProvider {
     fn len(&self) -> usize {
         CDS_SHORT_LEN
@@ -114,7 +155,68 @@ impl CcsdsTimeProvider for CdsShortTimeProvider {
         CcsdsTimeCodes::Cds
     }
 
-    fn as_unix_seconds(&self) -> u64 {
+    fn unix_seconds(&self) -> i64 {
         self.unix_seconds
     }
+
+    fn date_time(&self) -> DateTime<Utc> {
+        self.date_time.expect("Invalid date time")
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use chrono::{Datelike, Timelike};
+    #[cfg(feature = "std")]
+    use std::println;
+
+    #[test]
+    fn test_creation() {
+        assert_eq!(unix_to_ccsds_days(DAYS_CCSDS_TO_UNIX), 0);
+        assert_eq!(ccsds_to_unix_days(0), DAYS_CCSDS_TO_UNIX);
+    }
+
+    #[cfg(feature = "std")]
+    #[test]
+    fn test_get_current_time() {
+        let sec_floats = seconds_since_epoch();
+        assert!(sec_floats > 0.0);
+    }
+
+    #[test]
+    fn test_time_stamp_zero_args() {
+        let time_stamper = CdsShortTimeProvider::new(0, 0);
+        assert_eq!(
+            time_stamper.unix_seconds(),
+            (DAYS_CCSDS_TO_UNIX * 24 * 60 * 60) as i64
+        );
+        let date_time = time_stamper.date_time();
+        assert_eq!(date_time.year(), 1958);
+        assert_eq!(date_time.month(), 1);
+        assert_eq!(date_time.day(), 1);
+        assert_eq!(date_time.hour(), 0);
+        assert_eq!(date_time.minute(), 0);
+        assert_eq!(date_time.second(), 0);
+    }
+
+    #[test]
+    fn test_time_stamp_unix_epoch() {
+        let time_stamper = CdsShortTimeProvider::new((-DAYS_CCSDS_TO_UNIX) as u16, 0);
+        assert_eq!(time_stamper.unix_seconds(), 0);
+        let date_time = time_stamper.date_time();
+        assert_eq!(date_time.year(), 1970);
+        assert_eq!(date_time.month(), 1);
+        assert_eq!(date_time.day(), 1);
+        assert_eq!(date_time.hour(), 0);
+        assert_eq!(date_time.minute(), 0);
+        assert_eq!(date_time.second(), 0);
+    }
+
+    #[cfg(feature = "std")]
+    #[test]
+    fn test_time_now() {
+        let timestamp_now = CdsShortTimeProvider::from_now();
+        println!("{}", timestamp_now.date_time());
+    }
 }