Added Protocol300Transmission to also decode control codes

src/transmission.rs

@@ -0,0 +1,142 @@
+use crate::{Protocol300Message, message};
+use thiserror::Error;
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum Protocol300Transmission {
+    /// 0x06 - ACK, used by all clients as acknowledgement
+    Ack,
+    /// 0x05 - Gets sent periodically to indicate idle/not initialized connection by the heater
+    Enq,
+    /// 0x04 - Resets the connection to a known state
+    Eot,
+    /// 0x16 0x00 0x00 - Initializes the connection, sent by the client
+    Init,
+    /// 0x15 - Negative Acknowledgement, indicates an error in the last message
+    Nack,
+    /// A valid decoded message
+    Message(Protocol300Message)
+}
+
+impl Protocol300Transmission {
+    /// Try to convert bytes to a Protocol 300 Transmission
+    /// 
+    /// # Errors
+    /// Returns a `FromBytesError` if the conversion fails in some way
+    pub fn try_from_bytes(bytes: &[u8]) -> Result<Self, FromBytesError> {
+        match bytes {
+            [0x06] => Ok(Self::Ack),
+            [0x05] => Ok(Self::Enq),
+            [0x04] => Ok(Self::Eot),
+            [0x15] => Ok(Self::Nack),
+            [0x16, 0x00, 0x00] => Ok(Self::Init),
+            [0x41, ..] => Ok(Self::Message(Protocol300Message::try_from_bytes(bytes)?)),
+            _ => Err(FromBytesError::InvalidByte),
+        }
+    }
+
+    #[must_use]
+    pub fn to_bytes(&self) -> Vec<u8> {
+        match self {
+            Self::Ack => vec![0x06],
+            Self::Enq => vec![0x05],
+            Self::Eot => vec![0x04],
+            Self::Init => vec![0x16, 0x00, 0x00],
+            Self::Nack => vec![0x15],
+            Self::Message(protocol300_message) => protocol300_message.to_bytes(),
+        }
+    }
+}
+
+/// Errors that can occur when getting a Protocol 300 Transmission from bytes
+#[derive(Error, Debug, PartialEq, Eq)]
+pub enum FromBytesError{
+    #[error("Failed to parse message")]
+    MessageParsing(#[from] message::MessageDecodingError),
+    #[error("Invalid bytes in vec")]
+    InvalidByte
+
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{FunctionCode, MessageIdentifier, Protocol300Message, transmission::Protocol300Transmission};
+
+    #[test]
+    fn from_bytes_ack() {
+        assert_eq!(Protocol300Transmission::Ack, Protocol300Transmission::try_from_bytes(&[0x06]).unwrap());
+    }
+
+    #[test]
+    fn from_bytes_nack() {
+        assert_eq!(Protocol300Transmission::Nack, Protocol300Transmission::try_from_bytes(&[0x15]).unwrap());
+    }
+
+    #[test]
+    fn from_bytes_eot() {
+        assert_eq!(Protocol300Transmission::Eot, Protocol300Transmission::try_from_bytes(&[0x04]).unwrap());
+    }
+
+    #[test]
+    fn from_bytes_enq() {
+        assert_eq!(Protocol300Transmission::Enq, Protocol300Transmission::try_from_bytes(&[0x05]).unwrap());
+    }
+
+    #[test]
+    fn from_bytes_init() {
+        assert_eq!(Protocol300Transmission::Init, Protocol300Transmission::try_from_bytes(&[0x16, 0x00, 0x00]).unwrap());
+    }
+
+    #[test]
+    fn from_bytes_message() {
+        let message = Protocol300Message{
+            data_address: 0x5525,
+            telegram_length: 0x09,
+            function_code: FunctionCode::VirtualREAD,
+            message_identifier: MessageIdentifier::Response,
+            data_length: 0x04,
+            data: vec![0x07, 0x01, 0x27, 0x11],
+            checksum: 0xC9
+        };
+        let bytes = vec![0x41, 0x09, 0x01, 0x01, 0x55, 0x25, 0x04, 0x07, 0x01, 0x27, 0x11, 0xC9];
+        assert_eq!(Protocol300Transmission::Message(message), Protocol300Transmission::try_from_bytes(&bytes).unwrap());
+    }
+
+    #[test]
+    fn to_bytes_ack() {
+        assert_eq!(Protocol300Transmission::Ack.to_bytes(), &[0x06]);
+    }
+
+    #[test]
+    fn to_bytes_eot() {
+        assert_eq!(Protocol300Transmission::Eot.to_bytes(), &[0x04]);
+    }
+
+    #[test]
+    fn to_bytes_nack() {
+        assert_eq!(Protocol300Transmission::Nack.to_bytes(), &[0x15]);
+    }
+
+    #[test]
+    fn to_bytes_enq() {
+        assert_eq!(Protocol300Transmission::Enq.to_bytes(), &[0x05]);
+    }
+
+    #[test]
+    fn to_bytes_init() {
+        assert_eq!(Protocol300Transmission::Init.to_bytes(), &[0x16, 0x00, 0x00]);
+    }
+
+    #[test]
+    fn to_bytes_message() {
+        let message = Protocol300Message{
+            data_address: 0x5525,
+            telegram_length: 0x09,
+            function_code: FunctionCode::VirtualREAD,
+            message_identifier: MessageIdentifier::Response,
+            data_length: 0x04,
+            data: vec![0x07, 0x01, 0x27, 0x11],
+            checksum: 0xC9
+        };
+        assert_eq!(Protocol300Transmission::Message(message).to_bytes(), &[0x41, 0x09, 0x01, 0x01, 0x55, 0x25, 0x04, 0x07, 0x01, 0x27, 0x11, 0xC9]);
+    }
+}