1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142

use alloc::vec;
use serde::{Serialize, Deserialize};
use core::convert::TryInto;

use crate::convert_packet::{ConvertPacket, ConvertPacketError};
use crate::event::event_code::*;
use crate::event::EventError;
use crate::packet::Packet;

#[repr(C)]
#[derive(Serialize, Deserialize, Debug, PartialEq, Clone)]
pub enum MessageValue {
    U8(u8),
    U16(u16),
    U32(u32),
}

#[derive(Debug, PartialEq)]
pub struct MessageEvent {
    pub receiver_address: u16,
    pub transmitter_address: u16,
    pub code: u16,
    pub value: MessageValue,
}

impl ConvertPacket<MessageEvent> for MessageEvent {
    fn try_from_packet(packet: &Packet) -> Result<Self, ConvertPacketError> {
        if packet.data.len() != 11 {
            return Err(ConvertPacketError::WrongSize);
        }

        if packet.is_error {
            return Err(ConvertPacketError::WrongType);
        }

        if u16::from_be_bytes(packet.data[0..=1].try_into().unwrap()) != MESSAGE_EVENT_CODE {
            return Err(ConvertPacketError::Event(EventError::WrongEventType));
        }

        let receiver_address = packet.device_address;
        let transmitter_address = u16::from_be_bytes(packet.data[2..=3].try_into().unwrap());
        let code = u16::from_be_bytes(packet.data[4..=5].try_into().unwrap());
        let value = postcard::from_bytes(&packet.data[6..=10]).map_err(|err| ConvertPacketError::PostcardError(err))?;

        Ok(Self {
            receiver_address,
            transmitter_address,
            code,
            value,
        })
    }

    fn to_packet(&self) -> Packet {
        let mut data = vec![];

        for byte in u16::to_be_bytes(MESSAGE_EVENT_CODE).iter() {
            data.push(*byte);
        }

        for byte in u16::to_be_bytes(self.transmitter_address).iter() {
            data.push(*byte);
        }

        for byte in u16::to_be_bytes(self.code).iter() {
            data.push(*byte);
        }

        let mut value_buffer = [0u8; 5];
        postcard::to_slice(&self.value, &mut value_buffer).unwrap();
        for byte in value_buffer.iter() {
            data.push(*byte);
        }

        Packet {
            is_error: false,
            device_address: self.receiver_address,
            data,
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    const EVENT_PACKET: Packet = Packet {
        is_error: false,
        device_address: 0xabab,
        data: vec![],
    };

    #[test]
    fn try_from_packet_test() {
        let mut packet = EVENT_PACKET;
        packet.data = vec![
            ((MESSAGE_EVENT_CODE >> 8) & 0xff) as u8, // event code
            ((MESSAGE_EVENT_CODE >> 0) & 0xff) as u8, // event code
            0x00,                                     // transmitter address
            0x00,                                     // transmitter address
            0x01,                                     // code
            0x23,                                     // code
            0x02,                                     // value
            0xff,                                     // value
            0xff,                                     // value
            0xff,                                     // value
            0xff,                                     // value
        ];

        let event = MessageEvent::try_from_packet(&packet).unwrap();

        assert_eq!(event.receiver_address, 0xabab);
        assert_eq!(event.transmitter_address, 0x0000);
        assert_eq!(event.code, 0x0123);
    }

    #[test]
    fn to_packet_test() {
        let event = MessageEvent {
            receiver_address: 0xabab,
            transmitter_address: 0x0000,
            code: 0x0123,
            value: MessageValue::U32(0xffff_ffff),
        };

        let mut packet = EVENT_PACKET;
        packet.data = vec![
            ((MESSAGE_EVENT_CODE >> 8) & 0xff) as u8, // event code
            ((MESSAGE_EVENT_CODE >> 0) & 0xff) as u8, // event code
            0x00,                                     // transmitter address
            0x00,                                     // transmitter address
            0x01,                                     // code
            0x23,                                     // code
            0x02,                                     // value
            0xff,                                     // value
            0xff,                                     // value
            0xff,                                     // value
            0xff,                                     // value
        ];

        assert_eq!(event.to_packet(), packet);
    }
}