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
143
144
145
146
147
148
149
150
151
152
153
154

use bit_field::BitField;

use {
    UavcanFrame,
    UavcanIndexable,
    TransportFrame,
    UavcanHeader,
};

use parser::{
    ParseError,
    Parser,
};

use crc::calc;

#[derive(Debug)]
pub enum BuilderError {
    FirstFrameNotStartFrame,
    BlockAddedAfterEndFrame,
    ToggleError,
    CRCError,
    FormatError,
}


pub struct MessageBuilder<B: UavcanIndexable + Default> {
    parser: Parser<B>,
    started: bool,
    id: u32,
    crc: u16,
    crc_calculated: u16,
    toggle: bool,
    transfer_id: u8,    
}

impl<B: UavcanIndexable + Default> MessageBuilder<B> {
    pub fn new() -> Self {
        MessageBuilder{
            parser: Parser::new(),
            started: false,
            id: 0x00,
            crc: 0x00,
            crc_calculated: 0xffff,
            toggle: false,
            transfer_id: 0x00,
        }
    }
    
    pub fn add_frame<F: TransportFrame>(mut self, frame: F) -> Result<Self, BuilderError> {
        if !self.started {
            if !frame.is_start_frame() {
                return Err(BuilderError::FirstFrameNotStartFrame);
            }
            if frame.tail_byte().toggle {
                return Err(BuilderError::ToggleError);
            }
            self.toggle = false;
            self.crc.set_bits(0..8, frame.data()[0] as u16)
                .set_bits(8..16, frame.data()[1] as u16); 
            self.transfer_id = frame.tail_byte().transfer_id;
            self.id = frame.id();
            self.started = true;
        }

        let payload = if frame.is_start_frame() && !frame.is_end_frame() {
            &frame.data()[2..frame.data().len()-1]
        } else {
            &frame.data()[0..frame.data().len()-1]
        };

        self.parser = match self.parser.parse(payload) {
            Ok(x) => x,
            Err(ParseError::StructureExhausted) => return Err(BuilderError::FormatError),
        };
            

        return Ok(self);
    }

    pub fn build<H: UavcanHeader, F: UavcanFrame<H, B>>(self) -> Result<F, BuilderError> {
        Ok(F::from_parts(H::from_id(self.id), self.parser.to_structure()))
    }
                
}


#[cfg(test)]
mod tests {

    use{
        UavcanIndexable,
        UavcanPrimitiveField,
        UavcanHeader,
        UavcanFrame,
        TailByte,
    };
    
    use headers::{
        MessageFrameHeader,
    };

    use types::{
        Uint2,
        Uint3,
        Uint16,
        Uint32,
    };
    
    use can_frame::{
        CanFrame,
        CanID,
    };

    use message_builder::{
        MessageBuilder,
    };
    
    #[test]
    fn parse_from_can_frames_simple() {

        #[derive(UavcanIndexable, Default)]
        struct NodeStatus {
            uptime_sec: Uint32,
            health: Uint2,
            mode: Uint3,
            sub_mode: Uint3,
            vendor_specific_status_code: Uint16,
        }

        #[derive(UavcanFrame, Default)]
        struct NodeStatusMessage {
            header: MessageFrameHeader,
            body: NodeStatus,
        }
            
        
        let can_frame = CanFrame{id: CanID::Extended(MessageFrameHeader::from_id(0xaa).to_id()), dlc: 8, data: [1, 0, 0, 0, 0b10001110, 5, 0, TailByte{start_of_transfer: true, end_of_transfer: true, toggle: false, transfer_id: 0}.into()]};
        
        let mut message_builder = MessageBuilder::new();
        message_builder = message_builder.add_frame(can_frame).unwrap();
        let parsed_message: NodeStatusMessage = message_builder.build().unwrap();
        
        assert_eq!(parsed_message.body.uptime_sec, 1.into());
        assert_eq!(parsed_message.body.health, 2.into());
        assert_eq!(parsed_message.body.mode, 3.into());
        assert_eq!(parsed_message.body.sub_mode, 4.into());
        assert_eq!(parsed_message.body.vendor_specific_status_code, 5.into());
        assert_eq!(parsed_message.header, MessageFrameHeader::from_id(0xaa));
                                              
    }

}