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

use super::parsers::u8_to_bool;
use nom::bits::complete::take as take_bits;
use nom::combinator::map;
use nom::error::ErrorKind;
use nom::IResult;

#[derive(Debug, PartialEq)]
pub enum RadioStatus {
    Sotdma(SotdmaMessage),
    Itdma(ItdmaMessage),
}

#[derive(Debug, PartialEq, Copy, Clone)]
pub enum SyncState {
    UtcDirect,
    UtcIndirect,
    BaseStation,
    NumberOfReceivedStations,
    Unknown(u8),
}

impl SyncState {
    pub fn parse(data: u8) -> Self {
        match data {
            0 => SyncState::UtcDirect,
            1 => SyncState::UtcIndirect,
            2 => SyncState::BaseStation,
            3 => SyncState::NumberOfReceivedStations,
            // TODO: maybe this should panic?
            _ => Self::Unknown(data),
        }
    }
}

#[derive(Debug, PartialEq)]
pub enum SubMessage {
    SlotOffset(i16),
    UtcHourAndMinute(u8, u8),
    SlotNumber(u16),
    ReceivedStations(u16),
}

impl SubMessage {
    fn parse(input: (&[u8], usize), slot_timeout: u8) -> IResult<(&[u8], usize), SubMessage> {
        match slot_timeout {
            0 => Self::slot_offset(input),
            1 => Self::utc_hour_and_minute(input),
            2 | 4 | 6 => {
                let (data, slot_number) = Self::subm_u16(input)?;
                Ok((data, SubMessage::SlotNumber(slot_number)))
            }
            3 | 5 | 7 => {
                let (data, slot_number) = Self::subm_u16(input)?;
                Ok((data, SubMessage::ReceivedStations(slot_number)))
            }
            _ => unreachable!()
        }
    }

    fn utc_hour_and_minute(data: (&[u8], usize)) -> IResult<(&[u8], usize), Self> {
        let (data, hour) = take_bits::<_, _, _, (_, _)>(5u8)(data)?;
        let (data, _spare) = take_bits::<_, u8, _, (_, _)>(1u8)(data)?;
        let (data, minute) = take_bits::<_, _, _, (_, _)>(6u8)(data)?;
        let (data, _spare) = take_bits::<_, u8, _, (_, _)>(2u8)(data)?;
        Ok((data, Self::UtcHourAndMinute(hour, minute)))
    }

    fn slot_offset(data: (&[u8], usize)) -> IResult<(&[u8], usize), Self> {
        let (data, slot_offset) = take_bits::<_, _, _, (_, _)>(14u16)(data)?;
        Ok((data, Self::SlotOffset(slot_offset)))
    }

    fn subm_u16(data: (&[u8], usize)) -> IResult<(&[u8], usize), u16> {
        take_bits::<_, _, _, (_, _)>(14u16)(data)
    }
}

#[derive(Debug, PartialEq)]
pub struct SotdmaMessage {
    pub sync_state: SyncState,
    pub slot_timeout: u8,
    pub sub_message: SubMessage,
}

impl SotdmaMessage {
    pub fn parse(data: (&[u8], usize)) -> IResult<(&[u8], usize), RadioStatus> {
        let (data, sync_state) = map(take_bits::<_, _, _, (_, _)>(2u8), SyncState::parse)(data)?;
        let (data, slot_timeout) = take_bits::<_, _, _, (_, _)>(3u8)(data)?;
        let (data, sub_message) = SubMessage::parse(data, slot_timeout)?;
        Ok((
            data,
            RadioStatus::Sotdma(Self {
                sync_state,
                slot_timeout,
                sub_message,
            }),
        ))
    }
}

#[derive(Debug, PartialEq)]
pub struct ItdmaMessage {
    pub sync_state: SyncState,
    pub slot_increment: i16,
    pub num_slots: u8,
    pub keep: bool,
}

impl ItdmaMessage {
    pub fn parse(data: (&[u8], usize)) -> IResult<(&[u8], usize), RadioStatus> {
        let (data, sync_state) = map(take_bits::<_, _, _, (_, _)>(2u8), SyncState::parse)(data)?;
        let (data, slot_increment) = take_bits::<_, _, _, (_, _)>(13u16)(data)?;
        let (data, num_slots) = take_bits::<_, _, _, (_, _)>(3u8)(data)?;
        let (data, keep) = map(take_bits::<_, _, _, (_, _)>(1u8), u8_to_bool)(data)?;
        Ok((
            data,
            RadioStatus::Itdma(Self {
                sync_state,
                slot_increment,
                num_slots,
                keep,
            }),
        ))
    }
}

pub fn parse_radio(input: (&[u8], usize), msg_type: u8) -> IResult<(&[u8], usize), RadioStatus> {
    match msg_type {
        1 | 2 | 4 => SotdmaMessage::parse(input),
        3 => ItdmaMessage::parse(input),
        _ => Err(nom::Err::Error((input, ErrorKind::Digit))),
    }
}