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

use super::*;

/// https://docs.solace.com/MQTT-311-Prtl-Conformance-Spec/MQTT%20Control%20Packets.htm#_Toc430864901
const FIXED_HEADER_LEN: usize = 5;
const PID_LEN: usize = 2;

/// Base enum for all MQTT packet types.
///
/// This is the main type you'll be interacting with, as an output of [`decode_slice()`] and an input of
/// [`encode()`]. Most variants can be constructed directly without using methods.
///
/// ```
/// # use mqttrust::encoding::v4::*;
/// # use core::convert::TryFrom;
/// // Simplest form
/// let pkt = Packet::Connack(Connack { session_present: false,
///                                     code: ConnectReturnCode::Accepted });
/// // Using `Into` trait
/// let publish = Publish { dup: false,
///                         qos: QoS::AtMostOnce,
///                         retain: false,
///                         pid: None,
///                         topic_name: "to/pic",
///                         payload: b"payload" };
/// let pkt: Packet = publish.into();
/// // Identifyer-only packets
/// let pkt = Packet::Puback(Pid::try_from(42).unwrap());
/// ```
///
/// [`encode()`]: fn.encode.html
/// [`decode_slice()`]: fn.decode_slice.html
#[derive(Debug, Clone, PartialEq)]
pub enum Packet<'a> {
    /// [MQTT 3.1](http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718028)
    Connect(Connect<'a>),
    /// [MQTT 3.2](http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718033)
    Connack(Connack),
    /// [MQTT 3.3](http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718037)
    Publish(Publish<'a>),
    /// [MQTT 3.4](http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718043)
    Puback(Pid),
    /// [MQTT 3.5](http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718048)
    Pubrec(Pid),
    /// [MQTT 3.6](http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718053)
    Pubrel(Pid),
    /// [MQTT 3.7](http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718058)
    Pubcomp(Pid),
    /// [MQTT 3.8](http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718063)
    Subscribe(Subscribe<'a>),
    /// [MQTT 3.9](http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718068)
    Suback(Suback<'a>),
    /// [MQTT 3.10](http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718072)
    Unsubscribe(Unsubscribe<'a>),
    /// [MQTT 3.11](http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718077)
    Unsuback(Pid),
    /// [MQTT 3.12](http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718081)
    Pingreq,
    /// [MQTT 3.13](http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718086)
    Pingresp,
    /// [MQTT 3.14](http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718090)
    Disconnect,
}

impl<'a> Packet<'a> {
    /// Return the packet type variant.
    ///
    /// This can be used for matching, categorising, debuging, etc. Most users will match directly
    /// on `Packet` instead.
    pub fn get_type(&self) -> PacketType {
        match self {
            Packet::Connect(_) => PacketType::Connect,
            Packet::Connack(_) => PacketType::Connack,
            Packet::Publish(_) => PacketType::Publish,
            Packet::Puback(_) => PacketType::Puback,
            Packet::Pubrec(_) => PacketType::Pubrec,
            Packet::Pubrel(_) => PacketType::Pubrel,
            Packet::Pubcomp(_) => PacketType::Pubcomp,
            Packet::Subscribe(_) => PacketType::Subscribe,
            Packet::Suback(_) => PacketType::Suback,
            Packet::Unsubscribe(_) => PacketType::Unsubscribe,
            Packet::Unsuback(_) => PacketType::Unsuback,
            Packet::Pingreq => PacketType::Pingreq,
            Packet::Pingresp => PacketType::Pingresp,
            Packet::Disconnect => PacketType::Disconnect,
        }
    }

    pub fn len(&self) -> usize {
        let variable_len = match self {
            Packet::Connect(c) => c.len(),
            Packet::Connack(_) => 2,
            Packet::Publish(p) => p.len(),
            Packet::Puback(_)
            | Packet::Pubrec(_)
            | Packet::Pubrel(_)
            | Packet::Pubcomp(_)
            | Packet::Unsuback(_) => PID_LEN,
            Packet::Suback(_) => PID_LEN + 1,
            Packet::Subscribe(s) => s.len(),
            Packet::Unsubscribe(u) => u.len(),
            Packet::Pingreq | Packet::Pingresp | Packet::Disconnect => 0,
        };

        FIXED_HEADER_LEN + variable_len
    }
}

macro_rules! packet_from_borrowed {
    ($($t:ident),+) => {
        $(
            impl<'a> From<$t<'a>> for Packet<'a> {
                fn from(p: $t<'a>) -> Self {
                    Packet::$t(p)
                }
            }
        )+
    }
}
macro_rules! packet_from {
    ($($t:ident),+) => {
        $(
            impl<'a> From<$t> for Packet<'a> {
                fn from(p: $t) -> Self {
                    Packet::$t(p)
                }
            }
        )+
    }
}

packet_from_borrowed!(Suback, Connect, Publish, Subscribe, Unsubscribe);
packet_from!(Connack);

/// Packet type variant, without the associated data.
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
#[cfg_attr(feature = "defmt-impl", derive(defmt::Format))]
pub enum PacketType {
    Connect,
    Connack,
    Publish,
    Puback,
    Pubrec,
    Pubrel,
    Pubcomp,
    Subscribe,
    Suback,
    Unsubscribe,
    Unsuback,
    Pingreq,
    Pingresp,
    Disconnect,
}