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
155
156
157
158
159
160
161
162
163
164

use super::{Loadable, Dumpable};

/// Primitive types supported for communication between the USDPL back- and front-end.
/// These are used for sending over the TCP connection.
pub enum Primitive {
    Empty,
    String(String),
    F32(f32),
    F64(f64),
    U32(u32),
    U64(u64),
    I32(i32),
    I64(i64),
    Bool(bool),
    Json(String),
}

impl Primitive {
    const fn discriminant(&self) -> u8 {
        match self {
            Self::Empty => 1,
            Self::String(_) => 2,
            Self::F32(_)=> 3,
            Self::F64(_)=> 4,
            Self::U32(_)=> 5,
            Self::U64(_)=> 6,
            Self::I32(_)=> 7,
            Self::I64(_)=> 8,
            Self::Bool(_) => 9,
            Self::Json(_) => 10,
        }
    }
}

impl Loadable for Primitive {
    fn load(buf: &[u8]) -> (Option<Self>, usize) {
        if buf.len() == 0 {
            return (None, 1);
        }
        let mut result: (Option<Self>, usize) = match buf[0] {
            //0 => (None, 0),
            1 => (Some(Self::Empty), 0),
            2 => {
                let (obj, len) = String::load(&buf[1..]);
                (obj.map(Self::String), len)
            },
            3 => {
                let (obj, len) = f32::load(&buf[1..]);
                (obj.map(Self::F32), len)
            },
            4 => {
                let (obj, len) = f64::load(&buf[1..]);
                (obj.map(Self::F64), len)
            },
            5 => {
                let (obj, len) = u32::load(&buf[1..]);
                (obj.map(Self::U32), len)
            },
            6 => {
                let (obj, len) = u64::load(&buf[1..]);
                (obj.map(Self::U64), len)
            },
            7 => {
                let (obj, len) = i32::load(&buf[1..]);
                (obj.map(Self::I32), len)
            },
            8 => {
                let (obj, len) = i64::load(&buf[1..]);
                (obj.map(Self::I64), len)
            },
            9 => {
                let (obj, len) = bool::load(&buf[1..]);
                (obj.map(Self::Bool), len)
            },
            10 => {
                let (obj, len) = String::load(&buf[1..]);
                (obj.map(Self::Json), len)
            }
            _ => (None, 0)
        };
        result.1 += 1;
        result
    }
}


impl Dumpable for Primitive {
    fn dump(&self, buf: &mut [u8]) -> (bool, usize) {
        if buf.len() == 0 {
            return (false, 0);
        }
        buf[0] = self.discriminant();
        let mut result = match self {
            Self::Empty => (true, 0),
            Self::String(s) => s.dump(&mut buf[1..]),
            Self::F32(x)=> x.dump(&mut buf[1..]),
            Self::F64(x)=> x.dump(&mut buf[1..]),
            Self::U32(x)=> x.dump(&mut buf[1..]),
            Self::U64(x)=> x.dump(&mut buf[1..]),
            Self::I32(x)=> x.dump(&mut buf[1..]),
            Self::I64(x)=> x.dump(&mut buf[1..]),
            Self::Bool(x)=> x.dump(&mut buf[1..]),
            Self::Json(x) => x.dump(&mut buf[1..]),
        };
        result.1 += 1;
        result
    }
}

impl std::convert::Into<Primitive> for String {
    fn into(self) -> Primitive {
        Primitive::String(self)
    }
}

impl std::convert::Into<Primitive> for &str {
    fn into(self) -> Primitive {
        Primitive::String(self.to_string())
    }
}

impl std::convert::Into<Primitive> for () {
    fn into(self) -> Primitive {
        Primitive::Empty
    }
}

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

    #[test]
    fn string_idempotence_test() {
        let data = "Test";
        let primitive = Primitive::String(data.to_string());
        let mut buffer = [0u8; 128];
        let (ok, write_len) = primitive.dump(&mut buffer);
        assert!(ok, "Dump not ok");
        let (obj, read_len) = Primitive::load(&buffer);
        assert_eq!(write_len, read_len, "Amount written and amount read do not match");
        assert!(obj.is_some(), "Load not ok");
        if let Some(Primitive::String(result)) = obj {
            assert_eq!(data, result, "Data written and read does not match");
        } else {
            panic!("Read non-string primitive");
        }
    }

    #[test]
    fn empty_idempotence_test() {
        let primitive = Primitive::Empty;
        let mut buffer = [0u8; 128];
        let (ok, write_len) = primitive.dump(&mut buffer);
        assert!(ok, "Dump not ok");
        let (obj, read_len) = Primitive::load(&buffer);
        assert_eq!(write_len, read_len, "Amount written and amount read do not match");
        assert!(obj.is_some(), "Load not ok");
        if let Some(Primitive::Empty) = obj {
            //assert_eq!(data, result, "Data written and read does not match");
        } else {
            panic!("Read non-string primitive");
        }
    }
}