summaryrefslogtreecommitdiff
path: root/libangelshark/src/message.rs
blob: 0dac53416ed19d51e78d7f1c9fb2f2d68646dd09 (plain) (blame)
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
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
use anyhow::{Context, Result};
use std::{
    fmt::{Display, Formatter, Result as FmtResult},
    io::{BufRead, BufReader, Read},
};

/// OSSI Messaging Delimiters
const ACM_D: &str = "a";
const COMMAND_D: &str = "c";
const DATA_D: &str = "d";
const ERROR_D: &str = "e";
const FIELD_D: &str = "f";
const NEW_DATA_D: &str = "n";
const TERMINATOR_D: &str = "t";
const TAB: &str = "\t";

/// An OSSI protocol message. Used for input and output to and from the ACM. The
/// OSSI protocol is proprietary, and little documented. Here is a brief
/// overview. Every message consists of a single command and a
/// terminator used to separate messages. The message may also carry optional
/// tab-separated fields and datas when used for input. When used for output, it may
/// optionally carry an error. Example:
///
/// ```text
/// (input)
/// clist object
/// t
/// (output)
/// clist object
/// fhex_code\thex_code\thex_code
/// dentry\tentry\tentry
/// n
/// dentry\tentry\tentry
/// t
/// ```
#[derive(Debug, Default, Clone)]
pub struct Message {
    pub command: String,
    pub fields: Option<Vec<String>>,
    pub datas: Option<Vec<Vec<String>>>,
    pub error: Option<String>,
}

impl Message {
    /// Creates a new [Message] from its basic part: the command.
    pub fn new(command: &str) -> Self {
        Self {
            command: command.into(),
            ..Default::default()
        }
    }

    fn add_fields(&mut self, fields: Vec<String>) -> &mut Self {
        if !fields.is_empty() {
            if let Some(ref mut existing) = self.fields {
                existing.extend(fields.into_iter());
            } else {
                self.fields = Some(fields);
            }
        }

        self
    }

    fn add_data_entry(&mut self, data: Vec<String>) -> &mut Self {
        if !data.is_empty() {
            if let Some(ref mut existing) = self.datas {
                existing.push(data);
            } else {
                self.datas = Some(vec![data]);
            }
        }

        self
    }

    /// Reads from `readable`, parsing lines as Angelshark-formatted OSSI input.
    /// This closely follows the OSSI spec, but also parses ACM names/labels on
    /// lines beginning with `'a'`. The spec looks like this:
    ///
    /// ```text
    /// aACM01
    /// clist object
    /// fhex_code\thex_code\thex_code
    /// dentry\tentry\tentry
    /// t
    /// ...
    /// ```
    pub fn from_input(readable: impl Read) -> Result<Vec<(String, Self)>> {
        let mut data = Vec::new();
        let mut input = Self::default();
        let mut inputs = Vec::new();
        let mut names: Vec<String> = Vec::new();

        for line in BufReader::new(readable).lines() {
            let line = line.with_context(|| "Failed to read line of input.")?;
            let (delim, content) = (line.get(0..1).unwrap_or_default(), line.get(1..));

            match (delim, content) {
                (ACM_D, Some(a)) => {
                    names.extend(a.split(TAB).map(String::from));
                }
                (COMMAND_D, Some(c)) => {
                    input.command = c.into();
                }
                (FIELD_D, Some(f)) => {
                    input.add_fields(f.split(TAB).map(String::from).collect());
                }
                (DATA_D, Some(d)) => {
                    data.extend(d.split(TAB).map(String::from));
                }
                (TERMINATOR_D, _) => {
                    input.add_data_entry(data);
                    inputs.extend(names.into_iter().map(|n| (n, input.clone())));
                    names = Vec::new();
                    input = Message::default();
                    data = Vec::new();
                }
                _ => {
                    // Skip blank lines and unknown identifiers.
                }
            }
        }

        Ok(inputs)
    }

    /// Reads `readable` and parses lines as ACM OSSI output. This should exactly follow the OSSI spec.
    pub fn from_output(readable: impl Read) -> Result<Vec<Self>> {
        let mut data = Vec::new();
        let mut output = Self::default();
        let mut outputs = Vec::new();

        for line in BufReader::new(readable).lines() {
            let line = line.with_context(|| "Failed to read line of output.")?;
            let (delim, content) = (line.get(0..1).unwrap_or_default(), line.get(1..));

            match (delim, content) {
                (COMMAND_D, Some(c)) => {
                    output.command = c.into();
                }
                (ERROR_D, Some(e)) => {
                    output.error = Some(e.into());
                }
                (FIELD_D, Some(f)) => {
                    output.add_fields(f.split(TAB).map(String::from).collect());
                }
                (DATA_D, Some(d)) => {
                    data.extend(d.split(TAB).map(String::from));
                }
                (NEW_DATA_D, _) => {
                    output.add_data_entry(data);
                    data = Vec::new();
                }
                (TERMINATOR_D, _) => {
                    output.add_data_entry(data);
                    data = Vec::new();
                    outputs.push(output);
                    output = Self::default();
                }
                _ => {
                    // Ignore unknown identifiers and blank lines.
                }
            }
        }

        Ok(outputs)
    }
}

impl Display for Message {
    fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
        let mut message = format!("c{}\n", self.command);

        if let Some(error) = &self.error {
            message = message + &format!("e{}\n", error);
        }

        if let Some(fields) = &self.fields {
            message = message + &format!("f{}\n", fields.join(TAB));
        }

        if let Some(datas) = &self.datas {
            message = message
                + &datas
                    .iter()
                    .map(|d| format!("d{}\n", d.join(TAB)))
                    .collect::<Vec<String>>()
                    .join("n\n");
        }

        writeln!(f, "{}\nt", message)
    }
}