prt_core/
config.rs

1//! Configuration loading from `~/.config/prt/config.toml`.
2//!
3//! The config is read-only — `prt` never writes to this file.
4//! Missing file or parse errors fall back to defaults silently
5//! (a warning is printed to stderr on parse failure).
6
7use serde::Deserialize;
8use std::collections::HashMap;
9use std::path::PathBuf;
10
11/// Raw TOML representation (TOML table keys are always strings).
12#[derive(Debug, Clone, Default, Deserialize)]
13#[serde(default)]
14struct RawConfig {
15    known_ports: HashMap<String, String>,
16    alerts: Vec<AlertRuleConfig>,
17}
18
19/// Top-level configuration.
20#[derive(Debug, Clone, Default)]
21pub struct PrtConfig {
22    /// User-defined port → service name overrides.
23    /// These take precedence over the built-in known ports database.
24    ///
25    /// ```toml
26    /// [known_ports]
27    /// 9090 = "prometheus"
28    /// 3000 = "grafana"
29    /// ```
30    pub known_ports: HashMap<u16, String>,
31
32    /// Alert rules (populated by the alerts feature).
33    ///
34    /// ```toml
35    /// [[alerts]]
36    /// port = 22
37    /// action = "bell"
38    /// ```
39    pub alerts: Vec<AlertRuleConfig>,
40}
41
42impl From<RawConfig> for PrtConfig {
43    fn from(raw: RawConfig) -> Self {
44        let known_ports = raw
45            .known_ports
46            .into_iter()
47            .filter_map(|(k, v)| k.parse::<u16>().ok().map(|port| (port, v)))
48            .collect();
49        Self {
50            known_ports,
51            alerts: raw.alerts,
52        }
53    }
54}
55
56/// A single alert rule from the TOML config.
57#[derive(Debug, Clone, Default, Deserialize)]
58#[serde(default)]
59pub struct AlertRuleConfig {
60    pub port: Option<u16>,
61    pub process: Option<String>,
62    pub state: Option<String>,
63    pub connections_gt: Option<usize>,
64    #[serde(default = "default_action")]
65    pub action: String,
66}
67
68fn default_action() -> String {
69    "highlight".into()
70}
71
72/// Returns the config directory path: `~/.config/prt/`.
73pub fn config_dir() -> Option<PathBuf> {
74    dirs::config_dir().map(|d| d.join("prt"))
75}
76
77/// Returns the path to the main config file: `~/.config/prt/config.toml`.
78pub fn config_path() -> Option<PathBuf> {
79    config_dir().map(|d| d.join("config.toml"))
80}
81
82/// Load configuration from `~/.config/prt/config.toml`.
83///
84/// Returns [`PrtConfig::default()`] if the file does not exist.
85/// Prints a warning to stderr and returns defaults if the file
86/// exists but cannot be parsed.
87pub fn load_config() -> PrtConfig {
88    let path = match config_path() {
89        Some(p) => p,
90        None => return PrtConfig::default(),
91    };
92
93    let content = match std::fs::read_to_string(&path) {
94        Ok(c) => c,
95        Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
96            return PrtConfig::default();
97        }
98        Err(e) => {
99            eprintln!("prt: warning: cannot read {}: {e}", path.display());
100            return PrtConfig::default();
101        }
102    };
103
104    match toml::from_str::<RawConfig>(&content) {
105        Ok(raw) => raw.into(),
106        Err(e) => {
107            eprintln!("prt: warning: cannot parse {}: {e}", path.display());
108            PrtConfig::default()
109        }
110    }
111}
112
113#[cfg(test)]
114mod tests {
115    use super::*;
116
117    #[test]
118    fn default_config_is_empty() {
119        let config = PrtConfig::default();
120        assert!(config.known_ports.is_empty());
121        assert!(config.alerts.is_empty());
122    }
123
124    #[test]
125    fn parse_known_ports() {
126        let toml_str = r#"
127[known_ports]
1289090 = "prometheus"
1293000 = "grafana"
130"#;
131        let raw: RawConfig = toml::from_str(toml_str).unwrap();
132        let config: PrtConfig = raw.into();
133        assert_eq!(config.known_ports.get(&9090).unwrap(), "prometheus");
134        assert_eq!(config.known_ports.get(&3000).unwrap(), "grafana");
135    }
136
137    #[test]
138    fn parse_alert_rules() {
139        let toml_str = r#"
140[[alerts]]
141port = 22
142action = "bell"
143
144[[alerts]]
145process = "python"
146state = "LISTEN"
147action = "highlight"
148
149[[alerts]]
150connections_gt = 100
151"#;
152        let raw: RawConfig = toml::from_str(toml_str).unwrap();
153        let config: PrtConfig = raw.into();
154        assert_eq!(config.alerts.len(), 3);
155        assert_eq!(config.alerts[0].port, Some(22));
156        assert_eq!(config.alerts[0].action, "bell");
157        assert_eq!(config.alerts[1].process.as_deref(), Some("python"));
158        assert_eq!(config.alerts[2].connections_gt, Some(100));
159        assert_eq!(config.alerts[2].action, "highlight"); // default
160    }
161
162    #[test]
163    fn parse_empty_toml_returns_defaults() {
164        let raw: RawConfig = toml::from_str("").unwrap();
165        let config: PrtConfig = raw.into();
166        assert!(config.known_ports.is_empty());
167        assert!(config.alerts.is_empty());
168    }
169
170    #[test]
171    fn parse_invalid_port_key_is_skipped() {
172        let toml_str = r#"
173[known_ports]
1749090 = "prometheus"
175not_a_port = "ignored"
176"#;
177        let raw: RawConfig = toml::from_str(toml_str).unwrap();
178        let config: PrtConfig = raw.into();
179        assert_eq!(config.known_ports.len(), 1);
180        assert_eq!(config.known_ports.get(&9090).unwrap(), "prometheus");
181    }
182
183    #[test]
184    fn load_config_returns_defaults_when_no_file() {
185        // In test environment, config_path() likely points to a nonexistent file
186        let config = load_config();
187        assert!(config.known_ports.is_empty());
188    }
189}
prt_core/config.rs

prt_core/
config.rs
