[feat] config file. also: extreme over-engineering

src/cfg.rs

@@ -0,0 +1,64 @@
+use std::{
+    env,
+    fs::File,
+    io::{BufRead as _, BufReader},
+    path::PathBuf,
+    time::Duration,
+};
+
+use eyre::ContextCompat as _;
+
+pub(crate) struct Config {
+    pub(crate) netdev: Option<String>,
+    pub(crate) interval: Duration,
+}
+
+impl Config {
+    const CONFIG_FILE: &'static str = ".config/pfs/linkspeed";
+
+    pub(crate) fn from_file() -> eyre::Result<Self> {
+        let config_file = PathBuf::from(env::var("HOME")?).join(Self::CONFIG_FILE);
+
+        let mut config = Self::default();
+
+        if let Ok(file) = File::open(&config_file) {
+            let file = BufReader::new(file);
+
+            for line in file.lines() {
+                let line = line?;
+
+                match &line {
+                    line if line.starts_with("netdev") => {
+                        config.netdev = Some(Self::read_config_value(line)?.to_string());
+                    }
+                    line if line.starts_with("interval") => {
+                        let interval = Self::read_config_value(line)?.parse::<f64>()?;
+                        config.interval = Duration::from_secs_f64(interval);
+                    }
+                    _ => {}
+                }
+            }
+        }
+
+        Ok(config)
+    }
+
+    fn read_config_value(line: &str) -> eyre::Result<&str> {
+        let val = line
+            .split('=')
+            .nth(1)
+            .wrap_err("failed to parse value".to_string())?
+            .trim();
+
+        Ok(val)
+    }
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        Config {
+            netdev: None,
+            interval: Duration::from_secs(1),
+        }
+    }
+}