use std::{
collections::HashMap, env, fs::File, io::Read, process::Command, thread::sleep, time::Duration,
};
fn main() {
let mut args = env::args();
assert!(
args.len() > 2,
"Too few arguments, provide battery id and values with warning levels"
);
// Skip process (argc[0])
args.next();
// 1: Battery ID
let bat = args.next().expect("Invalid Battery id");
let bat_path = format!("/sys/class/power_supply/{bat}");
let cap_path = format!("{bat_path}/capacity");
let status_path = format!("{bat_path}/status");
// 2: Sleep
let sleep_secs = args
.next()
.expect("Invalid sleep duration")
.parse::<u64>()
.expect("Invalid sleep value");
let mut warnings: HashMap<u8, String> = HashMap::new();
for arg in args {
let (lvl, value) = arg.split_at(1);
assert!(
lvl == "l" || lvl == "n" || lvl == "c",
"Unknown notification level"
);
warnings.insert(
value.parse::<u8>().expect("Invalid battery value"),
lvl.to_string(),
);
}
let mut cap_cache = String::new();
loop {
let cur_cap = read_file(&cap_path);
if cur_cap != cap_cache {
cap_cache.clone_from(&cur_cap);
if &read_file(&status_path) == "Charging" { continue; };
let val = cur_cap
.parse::<u8>()
.expect("Couldn't parse capacity value");
if let Some(lvl) = warnings.get(&val) {
notify(lvl, val);
};
}
sleep(Duration::from_secs(sleep_secs));
}
}
fn read_file(path: &str) -> String {
let mut f = File::open(path).expect("Could't open file");
let mut buf = String::new();
f.read_to_string(&mut buf).expect("Couldn't read file");
buf.trim().to_string()
}
fn notify(lvl: &str, remaining: u8) {
let urgency = match lvl {
"l" => "low",
"n" => "normal",
"c" => "critical",
_ => unreachable!(),
};
let notif = format!("Remaining battery capacity: {remaining}");
Command::new("notify-send")
.arg("--app-name=esbnd")
.arg("--category=device")
.arg("--icon=battery-low-symbolic")
.arg("-u")
.arg(urgency)
.arg(notif)
.spawn()
.expect("Couldn't send notification");
}