use std::collections::HashMap;
use std::process::Command;

use std::io;

#[derive(Debug)]
pub struct Unit {
    pub name: String,
    pub type_: String
}

pub fn parse_key_value(line: &str) -> Option<(String, String)> {
    let pos = line.find('=');
    pos.map(|pos| {
        let (k, v) = line.split_at(pos);
        (k.to_owned(), v[1..].to_owned())
    })
}

#[test]
fn test_parse_key_value() {
    assert_eq!(None, parse_key_value("ab"));
    assert_eq!(Some(("a".to_owned(), "b".to_owned())), parse_key_value("a=b"));
    assert_eq!(Some(("a".to_owned(), "b=c".to_owned())), parse_key_value("a=b=c"));
}

pub fn get_jobs() -> io::Result<Vec<Unit>> {
    let mut units = Vec::new();
    let status = try!(Command::new("systemctl")
        .args(&["show", "*"]).output());

    let mut unit_info = HashMap::new();
    for line in String::from_utf8_lossy(&status.stdout).split('\n') {
        if let Some((k, v)) = parse_key_value(line) {
            unit_info.insert(k, v);
        } else {
            if let Some(id) = unit_info.remove("Id") {
                units.push(Unit { name: id, type_: String::new() });
            }
            unit_info = HashMap::new();
        }
    }
    return Ok(units);
}