pub(crate) struct Task {
    pub name: &'static str,
    pub exec: fn(&[&str]) -> Result<String, String>,
}

pub(crate) const TASKS: &[Task] = &[
    Task {
        name: "nop",
        exec: no_op,
    },
    Task {
        name: "exec",
        exec: exec,
    },
];

fn no_op(_: &[&str]) -> Result<String, String> {
    Ok("".to_string())
}

fn exec(cmds: &[&str]) -> Result<String, String> {
    use std::process::Command;
    // TODO: fmt and add exit code, and add support for both stdout and stderr, and support for no output
    match Command::new(cmds[0]).args(&cmds[1..]).output() {
        Ok(o) => {
            if o.status.success() {
                Ok(String::from_utf8(o.stdout)
                    .unwrap_or("Failed decoding vec<u8> -> String".to_string())
                    .to_string())
            } else {
                Err(String::from_utf8(o.stderr)
                    .unwrap_or("Failed decoding vec<u8> -> String".to_string())
                    .to_string())
            }
        }
        Err(e) => Err(e.to_string()),
    }
}

pub(crate) enum IntoTaskErr {
    NotFound,
}

pub(crate) trait IntoTask {
    fn into_task<'a>(self) -> Result<&'a Task, IntoTaskErr>;
}

impl IntoTask for String {
    fn into_task<'a>(self) -> Result<&'a Task, IntoTaskErr> {
        for task in TASKS {
            if task.name == self {
                return Ok(task);
            }
        }
        Err(IntoTaskErr::NotFound)
    }
}

impl IntoTask for &str {
    fn into_task<'a>(self) -> Result<&'a Task, IntoTaskErr> {
        for task in TASKS {
            if task.name == self {
                return Ok(task);
            }
        }
        Err(IntoTaskErr::NotFound)
    }
}