clap_conf 0.1.6

A library to unify commandline arguments with config files and environment variables. And make it easier for users to tell your program how to behave across the three main input sources
Documentation
use std::path::PathBuf;
use std::str::FromStr;

use crate::replace::{replace_env, ConfError};
use crate::{Filter, Getter};

#[derive(Clone, Debug)]
pub struct Grabber<'a, H>
where
    H: Getter<'a>,
{
    h: &'a H,
    res: Option<H::Out>,
}

impl<'a, H> Grabber<'a, H>
where
    H: Getter<'a>,
{
    pub fn new(h: &'a H) -> Self {
        Grabber { h, res: None }
    }

    pub fn op<S: AsRef<str>>(mut self, s: S, f: Filter) -> Self {
        if self.res == None {
            self.res = self.h.value(s, f);
        }
        self
    }

    pub fn conf<S: AsRef<str>>(self, s: S) -> Self {
        self.op(s, Filter::Conf)
    }

    pub fn env<S: AsRef<str>>(self, s: S) -> Self {
        self.op(s, Filter::Env)
    }
    pub fn arg<S: AsRef<str>>(self, s: S) -> Self {
        self.op(s, Filter::Arg)
    }

    pub fn done(self) -> Option<H::Out> {
        self.res
    }

    pub fn def<V>(self, v: V) -> H::Out
    where
        H::Out: From<V>,
    {
        self.res.unwrap_or(v.into())
    }

    pub fn req(self) -> Result<H::Out, ConfError> {
        self.res.ok_or("Item not supplied".into())
    }
}

impl<'a, H> Grabber<'a, H>
where
    H: Getter<'a>,
    H::Out: AsRef<str>,
{
    pub fn t_done<T: FromStr>(self) -> Option<T> {
        match self.res {
            Some(r) => r.as_ref().parse().ok(),
            None => None,
        }
    }
    pub fn t_def<T: FromStr>(self, def: T) -> T {
        match self.res {
            Some(r) => r.as_ref().parse().unwrap_or(def),
            None => def,
        }
    }
}
impl<'a, H> Grabber<'a, H>
where
    H: Getter<'a>,
    H::Out: AsRef<str>,
{
    pub fn rep_env(self) -> Result<String, ConfError> {
        replace_env(self.res.ok_or("No Res")?.as_ref())
    }

    pub fn ask<S: AsRef<str>>(self, s: S) -> Result<String, ConfError> {
        if let Some(r) = self.res {
            return Ok(r.as_ref().to_string());
        }
        println!("{}\n>", s.as_ref());
        let mut res = String::new();
        std::io::stdin().read_line(&mut res)?;
        Ok(res)
    }

    pub fn ask_def<S: AsRef<str>>(self, s: S, def: S) -> String {
        match self.ask(s) {
            Ok(r) => {
                if r == "".to_string() {
                    return def.as_ref().to_string();
                }
                r
            }
            Err(_) => def.as_ref().to_string(),
        }
    }
}

pub struct LocalGrabber<'a, G>
where
    G: Getter<'a>,
{
    g: &'a G,
    res: Option<PathBuf>,
}

impl<'a, G> LocalGrabber<'a, G>
where
    G: Getter<'a>,
{
    pub fn new(g: &'a G) -> Self {
        LocalGrabber { g, res: None }
    }

    pub fn op<S: AsRef<str>>(mut self, s: S, f: Filter) -> Self {
        if self.res == None {
            self.res = self.g.local_value(s, f);
        }
        self
    }

    pub fn conf<S: AsRef<str>>(self, s: S) -> Self {
        self.op(s, Filter::Conf)
    }

    pub fn env<S: AsRef<str>>(self, s: S) -> Self {
        self.op(s, Filter::Env)
    }
    pub fn arg<S: AsRef<str>>(self, s: S) -> Self {
        self.op(s, Filter::Arg)
    }

    pub fn done(self) -> Option<PathBuf> {
        self.res
    }

    pub fn req(self) -> Result<PathBuf, ConfError> {
        self.res.ok_or("Item not supplied".into())
    }

    pub fn def<V>(self, v: V) -> PathBuf
    where
        PathBuf: From<V>,
    {
        self.res.unwrap_or(v.into())
    }
}

pub struct MultiGrabber<'a, G>
where
    G: Getter<'a>,
{
    g: &'a G,
    res: Option<G::Iter>,
    //_i: PhantomData<I>,
}

impl<'a, G> MultiGrabber<'a, G>
where
    G: Getter<'a>,
{
    pub fn new(g: &'a G) -> Self {
        MultiGrabber { g, res: None }
    }

    pub fn op<S: AsRef<str>>(mut self, s: S, f: Filter) -> Self {
        if let None = self.res {
            self.res = self.g.values(s, f);
        }
        self
    }

    pub fn conf<S: AsRef<str>>(self, s: S) -> Self {
        self.op(s, Filter::Conf)
    }

    pub fn env<S: AsRef<str>>(self, s: S) -> Self {
        self.op(s, Filter::Env)
    }
    pub fn arg<S: AsRef<str>>(self, s: S) -> Self {
        self.op(s, Filter::Arg)
    }

    pub fn done(self) -> Option<G::Iter> {
        self.res
    }

    pub fn req(self) -> Result<G::Iter, ConfError> {
        self.res.ok_or("Item not supplied".into())
    }
}