oi4-dnp-encoding 0.1.0

#![cfg(feature = "std")]
use std::io::{self, Read};
use std::process::ExitCode;

fn read_all_stdin() -> io::Result<String> {
    let mut buf = String::new();
    io::stdin().read_to_string(&mut buf)?;
    if buf.ends_with('\n') {
        buf.pop();
        if buf.ends_with('\r') {
            buf.pop();
        }
    }
    Ok(buf)
}

fn usage() {
    eprintln!(
        "Usage: oi4-dnp-encoding-cli <encode|decode> [TEXT]\nIf TEXT omitted, reads from stdin."
    );
}

fn main() -> ExitCode {
    let mut args = std::env::args().skip(1);
    let cmd = match args.next() {
        Some(c) => c,
        None => {
            usage();
            return ExitCode::from(2);
        }
    };
    let data = match args.next() {
        Some(rest) => rest,
        None => match read_all_stdin() {
            Ok(s) => s,
            Err(e) => {
                eprintln!("stdin error: {e}");
                return ExitCode::from(3);
            }
        },
    };
    match cmd.as_str() {
        "encode" => {
            #[cfg(feature = "alloc")]
            {
                let out = oi4_dnp_encoding::encode(&data);
                println!("{out}");
                ExitCode::SUCCESS
            }
            #[cfg(not(feature = "alloc"))]
            {
                eprintln!("alloc feature required for encode CLI");
                ExitCode::from(4)
            }
        }
        "decode" => {
            #[cfg(feature = "alloc")]
            {
                match oi4_dnp_encoding::decode(&data) {
                    Ok(out) => {
                        println!("{out}");
                        ExitCode::SUCCESS
                    }
                    Err(e) => {
                        eprintln!("decode error: {e}");
                        ExitCode::from(5)
                    }
                }
            }
            #[cfg(not(feature = "alloc"))]
            {
                eprintln!("alloc feature required for decode CLI");
                ExitCode::from(4)
            }
        }
        _ => {
            usage();
            ExitCode::from(2)
        }
    }
}