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// Copyright (C) ~ Roy Ivy III <rivy.dev@gmail.com>; MIT license

extern crate proc_macro;
use proc_macro::TokenStream;
use quote::quote;

//## rust proc-macro background info
//* ref: <https://dev.to/naufraghi/procedural-macro-in-rust-101-k3f> @@ <http://archive.is/Vbr5e>
//* ref: [path construction from LitStr](https://oschwald.github.io/maxminddb-rust/syn/struct.LitStr.html) @@ <http://archive.is/8YDua>

#[proc_macro_attribute]
pub fn main(_args: TokenStream, stream: TokenStream) -> TokenStream {
    let stream = proc_macro2::TokenStream::from(stream);

    let new = quote!(
        pub fn uumain(args: impl uucore::Args) -> i32 {
            #stream
            let result = uumain(args);
            match result {
                Ok(()) => uucore::error::get_exit_code(),
                Err(e) => {
                    let s = format!("{}", e);
                    if s != "" {
                        uucore::show_error!("{}", s);
                    }
                    if e.usage() {
                        eprintln!("Try '{} --help' for more information.", uucore::execution_phrase());
                    }
                    e.code()
                }
            }
        }
    );

    TokenStream::from(new)
}