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#![warn(dead_code)]
#![warn(unused_imports)]
extern crate proc_macro;

use proc_macro::TokenStream;
use quote::quote;
use syn::{parse_macro_input, ItemFn};

#[proc_macro_attribute]
pub fn backoff(_attr: TokenStream, item: TokenStream) -> TokenStream {
    let input = parse_macro_input!(item as ItemFn);
    let fn_attrs = &input.attrs;
    let fn_vis = &input.vis;
    let fn_sig = &input.sig;
    let fn_block = &input.block;

    let expanded = quote! {
        #(#fn_attrs)*
        #fn_vis #fn_sig {
            backoff::future::retry(backoff::ExponentialBackoff::default(), || async {
                Ok(#fn_block?)
            }).await
        }
    };

    TokenStream::from(expanded)
}