use proc_macro::TokenStream;
use quote::{quote, ToTokens};

/// Service entry-point (main)
///
/// # Panics
///
/// Will panic if set not on a function
#[proc_macro_attribute]
pub fn svc_main(_args: TokenStream, input: TokenStream) -> TokenStream {
    let mut item: syn::Item = syn::parse(input).expect("Invalid input");
    let fn_item = match &mut item {
        syn::Item::Fn(fn_item) => fn_item,
        _ => panic!("expected fn"),
    };
    //fn_item.block.stmts.insert(
    //0,
    //syn::parse(
    //quote! {
    //let a = 2;
    //}
    //.into(),
    //)
    //.unwrap(),
    //);
    let block = &fn_item.block;
    let f = quote! {
        fn main() -> eva_common::EResult<()> {
            eva_sdk::service::svc_launch(eva_service_main)
        }
        async fn eva_service_main(mut initial: eva_sdk::prelude::Initial) -> eva_common::EResult<()>
            #block
    };
    f.into_token_stream().into()
}