/*
 * Copyright 2021 Fluence Labs Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

use std::io::Read;
use std::path::Path;

pub fn stream_from_file<P>(path: P) -> proc_macro2::TokenStream
where
    P: AsRef<Path>,
{
    let items = items_from_file(path);
    quote::quote! { #(#items)* }
}

pub fn items_from_file<P>(path: P) -> Vec<syn::Item>
where
    P: AsRef<Path>,
{
    let mut file = std::fs::File::open(path).expect("Unable to open file");

    let mut src = String::new();
    file.read_to_string(&mut src).expect("Unable to read file");

    let token_file = syn::parse_file(&src).expect("Unable to parse file");
    token_file.items
}

pub fn to_syn_item(token_stream: proc_macro2::TokenStream) -> Vec<syn::Item> {
    let file: syn::File = syn::parse2(token_stream).expect("token stream should be parsed");
    file.items
}