// Copyright (c) 2020 Huawei Technologies Co.,Ltd. All rights reserved.
//
// StratoVirt is licensed under Mulan PSL v2.
// You can use this software according to the terms and conditions of the Mulan
// PSL v2.
// You may obtain a copy of Mulan PSL v2 at:
//         http://license.coscl.org.cn/MulanPSL2
// THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY
// KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// NON-INFRINGEMENT, MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
// See the Mulan PSL v2 for more details.

use quote::{format_ident, quote};

use crate::field_parser::{parse_fields, parse_fields_default};

/// Parse `DeviceState` structure to `DeviceStateDesc`.
pub fn parse_struct(
    input: &syn::DataStruct,
    ident: &syn::Ident,
    current_version: u32,
    compat_version: u32,
) -> proc_macro2::TokenStream {
    let struct_ident = format_ident!("DeviceStateDesc");
    let name = format!("{}", ident);

    let fields = parse_fields(&input.fields, ident);

    use std::collections::hash_map::DefaultHasher;
    use std::hash::{Hash, Hasher};

    let id_remap = |s: &str| -> u64 {
        let mut hash = DefaultHasher::new();
        s.hash(&mut hash);
        hash.finish()
    };
    let alias = id_remap(&name);
    quote! {
        #struct_ident {
            name: #name.to_string(),
            alias: #alias,
            size: std::mem::size_of::<#ident>() as u32,
            current_version: #current_version,
            compat_version: #compat_version,
            fields: vec![#(#fields), *],
        }
    }
}

pub(crate) fn parse_struct_default(
    input: &syn::DataStruct,
    ident: &syn::Ident,
) -> proc_macro2::TokenStream {
    let fields_default = parse_fields_default(&input.fields);
    quote! {
        #ident {
            #(#fields_default),*
        }
    }
}