use crate::attribute_helpers::{contains_initialize_with, contains_skip};
use quote::quote;
use syn::export::TokenStream2;
use syn::{Fields, ItemStruct};
pub fn struct_de(input: &ItemStruct) -> syn::Result<TokenStream2> {
let name = &input.ident;
let generics = &input.generics;
let init_method = contains_initialize_with(&input.attrs)?;
let mut deserializable_field_types = TokenStream2::new();
let return_value = match &input.fields {
Fields::Named(fields) => {
let mut body = TokenStream2::new();
for field in &fields.named {
let field_name = field.ident.as_ref().unwrap();
let delta = if contains_skip(&field.attrs) {
quote! {
#field_name: Default::default(),
}
} else {
let field_type = &field.ty;
deserializable_field_types.extend(quote! {
#field_type: borsh::BorshDeserialize,
});
quote! {
#field_name: borsh::BorshDeserialize::deserialize(buf)?,
}
};
body.extend(delta);
}
quote! {
Self { #body }
}
}
Fields::Unnamed(fields) => {
let mut body = TokenStream2::new();
for _ in 0..fields.unnamed.len() {
let delta = quote! {
borsh::BorshDeserialize::deserialize(buf)?,
};
body.extend(delta);
}
quote! {
Self( #body )
}
}
Fields::Unit => {
quote! {
Self {}
}
}
};
if let Some(method_ident) = init_method {
Ok(quote! {
impl #generics borsh::de::BorshDeserialize for #name #generics where #deserializable_field_types {
fn deserialize(buf: &mut &[u8]) -> std::result::Result<Self, std::io::Error> {
let mut return_value = #return_value;
return_value.#method_ident();
Ok(return_value)
}
}
})
} else {
Ok(quote! {
impl #generics borsh::de::BorshDeserialize for #name #generics where #deserializable_field_types {
fn deserialize(buf: &mut &[u8]) -> std::result::Result<Self, std::io::Error> {
Ok(#return_value)
}
}
})
}
}