pub mod expand_enum;
pub mod expand_struct;

use attribute;
use proc_macro2::Span;
use quote;
use syn;
use syn::Ident;

pub fn expand_derive_deserialize(ast: &syn::DeriveInput) -> Result<quote::Tokens, String> {
  let name = &ast.ident;
  let attrs = &ast.attrs;
  let data = &ast.data;

  let root_attrs = attribute::YaSerdeAttribute::parse(&attrs);
  let root = root_attrs.clone().root.unwrap_or(name.to_string());

  let impl_block =
    match data {
      &syn::Data::Struct(ref data_struct) => {
        expand_struct::parse(data_struct, &name, &root, &root_attrs.namespaces)
      },
      &syn::Data::Enum(ref data_enum) => {
        expand_enum::parse(data_enum, &name, &root, &root_attrs.namespaces)
      },
      &syn::Data::Union(ref _data_union) => {
        unimplemented!()
      },
    };

  let dummy_const = Ident::new(&format!("_IMPL_YA_DESERIALIZE_FOR_{}", name), Span::def_site());

  let generated = quote! {
    #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
    const #dummy_const: () = {
      extern crate yaserde as _yaserde;
      #impl_block
    };
  };

  Ok(generated)
}