extern crate proc_macro;

use borsh_derive_internal::*;
use proc_macro::TokenStream;
use proc_macro2::{Span, TokenStream as TokenStream2};
use syn::{Ident, Item};

fn gen_borsh_serialize(input: TokenStream) -> TokenStream2 {
    let cratename = Ident::new("borsh", Span::call_site());

    let item: Item = syn::parse(input).unwrap();
    let res = match item {
        Item::Struct(item) => struct_ser(&item, cratename),
        Item::Enum(item) => enum_ser(&item, cratename),
        Item::Union(item) => union_ser(&item, cratename),
        // Derive macros can only be defined on structs, enums, and unions.
        _ => unreachable!(),
    };

    match res {
        Ok(res) => res,
        Err(err) => err.to_compile_error(),
    }
}

#[proc_macro_derive(AnchorSerialize, attributes(borsh_skip))]
pub fn anchor_serialize(input: TokenStream) -> TokenStream {
    #[cfg(not(feature = "idl-build"))]
    let ret = gen_borsh_serialize(input);
    #[cfg(feature = "idl-build")]
    let ret = gen_borsh_serialize(input.clone());

    #[cfg(feature = "idl-build")]
    {
        use anchor_syn::idl::build::*;
        use quote::quote;

        let idl_build_impl = match syn::parse(input).unwrap() {
            Item::Struct(item) => impl_idl_build_struct(&item),
            Item::Enum(item) => impl_idl_build_enum(&item),
            Item::Union(item) => impl_idl_build_union(&item),
            // Derive macros can only be defined on structs, enums, and unions.
            _ => unreachable!(),
        };

        return TokenStream::from(quote! {
            #ret
            #idl_build_impl
        });
    };

    #[allow(unreachable_code)]
    TokenStream::from(ret)
}

fn gen_borsh_deserialize(input: TokenStream) -> TokenStream2 {
    let cratename = Ident::new("borsh", Span::call_site());

    let item: Item = syn::parse(input).unwrap();
    let res = match item {
        Item::Struct(item) => struct_de(&item, cratename),
        Item::Enum(item) => enum_de(&item, cratename),
        Item::Union(item) => union_de(&item, cratename),
        // Derive macros can only be defined on structs, enums, and unions.
        _ => unreachable!(),
    };

    match res {
        Ok(res) => res,
        Err(err) => err.to_compile_error(),
    }
}

#[proc_macro_derive(AnchorDeserialize, attributes(borsh_skip, borsh_init))]
pub fn borsh_deserialize(input: TokenStream) -> TokenStream {
    TokenStream::from(gen_borsh_deserialize(input))
}