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use anchor_lang_idl::types::Idl;
use quote::{format_ident, quote};
use super::common::gen_discriminator;
pub fn gen_utils_mod(idl: &Idl) -> proc_macro2::TokenStream {
let event = gen_event(idl);
quote! {
/// Program utilities.
pub mod utils {
#event
}
}
}
fn gen_event(idl: &Idl) -> proc_macro2::TokenStream {
let variants = idl
.events
.iter()
.map(|ev| format_ident!("{}", ev.name))
.map(|name| quote! { #name(#name) });
let match_arms = idl.events.iter().map(|ev| {
let disc = gen_discriminator(&ev.discriminator);
let name = format_ident!("{}", ev.name);
let event = quote! {
#name::try_from_slice(&value[8..])
.map(Self::#name)
.map_err(Into::into)
};
quote! { #disc => #event }
});
quote! {
use super::*;
/// An enum that includes all events of the declared program as a tuple variant.
///
/// See [`Self::try_from_bytes`] to create an instance from bytes.
pub enum Event {
#(#variants,)*
}
impl Event {
/// Try to create an event based on the given bytes.
///
/// This method returns an error if the discriminator of the given bytes don't match
/// with any of the existing events, or if the deserialization fails.
pub fn try_from_bytes(bytes: &[u8]) -> Result<Self> {
Self::try_from(bytes)
}
}
impl TryFrom<&[u8]> for Event {
type Error = anchor_lang::error::Error;
fn try_from(value: &[u8]) -> Result<Self> {
if value.len() < 8 {
return Err(ProgramError::InvalidArgument.into());
}
match &value[..8] {
#(#match_arms,)*
_ => Err(ProgramError::InvalidArgument.into()),
}
}
}
}
}