use crate::args;
use crate::utils::{check_reserved_name, get_crate_name};
use inflector::Inflector;
use proc_macro::TokenStream;
use quote::quote;
use syn::{Data, DeriveInput, Error, Fields, Result};
pub fn generate(object_args: &args::Object, input: &mut DeriveInput) -> Result<TokenStream> {
let crate_name = get_crate_name(object_args.internal);
let ident = &input.ident;
let generics = &input.generics;
let extends = object_args.extends;
let s = match &mut input.data {
Data::Struct(e) => e,
_ => return Err(Error::new_spanned(input, "It should be a struct")),
};
let gql_typename = object_args
.name
.clone()
.unwrap_or_else(|| ident.to_string());
check_reserved_name(&gql_typename, object_args.internal)?;
let desc = object_args
.desc
.as_ref()
.map(|s| quote! { Some(#s) })
.unwrap_or_else(|| quote! {None});
let mut getters = Vec::new();
let mut resolvers = Vec::new();
let mut schema_fields = Vec::new();
let fields = match &mut s.fields {
Fields::Named(fields) => Some(fields),
Fields::Unit => None,
_ => return Err(Error::new_spanned(input, "All fields must be named.")),
};
if let Some(fields) = fields {
for item in &mut fields.named {
if let Some(field) = args::Field::parse(&item.attrs)? {
let field_name = field
.name
.clone()
.unwrap_or_else(|| item.ident.as_ref().unwrap().to_string().to_camel_case());
let field_desc = field
.desc
.as_ref()
.map(|s| quote! {Some(#s)})
.unwrap_or_else(|| quote! {None});
let field_deprecation = field
.deprecation
.as_ref()
.map(|s| quote! {Some(#s)})
.unwrap_or_else(|| quote! {None});
let external = field.external;
let requires = match &field.requires {
Some(requires) => quote! { Some(#requires) },
None => quote! { None },
};
let provides = match &field.provides {
Some(provides) => quote! { Some(#provides) },
None => quote! { None },
};
let vis = &item.vis;
let ty = &item.ty;
let cache_control = {
let public = field.cache_control.public;
let max_age = field.cache_control.max_age;
quote! {
#crate_name::CacheControl {
public: #public,
max_age: #max_age,
}
}
};
schema_fields.push(quote! {
fields.insert(#field_name.to_string(), #crate_name::registry::Field {
name: #field_name.to_string(),
description: #field_desc,
args: Default::default(),
ty: <#ty as #crate_name::Type>::create_type_info(registry),
deprecation: #field_deprecation,
cache_control: #cache_control,
external: #external,
provides: #provides,
requires: #requires,
});
});
let ident = &item.ident;
if field.is_ref {
getters.push(quote! {
#[inline]
#vis async fn #ident(&self) -> &#ty {
&self.#ident
}
});
} else {
getters.push(quote! {
#[inline]
#vis async fn #ident(&self) -> #ty {
self.#ident.clone()
}
});
}
resolvers.push(quote! {
if ctx.name.as_str() == #field_name {
let ctx_obj = ctx.with_selection_set(&ctx.selection_set);
return #crate_name::OutputValueType::resolve(&self.#ident, &ctx_obj, ctx.position).await;
}
});
}
if let Some((idx, _)) = item
.attrs
.iter()
.enumerate()
.find(|(_, a)| a.path.is_ident("field"))
{
item.attrs.remove(idx);
}
}
}
let cache_control = {
let public = object_args.cache_control.public;
let max_age = object_args.cache_control.max_age;
quote! {
#crate_name::CacheControl {
public: #public,
max_age: #max_age,
}
}
};
let expanded = quote! {
#input
impl #generics #ident {
#(#getters)*
}
impl #generics #crate_name::Type for #ident #generics {
fn type_name() -> std::borrow::Cow<'static, str> {
std::borrow::Cow::Borrowed(#gql_typename)
}
fn create_type_info(registry: &mut #crate_name::registry::Registry) -> String {
registry.create_type::<Self, _>(|registry| #crate_name::registry::Type::Object {
name: #gql_typename.to_string(),
description: #desc,
fields: {
let mut fields = std::collections::HashMap::new();
#(#schema_fields)*
fields
},
cache_control: #cache_control,
extends: #extends,
keys: None,
})
}
}
#[#crate_name::async_trait::async_trait]
impl #generics #crate_name::ObjectType for #ident #generics {
async fn resolve_field(&self, ctx: &#crate_name::Context<'_>) -> #crate_name::Result<#crate_name::serde_json::Value> {
#(#resolvers)*
Err(#crate_name::QueryError::FieldNotFound {
field_name: ctx.name.clone(),
object: #gql_typename.to_string(),
}.into_error(ctx.position))
}
}
#[#crate_name::async_trait::async_trait]
impl #generics #crate_name::OutputValueType for #ident #generics {
async fn resolve(value: &Self, ctx: &#crate_name::ContextSelectionSet<'_>, _pos: #crate_name::Pos) -> #crate_name::Result<#crate_name::serde_json::Value> {
#crate_name::do_resolve(ctx, value).await
}
}
};
Ok(expanded.into())
}