use crate::args;
use crate::utils::{build_value_repr, check_reserved_name, get_crate_name};
use inflector::Inflector;
use proc_macro::TokenStream;
use quote::quote;
use syn::{Error, FnArg, ImplItem, ItemImpl, Pat, Result, ReturnType, Type};
pub fn generate(object_args: &args::Object, item_impl: &mut ItemImpl) -> Result<TokenStream> {
let crate_name = get_crate_name(object_args.internal);
let (self_ty, self_name) = match item_impl.self_ty.as_ref() {
Type::Path(path) => (
path,
path.path
.segments
.last()
.map(|s| s.ident.to_string())
.unwrap(),
),
_ => return Err(Error::new_spanned(&item_impl.self_ty, "Invalid type")),
};
let generics = &item_impl.generics;
let gql_typename = object_args
.name
.clone()
.unwrap_or_else(|| self_name.clone());
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 create_types = Vec::new();
let mut filters = Vec::new();
let mut schema_fields = Vec::new();
for item in &mut item_impl.items {
if let ImplItem::Method(method) = item {
if let Some(field) = args::Field::parse(&method.attrs)? {
let ident = &method.sig.ident;
let field_name = field
.name
.clone()
.unwrap_or_else(|| method.sig.ident.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});
if method.sig.inputs.len() < 2 {
return Err(Error::new_spanned(
&method.sig.inputs,
"The filter function needs at least two arguments",
));
}
if method.sig.asyncness.is_some() {
return Err(Error::new_spanned(
&method.sig.inputs,
"The filter function must be synchronous",
));
}
let mut res_typ_ok = false;
if let ReturnType::Type(_, res_ty) = &method.sig.output {
if let Type::Path(p) = res_ty.as_ref() {
if p.path.is_ident("bool") {
res_typ_ok = true;
}
}
}
if !res_typ_ok {
return Err(Error::new_spanned(
&method.sig.output,
"The filter function must return a boolean value",
));
}
match &method.sig.inputs[0] {
FnArg::Receiver(_) => {}
_ => {
return Err(Error::new_spanned(
&method.sig.inputs[0],
"The first argument must be self receiver",
));
}
}
let ty = if let FnArg::Typed(ty) = &method.sig.inputs[1] {
match ty.ty.as_ref() {
Type::Reference(r) => r.elem.as_ref().clone(),
_ => {
return Err(Error::new_spanned(ty, "Incorrect object type"));
}
}
} else {
return Err(Error::new_spanned(
&method.sig.inputs[1],
"Incorrect object type",
));
};
let mut args = Vec::new();
for arg in method.sig.inputs.iter_mut().skip(2) {
if let FnArg::Typed(pat) = arg {
match (&*pat.pat, &*pat.ty) {
(Pat::Ident(arg_ident), Type::Path(arg_ty)) => {
args.push((
arg_ident,
arg_ty,
args::Argument::parse(&crate_name, &pat.attrs)?,
));
pat.attrs.clear();
}
_ => {
return Err(Error::new_spanned(arg, "Incorrect argument type"));
}
}
} else {
return Err(Error::new_spanned(arg, "Incorrect argument type"));
}
}
let mut schema_args = Vec::new();
let mut use_params = Vec::new();
let mut get_params = Vec::new();
for (
ident,
ty,
args::Argument {
name,
desc,
default,
validator,
},
) in args
{
let name = name
.clone()
.unwrap_or_else(|| ident.ident.to_string().to_camel_case());
let desc = desc
.as_ref()
.map(|s| quote! {Some(#s)})
.unwrap_or_else(|| quote! {None});
let schema_default = default
.as_ref()
.map(|v| {
let s = v.to_string();
quote! {Some(#s)}
})
.unwrap_or_else(|| quote! {None});
schema_args.push(quote! {
args.insert(#name, #crate_name::registry::InputValue {
name: #name,
description: #desc,
ty: <#ty as #crate_name::Type>::create_type_info(registry),
default_value: #schema_default,
validator: #validator,
});
});
use_params.push(quote! { #ident });
let default = match &default {
Some(default) => {
let repr = build_value_repr(&crate_name, &default);
quote! {|| #repr }
}
None => quote! { || #crate_name::Value::Null },
};
get_params.push(quote! {
let #ident: #ty = ctx_field.param_value(#name, #default)?;
});
}
schema_fields.push(quote! {
fields.insert(#field_name.to_string(), #crate_name::registry::Field {
name: #field_name.to_string(),
description: #field_desc,
args: {
let mut args = std::collections::HashMap::new();
#(#schema_args)*
args
},
ty: <#ty as #crate_name::Type>::create_type_info(registry),
deprecation: #field_deprecation,
cache_control: Default::default(),
});
});
create_types.push(quote! {
if field.name.as_str() == #field_name {
types.insert(std::any::TypeId::of::<#ty>(), field.clone());
return Ok(());
}
});
filters.push(quote! {
if let Some(msg) = msg.downcast_ref::<#ty>() {
#(#get_params)*
if self.#ident(msg, #(#use_params)*) {
let ctx_selection_set = ctx_field.with_selection_set(&field.selection_set);
let value =
#crate_name::OutputValueType::resolve(msg, &ctx_selection_set).await?;
let mut res = #crate_name::serde_json::Map::new();
res.insert(ctx_field.result_name().to_string(), value);
return Ok(Some(res.into()));
}
}
});
method.attrs.clear();
}
}
}
let expanded = quote! {
#item_impl
impl #generics #crate_name::Type for #self_ty {
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: Default::default(),
})
}
}
#[#crate_name::async_trait::async_trait]
impl #crate_name::SubscriptionType for SubscriptionRoot {
fn create_type(field: &#crate_name::graphql_parser::query::Field, types: &mut std::collections::HashMap<std::any::TypeId, #crate_name::graphql_parser::query::Field>) -> #crate_name::Result<()> {
use #crate_name::ErrorWithPosition;
#(#create_types)*
#crate_name::anyhow::bail!(#crate_name::QueryError::FieldNotFound {
field_name: field.name.clone(),
object: #gql_typename.to_string(),
}
.with_position(field.position));
}
async fn resolve(
&self,
ctx: &#crate_name::ContextBase<'_, ()>,
types: &std::collections::HashMap<std::any::TypeId, #crate_name::graphql_parser::query::Field>,
msg: &(dyn std::any::Any + Send + Sync),
) -> #crate_name::Result<Option<#crate_name::serde_json::Value>> {
let tid = msg.type_id();
if let Some(field) = types.get(&tid) {
let ctx_field = ctx.with_field(field);
#(#filters)*
}
Ok(None)
}
}
};
Ok(expanded.into())
}