use std::collections::HashSet;
use darling::util::SpannedValue;
use darling::FromMeta;
use proc_macro2::{Span, TokenStream, TokenTree};
use proc_macro_crate::{crate_name, FoundCrate};
use quote::quote;
use syn::visit::Visit;
use syn::{
Attribute, Error, Expr, ExprPath, FnArg, Ident, ImplItemMethod, Lit, LitStr, Meta, Pat,
PatIdent, Type, TypeGroup, TypeParamBound, TypeReference,
};
use thiserror::Error;
use crate::args::{self, Argument, Deprecation, Visible};
#[derive(Error, Debug)]
pub enum GeneratorError {
#[error("{0}")]
Syn(#[from] syn::Error),
#[error("{0}")]
Darling(#[from] darling::Error),
}
impl GeneratorError {
pub fn write_errors(self) -> TokenStream {
match self {
GeneratorError::Syn(err) => err.to_compile_error(),
GeneratorError::Darling(err) => err.write_errors(),
}
}
}
pub type GeneratorResult<T> = std::result::Result<T, GeneratorError>;
pub fn get_crate_name(internal: bool) -> TokenStream {
if internal {
quote! { crate }
} else {
let name = match crate_name("async-graphql") {
Ok(FoundCrate::Name(name)) => name,
Ok(FoundCrate::Itself) | Err(_) => "async_graphql".to_string(),
};
TokenTree::from(Ident::new(&name, Span::call_site())).into()
}
}
pub fn generate_guards(
crate_name: &TokenStream,
code: &SpannedValue<String>,
map_err: TokenStream,
) -> GeneratorResult<TokenStream> {
let expr: Expr =
syn::parse_str(code).map_err(|err| Error::new(code.span(), err.to_string()))?;
let code = quote! {{
use #crate_name::GuardExt;
#expr
}};
Ok(quote! {
#crate_name::Guard::check(&#code, &ctx).await #map_err ?;
})
}
pub fn get_rustdoc(attrs: &[Attribute]) -> GeneratorResult<Option<String>> {
let mut full_docs = String::new();
for attr in attrs {
match attr.parse_meta()? {
Meta::NameValue(nv) if nv.path.is_ident("doc") => {
if let Lit::Str(doc) = nv.lit {
let doc = doc.value();
let doc_str = doc.trim();
if !full_docs.is_empty() {
full_docs += "\n";
}
full_docs += doc_str;
}
}
_ => {}
}
}
Ok(if full_docs.is_empty() {
None
} else {
Some(full_docs)
})
}
fn generate_default_value(lit: &Lit) -> GeneratorResult<TokenStream> {
match lit {
Lit::Str(value) =>{
let value = value.value();
Ok(quote!({ ::std::borrow::ToOwned::to_owned(#value) }))
}
Lit::Int(value) => {
let value = value.base10_parse::<i32>()?;
Ok(quote!({ ::std::convert::TryInto::try_into(#value).unwrap() }))
}
Lit::Float(value) => {
let value = value.base10_parse::<f64>()?;
Ok(quote!({ ::std::convert::TryInto::try_into(#value) }))
}
Lit::Bool(value) => {
let value = value.value;
Ok(quote!({ #value }))
}
_ => Err(Error::new_spanned(
lit,
"The default value type only be string, integer, float and boolean, other types should use default_with",
).into()),
}
}
fn generate_default_with(lit: &LitStr) -> GeneratorResult<TokenStream> {
let str = lit.value();
let tokens: TokenStream = str
.parse()
.map_err(|err| GeneratorError::Syn(syn::Error::from(err)))?;
Ok(quote! { (#tokens) })
}
pub fn generate_default(
default: &Option<args::DefaultValue>,
default_with: &Option<LitStr>,
) -> GeneratorResult<Option<TokenStream>> {
match (default, default_with) {
(Some(args::DefaultValue::Default), _) => {
Ok(Some(quote! { ::std::default::Default::default() }))
}
(Some(args::DefaultValue::Value(lit)), _) => Ok(Some(generate_default_value(lit)?)),
(None, Some(lit)) => Ok(Some(generate_default_with(lit)?)),
(None, None) => Ok(None),
}
}
pub fn get_cfg_attrs(attrs: &[Attribute]) -> Vec<Attribute> {
attrs
.iter()
.filter(|attr| !attr.path.segments.is_empty() && attr.path.segments[0].ident == "cfg")
.cloned()
.collect()
}
pub fn parse_graphql_attrs<T: FromMeta>(attrs: &[Attribute]) -> GeneratorResult<Option<T>> {
for attr in attrs {
if attr.path.is_ident("graphql") {
let meta = attr.parse_meta()?;
return Ok(Some(T::from_meta(&meta)?));
}
}
Ok(None)
}
pub fn remove_graphql_attrs(attrs: &mut Vec<Attribute>) {
if let Some((idx, _)) = attrs
.iter()
.enumerate()
.find(|(_, a)| a.path.is_ident("graphql"))
{
attrs.remove(idx);
}
}
pub fn get_type_path_and_name(ty: &Type) -> GeneratorResult<(&Type, String)> {
match ty {
Type::Path(path) => Ok((
ty,
path.path
.segments
.last()
.map(|s| s.ident.to_string())
.unwrap(),
)),
Type::Group(TypeGroup { elem, .. }) => get_type_path_and_name(elem),
Type::TraitObject(trait_object) => Ok((
ty,
trait_object
.bounds
.iter()
.find_map(|bound| match bound {
TypeParamBound::Trait(t) => {
Some(t.path.segments.last().map(|s| s.ident.to_string()).unwrap())
}
_ => None,
})
.unwrap(),
)),
_ => Err(Error::new_spanned(ty, "Invalid type").into()),
}
}
pub fn visible_fn(visible: &Option<Visible>) -> TokenStream {
match visible {
None | Some(Visible::None) => quote! { ::std::option::Option::None },
Some(Visible::HiddenAlways) => quote! { ::std::option::Option::Some(|_| false) },
Some(Visible::FnName(name)) => {
quote! { ::std::option::Option::Some(#name) }
}
}
}
pub fn parse_complexity_expr(s: &str) -> GeneratorResult<(HashSet<String>, Expr)> {
#[derive(Default)]
struct VisitComplexityExpr {
variables: HashSet<String>,
}
impl<'a> Visit<'a> for VisitComplexityExpr {
fn visit_expr_path(&mut self, i: &'a ExprPath) {
if let Some(ident) = i.path.get_ident() {
if ident != "child_complexity" {
self.variables.insert(ident.to_string());
}
}
}
}
let expr: Expr = syn::parse_str(s)?;
let mut visit = VisitComplexityExpr::default();
visit.visit_expr(&expr);
Ok((visit.variables, expr))
}
pub fn gen_deprecation(deprecation: &Deprecation, crate_name: &TokenStream) -> TokenStream {
match deprecation {
Deprecation::NoDeprecated => {
quote! { #crate_name::registry::Deprecation::NoDeprecated }
}
Deprecation::Deprecated {
reason: Some(reason),
} => {
quote! { #crate_name::registry::Deprecation::Deprecated { reason: ::std::option::Option::Some(#reason) } }
}
Deprecation::Deprecated { reason: None } => {
quote! { #crate_name::registry::Deprecation::Deprecated { reason: ::std::option::Option::None } }
}
}
}
pub fn extract_input_args(
crate_name: &proc_macro2::TokenStream,
method: &mut ImplItemMethod,
) -> GeneratorResult<Vec<(PatIdent, Type, Argument)>> {
let mut args = Vec::new();
let mut create_ctx = true;
if method.sig.inputs.is_empty() {
return Err(Error::new_spanned(
&method.sig,
"The self receiver must be the first parameter.",
)
.into());
}
for (idx, arg) in method.sig.inputs.iter_mut().enumerate() {
if let FnArg::Receiver(receiver) = arg {
if idx != 0 {
return Err(Error::new_spanned(
receiver,
"The self receiver must be the first parameter.",
)
.into());
}
} else if let FnArg::Typed(pat) = arg {
if idx == 0 {
return Err(Error::new_spanned(
pat,
"The self receiver must be the first parameter.",
)
.into());
}
match (&*pat.pat, &*pat.ty) {
(Pat::Ident(arg_ident), Type::Reference(TypeReference { elem, .. })) => {
if let Type::Path(path) = elem.as_ref() {
if idx != 1 || path.path.segments.last().unwrap().ident != "Context" {
args.push((
arg_ident.clone(),
pat.ty.as_ref().clone(),
parse_graphql_attrs::<args::Argument>(&pat.attrs)?
.unwrap_or_default(),
));
} else {
create_ctx = false;
}
}
}
(Pat::Ident(arg_ident), ty) => {
args.push((
arg_ident.clone(),
ty.clone(),
parse_graphql_attrs::<args::Argument>(&pat.attrs)?.unwrap_or_default(),
));
remove_graphql_attrs(&mut pat.attrs);
}
_ => {
return Err(Error::new_spanned(arg, "Invalid argument type.").into());
}
}
}
}
if create_ctx {
let arg = syn::parse2::<FnArg>(quote! { _: &#crate_name::Context<'_> }).unwrap();
method.sig.inputs.insert(1, arg);
}
Ok(args)
}