#![recursion_limit = "256"]

use proc_macro::TokenStream;

use quote::{format_ident, quote};

use syn::parse::Parser;

use syn::DeriveInput;

use syn::{parse_macro_input, ItemStruct};

mod field_setter;

#[proc_macro_derive(FieldSetter, attributes(field_setter))]

pub fn field_setter(input: proc_macro::TokenStream) -> proc_macro::TokenStream {

let input = syn::parse::<DeriveInput>(input).unwrap();

field_setter::field_setter_impl(input)

}

#[proc_macro_attribute]

pub fn layout_structs(_attr: TokenStream, item: TokenStream) -> TokenStream {

let input = parse_macro_input!(item as ItemStruct);

let vis = &input.vis;

let fields = &input.fields;

let attrs = &input.attrs;

// Generate LayoutTemplate (no template field, no #[field_setter(kind =

// "layout")])

let template_struct_name = format_ident!("LayoutTemplate");

let template_struct = quote! {

#(#attrs)*

#[serde_with::skip_serializing_none]

#[derive(Serialize, Debug, Clone, FieldSetter)]

#vis struct #template_struct_name #fields

};

// Generate Layout (with template field and #[field_setter(kind = "layout")])

let layout_struct_name = format_ident!("Layout");

let mut layout_fields = fields.clone();

// Add the template field

if let syn::Fields::Named(ref mut named) = layout_fields {

named.named.push(

syn::Field::parse_named

.parse2(quote! {

#[field_setter(skip)]

template: Option<Box<std::borrow::Cow<'static, Template>>>

})

.unwrap(),

);

}

let layout_struct = quote! {

#(#attrs)*

#[serde_with::skip_serializing_none]

#[derive(Serialize, Debug, Clone, FieldSetter)]

#[field_setter(kind = "layout")]

#vis struct #layout_struct_name #layout_fields

};

// Generate impls (add your methods as needed)

let template_impl = quote! {

impl #template_struct_name {

pub fn new() -> Self { Default::default() }

pub fn add_annotation(&mut self, annotation: Annotation) {

if self.annotations.is_none() { self.annotations = Some(Vec::new()); }

self.annotations.as_mut().unwrap().push(annotation);

}

pub fn add_shape(&mut self, shape: Shape) {

if self.shapes.is_none() { self.shapes = Some(Vec::new()); }

self.shapes.as_mut().unwrap().push(shape);

}

}

};

let layout_impl = quote! {

impl #layout_struct_name {

pub fn new() -> Self { Default::default() }

pub fn to_json(&self) -> String { serde_json::to_string(self).unwrap() }

pub fn add_annotation(&mut self, annotation: Annotation) {

if self.annotations.is_none() { self.annotations = Some(Vec::new()); }

self.annotations.as_mut().unwrap().push(annotation);

}

pub fn add_shape(&mut self, shape: Shape) {

if self.shapes.is_none() { self.shapes = Some(Vec::new()); }

self.shapes.as_mut().unwrap().push(shape);

}

pub fn template<T>(mut self, template: T) -> Self

where T: Into<std::borrow::Cow<'static, Template>> {

self.template = Some(Box::new(template.into()));

self

}

}

};

let expanded = quote! {

#template_struct

#layout_struct

#template_impl

#layout_impl

};

TokenStream::from(expanded)

}