// SPDX-License-Identifier: LGPL-3.0-or-later
// See Notices.txt for copyright information
use crate::{
    value_derive_common::{
        append_field, derive_clone_hash_eq_partialeq_for_struct, get_target, make_connect_impl,
        Bounds, Builder, FieldsKind, ParsedField, ValueDeriveGenerics,
    },
    Errors, HdlAttr,
};
use proc_macro2::TokenStream;
use quote::{format_ident, quote, quote_spanned, ToTokens};
use syn::{
    parse_quote, parse_quote_spanned, spanned::Spanned, FieldMutability, Generics, Ident,
    ItemStruct, Member, Path, Token, Visibility,
};

crate::options! {
    #[options = StructOptions]
    pub(crate) enum StructOption {
        OutlineGenerated(outline_generated),
        FixedType(fixed_type),
        ConnectInexact(connect_inexact),
        Bounds(where_, Bounds),
        Target(target, Path),
    }
}

crate::options! {
    #[options = FieldOptions]
    pub(crate) enum FieldOption {
        Flip(flip),
        Skip(skip),
    }
}

pub(crate) struct ParsedStructNames<I, S> {
    pub(crate) ident: Ident,
    pub(crate) type_struct_debug_ident: S,
    pub(crate) type_struct_ident: Ident,
    pub(crate) match_variant_ident: I,
    pub(crate) builder_struct_ident: I,
    pub(crate) mask_match_variant_ident: I,
    pub(crate) mask_type_ident: I,
    pub(crate) mask_type_debug_ident: S,
    pub(crate) mask_value_ident: I,
    pub(crate) mask_value_debug_ident: S,
    pub(crate) mask_builder_struct_ident: I,
}

pub(crate) struct ParsedStruct {
    pub(crate) options: HdlAttr<StructOptions>,
    pub(crate) vis: Visibility,
    pub(crate) struct_token: Token![struct],
    pub(crate) generics: Generics,
    pub(crate) fields_kind: FieldsKind,
    pub(crate) fields: Vec<ParsedField<FieldOptions>>,
    pub(crate) semi_token: Option<Token![;]>,
    pub(crate) skip_check_fields: bool,
    pub(crate) names: ParsedStructNames<Option<Ident>, Option<String>>,
}

impl ParsedStruct {
    pub(crate) fn parse(item: &mut ItemStruct) -> syn::Result<Self> {
        let ItemStruct {
            attrs,
            vis,
            struct_token,
            ident,
            generics,
            fields,
            semi_token,
        } = item;
        let mut errors = Errors::new();
        let struct_options = errors
            .unwrap_or_default(HdlAttr::parse_and_take_attr(attrs))
            .unwrap_or_default();
        let (fields_kind, fields) = ParsedField::parse_fields(&mut errors, fields, false);
        errors.finish()?;
        Ok(ParsedStruct {
            options: struct_options,
            vis: vis.clone(),
            struct_token: *struct_token,
            generics: generics.clone(),
            fields_kind,
            fields,
            semi_token: *semi_token,
            skip_check_fields: false,
            names: ParsedStructNames {
                ident: ident.clone(),
                type_struct_debug_ident: None,
                type_struct_ident: format_ident!("__{}__Type", ident),
                match_variant_ident: None,
                builder_struct_ident: None,
                mask_match_variant_ident: None,
                mask_type_ident: None,
                mask_type_debug_ident: None,
                mask_value_ident: None,
                mask_value_debug_ident: None,
                mask_builder_struct_ident: None,
            },
        })
    }
    pub(crate) fn write_body(
        &self,
        target: Path,
        names: ParsedStructNames<&Ident, &String>,
        is_for_mask: bool,
        tokens: &mut TokenStream,
    ) {
        let Self {
            options,
            vis,
            struct_token,
            generics,
            fields_kind,
            fields,
            semi_token,
            skip_check_fields,
            names: _,
        } = self;
        let skip_check_fields = *skip_check_fields || is_for_mask;
        let ParsedStructNames {
            ident: struct_ident,
            type_struct_debug_ident,
            type_struct_ident,
            match_variant_ident,
            builder_struct_ident,
            mask_match_variant_ident: _,
            mask_type_ident,
            mask_type_debug_ident: _,
            mask_value_ident,
            mask_value_debug_ident,
            mask_builder_struct_ident: _,
        } = names;
        let StructOptions {
            outline_generated: _,
            where_,
            target: _,
            fixed_type,
            connect_inexact,
        } = &options.body;
        let ValueDeriveGenerics {
            generics,
            fixed_type_generics,
        } = ValueDeriveGenerics::get(generics.clone(), where_);
        let (impl_generics, type_generics, where_clause) = generics.split_for_impl();
        let unskipped_fields = fields
            .iter()
            .filter(|field| field.options.body.skip.is_none());
        let _field_names = Vec::from_iter(fields.iter().map(|field| field.name.clone()));
        let unskipped_field_names =
            Vec::from_iter(unskipped_fields.clone().map(|field| field.name.clone()));
        let unskipped_field_name_strs = Vec::from_iter(
            unskipped_field_names
                .iter()
                .map(|field_name| field_name.to_token_stream().to_string()),
        );
        let unskipped_field_vars = Vec::from_iter(
            unskipped_field_names
                .iter()
                .map(|field_name| format_ident!("__v_{}", field_name)),
        );
        let unskipped_field_flips = Vec::from_iter(
            unskipped_fields
                .clone()
                .map(|field| field.options.body.flip.is_some()),
        );
        let mut any_fields_skipped = false;
        let type_fields = Vec::from_iter(fields.iter().filter_map(|field| {
            let ParsedField {
                options,
                vis,
                name,
                ty,
            } = field;
            let FieldOptions { flip: _, skip } = &options.body;
            if skip.is_some() {
                any_fields_skipped = true;
                return None;
            }
            let ty = if is_for_mask {
                parse_quote! { ::fayalite::ty::AsMask<#ty> }
            } else {
                ty.to_token_stream()
            };
            Some(syn::Field {
                attrs: vec![],
                vis: vis.clone(),
                mutability: FieldMutability::None,
                ident: match name.clone() {
                    Member::Named(name) => Some(name),
                    Member::Unnamed(_) => None,
                },
                colon_token: None,
                ty: parse_quote! { <#ty as ::fayalite::expr::ToExpr>::Type },
            })
        }));
        let field_types = Vec::from_iter(type_fields.iter().map(|field| field.ty.clone()));
        let match_variant_fields = Vec::from_iter(fields.iter().zip(&type_fields).map(
            |(parsed_field, type_field)| {
                let field_ty = &parsed_field.ty;
                syn::Field {
                    ty: parse_quote! { ::fayalite::expr::Expr<#field_ty> },
                    ..type_field.clone()
                }
            },
        ));

        let mask_value_fields = Vec::from_iter(fields.iter().zip(&type_fields).map(
            |(parsed_field, type_field)| {
                let field_ty = &parsed_field.ty;
                syn::Field {
                    ty: parse_quote! { ::fayalite::ty::AsMask<#field_ty> },
                    ..type_field.clone()
                }
            },
        ));

        let mut type_struct_fields = fields_kind.into_fields(type_fields);
        let mut match_variant_fields = fields_kind.into_fields(match_variant_fields);
        let mut mask_value_fields = fields_kind.into_fields(mask_value_fields);
        let phantom_data_field_name = any_fields_skipped.then(|| {
            let phantom_data_field_name = Ident::new("__phantom_data", type_struct_ident.span());
            let member = append_field(
                &mut type_struct_fields,
                syn::Field {
                    attrs: vec![],
                    vis: vis.clone(),
                    mutability: FieldMutability::None,
                    ident: Some(phantom_data_field_name.clone()),
                    colon_token: None,
                    ty: parse_quote_spanned! {type_struct_ident.span()=>
                        ::fayalite::__std::marker::PhantomData<#struct_ident #type_generics>
                    },
                },
            );
            append_field(
                &mut match_variant_fields,
                syn::Field {
                    attrs: vec![],
                    vis: Visibility::Inherited,
                    mutability: FieldMutability::None,
                    ident: Some(phantom_data_field_name.clone()),
                    colon_token: None,
                    ty: parse_quote_spanned! {type_struct_ident.span()=>
                        ::fayalite::__std::marker::PhantomData<#struct_ident #type_generics>
                    },
                },
            );
            append_field(
                &mut mask_value_fields,
                syn::Field {
                    attrs: vec![],
                    vis: Visibility::Inherited,
                    mutability: FieldMutability::None,
                    ident: Some(phantom_data_field_name),
                    colon_token: None,
                    ty: parse_quote_spanned! {type_struct_ident.span()=>
                        ::fayalite::__std::marker::PhantomData<#struct_ident #type_generics>
                    },
                },
            );
            member
        });
        let phantom_data_field_name_slice = phantom_data_field_name.as_slice();
        let type_struct = ItemStruct {
            attrs: vec![parse_quote! {#[allow(non_camel_case_types)]}],
            vis: vis.clone(),
            struct_token: *struct_token,
            ident: type_struct_ident.clone(),
            generics: generics.clone(),
            fields: type_struct_fields,
            semi_token: *semi_token,
        };
        type_struct.to_tokens(tokens);
        let match_variant_struct = ItemStruct {
            attrs: vec![parse_quote! {#[allow(non_camel_case_types)]}],
            vis: vis.clone(),
            struct_token: *struct_token,
            ident: match_variant_ident.clone(),
            generics: generics.clone(),
            fields: match_variant_fields,
            semi_token: *semi_token,
        };
        match_variant_struct.to_tokens(tokens);
        let mask_type_body = if is_for_mask {
            quote! {
                ::fayalite::__std::clone::Clone::clone(self)
            }
        } else {
            let mask_value_struct = ItemStruct {
                attrs: vec![parse_quote! {#[allow(non_camel_case_types)]}],
                vis: vis.clone(),
                struct_token: *struct_token,
                ident: mask_value_ident.clone(),
                generics: generics.clone(),
                fields: mask_value_fields,
                semi_token: *semi_token,
            };
            mask_value_struct.to_tokens(tokens);
            let debug_mask_value_body = match fields_kind {
                FieldsKind::Unit => quote! {
                    f.debug_struct(#mask_value_debug_ident).finish()
                },
                FieldsKind::Named(_) => quote! {
                    f.debug_struct(#mask_value_debug_ident)
                        #(.field(#unskipped_field_name_strs, &self.#unskipped_field_names))*
                        .finish()
                },
                FieldsKind::Unnamed(_) => quote! {
                    f.debug_tuple(#mask_value_debug_ident)
                        #(.field(&self.#unskipped_field_names))*
                        .finish()
                },
            };
            quote! {
                #[automatically_derived]
                impl #impl_generics ::fayalite::__std::fmt::Debug
                    for #mask_value_ident #type_generics
                #where_clause
                {
                    fn fmt(
                        &self,
                        f: &mut ::fayalite::__std::fmt::Formatter<'_>,
                    ) -> ::fayalite::__std::fmt::Result {
                        #debug_mask_value_body
                    }
                }
            }
            .to_tokens(tokens);
            quote! {
                #mask_type_ident {
                    #(#unskipped_field_names:
                        ::fayalite::ty::Type::mask_type(&self.#unskipped_field_names),)*
                    #(#phantom_data_field_name_slice: ::fayalite::__std::marker::PhantomData,)*
                }
            }
        };
        let debug_type_body = match fields_kind {
            FieldsKind::Unit => quote! {
                f.debug_struct(#type_struct_debug_ident).finish()
            },
            FieldsKind::Named(_) => quote! {
                f.debug_struct(#type_struct_debug_ident)
                    #(.field(#unskipped_field_name_strs, &self.#unskipped_field_names))*
                    .finish()
            },
            FieldsKind::Unnamed(_) => quote! {
                f.debug_tuple(#type_struct_debug_ident)
                    #(.field(&self.#unskipped_field_names))*
                    .finish()
            },
        };
        for the_struct_ident in [&type_struct_ident, match_variant_ident]
            .into_iter()
            .chain(is_for_mask.then_some(mask_value_ident))
        {
            derive_clone_hash_eq_partialeq_for_struct(
                the_struct_ident,
                &generics,
                &Vec::from_iter(
                    unskipped_field_names
                        .iter()
                        .cloned()
                        .chain(phantom_data_field_name.clone()),
                ),
            )
            .to_tokens(tokens);
        }
        let check_v = format_ident!("__v");
        let field_checks = Vec::from_iter(fields.iter().map(|ParsedField { ty, name, .. }| {
            quote_spanned! {ty.span()=>
                __check_field(#check_v.#name);
            }
        }));
        if fixed_type.is_some() {
            let (impl_generics, type_generics, where_clause) = fixed_type_generics.split_for_impl();
            quote! {
                #[automatically_derived]
                impl #impl_generics ::fayalite::ty::FixedType for #type_struct_ident #type_generics
                #where_clause
                {
                    fn fixed_type() -> Self {
                        Self {
                            #(#unskipped_field_names: ::fayalite::ty::FixedType::fixed_type(),)*
                            #(#phantom_data_field_name_slice:
                                ::fayalite::__std::marker::PhantomData,)*
                        }
                    }
                }
            }
            .to_tokens(tokens);
        }
        if !skip_check_fields {
            quote! {
                fn __check_field<T: ::fayalite::ty::Value>(_v: T)
                where
                    <T as ::fayalite::expr::ToExpr>::Type: ::fayalite::ty::Type<Value = T>,
                {}
                fn __check_fields #impl_generics(#check_v: #target #type_generics)
                #where_clause
                {
                    #(#field_checks)*
                }
            }
            .to_tokens(tokens);
        }
        let mut builder = Builder::new(builder_struct_ident.clone(), vis.clone());
        for field in unskipped_fields.clone() {
            builder.insert_field(
                field.name.clone(),
                |v| {
                    parse_quote_spanned! {v.span()=>
                        ::fayalite::expr::ToExpr::to_expr(&#v)
                    }
                },
                |t| {
                    parse_quote_spanned! {t.span()=>
                        ::fayalite::expr::Expr<<
                            <#t as ::fayalite::expr::ToExpr>::Type
                            as ::fayalite::ty::Type
                        >::Value>
                    }
                },
                |t| {
                    parse_quote_spanned! {t.span()=>
                        where
                            #t: ::fayalite::expr::ToExpr,
                    }
                },
            );
        }
        let builder = builder.finish_filling_in_fields();
        builder.to_tokens(tokens);
        let build_type_fields =
            Vec::from_iter(unskipped_fields.clone().map(|ParsedField { name, .. }| {
                let builder_field_name = &builder.get_field(name).unwrap().1.builder_field_name;
                quote_spanned! {struct_ident.span()=>
                    #name: ::fayalite::expr::ToExpr::ty(&#builder_field_name)
                }
            }));
        let build_expr_fields =
            Vec::from_iter(unskipped_fields.clone().map(|ParsedField { name, .. }| {
                let builder_field_name = &builder.get_field(name).unwrap().1.builder_field_name;
                quote_spanned! {struct_ident.span()=>
                    #builder_field_name.to_canonical_dyn()
                }
            }));
        let build_specified_fields = unskipped_fields.clone().map(
            |ParsedField {
                 options: _,
                 vis: _,
                 name,
                 ty,
             }| {
                let ty = if is_for_mask {
                    parse_quote_spanned! {name.span()=>
                        ::fayalite::expr::Expr<::fayalite::ty::AsMask<#ty>>
                    }
                } else {
                    parse_quote_spanned! {name.span()=>
                        ::fayalite::expr::Expr<#ty>
                    }
                };
                (name.clone(), ty)
            },
        );
        let build_body = parse_quote_spanned! {struct_ident.span()=>
            {
                ::fayalite::expr::ToExpr::to_expr(
                    &::fayalite::expr::ops::BundleLiteral::new_unchecked(
                        ::fayalite::intern::Intern::intern(&[#(
                            #build_expr_fields,
                        )*][..]),
                        #type_struct_ident {
                            #(#build_type_fields,)*
                            #(#phantom_data_field_name_slice:
                                ::fayalite::__std::marker::PhantomData,)*
                        },
                    ),
                )
            }
        };
        builder
            .make_build_method(
                &Ident::new("build", struct_ident.span()),
                build_specified_fields,
                &generics,
                &parse_quote_spanned! {struct_ident.span()=>
                    #type_struct_ident #type_generics
                },
                &parse_quote_spanned! {struct_ident.span()=>
                    ::fayalite::expr::Expr<#target #type_generics>
                },
                build_body,
            )
            .to_tokens(tokens);
        make_connect_impl(
            *connect_inexact,
            &generics,
            &type_struct_ident,
            unskipped_fields.clone().map(|field| {
                let ty = &field.ty;
                parse_quote_spanned! {field.name.span()=>
                    <#ty as ::fayalite::expr::ToExpr>::Type
                }
            }),
        )
        .to_tokens(tokens);
        let empty_builder_ty = builder.ty([], Some(&parse_quote! { Self }), false);
        quote! {
            #[automatically_derived]
            impl #impl_generics ::fayalite::__std::fmt::Debug for #type_struct_ident #type_generics
            #where_clause
            {
                fn fmt(
                    &self,
                    f: &mut ::fayalite::__std::fmt::Formatter<'_>,
                ) -> ::fayalite::__std::fmt::Result {
                    #debug_type_body
                }
            }

            #[automatically_derived]
            impl #impl_generics ::fayalite::ty::Type for #type_struct_ident #type_generics
            #where_clause
            {
                type CanonicalType = ::fayalite::bundle::DynBundleType;
                type Value = #target #type_generics;
                type CanonicalValue = ::fayalite::bundle::DynBundle;
                type MaskType = #mask_type_ident #type_generics;
                type MaskValue = #mask_value_ident #type_generics;
                type MatchVariant = #match_variant_ident #type_generics;
                type MatchActiveScope = ();
                type MatchVariantAndInactiveScope = ::fayalite::ty::MatchVariantWithoutScope<
                    #match_variant_ident #type_generics,
                >;
                type MatchVariantsIter = ::fayalite::__std::iter::Once<
                    <Self as ::fayalite::ty::Type>::MatchVariantAndInactiveScope,
                >;
                #[allow(unused_variables)]
                fn match_variants<IO: ::fayalite::bundle::BundleValue>(
                    this: ::fayalite::expr::Expr<<Self as ::fayalite::ty::Type>::Value>,
                    module_builder: &mut ::fayalite::module::ModuleBuilder<
                        IO,
                        ::fayalite::module::NormalModule,
                    >,
                    source_location: ::fayalite::source_location::SourceLocation,
                ) -> <Self as ::fayalite::ty::Type>::MatchVariantsIter
                where
                    <IO as ::fayalite::expr::ToExpr>::Type:
                        ::fayalite::bundle::BundleType<Value = IO>,
                {
                    ::fayalite::__std::iter::once(::fayalite::ty::MatchVariantWithoutScope(
                        #match_variant_ident {
                            #(#unskipped_field_names: this.field(#unskipped_field_name_strs),)*
                            #(#phantom_data_field_name_slice:
                                ::fayalite::__std::marker::PhantomData,)*
                        },
                    ))
                }
                fn mask_type(&self) -> <Self as ::fayalite::ty::Type>::MaskType {
                    #mask_type_body
                }
                fn canonical(&self) -> <Self as ::fayalite::ty::Type>::CanonicalType {
                    let fields = ::fayalite::bundle::BundleType::fields(self);
                    ::fayalite::bundle::DynBundleType::new(fields)
                }
                fn source_location(&self) -> ::fayalite::source_location::SourceLocation {
                    ::fayalite::source_location::SourceLocation::caller()
                }
                fn type_enum(&self) -> ::fayalite::ty::TypeEnum {
                    ::fayalite::ty::TypeEnum::BundleType(::fayalite::ty::Type::canonical(self))
                }
                fn from_canonical_type(t: <Self as ::fayalite::ty::Type>::CanonicalType) -> Self {
                    let [#(#unskipped_field_vars),*] = *::fayalite::bundle::BundleType::fields(&t)
                    else {
                        ::fayalite::__std::panic!("wrong number of fields");
                    };
                    Self {
                        #(#unskipped_field_names: #unskipped_field_vars.from_canonical_type_helper(
                            #unskipped_field_name_strs,
                            #unskipped_field_flips,
                        ),)*
                        #(#phantom_data_field_name_slice: ::fayalite::__std::marker::PhantomData,)*
                    }
                }
            }

            #[automatically_derived]
            impl #impl_generics ::fayalite::ty::TypeWithDeref for #type_struct_ident #type_generics
            #where_clause
            {
                #[allow(unused_variables)]
                fn expr_deref(this: &::fayalite::expr::Expr<<Self as ::fayalite::ty::Type>::Value>)
                    -> &<Self as ::fayalite::ty::Type>::MatchVariant
                {
                    ::fayalite::intern::Interned::<_>::into_inner(
                        ::fayalite::intern::Intern::intern_sized(#match_variant_ident {
                            #(#unskipped_field_names: this.field(#unskipped_field_name_strs),)*
                            #(#phantom_data_field_name_slice:
                                ::fayalite::__std::marker::PhantomData,)*
                        }),
                    )
                }
            }

            #[automatically_derived]
            impl #impl_generics ::fayalite::bundle::BundleType for #type_struct_ident #type_generics
            #where_clause
            {
                type Builder = #empty_builder_ty;
                fn builder() -> <Self as ::fayalite::bundle::BundleType>::Builder {
                    #empty_builder_ty::new()
                }
                fn fields(&self) -> ::fayalite::intern::Interned<
                        [::fayalite::bundle::FieldType<::fayalite::intern::Interned<
                            dyn ::fayalite::ty::DynCanonicalType,
                        >>],
                    >
                {
                    ::fayalite::intern::Intern::intern(&[#(
                        ::fayalite::bundle::FieldType {
                            name: ::fayalite::intern::Intern::intern(#unskipped_field_name_strs),
                            flipped: #unskipped_field_flips,
                            ty: ::fayalite::ty::DynType::canonical_dyn(
                                &self.#unskipped_field_names,
                            ),
                        },
                    )*][..])
                }
                fn fields_hint() -> ::fayalite::bundle::FieldsHint {
                    ::fayalite::bundle::FieldsHint::new([#(
                        ::fayalite::bundle::FieldType {
                            name: ::fayalite::intern::Intern::intern(#unskipped_field_name_strs),
                            flipped: #unskipped_field_flips,
                            ty: ::fayalite::bundle::TypeHint::<#field_types>::intern_dyn(),
                        },
                    )*], false)
                }
            }

            #[automatically_derived]
            impl #impl_generics ::fayalite::expr::ToExpr for #target #type_generics
            #where_clause
            {
                type Type = #type_struct_ident #type_generics;
                fn ty(&self) -> <Self as ::fayalite::expr::ToExpr>::Type {
                    #type_struct_ident {
                        #(#unskipped_field_names: ::fayalite::expr::ToExpr::ty(
                            &self.#unskipped_field_names,
                        ),)*
                        #(#phantom_data_field_name_slice: ::fayalite::__std::marker::PhantomData,)*
                    }
                }
                fn to_expr(&self) -> ::fayalite::expr::Expr<Self> {
                    ::fayalite::expr::Expr::from_value(self)
                }
            }

            #[automatically_derived]
            impl #impl_generics ::fayalite::ty::Value for #target #type_generics
            #where_clause
            {
                fn to_canonical(&self) -> <
                        <Self as ::fayalite::expr::ToExpr>::Type
                        as ::fayalite::ty::Type
                    >::CanonicalValue
                {
                    let ty = ::fayalite::ty::Type::canonical(&::fayalite::expr::ToExpr::ty(self));
                    ::fayalite::bundle::DynBundle::new(ty, ::fayalite::__std::sync::Arc::new([
                        #(::fayalite::ty::DynValueTrait::to_canonical_dyn(
                            &self.#unskipped_field_names,
                        ),)*
                    ]))
                }
            }

            #[automatically_derived]
            impl #impl_generics ::fayalite::bundle::BundleValue for #target #type_generics
            #where_clause
            {
            }
        }
        .to_tokens(tokens);
    }
}

impl ToTokens for ParsedStruct {
    fn to_tokens(&self, tokens: &mut TokenStream) {
        let ParsedStructNames {
            ident: struct_ident,
            type_struct_debug_ident,
            type_struct_ident,
            match_variant_ident,
            builder_struct_ident,
            mask_match_variant_ident,
            mask_type_ident,
            mask_type_debug_ident,
            mask_value_ident,
            mask_value_debug_ident,
            mask_builder_struct_ident,
        } = &self.names;
        macro_rules! unwrap_or_set {
            ($(let $var:ident =? $fallback_value:expr;)*) => {
                $(let $var = $var.clone().unwrap_or_else(|| $fallback_value);)*
            };
        }
        unwrap_or_set! {
            let type_struct_debug_ident =? format!("{struct_ident}::Type");
            let match_variant_ident =? format_ident!("__{}__MatchVariant", struct_ident);
            let builder_struct_ident =? format_ident!("__{}__Builder", struct_ident);
            let mask_match_variant_ident =? format_ident!("__AsMask__{}__MatchVariant", struct_ident);
            let mask_type_ident =? format_ident!("__AsMask__{}__Type", struct_ident);
            let mask_type_debug_ident =? format!("AsMask<{struct_ident}>::Type");
            let mask_value_ident =? format_ident!("__AsMask__{}", struct_ident);
            let mask_value_debug_ident =? format!("AsMask<{struct_ident}>");
            let mask_builder_struct_ident =? format_ident!("__AsMask__{}__Builder", struct_ident);
        }
        let target = get_target(&self.options.body.target, struct_ident);
        let names = ParsedStructNames {
            ident: struct_ident.clone(),
            type_struct_debug_ident: &type_struct_debug_ident,
            type_struct_ident: type_struct_ident.clone(),
            match_variant_ident: &match_variant_ident,
            builder_struct_ident: &builder_struct_ident,
            mask_match_variant_ident: &mask_match_variant_ident,
            mask_type_ident: &mask_type_ident,
            mask_type_debug_ident: &mask_type_debug_ident,
            mask_value_ident: &mask_value_ident,
            mask_value_debug_ident: &mask_value_debug_ident,
            mask_builder_struct_ident: &mask_builder_struct_ident,
        };
        self.write_body(target, names, false, tokens);
        let mask_names = ParsedStructNames {
            ident: mask_value_ident.clone(),
            type_struct_debug_ident: &mask_type_debug_ident,
            type_struct_ident: mask_type_ident.clone(),
            match_variant_ident: &mask_match_variant_ident,
            builder_struct_ident: &mask_builder_struct_ident,
            mask_match_variant_ident: &mask_match_variant_ident,
            mask_type_ident: &mask_type_ident,
            mask_type_debug_ident: &mask_type_debug_ident,
            mask_value_ident: &mask_value_ident,
            mask_value_debug_ident: &mask_value_debug_ident,
            mask_builder_struct_ident: &mask_builder_struct_ident,
        };
        self.write_body(mask_value_ident.clone().into(), mask_names, true, tokens);
    }
}

pub(crate) fn value_derive_struct(mut item: ItemStruct) -> syn::Result<TokenStream> {
    let item = ParsedStruct::parse(&mut item)?;
    let outline_generated = item.options.body.outline_generated;
    let mut contents = quote! {
        const _: () = {
            #item
        };
    };
    if outline_generated.is_some() {
        contents = crate::outline_generated(contents, "value-struct-");
    }
    Ok(contents)
}