rustio_macros/
lib.rs

1use proc_macro::TokenStream;
2use proc_macro2::TokenStream as TokenStream2;
3use quote::quote;
4use syn::{parse_macro_input, Data, DeriveInput, Fields, Type};
5
6#[derive(Clone, Copy)]
7enum FieldKind {
8    I32,
9    I64,
10    String,
11    Bool,
12}
13
14struct FieldInfo {
15    ident: syn::Ident,
16    name_str: String,
17    kind: FieldKind,
18    editable: bool,
19}
20
21#[proc_macro_derive(RustioAdmin)]
22pub fn derive_rustio_admin(input: TokenStream) -> TokenStream {
23    let input = parse_macro_input!(input as DeriveInput);
24    let name = &input.ident;
25
26    let data = match &input.data {
27        Data::Struct(d) => d,
28        _ => {
29            return syn::Error::new_spanned(
30                &input.ident,
31                "RustioAdmin only supports structs with named fields",
32            )
33            .to_compile_error()
34            .into();
35        }
36    };
37
38    let named = match &data.fields {
39        Fields::Named(n) => n,
40        _ => {
41            return syn::Error::new_spanned(&input.ident, "RustioAdmin requires named fields")
42                .to_compile_error()
43                .into();
44        }
45    };
46
47    let mut fields: Vec<FieldInfo> = Vec::new();
48    for f in &named.named {
49        let ident = f.ident.clone().expect("named field");
50        let name_str = ident.to_string();
51        let kind = match classify_type(&f.ty) {
52            Some(k) => k,
53            None => {
54                return syn::Error::new_spanned(
55                    &f.ty,
56                    "RustioAdmin: unsupported field type (supported: i32, i64, String, bool)",
57                )
58                .to_compile_error()
59                .into();
60            }
61        };
62        let editable = name_str != "id";
63        fields.push(FieldInfo {
64            ident,
65            name_str,
66            kind,
67            editable,
68        });
69    }
70
71    let admin_name = pluralize(&name.to_string().to_lowercase());
72    let display_name = pluralize(&name.to_string());
73
74    let field_entries: Vec<TokenStream2> = fields
75        .iter()
76        .map(|f| {
77            let n = &f.name_str;
78            let kind_token = kind_token(f.kind);
79            let editable = f.editable;
80            quote! {
81                ::rustio_core::admin::AdminField {
82                    name: #n,
83                    ty: #kind_token,
84                    editable: #editable,
85                }
86            }
87        })
88        .collect();
89
90    let display_arms: Vec<TokenStream2> = fields
91        .iter()
92        .map(|f| {
93            let ident = &f.ident;
94            let name_str = &f.name_str;
95            quote! {
96                #name_str => Some(self.#ident.to_string()),
97            }
98        })
99        .collect();
100
101    let from_form_assignments: Vec<TokenStream2> =
102        fields.iter().map(from_form_assignment).collect();
103
104    let expanded = quote! {
105        impl ::rustio_core::admin::AdminModel for #name {
106            const ADMIN_NAME: &'static str = #admin_name;
107            const DISPLAY_NAME: &'static str = #display_name;
108            const FIELDS: &'static [::rustio_core::admin::AdminField] = &[
109                #( #field_entries ),*
110            ];
111
112            fn field_display(&self, name: &str) -> Option<String> {
113                match name {
114                    #( #display_arms )*
115                    _ => None,
116                }
117            }
118
119            fn from_form(
120                form: &::rustio_core::admin::FormData,
121                id: Option<i64>,
122            ) -> Result<Self, ::rustio_core::Error> {
123                Ok(Self {
124                    #( #from_form_assignments )*
125                })
126            }
127        }
128    };
129
130    expanded.into()
131}
132
133fn pluralize(name: &str) -> String {
134    if name.ends_with('s') {
135        name.to_string()
136    } else {
137        format!("{name}s")
138    }
139}
140
141fn classify_type(ty: &Type) -> Option<FieldKind> {
142    if let Type::Path(syn::TypePath { path, .. }) = ty {
143        if let Some(last) = path.segments.last() {
144            let ident = last.ident.to_string();
145            return match ident.as_str() {
146                "i32" => Some(FieldKind::I32),
147                "i64" => Some(FieldKind::I64),
148                "String" => Some(FieldKind::String),
149                "bool" => Some(FieldKind::Bool),
150                _ => None,
151            };
152        }
153    }
154    None
155}
156
157fn kind_token(kind: FieldKind) -> TokenStream2 {
158    match kind {
159        FieldKind::I32 => quote! { ::rustio_core::admin::FieldType::I32 },
160        FieldKind::I64 => quote! { ::rustio_core::admin::FieldType::I64 },
161        FieldKind::String => quote! { ::rustio_core::admin::FieldType::String },
162        FieldKind::Bool => quote! { ::rustio_core::admin::FieldType::Bool },
163    }
164}
165
166fn from_form_assignment(f: &FieldInfo) -> TokenStream2 {
167    let ident = &f.ident;
168    let name_str = &f.name_str;
169    if !f.editable {
170        return quote! { #ident: id.unwrap_or(0), };
171    }
172    match f.kind {
173        FieldKind::String => quote! {
174            #ident: form.get(#name_str).unwrap_or("").to_owned(),
175        },
176        FieldKind::Bool => quote! {
177            #ident: matches!(form.get(#name_str), Some(v) if v == "on" || v == "true"),
178        },
179        FieldKind::I64 => quote! {
180            #ident: form
181                .get(#name_str)
182                .unwrap_or("0")
183                .parse::<i64>()
184                .map_err(|_| ::rustio_core::Error::BadRequest(
185                    format!("invalid integer for field `{}`", #name_str)
186                ))?,
187        },
188        FieldKind::I32 => quote! {
189            #ident: form
190                .get(#name_str)
191                .unwrap_or("0")
192                .parse::<i32>()
193                .map_err(|_| ::rustio_core::Error::BadRequest(
194                    format!("invalid integer for field `{}`", #name_str)
195                ))?,
196        },
197    }
198}
rustio_macros/lib.rs

rustio_macros/
lib.rs
