From a03c1891c86c4ccc7960e2456f6f73e51adfd796 Mon Sep 17 00:00:00 2001
From: Jonas Rabenstein <nonapode@fbs42.ddnss.de>
Date: Fri, 27 Feb 2026 05:46:12 +0100
Subject: [PATCH] v1

---
 macros/Cargo.toml |  12 +++++
 macros/src/lib.rs | 109 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 121 insertions(+)
 create mode 100644 macros/Cargo.toml
 create mode 100644 macros/src/lib.rs

diff --git a/macros/Cargo.toml b/macros/Cargo.toml
new file mode 100644
index 0000000..38091e7
--- /dev/null
+++ b/macros/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "spond-macros"
+version = "0.1.0"
+edition = "2024"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2 = "1.0.106"
+quote = "1.0.44"
+syn = { version = "2.0.117", features = ["extra-traits", "full"] }
diff --git a/macros/src/lib.rs b/macros/src/lib.rs
new file mode 100644
index 0000000..4b489f0
--- /dev/null
+++ b/macros/src/lib.rs
@@ -0,0 +1,109 @@
+use proc_macro::TokenStream;
+use quote::{quote, ToTokens};
+use syn::{
+    parse_macro_input, Attribute, FnArg, ItemFn, Lit, Meta, Pat, PatType, Type, spanned::Spanned,
+};
+
+/// Endpoint macro
+#[proc_macro_attribute]
+pub fn endpoint(attr: TokenStream, item: TokenStream) -> TokenStream {
+    // parse the endpoint attribute
+    let attr = proc_macro2::TokenStream::from(attr);
+    let func = parse_macro_input!(item as ItemFn);
+
+    let vis = &func.vis;
+    let name = &func.sig.ident;
+    let inputs = &func.sig.inputs;
+    let output = &func.sig.output;
+
+    // must be async
+    if func.sig.asyncness.is_none() {
+        return syn::Error::new(name.span(), "endpoint function must be async")
+            .to_compile_error()
+            .into();
+    }
+
+    // defaults
+    let mut method = quote! { GET };
+    let mut path = None;
+
+    // parse #[endpoint(...)]
+    if !attr.is_empty() {
+        let attr_str = attr.to_string();
+        // simple heuristic: if contains "POST", switch
+        if attr_str.contains("POST") {
+            method = quote! { POST };
+        }
+        // simple heuristic: extract path in quotes
+        if let Some(start) = attr_str.find('"') {
+            if let Some(end) = attr_str[start+1..].find('"') {
+                path = Some(attr_str[start+1..start+1+end].to_string());
+            }
+        }
+    }
+
+    let path = match path {
+        Some(p) => p,
+        None => return syn::Error::new(name.span(), "endpoint path must be provided")
+            .to_compile_error()
+            .into(),
+    };
+
+    // process arguments
+    let mut client_arg = None;
+    let mut other_args = Vec::new();
+
+    for input in inputs {
+        match input {
+            FnArg::Receiver(_) => continue, // skip self
+            FnArg::Typed(PatType { pat, ty, .. }) => {
+                if let Pat::Ident(ident) = &**pat {
+                    if ident.ident == "client" {
+                        client_arg = Some((ident.ident.clone(), ty));
+                    } else {
+                        other_args.push((ident.ident.clone(), ty));
+                    }
+                }
+            }
+        }
+    }
+
+    // generate tokens for function with builder
+    let arg_defs: Vec<proc_macro2::TokenStream> = other_args.iter().map(|(id, ty)| {
+        // wrap Option<T> with #[builder(default)]
+        if let Type::Path(tp) = ty.as_ref() {
+            let is_option = tp.path.segments.last().map(|seg| seg.ident == "Option").unwrap_or(false);
+            if is_option {
+                quote! { #[builder(default)] #id: #ty }
+            } else {
+                quote! { #id: #ty }
+            }
+        } else {
+            quote! { #id: #ty }
+        }
+    }).collect();
+
+    let client_def = match client_arg {
+        Some((id, ty)) => quote! { #[builder(finish_fn)] #id: #ty },
+        None => quote! { #[builder(finish_fn)] client: &restson::RestClient },
+    };
+
+    let call_args: Vec<proc_macro2::TokenStream> = other_args.iter().map(|(id, _)| {
+        quote! { #id }
+    }).collect();
+
+    let expanded = quote! {
+        #[bon::builder]
+        #vis fn #name(
+            #client_def,
+            #(#arg_defs),*
+        ) -> impl std::future::Future<Output = Result<_, restson::Error>> + '_ {
+            async move {
+                let result = client.get::<_, serde_json::Value>(#path).await?;
+                Ok(result)
+            }
+        }
+    };
+
+    expanded.into()
+}