From 13d060776fa8f06f4649bbe2d11ca0c48ba1b3df Mon Sep 17 00:00:00 2001
From: Albin Chaboissier <chalbin73@gmail.com>
Date: Wed, 11 Mar 2026 18:40:58 +0100
Subject: [PATCH] Blocks and flowgraph

---
 oxydsp-flowgraph-macros/Cargo.toml |  12 +++
 oxydsp-flowgraph-macros/src/lib.rs | 124 +++++++++++++++++++++++++++++
 2 files changed, 136 insertions(+)
 create mode 100644 oxydsp-flowgraph-macros/Cargo.toml
 create mode 100644 oxydsp-flowgraph-macros/src/lib.rs

diff --git a/oxydsp-flowgraph-macros/Cargo.toml b/oxydsp-flowgraph-macros/Cargo.toml
new file mode 100644
index 0000000..3b618b7
--- /dev/null
+++ b/oxydsp-flowgraph-macros/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "oxydsp-flowgraph-macros"
+version = "0.1.0"
+edition = "2024"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2 = "1.0.106"
+quote = "1.0.45"
+syn = "2.0.117"
diff --git a/oxydsp-flowgraph-macros/src/lib.rs b/oxydsp-flowgraph-macros/src/lib.rs
new file mode 100644
index 0000000..46ba18c
--- /dev/null
+++ b/oxydsp-flowgraph-macros/src/lib.rs
@@ -0,0 +1,124 @@
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{DeriveInput, Fields, Ident, parse_macro_input};
+
+#[proc_macro_derive(BlockIO, attributes(input, output))]
+pub fn derive_block_io(item: TokenStream) -> TokenStream
+{
+    let input = parse_macro_input!(item as DeriveInput);
+    let inputs;
+    let outputs;
+    match input.data
+    {
+        syn::Data::Struct(data_struct) =>
+        {
+            inputs = derive_block_get_marked_idents(&data_struct.fields, "input");
+            outputs = derive_block_get_marked_idents(&data_struct.fields, "output");
+        }
+        syn::Data::Enum(_) | syn::Data::Union(_) => unimplemented!("Enum/Unions not supported"),
+    }
+
+    let struct_name = input.ident;
+    let func_set_index = derive_block_set_index(&inputs, &outputs);
+    let func_get_successors = derive_block_get_successors(&outputs);
+    let (impl_generics, type_generics, where_clause) = input.generics.split_for_impl();
+
+    quote! {
+        impl #impl_generics oxydsp_flowgraph::block::BlockIO for #struct_name #type_generics
+            #where_clause
+        {
+            #func_set_index
+
+            #func_get_successors
+        }
+    }
+    .into()
+}
+
+fn derive_block_get_successors(outputs: &Vec<Ident>) -> proc_macro2::TokenStream
+{
+    quote! {
+        fn get_successors(&self) -> Vec<oxydsp_flowgraph::edge::BlockIOIndex>
+        {
+            let mut successors = Vec::new();
+            #(
+                if let Some(next) = self.#outputs.get_consumer_block()
+                {
+                    successors.push(next);
+                }
+            )*
+            successors
+        }
+    }
+}
+
+fn derive_block_io_count(inputs: &Vec<Ident>, outputs: &Vec<Ident>) -> proc_macro2::TokenStream
+{
+    let input_count = inputs.len();
+    let output_count = outputs.len();
+    quote! {
+        fn input_count(&self) -> usize
+        {
+            #input_count
+        }
+
+        fn output_count(&self) -> usize
+        {
+            #output_count
+        }
+    }
+}
+
+fn derive_block_set_index(inputs: &Vec<Ident>, outputs: &Vec<Ident>) -> proc_macro2::TokenStream
+{
+    quote! {
+        fn set_index(&self, block_index: usize)
+        {
+            use oxydsp_flowgraph::edge::BlockIOIndex;
+            let mut counter = 0;
+            #(
+                self.#inputs.set_block_index(
+                    BlockIOIndex
+                    {
+                        block_index,
+                        port_index: counter,
+                    }
+                    );
+                counter += 1;
+            )*
+                counter = 0;
+            #(
+                self.#outputs.set_block_index(
+                    BlockIOIndex
+                    {
+                        block_index,
+                        port_index: counter,
+                    }
+                    );
+                counter += 1;
+            )*
+        }
+    }
+}
+
+fn derive_block_get_marked_idents<S: AsRef<str>>(
+    fields: &Fields,
+    required_attribute: S,
+) -> Vec<Ident>
+{
+    let mut idents = vec![];
+    for field in fields
+    {
+        'inner: for attribute in field.attrs.iter()
+        {
+            if let Some(name) = attribute.meta.path().segments.first()
+                && name.ident == required_attribute.as_ref()
+            {
+                idents.push(field.ident.clone().unwrap());
+                break 'inner;
+            }
+        }
+    }
+
+    idents
+}