From 87a5ae67c749933606fa3b13b6cd67c2249526e9 Mon Sep 17 00:00:00 2001
From: Lee Smet <lee.smet@hotmail.com>
Date: Thu, 31 Jul 2025 13:21:12 +0200
Subject: [PATCH] Add indexed_fields method on Model

For postgres indexes we want to know the indexed field names upfront
without an actual instance of Model

Signed-off-by: Lee Smet <lee.smet@hotmail.com>
---
 heromodels-derive/src/lib.rs | 11 +++++++++++
 heromodels_core/src/lib.rs   |  5 +++++
 2 files changed, 16 insertions(+)

diff --git a/heromodels-derive/src/lib.rs b/heromodels-derive/src/lib.rs
index d2021a2..d51c635 100644
--- a/heromodels-derive/src/lib.rs
+++ b/heromodels-derive/src/lib.rs
@@ -123,6 +123,11 @@ pub fn model(_attr: TokenStream, item: TokenStream) -> TokenStream {
         }
     };
 
+    let indexed_field_names = indexed_fields
+        .iter()
+        .map(|f| f.0.to_string())
+        .collect::<Vec<_>>();
+
     let model_impl = quote! {
         impl heromodels_core::Model for #struct_name {
             fn db_prefix() -> &'static str {
@@ -137,6 +142,12 @@ pub fn model(_attr: TokenStream, item: TokenStream) -> TokenStream {
                 &mut self.base_data
             }
 
+            fn indexed_fields() -> Vec<&'static str> {
+                vec![
+                    #(#indexed_field_names),*
+                ]
+            }
+
             #db_keys_impl
         }
     };
diff --git a/heromodels_core/src/lib.rs b/heromodels_core/src/lib.rs
index ca7cb2a..a593008 100644
--- a/heromodels_core/src/lib.rs
+++ b/heromodels_core/src/lib.rs
@@ -58,6 +58,11 @@ pub trait Model:
         Vec::new()
     }
 
+    /// Return a list of field names which have an index applied.
+    fn indexed_fields() -> Vec<&'static str> {
+        Vec::new()
+    }
+
     /// Get the unique ID for this model
     fn get_id(&self) -> u32;