From b07a37d99b97b926c1057d1eefc4b425a341743d Mon Sep 17 00:00:00 2001
From: laurentketterle-hub <noreply@users.noreply.github.com>
Date: Wed, 12 Aug 2026 23:10:37 +0200
Subject: [PATCH] refactor: remove dead storage helpers and unify interest-rate
 calculation (Closes #331)

storage.rs exposed six accessor helpers (read/write_project, read/write_proposal, read/write_whitelist) that lib.rs never referenced, and logic::calculate_interest_rate duplicated the private compute_rate formula in lib.rs.

This removes the dead storage helpers and makes compute_rate delegate to logic::calculate_interest_rate (which already includes the underflow guard the local copy lacked), unifying the rate formula into a single implementation.

Signed-off-by: laurentketterle-hub <laurentketterle-hub@users.noreply.github.com>
---
 project_registry/src/lib.rs     |  6 ++---
 project_registry/src/logic.rs   |  3 ---
 project_registry/src/storage.rs | 42 ++++++---------------------------
 3 files changed, 10 insertions(+), 41 deletions(-)

diff --git a/project_registry/src/lib.rs b/project_registry/src/lib.rs
index 12905686..6632ab7c 100644
--- a/project_registry/src/lib.rs
+++ b/project_registry/src/lib.rs
@@ -1223,9 +1223,9 @@ fn require_multisig_disabled(env: &Env) {
 }
 
 fn compute_rate(credit_quality: u32, green_impact: u32) -> u32 {
-    let avg = (credit_quality + green_impact) / 2;
-    let discount = avg * MAX_DISCOUNT_BPS / 100;
-    BASE_RATE_BPS - discount
+    // Single source of truth: logic::calculate_interest_rate already applies
+    // the underflow guard this local copy lacked.
+    logic::calculate_interest_rate(BASE_RATE_BPS, MAX_DISCOUNT_BPS, credit_quality, green_impact)
 }
 
 fn read_state_version(env: &Env) -> u32 {
diff --git a/project_registry/src/logic.rs b/project_registry/src/logic.rs
index 2f5de543..4d174038 100644
--- a/project_registry/src/logic.rs
+++ b/project_registry/src/logic.rs
@@ -1,6 +1,3 @@
-use crate::types::{CertificationStatus, ProjectData};
-use soroban_sdk::{Address, Env, String};
-
 /// Interest-rate calculation for green-bond projects.
 ///
 /// Heliobond uses a two-dimensional scoring model to determine each project's
diff --git a/project_registry/src/storage.rs b/project_registry/src/storage.rs
index 0c7c83d8..6cd8781c 100644
--- a/project_registry/src/storage.rs
+++ b/project_registry/src/storage.rs
@@ -1,35 +1,7 @@
-use crate::types::{DataKey, ProjectData, Proposal};
-use soroban_sdk::{Address, Env};
-
-pub fn read_project(env: &Env, id: u32) -> Option<ProjectData> {
-    env.storage().persistent().get(&DataKey::Project(id))
-}
-
-pub fn write_project(env: &Env, id: u32, project: &ProjectData) {
-    env.storage()
-        .persistent()
-        .set(&DataKey::Project(id), project);
-}
-
-pub fn read_proposal(env: &Env, id: u32) -> Option<Proposal> {
-    env.storage().persistent().get(&DataKey::Proposal(id))
-}
-
-pub fn write_proposal(env: &Env, id: u32, proposal: &Proposal) {
-    env.storage()
-        .persistent()
-        .set(&DataKey::Proposal(id), proposal);
-}
-
-pub fn read_whitelist(env: &Env, account: Address) -> bool {
-    env.storage()
-        .persistent()
-        .get(&DataKey::Whitelist(account))
-        .unwrap_or(false)
-}
-
-pub fn write_whitelist(env: &Env, account: Address, status: bool) {
-    env.storage()
-        .persistent()
-        .set(&DataKey::Whitelist(account), &status);
-}
+//! Storage-accessor helpers.
+//!
+//! Historically this module exposed read_project / write_project /
+//! read_proposal / write_proposal / read_whitelist / write_whitelist wrappers
+//! around env.storage(), but lib.rs inlines env.storage() calls directly and
+//! never referenced them. They were removed to eliminate dead, drift-prone
+//! abstractions (#331).