From a09f6dd36288f46868efbaed6c582214d1381312 Mon Sep 17 00:00:00 2001
From: Josue19-08 <josuemarin2009@hotmail.com>
Date: Tue, 24 Mar 2026 20:04:46 -0600
Subject: [PATCH] feat(identity-registry): implement expert directory
 pagination

Add get_experts_paginated function to efficiently fetch experts in batches.
This addresses the performance issue of fetching large expert lists.

- Implement get_experts_paginated in contract.rs with start_index and limit
- Expose function in public API (lib.rs)
- Add comprehensive test with 15 experts, validating pagination behavior
---
 .../src/contract.rs                           | 22 ++++++++++
 .../identity-registry-contract/src/lib.rs     |  6 +++
 .../identity-registry-contract/src/test.rs    | 42 +++++++++++++++++++
 3 files changed, 70 insertions(+)

diff --git a/contracts/identity-registry-contract/src/contract.rs b/contracts/identity-registry-contract/src/contract.rs
index 051493f..f19d671 100644
--- a/contracts/identity-registry-contract/src/contract.rs
+++ b/contracts/identity-registry-contract/src/contract.rs
@@ -157,3 +157,25 @@ pub fn update_profile(env: &Env, expert: &Address, new_uri: String) -> Result<()
     events::emit_profile_updated(env, expert.clone(), new_uri);
     Ok(())
 }
+
+/// Get a paginated list of experts
+/// Returns a vector of expert addresses from start_index to start_index + limit
+pub fn get_experts_paginated(env: &Env, start_index: u64, limit: u64) -> Vec<Address> {
+    let total = storage::get_total_experts(env);
+    let mut experts = Vec::new(env);
+
+    // Calculate the actual end index (don't exceed total)
+    let end_index = if start_index + limit > total {
+        total
+    } else {
+        start_index + limit
+    };
+
+    // Fetch experts from start_index to end_index
+    for i in start_index..end_index {
+        let expert = storage::get_expert_by_index(env, i);
+        experts.push_back(expert);
+    }
+
+    experts
+}
diff --git a/contracts/identity-registry-contract/src/lib.rs b/contracts/identity-registry-contract/src/lib.rs
index b226d4b..ae4e86d 100644
--- a/contracts/identity-registry-contract/src/lib.rs
+++ b/contracts/identity-registry-contract/src/lib.rs
@@ -68,4 +68,10 @@ impl IdentityRegistryContract {
     pub fn update_profile(env: Env, expert: Address, new_uri: String) -> Result<(), RegistryError> {
         contract::update_profile(&env, &expert, new_uri)
     }
+
+    /// Get a paginated list of experts
+    /// Returns a vector of expert addresses from start_index to start_index + limit
+    pub fn get_experts_paginated(env: Env, start_index: u64, limit: u64) -> Vec<Address> {
+        contract::get_experts_paginated(&env, start_index, limit)
+    }
 }
diff --git a/contracts/identity-registry-contract/src/test.rs b/contracts/identity-registry-contract/src/test.rs
index 41c7195..5c03da1 100644
--- a/contracts/identity-registry-contract/src/test.rs
+++ b/contracts/identity-registry-contract/src/test.rs
@@ -581,3 +581,45 @@ fn test_expert_directory_via_batch_add() {
     assert_eq!(client.get_expert_by_index(&1u64), expert2);
     assert_eq!(client.get_expert_by_index(&2u64), expert3);
 }
+
+#[test]
+fn test_expert_pagination() {
+    let env = Env::default();
+    env.mock_all_auths();
+
+    let contract_id = env.register(IdentityRegistryContract, ());
+    let client = IdentityRegistryContractClient::new(&env, &contract_id);
+
+    let admin = Address::generate(&env);
+    client.init(&admin);
+
+    // Add 15 experts
+    let mut experts = vec![&env];
+    for _ in 0..15 {
+        let expert = Address::generate(&env);
+        let uri = String::from_str(&env, "ipfs://expert");
+        client.add_expert(&expert, &uri);
+        experts.push_back(expert);
+    }
+
+    // Verify total count
+    assert_eq!(client.get_total_experts(), 15u64);
+
+    // Fetch start: 0, limit: 10 (should return 10)
+    let page1 = client.get_experts_paginated(&0u64, &10u64);
+    assert_eq!(page1.len(), 10);
+
+    // Verify the first 10 experts match
+    for i in 0..10 {
+        assert_eq!(page1.get(i as u32).unwrap(), experts.get(i as u32).unwrap());
+    }
+
+    // Fetch start: 10, limit: 10 (should return 5)
+    let page2 = client.get_experts_paginated(&10u64, &10u64);
+    assert_eq!(page2.len(), 5);
+
+    // Verify the last 5 experts match
+    for i in 0..5 {
+        assert_eq!(page2.get(i as u32).unwrap(), experts.get((i + 10) as u32).unwrap());
+    }
+}