From 8217e858367cf2b7fb1617fd46582be2d7a9cf8a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A2u=20Cao?= <raucao@kosmos.org>
Date: Mon, 23 Feb 2026 21:14:40 +0400
Subject: [PATCH] Improve display of boundaries like cities, states, etc.

---
 app/services/osm.js             | 25 +++++++++++++++++++++-
 tests/unit/services/osm-test.js | 37 ++++++++++++++++++++++++++-------
 2 files changed, 53 insertions(+), 9 deletions(-)

diff --git a/app/services/osm.js b/app/services/osm.js
index 47d81f5..f097424 100644
--- a/app/services/osm.js
+++ b/app/services/osm.js
@@ -165,12 +165,35 @@ out center;
   normalizeOsmApiData(elements, targetId, targetType) {
     if (!elements || elements.length === 0) return null;
 
-    const mainElement = elements.find(
+    let mainElement = elements.find(
       (el) => String(el.id) === String(targetId) && el.type === targetType
     );
 
     if (!mainElement) return null;
 
+    // If it's a boundary relation, try to find the label or admin_centre node
+    // and use that as the main element (better coordinates and tags).
+    if (targetType === 'relation' && mainElement.members) {
+      const labelMember = mainElement.members.find(
+        (m) => m.role === 'label' && m.type === 'node'
+      );
+      const adminCentreMember = mainElement.members.find(
+        (m) => m.role === 'admin_centre' && m.type === 'node'
+      );
+
+      const targetMember = labelMember || adminCentreMember;
+
+      if (targetMember) {
+        const targetNode = elements.find(
+          (el) =>
+            String(el.id) === String(targetMember.ref) && el.type === 'node'
+        );
+        if (targetNode) {
+          mainElement = targetNode;
+        }
+      }
+    }
+
     let lat = mainElement.lat;
     let lon = mainElement.lon;
 
diff --git a/tests/unit/services/osm-test.js b/tests/unit/services/osm-test.js
index 1c28b1e..74a8e64 100644
--- a/tests/unit/services/osm-test.js
+++ b/tests/unit/services/osm-test.js
@@ -52,7 +52,7 @@ module('Unit | Service | osm', function (hooks) {
     assert.strictEqual(result.osmType, 'way');
   });
 
-  test('normalizeOsmApiData calculates centroid for relations with member nodes', function (assert) {
+  test('normalizeOsmApiData prioritizes label node for relations', function (assert) {
     let service = this.owner.lookup('service:osm');
     const elements = [
       {
@@ -64,17 +64,38 @@ module('Unit | Service | osm', function (hooks) {
         ],
         tags: { name: 'Test Relation' },
       },
-      { id: 1, type: 'node', lat: 10, lon: 10 },
-      { id: 2, type: 'node', lat: 30, lon: 30 },
+      { id: 1, type: 'node', lat: 10, lon: 10, tags: { name: 'Admin Centre' } },
+      { id: 2, type: 'node', lat: 30, lon: 30, tags: { name: 'Label Node' } },
     ];
 
     const result = service.normalizeOsmApiData(elements, 789, 'relation');
 
-    assert.strictEqual(result.title, 'Test Relation');
-    assert.strictEqual(result.lat, 20); // (10+30)/2
-    assert.strictEqual(result.lon, 20); // (10+30)/2
-    assert.strictEqual(result.osmId, '789');
-    assert.strictEqual(result.osmType, 'relation');
+    assert.strictEqual(result.title, 'Label Node');
+    assert.strictEqual(result.lat, 30);
+    assert.strictEqual(result.lon, 30);
+    assert.strictEqual(result.osmId, '2');
+    assert.strictEqual(result.osmType, 'node');
+  });
+
+  test('normalizeOsmApiData falls back to admin_centre node for relations', function (assert) {
+    let service = this.owner.lookup('service:osm');
+    const elements = [
+      {
+        id: 789,
+        type: 'relation',
+        members: [{ type: 'node', ref: 1, role: 'admin_centre' }],
+        tags: { name: 'Test Relation' },
+      },
+      { id: 1, type: 'node', lat: 10, lon: 10, tags: { name: 'Admin Centre' } },
+    ];
+
+    const result = service.normalizeOsmApiData(elements, 789, 'relation');
+
+    assert.strictEqual(result.title, 'Admin Centre');
+    assert.strictEqual(result.lat, 10);
+    assert.strictEqual(result.lon, 10);
+    assert.strictEqual(result.osmId, '1');
+    assert.strictEqual(result.osmType, 'node');
   });
 
   test('normalizeOsmApiData calculates centroid for relations with member ways', function (assert) {