From d31f20aead71a14850ac83bf828d22d1f252aade Mon Sep 17 00:00:00 2001
From: Chris Alfano <chris@jarv.us>
Date: Mon, 11 Nov 2024 02:03:20 -0500
Subject: [PATCH] refactor: use maplibre method to find current division

---
 src/components/map/divisionUtils.js | 38 +++++++++--------------------
 1 file changed, 11 insertions(+), 27 deletions(-)

diff --git a/src/components/map/divisionUtils.js b/src/components/map/divisionUtils.js
index 35d26ea..aadbb39 100644
--- a/src/components/map/divisionUtils.js
+++ b/src/components/map/divisionUtils.js
@@ -30,38 +30,22 @@ export function debounce(fn, delay = 300) {
     }
 }
 
-// Find division that contains the given coordinates
+// Find division that contains the given coordinates using MapLibre's queryRenderedFeatures
 export function findDivisionByCoordinates(map, lngLat) {
-    if (!map || !map.getSource('divisions') || !map.getSource('divisions')._data) {
+    if (!map) {
         return null;
     }
 
-    const point = [lngLat.lng, lngLat.lat];
-    const features = map.getSource('divisions')._data.features;
+    // Query features at the point
+    const features = map.queryRenderedFeatures(
+        map.project([lngLat.lng, lngLat.lat]),
+        { layers: ['divisions-fill'] }
+    );
 
-    // Find the first division polygon that contains the point
-    const containingFeature = features.find(feature => {
-        if (feature.geometry.type !== 'Polygon') return false;
-        return pointInPolygon(point, feature.geometry.coordinates[0]);
-    });
-
-    return containingFeature ? containingFeature.properties.DIVISION_NUM : null;
-}
-
-// Helper function to check if a point is inside a polygon
-function pointInPolygon(point, polygon) {
-    const [x, y] = point;
-    let inside = false;
-
-    for (let i = 0, j = polygon.length - 1; i < polygon.length; j = i++) {
-        const [xi, yi] = polygon[i];
-        const [xj, yj] = polygon[j];
-
-        const intersect = ((yi > y) !== (yj > y)) &&
-            (x < (xj - xi) * (y - yi) / (yj - yi) + xi);
-
-        if (intersect) inside = !inside;
+    // Return the division number of the first matching feature
+    if (features.length > 0) {
+        return features[0].properties.DIVISION_NUM;
     }
 
-    return inside;
+    return null;
 }