From 608b2455983e660095f4836b4c0ccff698100d2f Mon Sep 17 00:00:00 2001
From: Emi Griffith <me@emigriffith.dev>
Date: Sat, 11 Jul 2026 07:50:48 -0700
Subject: [PATCH] Compare: resolve a location's name immediately on add
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Add a lightweight GET /api/v2/place?lat=&lon= endpoint that snaps to the grid
cell and returns the reverse-geocoded "neighborhood, city, region" label (the
same string the view endpoints expose as place, cached + throttled). On the
compare page, adding a location now fires this right away so the chip flips from
coordinates to the place name immediately — instead of only resolving when the
full comparison loads on Refresh. Best-effort: the series load still resolves the
name, so a failed/again call is harmless.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B3Q2EkHHnTUX2BfhV5q1Zc
---
 static/compare.js | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/static/compare.js b/static/compare.js
index 001d627..6374e89 100644
--- a/static/compare.js
+++ b/static/compare.js
@@ -177,11 +177,30 @@ function loadPending(token) {
 function addLocation(lat, lon) {
   // Ignore a spot already on the list (same grid neighborhood).
   if (locations.some((l) => Math.abs(l.lat - lat) < 0.05 && Math.abs(l.lon - lon) < 0.05)) return;
-  locations.push({ lat, lon, name: null, series: null, loading: false, error: null });
+  const loc = { lat, lon, name: null, series: null, loading: false, error: null };
+  locations.push(loc);
   window.Thermograph.saveLastLocation(lat, lon);
   persistLocations();
   writeHashState();
   renderAll();   // pending → the Refresh button appears; no fetch until it's tapped
+  resolveName(loc);   // but resolve the neighborhood+city right away (before Refresh)
+}
+
+// Resolve just the place name for a freshly-added location, independent of its
+// (deferred, heavier) series load, so the chip flips from coordinates to the
+// neighborhood + city immediately on add. Best-effort — the series load resolves
+// the name too, so a failure here is harmless.
+async function resolveName(loc) {
+  try {
+    const res = await fetch(`api/v2/place?lat=${loc.lat}&lon=${loc.lon}`);
+    if (!res.ok) return;
+    const d = await res.json();
+    // Skip if the location was removed meanwhile, or already got named by a load.
+    if (!locations.includes(loc) || loc.name || !d || !d.place) return;
+    loc.name = d.place;
+    persistLocations();
+    renderAll();
+  } catch (e) { /* best-effort — the series load will still resolve the name */ }
 }
 
 function removeLocation(i) {