Fix Overpass timeouts, cancellation and endpoint priority

src/osm/overpass.ts

@@ -15,14 +15,32 @@ export interface OsmElement {
 }
 
 export const OVERPASS_ENDPOINTS = [
+  'https://maps.mail.ru/osm/tools/overpass/api/interpreter',
   'https://overpass-api.de/api/interpreter',
   'https://overpass.private.coffee/api/interpreter',
-  'https://maps.mail.ru/osm/tools/overpass/api/interpreter',
 ];
 
+const REQUEST_TIMEOUT_MS = 45_000;
+
+function waitForRetry(ms: number, signal?: AbortSignal): Promise<void> {
+  return new Promise((resolve, reject) => {
+    const cancel = () => {
+      clearTimeout(timer);
+      signal?.removeEventListener('abort', cancel);
+      reject(new DOMException('Отменено', 'AbortError'));
+    };
+    const timer = setTimeout(() => {
+      signal?.removeEventListener('abort', cancel);
+      resolve();
+    }, ms);
+    signal?.addEventListener('abort', cancel, { once: true });
+    if (signal?.aborted) cancel();
+  });
+}
+
 export function buildQuery(b: BBox): string {
   const bb = `(${b[0]},${b[1]},${b[2]},${b[3]})`;
-  return `[out:json][timeout:120];
+  return `[out:json][timeout:30];
 (
   way["building"]${bb};
   relation["building"]["type"="multipolygon"]${bb};
@@ -56,27 +74,42 @@ export async function fetchOverpass(b: BBox, onStatus?: (s: string) => void, sig
   let lastErr: unknown = null;
   for (const url of OVERPASS_ENDPOINTS) {
     for (let attempt = 0; attempt < 2; attempt++) {
+      if (signal?.aborted) throw new DOMException('Отменено', 'AbortError');
+      const controller = new AbortController();
+      const cancel = () => controller.abort();
+      signal?.addEventListener('abort', cancel, { once: true });
+      let timedOut = false;
+      const timer = setTimeout(() => {
+        timedOut = true;
+        controller.abort();
+      }, REQUEST_TIMEOUT_MS);
       try {
-        onStatus?.(`Запрос к ${new URL(url).host}${attempt ? ' (повтор)' : ''}…`);
+        onStatus?.(`Запрос к ${new URL(url).host}${attempt ? ' (повтор)' : ''} — до 45 секунд…`);
         const res = await fetch(url, {
           method: 'POST',
           body: 'data=' + encodeURIComponent(query),
           headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
-          signal,
+          signal: controller.signal,
         });
         if (res.status === 429 || res.status === 504) {
           lastErr = new Error(`Сервер перегружен (${res.status})`);
-          await new Promise((r) => setTimeout(r, 3000 * (attempt + 1)));
+          clearTimeout(timer);
+          if (attempt === 0) await waitForRetry(3000, signal);
           continue;
         }
         if (!res.ok) throw new Error(`HTTP ${res.status}`);
         const json = await res.json();
+        if (signal?.aborted) throw new DOMException('Отменено', 'AbortError');
         if (json.remark && /error|timed out|runtime/i.test(json.remark)) throw new Error(json.remark);
+        if (!Array.isArray(json.elements)) throw new Error('Сервер вернул ответ без списка elements');
         return json.elements as OsmElement[];
       } catch (e) {
-        if (signal?.aborted) throw e;
-        lastErr = e;
+        if (signal?.aborted) throw new DOMException('Отменено', 'AbortError');
+        lastErr = timedOut ? new Error(`Таймаут ${new URL(url).host}: 45 секунд`) : e;
         break;
+      } finally {
+        clearTimeout(timer);
+        signal?.removeEventListener('abort', cancel);
       }
     }
   }