API, Backend & Frontend

API/osm-overpass.js

@@ -0,0 +1,124 @@
+/**
+ * Pharmacies from OpenStreetMap via Overpass API (no API key).
+ * @see https://wiki.openstreetmap.org/wiki/Overpass_API
+ */
+
+import { osmElementToPharmacy } from './normalize.js';
+
+const OVERPASS_ENDPOINTS = (
+  process.env.OVERPASS_API_URL ||
+  'https://overpass-api.de/api/interpreter,https://overpass.openstreetmap.fr/api/interpreter'
+)
+  .split(',')
+  .map((s) => s.trim())
+  .filter(Boolean);
+
+function buildOverpassQuery(lat, lon, radiusM) {
+  // Nodes only (fast); ways/relations are rarer for pharmacies and heavy on public Overpass.
+  return `[out:json][timeout:25];
+(
+  node["amenity"="pharmacy"](around:${radiusM},${lat},${lon});
+  node["healthcare"="pharmacy"](around:${radiusM},${lat},${lon});
+);
+out;`;
+}
+
+const FETCH_MS = 35000;
+
+async function fetchOverpass(endpoint, body) {
+  const ctrl = new AbortController();
+  const timer = setTimeout(() => ctrl.abort(), FETCH_MS);
+  try {
+    return await fetch(endpoint, {
+      method: 'POST',
+      signal: ctrl.signal,
+      headers: {
+        'Content-Type': 'application/x-www-form-urlencoded',
+        Accept: 'application/json',
+        'User-Agent': 'FarmaFinder/1.0 (OSM pharmacy import; local admin)',
+      },
+      body,
+    });
+  } finally {
+    clearTimeout(timer);
+  }
+}
+
+/**
+ * @param {{ lat: number, lon: number, radiusMeters?: number }} opts
+ * @returns {Promise<Array<{name,address,phone,latitude,longitude}>>}
+ */
+export async function fetchPharmaciesFromOsm({ lat, lon, radiusMeters = 1500 }) {
+  const latN = Number(lat);
+  const lonN = Number(lon);
+  if (!Number.isFinite(latN) || !Number.isFinite(lonN)) {
+    throw new Error('fetchPharmaciesFromOsm: invalid lat or lon');
+  }
+  const r = Math.round(
+    Math.min(Math.max(Number(radiusMeters) || 1500, 50), 25000)
+  );
+
+  const body = `data=${encodeURIComponent(buildOverpassQuery(latN, lonN, r))}`;
+  let lastErr = null;
+  let json = null;
+  let text = '';
+
+  for (const endpoint of OVERPASS_ENDPOINTS) {
+    let res;
+    try {
+      res = await fetchOverpass(endpoint, body);
+    } catch (e) {
+      lastErr =
+        e.name === 'AbortError'
+          ? new Error(`Overpass timeout (${FETCH_MS / 1000}s) at ${new URL(endpoint).host}`)
+          : e;
+      continue;
+    }
+    text = await res.text();
+    let parsed;
+    try {
+      parsed = text ? JSON.parse(text) : {};
+    } catch {
+      lastErr = new Error(
+        `Overpass returned non-JSON (HTTP ${res.status}): ${(text || '').slice(0, 120)}`
+      );
+      continue;
+    }
+    if (!res.ok && (res.status === 504 || res.status === 502 || res.status === 429)) {
+      lastErr = new Error(
+        `Overpass busy (HTTP ${res.status}) at ${new URL(endpoint).host}`
+      );
+      continue;
+    }
+    if (!res.ok) {
+      const msg = parsed.remark || parsed.error || text.slice(0, 200);
+      throw new Error(`Overpass HTTP ${res.status}: ${msg}`);
+    }
+    json = parsed;
+    lastErr = null;
+    break;
+  }
+
+  if (lastErr && !json) {
+    throw lastErr;
+  }
+  if (!json || !Array.isArray(json.elements)) {
+    throw lastErr || new Error('Overpass: no usable response');
+  }
+
+  const elements = json.elements;
+  const seen = new Set();
+  const out = [];
+
+  for (const el of elements) {
+    const key = `${el.type}/${el.id}`;
+    if (seen.has(key)) continue;
+    seen.add(key);
+    const row = osmElementToPharmacy(el);
+    if (row.name && row.address) {
+      out.push(row);
+    }
+  }
+
+  return out;
+}