refactor: separate Overpass and installation services

server/providers/overpass/constants.js

@@ -0,0 +1,108 @@
+import path from 'node:path';
+
+// ---------------------------------------------------------------------------
+// Overpass API proxy constants and cache state
+// ---------------------------------------------------------------------------
+/** Ordered list of Overpass API mirrors; tried sequentially on failure/rate-limit. */
+const OVERPASS_UPSTREAMS = [
+  'https://overpass-api.de/api/interpreter',
+  'https://overpass.kumi.systems/api/interpreter',
+  'https://lz4.overpass-api.de/api/interpreter',
+  // Community full-planet instance (privateforge nonprofit) — added 2026-07-30
+  // when all three mirrors above refused this IP (likely a dev-traffic rate
+  // ban; refused connections fail in ms, so healthy mirrors above still win).
+  // Verified: planet coverage (Texas query), CORS *, ~5-20 s cold latency.
+  'https://overpass.private.coffee/api/interpreter',
+];
+
+/**
+ * TTL for FRESH cached Overpass responses (ms). Road geometry is static for
+ * months — the original 45 s TTL forced a public-mirror round-trip on nearly
+ * every viewport revisit and left nothing to serve when the mirrors 502
+ * (field-test 2026-07-17: all three mirrors down during US morning peak =
+ * "traffic takes forever to load"). 24 h in memory; the disk layer below
+ * keeps 7 days and also survives dev-server restarts.
+ */
+const OVERPASS_CACHE_MS = 86_400_000;
+
+/** Disk-cache TTL for Overpass responses (ms) — 7 days. */
+const OVERPASS_DISK_TTL_MS = 7 * 86_400_000;
+
+/**
+ * Disk-cache TTL for BOUNDARY-class queries (is_in / admin-relation pivots) — 30
+ * days. Admin boundaries change ≈never, and their pivots are the most expensive
+ * queries the app issues (multi-MB coastline geometry, 10–25 s on public mirrors —
+ * field test 2026-07-23: outline latency + the Sicily miss). Keeping them a month
+ * means each boundary is fetched roughly once per machine, ever.
+ */
+const OVERPASS_BOUNDARY_DISK_TTL_MS = 30 * 86_400_000;
+
+/** Disk-cache directory for Overpass responses. */
+const OVERPASS_DISK_DIR = path.join(process.cwd(), '.gev-cache', 'overpass');
+
+/** Per-upstream fetch timeout (ms). */
+const OVERPASS_TIMEOUT_MS = 22000;
+
+/** Max entries in the Overpass response cache (LRU-like, oldest evicted first). */
+const OVERPASS_CACHE_MAX_ENTRIES = 120;
+
+// --- Abuse guards shared by the Overpass + route proxies --------------------
+/** Max accepted POST body for the Overpass proxy (Overpass QL queries are tiny). */
+const OVERPASS_MAX_BODY_BYTES = 24 * 1024;
+
+// 24 KB
+/**
+ * Hard cap on a single Overpass upstream response we will buffer into memory.
+ * 32 MB (was 12 MB): a dense island/state admin boundary at full `out geom`
+ * fidelity — Sicilia's Mediterranean coastline — can exceed 12 MB, and clipping
+ * it read as a permanent "transient" failure (field test 2026-07-23, Sicily
+ * never traced). The buffered payload is SIMPLIFIED server-side before it is
+ * cached or sent (simplifyOverpassPayloadBody), so the raised cap does not
+ * raise what clients receive or what the disk stores.
+ */
+const OVERPASS_MAX_RESPONSE_BYTES = 32 * 1024 * 1024;
+
+// 32 MB
+/** Only payloads at least this large go through geometry simplification. */
+const OVERPASS_SIMPLIFY_MIN_BYTES = 1_500_000;
+
+/** Only per-element geometry arrays with at least this many points are simplified. */
+const OVERPASS_SIMPLIFY_MIN_POINTS = 1200;
+
+/**
+ * Douglas-Peucker tolerance (degrees, ≈44 m of latitude). Region/state boundary
+ * rings are drawn at regional camera scale and the client simplifies again for
+ * draw, so ~44 m fidelity is invisible; building footprints never reach the
+ * point threshold above and pass through untouched.
+ */
+const OVERPASS_SIMPLIFY_TOLERANCE_DEG = 0.0004;
+
+/** Max concurrent in-flight upstream Overpass fetches across all distinct queries. */
+const OVERPASS_MAX_CONCURRENT = 6;
+
+/** Server-side timeout ceiling (seconds) we allow inside an Overpass QL query. */
+const OVERPASS_MAX_QL_TIMEOUT = 30;
+
+/** Max `around:` radius (m) — every app caller uses <= 1800 m. */
+const OVERPASS_MAX_AROUND_M = 50000;
+
+/** Max bbox span (degrees) — app bboxes are small viewport tiles. */
+const OVERPASS_MAX_BBOX_DEG = 12;
+
+/**
+ * Every Overpass element-type specifier, including the combined shortcuts
+ * (nwr/nw/nr/wr) and `rel`. Shared by the selector + area-element-deny regexes so
+ * they can't drift (a missing shortcut like `wr` was an area-scan bypass).
+ */
+const OVERPASS_ELEMENT_TYPES = 'node|way|relation|nwr|nw|nr|wr|rel';
+
+/** Element-selector (incl. `area`) whose statements must be individually bounded. */
+const OVERPASS_SELECTOR_RE = new RegExp(`\\b(?:${OVERPASS_ELEMENT_TYPES}|area)\\b`);
+
+/** An element selector bounded BY an area — the country-scan abuse shape. */
+const OVERPASS_AREA_ELEMENT_RE = new RegExp(`\\b(?:${OVERPASS_ELEMENT_TYPES})\\s*\\(\\s*area\\b`, 'i');
+
+/** A single bbox 4-tuple `(s,w,n,e)` (non-global so it does not advance lastIndex). */
+const OVERPASS_BBOX_RE = /\(\s*-?\d+(?:\.\d+)?\s*,\s*-?\d+(?:\.\d+)?\s*,\s*-?\d+(?:\.\d+)?\s*,\s*-?\d+(?:\.\d+)?\s*\)/;
+
+export { OVERPASS_BOUNDARY_DISK_TTL_MS, OVERPASS_DISK_TTL_MS, OVERPASS_DISK_DIR, OVERPASS_CACHE_MS, OVERPASS_CACHE_MAX_ENTRIES, OVERPASS_MAX_BODY_BYTES, OVERPASS_MAX_CONCURRENT, OVERPASS_MAX_AROUND_M, OVERPASS_MAX_BBOX_DEG, OVERPASS_AREA_ELEMENT_RE, OVERPASS_SELECTOR_RE, OVERPASS_BBOX_RE, OVERPASS_MAX_QL_TIMEOUT, OVERPASS_SIMPLIFY_MIN_BYTES, OVERPASS_SIMPLIFY_MIN_POINTS, OVERPASS_SIMPLIFY_TOLERANCE_DEG, OVERPASS_MAX_RESPONSE_BYTES, OVERPASS_UPSTREAMS, OVERPASS_TIMEOUT_MS };