feat(config): load the min/max zoom levels of a cotar overview from the wmtscapabilties

packages/cli/src/cli/overview/__test__/wmts.overview.test.ts

@@ -0,0 +1,26 @@
+import o from 'ospec';
+import { zoomLevelsFromWmts } from '@basemaps/config';
+import { GoogleTms, Nztm2000QuadTms } from '@basemaps/geo';
+import { createOverviewWmtsCapabilities } from '../overview.wmts.js';
+
+// This test should really live in @basemaps/config, but all the WMTS generation logic does not live in @basemaps/config
+o.spec('zoomLevelsFromWmts', () => {
+  o('should extract zoom levels', () => {
+    const wmts = createOverviewWmtsCapabilities(Nztm2000QuadTms, 10, 'Test Title');
+    o(zoomLevelsFromWmts(wmts, Nztm2000QuadTms)).deepEquals({ minZoom: 0, maxZoom: 10 });
+  });
+
+  o('should include all zoom levels', () => {
+    const wmts = createOverviewWmtsCapabilities(GoogleTms, GoogleTms.maxZoom, 'Test Title');
+    o(zoomLevelsFromWmts(wmts, GoogleTms)).deepEquals({ minZoom: 0, maxZoom: GoogleTms.maxZoom });
+  });
+  o('should not extract zoom levels for wrong projection', () => {
+    const wmts = createOverviewWmtsCapabilities(GoogleTms, 10, 'Test Title');
+    o(zoomLevelsFromWmts(wmts, Nztm2000QuadTms)).equals(null);
+  });
+
+  o('should not return if zooms are invalid', () => {
+    const wmts = createOverviewWmtsCapabilities(Nztm2000QuadTms, 0, 'Test Title');
+    o(zoomLevelsFromWmts(wmts, Nztm2000QuadTms)).equals(null);
+  });
+});

packages/config/src/index.ts

@@ -24,7 +24,7 @@ export { ConfigDynamoBase } from './dynamo/dynamo.config.base.js';
 export { ConfigProviderMemory, ConfigBundled } from './memory/memory.config.js';
 export { TileSetNameComponents, TileSetNameParser } from './tile.set.name.js';
 export { parseHex, parseRgba } from './color.js';
-export { ConfigJson } from './json/json.config.js';
+export { ConfigJson, zoomLevelsFromWmts } from './json/json.config.js';
 export { standardizeLayerName } from './json/name.convertor.js';
 export { base58, isBase58 } from './base58.js';
 export { sha256base58, ensureBase58 } from './base58.node.js';

packages/config/src/json/json.config.ts

@@ -3,7 +3,6 @@ import {
   GoogleTms,
   ImageFormat,
   Nztm2000QuadTms,
-  QuadKey,
   TileMatrixSet,
   TileMatrixSets,
   VectorFormat,
@@ -277,45 +276,44 @@ export class ConfigJson {
     const exists = await fsa.exists(targetOverviews);
     if (!exists) return;
 
-    const smallestTiff = cfg.files.reduce((prev, current) => {
-      if (prev.width < current.width) return prev;
-      return current;
-    }, cfg.files[0]);
-
     const tileMatrix = TileMatrixSets.find(cfg.tileMatrix);
     if (tileMatrix == null) throw new Error('Missing tileMatrix for imagery:' + cfg.id);
 
-    // Find a maximum tile that could be used in this overview
-    const maxZoomLoc = tileMatrix.sourceToPixels(smallestTiff.x, smallestTiff.y, tileMatrix.maxZoom);
-    const maxTile = tileMatrix.pixelsToTile(maxZoomLoc.x, maxZoomLoc.y, tileMatrix.maxZoom);
-    let qk = QuadKey.fromTile(maxTile);
-
     const cotar = await Cotar.fromTar(fsa.source(targetOverviews));
 
-    // Query all the quadkeys looking to see what tiles exists
-    const queries: Promise<string | null>[] = [];
-    while (qk.length > 0) {
-      qk = QuadKey.parent(qk);
-      const tile = QuadKey.toTile(qk);
-      queries.push(
-        cotar.index.find(`tiles/${tile.z}/${tile.x}/${tile.y}.webp`).then((c) => {
-          if (c == null) return null;
-          return qk;
-        }),
-      );
-    }
+    // When the cotars are made a WMTSCapabilties is added so it easy to view in something like QGIS
+    // We can use the WMTSCapabitities to figure out the tileMatrix and zoom levels
+    const wmtsRaw = await cotar.get('WMTSCapabilities.xml');
+    if (wmtsRaw == null) return;
 
-    const result = await Promise.all(queries);
+    const wmts = Buffer.from(wmtsRaw).toString();
 
-    const overview: ConfigImageryOverview = { path: 'overviews.tar.co', minZoom: tileMatrix.maxZoom, maxZoom: 0 };
-    for (const r of result) {
-      if (r == null) continue;
-      if (r.length < overview.minZoom) overview.minZoom = r.length;
-      if (r.length > overview.maxZoom) overview.maxZoom = r.length;
-    }
+    const zoomLevels = zoomLevelsFromWmts(wmts, tileMatrix);
+    if (zoomLevels == null) return;
 
-    if (overview.minZoom === tileMatrix.maxZoom) return;
-    if (overview.maxZoom === 0) return;
-    return overview;
+    return { path: 'overviews.tar.co', minZoom: zoomLevels.minZoom, maxZoom: zoomLevels.maxZoom };
   }
 }
+
+/** Attempt to parse a cotar WMTSCapabilties to figure out what zoom levels are applicable */
+export function zoomLevelsFromWmts(
+  wmts: string,
+  tileMatrix: TileMatrixSet,
+): { minZoom: number; maxZoom: number } | null {
+  const owsIds = wmts
+    .split('\n')
+    .filter((f) => f.includes('ows:Identifier'))
+    .map((c) => c.trim().replace('<ows:Identifier>', '').replace('</ows:Identifier>', ''));
+
+  const tileMatrixOffset = owsIds.indexOf(tileMatrix.identifier);
+  if (tileMatrixOffset === -1) return null;
+
+  const minZoom = Number(owsIds[tileMatrixOffset + 1]);
+  const maxZoom = Number(owsIds[owsIds.length - 1]);
+
+  if (isNaN(minZoom)) return null;
+  if (isNaN(maxZoom)) return null;
+  if (maxZoom < minZoom) return null;
+  if (maxZoom === 0) return null;
+  return { minZoom, maxZoom };
+}

packages/lambda-tiler/src/wmts.capability.ts

@@ -270,7 +270,7 @@ export class WmtsCapabilities {
       V('ows:Identifier', tms.identifier),
       V('ows:SupportedCRS', tms.projection.toUrn()),
       tms.def.wellKnownScaleSet ? V('WellKnownScaleSet', tms.def.wellKnownScaleSet) : null,
-      ...tms.def.tileMatrix.slice(this.minZoom, this.maxZoom).map((c) => {
+      ...tms.def.tileMatrix.slice(this.minZoom, this.maxZoom + 1).map((c) => {
         return V('TileMatrix', [
           V('ows:Identifier', c.identifier),
           V('ScaleDenominator', c.scaleDenominator),

packages/shared/package.json

@@ -34,14 +34,12 @@
     "entities": "^4.3.0",
     "pino": "^8.6.1",
     "proj4": "^2.8.0",
-    "sax": "^1.2.4",
     "source-map-support": "^0.5.19",
     "ulid": "^2.3.0"
   },
   "devDependencies": {
     "@types/aws-lambda": "^8.10.75",
-    "@types/proj4": "^2.5.2",
-    "@types/sax": "^1.2.1"
+    "@types/proj4": "^2.5.2"
   },
   "publishConfig": {
     "access": "public"

yarn.lock

@@ -1977,13 +1977,6 @@
     "@types/scheduler" "*"
     csstype "^3.0.2"
 
-"@types/sax@^1.2.1":
-  version "1.2.2"
-  resolved "https://registry.yarnpkg.com/@types/sax/-/sax-1.2.2.tgz#0b8996ffb9ca0b0491e791a09b550d77fa852f5d"
-  integrity sha512-nfnUx5UQ1R+/riXydS0UyYJiqtxgOeObr9Hw8xSTtpB4LNoHa1z31rsvGXN0JKz/7/kDXw0bT2Q/VQkXAbCYoA==
-  dependencies:
-    "@types/node" "*"
-
 "@types/scheduler@*":
   version "0.16.2"
   resolved "https://registry.yarnpkg.com/@types/scheduler/-/scheduler-0.16.2.tgz#1a62f89525723dde24ba1b01b092bf5df8ad4d39"
@@ -7295,7 +7288,7 @@ sax@1.2.1:
   resolved "https://registry.yarnpkg.com/sax/-/sax-1.2.1.tgz#7b8e656190b228e81a66aea748480d828cd2d37a"
   integrity sha1-e45lYZCyKOgaZq6nSEgNgozS03o=
 
-sax@>=0.6.0, sax@^1.2.4:
+sax@>=0.6.0:
   version "1.2.4"
   resolved "https://registry.yarnpkg.com/sax/-/sax-1.2.4.tgz#2816234e2378bddc4e5354fab5caa895df7100d9"
   integrity sha512-NqVDv9TpANUjFm0N8uM5GxL36UgKi9/atZw+x7YFnQ8ckwFGKrl4xX4yWtrey3UJm5nP1kUbnYgLopqWNSRhWw==