feat: support OGC API styles in collections

contains smaller improvements:
- remove redundant listAllStyles
- merge  getStyleMetadata into getStyle and handle fallback internally

fixtures/ogc-api/sample-data/collections/airports/styles/Tritanopia/metadata.json

@@ -0,0 +1,39 @@
+{
+  "title" : "Tritanopia",
+  "links" : [ {
+    "rel" : "self",
+    "type" : "application/json",
+    "title" : "This document",
+    "href" : "https://my.server.org/sample-data/collections/airports/styles/Tritanopia/metadata?f=json"
+  }, {
+    "rel" : "alternate",
+    "type" : "text/html",
+    "title" : "This document as HTML",
+    "href" : "https://my.server.org/sample-data/collections/airports/styles/Tritanopia/metadata?f=html"
+  } ],
+  "id" : "Tritanopia",
+  "scope" : "style",
+  "stylesheets" : [ {
+    "title" : "QGIS",
+    "version" : "3.16",
+    "specification" : "https://docs.qgis.org/3.16/en/docs/user_manual/appendices/qgis_file_formats.html#qml-the-qgis-style-file-format",
+    "native" : true,
+    "link" : {
+      "rel" : "stylesheet",
+      "type" : "application/vnd.qgis.qml",
+      "title" : "Style in format 'QGIS'",
+      "href" : "https://my.server.org/sample-data/collections/airports/styles/Tritanopia?f=qml"
+    }
+  }, {
+    "title" : "SLD 1.0",
+    "version" : "1.0",
+    "specification" : "https://www.ogc.org/standards/sld",
+    "native" : true,
+    "link" : {
+      "rel" : "stylesheet",
+      "type" : "application/vnd.ogc.sld+xml;version=1.0",
+      "title" : "Style in format 'SLD 1.0'",
+      "href" : "https://my.server.org/sample-data/collections/airports/styles/Tritanopia?f=sld10"
+    }
+  } ]
+}

src/ogc-api/endpoint.spec.ts

@@ -1944,22 +1944,9 @@ The document at http://local/nonexisting?f=json could not be fetched.`
     beforeEach(() => {
       endpoint = new OgcApiEndpoint('http://local/sample-data/');
     });
-    describe('#listAllStyles', () => {
-      it('returns a list of style ids', async () => {
-        await expect(endpoint.listAllStyles).resolves.toEqual([
-          'Deuteranopia',
-          'Light',
-          'Night',
-          'Outdoor',
-          'OutdoorHillshade',
-          'Road',
-          'Tritanopia',
-        ]);
-      });
-    });
     describe('#allStyles', () => {
       it('returns a list of styles', async () => {
-        await expect(endpoint.allStyles).resolves.toEqual([
+        await expect(endpoint.allStyles()).resolves.toEqual([
           {
             title: 'Deuteranopia',
             id: 'Deuteranopia',
@@ -2010,7 +1997,71 @@ The document at http://local/nonexisting?f=json could not be fetched.`
         ]);
       });
     });
-    describe('#getStyleMetadata', () => {
+    describe('#allStyles for a given collection', () => {
+      it('returns a list of styles', async () => {
+        await expect(endpoint.allStyles('airports')).resolves.toEqual([
+          {
+            title: 'Deuteranopia',
+            id: 'Deuteranopia',
+            formats: [
+              'application/vnd.qgis.qml',
+              'application/vnd.ogc.sld+xml;version=1.0',
+            ],
+          },
+          {
+            title: 'Light',
+            id: 'Light',
+            formats: [
+              'application/vnd.qgis.qml',
+              'application/vnd.ogc.sld+xml;version=1.0',
+              'application/vnd.mapbox.style+json',
+            ],
+          },
+          {
+            title: 'Night',
+            id: 'Night',
+            formats: [
+              'application/vnd.qgis.qml',
+              'application/vnd.ogc.sld+xml;version=1.0',
+              'application/vnd.mapbox.style+json',
+            ],
+          },
+          {
+            title: 'Outdoor',
+            id: 'Outdoor',
+            formats: [
+              'application/vnd.qgis.qml',
+              'application/vnd.ogc.sld+xml;version=1.0',
+              'application/vnd.mapbox.style+json',
+            ],
+          },
+          {
+            title: 'Road',
+            id: 'Road',
+            formats: [
+              'application/vnd.qgis.qml',
+              'application/vnd.ogc.sld+xml;version=1.0',
+              'application/vnd.mapbox.style+json',
+            ],          },
+          {
+            title: 'Tritanopia',
+            id: 'Tritanopia',
+            formats: [
+              'application/vnd.qgis.qml',
+              'application/vnd.ogc.sld+xml;version=1.0',
+            ],
+          },
+          {
+            title: 'OS Open Zoomstack - Outdoor with Hillshade',
+            id: 'OutdoorHillshade',
+            formats: [
+              'application/vnd.mapbox.style+json',
+            ],
+          },
+        ]);
+      });
+    });
+    describe('#getStyle', () => {
       it('returns style metadata', async () => {
         await expect(endpoint.getStyle('Deuteranopia')).resolves.toEqual({
           title: 'Deuteranopia',
@@ -2034,19 +2085,67 @@ The document at http://local/nonexisting?f=json could not be fetched.`
         });
       });
     });
+    describe('#getStyle for a given collection', () => {
+      it('returns style metadata', async () => {
+        await expect(endpoint.getStyle('Tritanopia', 'airports')).resolves.toEqual({
+          title: 'Tritanopia',
+          id: 'Tritanopia',
+          scope: 'style',
+          stylesheetFormats: [
+            'application/vnd.qgis.qml',
+            'application/vnd.ogc.sld+xml;version=1.0'
+          ],
+          stylesheets: [
+            {
+              title: 'QGIS',
+              version: '3.16',
+              specification: 'https://docs.qgis.org/3.16/en/docs/user_manual/appendices/qgis_file_formats.html#qml-the-qgis-style-file-format',
+              native: true,
+              link: {
+                rel: 'stylesheet',
+                type: 'application/vnd.qgis.qml',
+                title: "Style in format 'QGIS'",
+                href: 'https://my.server.org/sample-data/collections/airports/styles/Tritanopia?f=qml',
+              },
+            },
+            {
+              title: 'SLD 1.0',
+              version: '1.0',
+              specification: 'https://www.ogc.org/standards/sld',
+              native: true,
+              link: {
+                rel: 'stylesheet',
+                type: 'application/vnd.ogc.sld+xml;version=1.0',
+                title: "Style in format 'SLD 1.0'",
+                href: 'https://my.server.org/sample-data/collections/airports/styles/Tritanopia?f=sld10',
+              },
+            },
+          ],
+        });
+      });
+    });
     describe('#getStylesheetUrl', () => {
       it('returns the correct stylesheet URL', async () => {
         await expect(
           endpoint.getStylesheetUrl('Deuteranopia', 'application/vnd.esri.lyr')
         ).resolves.toEqual('http://local/zoomstack/styles/Deuteranopia?f=lyr');
       });
     });
-    describe('#getStylesheetUrl with type html', () => {
+    describe('#getStylesheetUrl with type Mapbox', () => {
+      it('returns the correct stylesheet URL', async () => {
+        await expect(
+          endpoint.getStylesheetUrl('Road', 'application/vnd.mapbox.style+json')
+        ).resolves.toEqual(
+          'http://local/zoomstack/styles/Road?f=mbs'
+        );
+      });
+    });
+    describe('#getStylesheetUrl for a given collection', () => {
       it('returns the correct stylesheet URL', async () => {
         await expect(
-          endpoint.getStylesheetUrl('Road', 'text/html')
+          endpoint.getStylesheetUrl('Tritanopia', 'application/vnd.ogc.sld+xml;version=1.0', 'airports')
         ).resolves.toEqual(
-          'https://my.server.org/sample-data/styles/Road?f=html'
+          'https://my.server.org/sample-data/collections/airports/styles/Tritanopia?f=sld10'
         );
       });
     });

src/ogc-api/endpoint.ts

@@ -10,7 +10,6 @@ import {
   parseConformance,
   parseEndpointInfo,
   parseBasicStyleInfo,
-  parseStylesAsList,
   parseTileMatrixSets,
 } from './info.js';
 import {
@@ -21,7 +20,8 @@ import {
   OgcApiEndpointInfo,
   OgcApiStyleMetadata,
   OgcApiStylesDocument,
-  StyleItem,
+  OgcStyleBrief,
+  OgcStyleFull,
   TileMatrixSet,
 } from './model.js';
 import {
@@ -271,17 +271,32 @@ ${e.message}`);
   }
 
   private async getStyleMetadataDocument(
-    styleId: string
+    styleId: string,
+    collectionId?: string
   ): Promise<OgcApiDocument> {
-    const styleData = await this.styles;
+    const doc = collectionId ? await this.getCollectionDocument(collectionId) : await this.root;
+    const stylesLinkJson = getLinkUrl(
+      doc as OgcApiDocument,
+      ['styles', 'http://www.opengis.net/def/rel/ogc/1.0/styles'],
+      this.baseUrl,
+      'application/json'
+    );
+    const stylesLink = getLinkUrl(
+      doc as OgcApiDocument,
+      ['styles', 'http://www.opengis.net/def/rel/ogc/1.0/styles'],
+      this.baseUrl
+    );
+    const styleData = await fetchDocument(stylesLinkJson ?? stylesLink) as OgcApiStylesDocument;
+
     if (!styleData.styles.some((style) => style.id === styleId)) {
       throw new EndpointError(`Style not found: "${styleId}".`);
     }
     const styleDoc = styleData?.styles?.find((style) => style.id === styleId);
     if (hasLinks(styleDoc as OgcApiDocument, ['describedby'])) {
       return fetchLink(styleDoc as OgcApiDocument, 'describedby', this.baseUrl);
     } else {
-      return null;
+      // fallback: return style document
+      return styleDoc as OgcApiDocument;
     }
   }
 
@@ -597,74 +612,70 @@ ${e.message}`);
       });
   }
 
-  /**
-   * A Promise which resolves to an array of all style identifiers as strings.
-   */
-  get listAllStyles(): Promise<string[]> {
-    return this.styles.then(parseStylesAsList());
-  }
-
   /**
    * A Promise which resolves to an array of all style items. This includes the supported style formats.
+   * @param collectionId - Optional unique identifier for the collection.
    */
-  get allStyles(): Promise<StyleItem[]> {
-    return this.styles.then(async (stylesDoc) => {
-      const metadataPromises = stylesDoc.styles.map((style) =>
-        this.getStyleMetadataDocument(style.id)
+  async allStyles(collectionId?: string): Promise<OgcStyleBrief[]> {
+    const doc = collectionId ? await this.getCollectionDocument(collectionId) : await this.root;
+    const stylesLink = getLinkUrl(
+      doc as OgcApiDocument,
+      ['styles', 'http://www.opengis.net/def/rel/ogc/1.0/styles'],
+      this.baseUrl
+    );
+    if (!stylesLink) {
+      throw new EndpointError(
+        'Could not get styles: there is no relation of type "styles"'
       );
-      return Promise.all(metadataPromises).then((results) => {
-        return results.map((r) =>
-          parseBasicStyleInfo(r as OgcApiStyleMetadata)
-        );
-      });
-    });
+    }
+    const styleData = await fetchDocument(stylesLink) as OgcApiStylesDocument;
+    return styleData.styles.map(parseBasicStyleInfo);
   }
 
   /**
-   * Returns a promise resolving to a document describing the style.
-   * @param styleId The style identifier
+   * Returns a promise resolving to a document describing the style. Looks for a relation of type
+   * "describedby" to fetch metadata. If no relation is found, only basic info will be returned.
+   * @param styleId - The style identifier
+   * @param collectionId - Optional unique identifier for the collection.
    */
-  async getStyle(styleId: string): Promise<OgcApiStyleMetadata> {
-    const metadataDoc = await this.getStyleMetadataDocument(styleId);
-    if (!metadataDoc) {
-      throw new EndpointError(
-        `Could not get style metadata: there is no relation of type "describedby" for style "${styleId}".`
-      );
+  async getStyle(styleId: string, collectionId?: string): Promise<OgcStyleFull | OgcStyleBrief> {
+    const metadataDoc = await this.getStyleMetadataDocument(styleId, collectionId);
+    if (!metadataDoc?.stylesheets) {
+      return parseBasicStyleInfo(metadataDoc as OgcApiStyleMetadata);
     }
     return parseFullStyleInfo(metadataDoc as OgcApiStyleMetadata);
   }
 
   /**
    * Returns a promise resolving to a stylesheet URL for a given style and type.
-   * @param styleId The style identifier
-   * @param mimeType Stylesheet MIME type
+   * @param styleId - The style identifier
+   * @param mimeType - Stylesheet MIME type
+   * @param collectionId - Optional unique identifier for the collection.
    */
-  async getStylesheetUrl(styleId: string, mimeType: string): Promise<string> {
-    const metadataDoc = await this.getStyleMetadataDocument(styleId);
-    const urlFromMetadata = (
-      metadataDoc as OgcApiStyleMetadata
-    )?.stylesheets?.find(
-      (s) => s.link.type === mimeType && s.link.rel === 'stylesheet'
-    )?.link?.href;
-
-    if (!urlFromMetadata) {
-      // fallback which retrieves the URL from the style document itself
-      const style = (await this.styles).styles?.find(
-        (style) => style.id === styleId
-      );
-      const urlFromStyle = getLinkUrl(
-        style as unknown as OgcApiDocument,
-        'stylesheet',
-        this.baseUrl,
-        mimeType
+  async getStylesheetUrl(styleId: string, mimeType: string, collectionId?: string): Promise<string> {
+    const stylesDoc = await this.getStyleMetadataDocument(styleId, collectionId);
+
+    if (stylesDoc.stylesheets) {
+      const urlFromMetadata = (
+        stylesDoc as OgcApiStyleMetadata
+      )?.stylesheets?.find(
+        (s) => s.link.type === mimeType && s.link.rel === 'stylesheet'
+      )?.link?.href;
+      return urlFromMetadata;
+    }
+
+    const urlFromStyle = getLinkUrl(
+      stylesDoc,
+      'stylesheet',
+      this.baseUrl,
+      mimeType
+    );
+
+    if (!urlFromStyle) {
+      throw new EndpointError(
+        'Could not find stylesheet URL for given style ID and type.'
       );
-      if (!urlFromStyle) {
-        throw new EndpointError(
-          'Could not find stylesheet URL for given style ID and type.'
-        );
-      }
-      return urlFromStyle;
     }
-    return urlFromMetadata;
+    return urlFromStyle;
   }
 }