Refactoring of image detection, fix loading wikimedia images

Logic/ImageProviders/WikidataImageProvider.ts

@@ -0,0 +1,51 @@
+import {Utils} from "../../Utils";
+import ImageProvider, {ProvidedImage} from "./ImageProvider";
+import BaseUIElement from "../../UI/BaseUIElement";
+import Svg from "../../Svg";
+import {WikimediaImageProvider} from "./WikimediaImageProvider";
+
+export class WikidataImageProvider extends ImageProvider {
+
+    public SourceIcon(backlinkSource?: string): BaseUIElement {
+        throw Svg.wikidata_svg();
+    }
+
+    public static readonly singleton = new WikidataImageProvider()
+    public readonly defaultKeyPrefixes = ["wikidata"]
+
+    private constructor() {
+        super()
+    }
+
+    protected DownloadAttribution(url: string): Promise<any> {
+        throw new Error("Method not implemented; shouldn't be needed!");
+    }
+
+    public async ExtractUrls(key: string, value: string): Promise<Promise<ProvidedImage>[]> {
+        const wikidataUrl = "https://www.wikidata.org/wiki/"
+        if (value.startsWith(wikidataUrl)) {
+            value = value.substring(wikidataUrl.length)
+        }
+        if (!value.startsWith("Q")) {
+            value = "Q" + value
+        }
+        const url = "https://www.wikidata.org/wiki/Special:EntityData/" + value + ".json";
+        const response = await Utils.downloadJson(url)
+        const entity = response.entities[value];
+        const commons = entity.sitelinks.commonswiki;
+        // P18 is the claim 'depicted in this image'
+        const image = entity.claims.P18?.[0]?.mainsnak?.datavalue?.value;
+        const allImages = []
+        if (image !== undefined) {
+            // We found a 'File://' 
+            const promises = await WikimediaImageProvider.singleton.ExtractUrls(key, image)
+            allImages.push(...promises)
+        }
+        if (commons !== undefined) {
+            const promises = await WikimediaImageProvider.singleton.ExtractUrls(commons, image)
+            allImages.push(...promises)
+        }
+        return allImages
+    }
+
+}