import ImageProvider, { ProvidedImage } from "./ImageProvider"
import BaseUIElement from "../../UI/BaseUIElement"
import { WikimediaImageProvider } from "./WikimediaImageProvider"
import Wikidata from "../Web/Wikidata"
import SvelteUIElement from "../../UI/Base/SvelteUIElement"
import * as Wikidata_icon from "../../assets/svg/Wikidata.svelte"
import { Utils } from "../../Utils"

export class WikidataImageProvider extends ImageProvider {
    public static readonly singleton = new WikidataImageProvider()
    public readonly defaultKeyPrefixes = ["wikidata"]
    public readonly name = "Wikidata"
    private static readonly keyBlacklist: ReadonlySet<string> = new Set([
        "mapillary",
        ...Utils.Times((i) => "mapillary:" + i, 10),
    ])

    private constructor() {
        super()
    }

    public apiUrls(): string[] {
        return Wikidata.neededUrls
    }

    public SourceIcon(): BaseUIElement {
        return new SvelteUIElement(Wikidata_icon)
    }

    public async ExtractUrls(key: string, value: string): Promise<ProvidedImage[]> {
        if (WikidataImageProvider.keyBlacklist.has(key)) {
            return undefined
        }
        const entity = await Wikidata.LoadWikidataEntryAsync(value)
        if (entity === undefined) {
            return undefined
        }

        const allImages: Promise<ProvidedImage[]>[] = []
        // P18 is the claim 'depicted in this image'
        for (const img of Array.from(entity.claims.get("P18") ?? [])) {
            const promises = WikimediaImageProvider.singleton.ExtractUrls(undefined, img)
            allImages.push(promises)
        }
        // P373 is 'commons category'
        for (let cat of Array.from(entity.claims.get("P373") ?? [])) {
            if (!cat.startsWith("Category:")) {
                cat = "Category:" + cat
            }
            const promises = WikimediaImageProvider.singleton.ExtractUrls(undefined, cat)
            allImages.push(promises)
        }

        const commons = entity.commons
        if (
            commons !== undefined &&
            (commons.startsWith("Category:") || commons.startsWith("File:"))
        ) {
            const promises = WikimediaImageProvider.singleton.ExtractUrls(undefined, commons)
            allImages.push(promises)
        }
        const resolved = await Promise.all(Utils.NoNull(allImages))
        return [].concat(...resolved)
    }

    public DownloadAttribution(): Promise<undefined> {
        throw new Error("Method not implemented; shouldn't be needed!")
    }
}