import { useQuery, UseQueryResult } from '@tanstack/react-query';
import { decodeEntities } from 'calypso/lib/formatting';
import wpcom from 'calypso/lib/wp';

export interface RelatedSite {
	global_ID: string;
	site_ID: number;
	name: string;
	URL: string;
	last_updated: number;
	unseen_count: number;
	site_icon: string | null;
	post_author: number;
	feed_ID: number;
	description: string;
}

interface Site {
	global_ID: string;
	site_ID: number;
	site_name: string;
	site_URL: string;
	site_icon: {
		img: string;
		ico: string;
	} | null;
	description: string;
	author: number;
	feed_ID: number;
}

const selectRelatedSites = ( response: { sites?: Site[] } ): RelatedSite[] | null => {
	if ( ! response?.sites ) {
		return null;
	}
	const relatedSites: RelatedSite[] = response.sites.map( ( site: Site ) => {
		return {
			global_ID: site.global_ID,
			site_ID: site.site_ID,
			name: decodeEntities( site.site_name ),
			URL: site.site_URL,
			last_updated: 0,
			unseen_count: 0,
			site_icon: site.site_icon?.img || site.site_icon?.ico || null,
			post_author: site.author,
			feed_ID: site.feed_ID,
			description: decodeEntities( site.description ),
		};
	} );

	// Filter out any undefined values that may have been created by the map function.
	const validRelatedSites = relatedSites.filter( Boolean );

	return validRelatedSites.length > 0 ? validRelatedSites : null;
};

export const useRelatedSites = (
	siteId: number,
	postId?: number
): UseQueryResult< RelatedSite[] | null > => {
	const SITE_RECOMMENDATIONS_COUNT = 5;
	return useQuery( {
		queryKey: [ 'related-sites', SITE_RECOMMENDATIONS_COUNT, siteId, postId ],
		queryFn: () =>
			wpcom.req.get(
				{
					path: `/read/site/${ siteId }/sites/related`,
					apiNamespace: 'rest/v1.2',
				},
				{
					size_global: SITE_RECOMMENDATIONS_COUNT,
					post_id: postId,
					http_envelope: 1,
				}
			),
		enabled: !! siteId,
		staleTime: 3600000, // 1 hour
		select: selectRelatedSites,
		retry: false,
		refetchOnMount: false,
		retryOnMount: false,
		refetchOnWindowFocus: false,
	} );
};