import type { INodeListSearchItems, INodeListSearchResult } from 'n8n-workflow';

import type { AuthContext, GraphListResponse, NamedGraphItem } from './interfaces';
import { microsoftApiRequest } from '../transport';

const PAGE_SIZE = 100;

export type ListSearchItemMapper<T extends NamedGraphItem = NamedGraphItem> = (
	item: T,
) => INodeListSearchItems;

/**
 * Lists one page of a Graph collection for a searchable resourceLocator dropdown.
 * Neither the worksheets nor the tables endpoint supports server-side `$search`,
 * so a typed filter narrows each page's `name` client-side instead. A
 * `paginationToken` is always a previous page's `@odata.nextLink`, followed
 * verbatim — never rebuilt with `endpoint` or extra query params.
 *
 * The editor disables "load more" while a filter is active (it assumes a
 * searchable dropdown does server-side search across the whole collection),
 * so a filter that only ever looked at the page it was given would make an
 * item past that page look like it doesn't exist, with no way to reach it.
 * While filtering, keep following `@odata.nextLink` on our own until a page
 * has a match or there are no more pages — matching, not exhaustive: this
 * stops at the first non-empty page rather than collecting every match in
 * the collection.
 */
export async function listSearchPage<T extends NamedGraphItem = NamedGraphItem>(
	this: AuthContext,
	endpoint: string,
	mapItem: ListSearchItemMapper<T>,
	filter?: string,
	paginationToken?: string,
): Promise<INodeListSearchResult> {
	let nextLink = paginationToken;
	let matches: T[] = [];

	do {
		const response = nextLink
			? await (microsoftApiRequest<GraphListResponse<T>>).call(this, 'GET', '', {}, {}, nextLink)
			: await (microsoftApiRequest<GraphListResponse<T>>).call(
					this,
					'GET',
					endpoint,
					{},
					{ $top: PAGE_SIZE },
				);

		const items = response.value ?? [];
		matches = filter
			? items.filter((item) => item.name.toLowerCase().includes(filter.toLowerCase()))
			: items;

		nextLink = response['@odata.nextLink'];
	} while (filter && matches.length === 0 && nextLink !== undefined);

	return {
		results: matches.map(mapItem),
		paginationToken: nextLink,
	};
}