import type { CatalogItemData } from "@/app/admin/catalog/[id]/catalog-items-table/types";

export const OFFER_FILTERS = [
	"all",
	"free",
	"paid",
	"bundles",
	"limited",
] as const;
export type OfferFilter = (typeof OFFER_FILTERS)[number];
type DiscoverableOffer = Pick<
	CatalogItemData,
	| "id"
	| "catalogName"
	| "baseItemName"
	| "baseName"
	| "itemIds"
	| "costCredits"
	| "costPoints"
	| "limitedStack"
>;

function matchesFilter(item: DiscoverableOffer, filter: OfferFilter) {
	switch (filter) {
		case "all":
			return true;
		case "free":
			return item.costCredits === 0 && item.costPoints === 0;
		case "paid":
			return item.costCredits > 0 || item.costPoints > 0;
		case "bundles":
			return (
				item.itemIds.split(";").filter((part) => part.trim().length > 0)
					.length > 1
			);
		case "limited":
			return item.limitedStack > 0;
	}
}

/** Facet counts apply to the text search so changing a facet never hides its available matches. */
export function discoverOffers<T extends DiscoverableOffer>(
	items: readonly T[],
	query: string,
	filter: OfferFilter,
) {
	const normalized = query.trim().toLowerCase();
	const exactId = /^#\d+$/.test(normalized) ? normalized.slice(1) : null;
	const matches =
		exactId !== null
			? items.filter((item) => String(item.id) === exactId)
			: normalized
				? items.filter((item) =>
						[
							item.catalogName,
							item.baseItemName,
							item.baseName,
							item.itemIds,
							String(item.id),
						].some((value) => value.toLowerCase().includes(normalized)),
					)
				: [...items];
	const counts = {
		all: matches.length,
		free: 0,
		paid: 0,
		bundles: 0,
		limited: 0,
	};
	for (const item of matches)
		for (const facet of OFFER_FILTERS) {
			if (facet !== "all" && matchesFilter(item, facet)) counts[facet] += 1;
		}
	return {
		items: matches.filter((item) => matchesFilter(item, filter)),
		counts,
	};
}