import type { Dropshop } from '../../../types';

/** Flatten shops from API (keyed by provider) into a list with provider label. */
export function flattenDropshops(
	shops: Record<string, Dropshop[]>
): { shop: Dropshop; provider: string }[] {
	return Object.entries(shops).flatMap(([provider, list]) =>
		(Array.isArray(list) ? list : []).map((shop) => ({ shop, provider }))
	);
}

/** One-line address from dropshop fields. */
export function formatDropshopAddress(shop: Dropshop): string {
	const parts = [
		shop.address1 ?? shop.address,
		shop.address2,
		shop.city,
		shop.postcode,
		shop.country ?? shop.countryCode,
	].filter(Boolean);
	return parts.length ? parts.join(', ') : '—';
}

/** Nearest dropshop per provider (by distance). Provider key lowercased for lookup. */
export function nearestDropshopByProvider(
	shops: Record<string, Dropshop[]>
): Record<string, Dropshop> {
	const entries = flattenDropshops(shops);
	const byProvider: Record<string, Dropshop> = {};
	for (const { shop, provider } of entries) {
		const key = provider.toLowerCase();
		const existing = byProvider[key];
		const dist = Number(shop.distance);
		if (!existing || (Number.isFinite(dist) && (existing.distance == null || dist < Number(existing.distance)))) {
			byProvider[key] = shop;
		}
	}
	return byProvider;
}