// viz/app/linker/store_cache.js

function canonKeyForSku(rules, skuKey) {
	const s = String(skuKey || "").trim();
	if (!s) return "";
	return String(rules.canonicalSku(s) || s);
}

export function buildCanonStoreCache(allAgg, rules) {
	const m = new Map(); // canonSku -> Set<storeLabel>

	for (const it of allAgg) {
		if (!it) continue;

		const skuKey = String(it.sku || "").trim();
		if (!skuKey) continue;

		const canon = String(rules.canonicalSku(skuKey) || skuKey);
		let set = m.get(canon);
		if (!set) m.set(canon, (set = new Set()));

		const stores = it.stores;
		if (stores && stores.size) for (const s of stores) set.add(s);
	}

	return m;
}

function canonStoresForSku(rules, canonStoreCache, skuKey) {
	const canon = canonKeyForSku(rules, skuKey);
	return canon ? canonStoreCache.get(canon) || new Set() : new Set();
}

export function makeSameStoreCanonFn(rules, canonStoreCache) {
	return function sameStoreCanon(aSku, bSku) {
		const A = canonStoresForSku(rules, canonStoreCache, String(aSku || ""));
		const B = canonStoresForSku(rules, canonStoreCache, String(bSku || ""));
		if (!A.size || !B.size) return false;
		for (const s of A) if (B.has(s)) return true;
		return false;
	};
}