import type { TransactionsRecord } from "@olenbetong/appframe-updater";
import { useCallback, useEffect, useState } from "react";

type TransactionsLike = Pick<TransactionsRecord, "PrimKey">;

type UseTransactionsSelectionResult = {
	selectedPrimKeys: Set<string>;
	toggleSelection: (primKey: string | null | undefined) => void;
	resetSelection: () => void;
};

export function useTransactionsSelection(transactions: TransactionsLike[]): UseTransactionsSelectionResult {
	let [selectedPrimKeys, setSelectedPrimKeys] = useState<Set<string>>(new Set());

	useEffect(() => {
		let availablePrimKeys = new Set(transactions.map((transaction) => transaction.PrimKey));
		setSelectedPrimKeys((current) => {
			if (current.size === 0) {
				return current;
			}
			let next = new Set<string>();
			let changed = false;
			for (let key of current) {
				if (availablePrimKeys.has(key)) {
					next.add(key);
				} else {
					changed = true;
				}
			}
			return changed ? next : current;
		});
	}, [transactions]);

	let toggleSelection = useCallback((primKey: string | null | undefined) => {
		if (!primKey) {
			return;
		}
		setSelectedPrimKeys((current) => {
			let next = new Set(current);
			if (next.has(primKey)) {
				next.delete(primKey);
			} else {
				next.add(primKey);
			}
			return next;
		});
	}, []);

	let resetSelection = useCallback(() => {
		setSelectedPrimKeys(new Set());
	}, []);

	return { selectedPrimKeys, toggleSelection, resetSelection };
}