import { useCallback, useMemo, useRef } from 'react';
import { validationRules } from '../constants/validation';
import { buildColumnHeaderPaths, collectInvalidErrors, isValidationRuleEnabled } from '../utils/validationUtils';

const EMPTY_ARRAY = [];

export const useValidationRules = (data, columns, formType, sheetName) => {
	const safeData = data || EMPTY_ARRAY;
	const safeColumns = columns || EMPTY_ARRAY;
	const stableErrorsRef = useRef([]);
	const headerPaths = useMemo(() => buildColumnHeaderPaths(safeColumns), [safeColumns]);
	const activeRules = useMemo(
		() => validationRules.filter((rule) => isValidationRuleEnabled(rule, { formType, sheetName })),
		[formType, sheetName],
	);

	const calculatedErrors = useMemo(() => {
		const result = [];
		const seen = new Set();

		for (const rule of activeRules) {
			collectInvalidErrors(safeData, rule, headerPaths, result, seen);
		}

		return result;
	}, [activeRules, headerPaths, safeData]);

	const previousErrors = stableErrorsRef.current;
	const errorsAreEqual =
		previousErrors.length === calculatedErrors.length &&
		previousErrors.every(
			(error, index) =>
				error.id === calculatedErrors[index].id &&
				error.columnId === calculatedErrors[index].columnId &&
				error.message === calculatedErrors[index].message,
		);
	if (!errorsAreEqual) {
		stableErrorsRef.current = calculatedErrors;
	}
	const errors = stableErrorsRef.current;

	const isCellInvalid = useCallback(
		(columnId, value, row) =>
			activeRules.some(
				(rule) =>
					rule.columnKeys.includes(columnId) && (!rule.appliesToRow || rule.appliesToRow(row)) && rule.isInvalid(value, row, columnId),
			),
		[activeRules],
	);

	return { errors, isCellInvalid, headerPaths };
};