handlers/filterHandler/filterHandler.ts

import { DataElementInterface } from '../../utils/types/types';

/**
 * Filter the data according to the filter keyword.
 * Filtering is not sensitive to case but do not use a normalizer function for accent or hyphens.
 * Return unmodified data if keyword is empty.
 * Has an exact search behavior for parts of the string being between double quotes.
 * Builds the searchingKeywords array by spliting the string :
 *  1) according to double quote to isolate fragment inside and outside of double quotes.
 *  2) splitting the fragment outside of double quote according to spaces.
 * Then make the fitlering research according to all elements of the searchingKeyword array.
 * @param {array} data - the  data to filter.
 * @param {string} keyword - the keyword string use to filter.
 * @memberof handlers
 * @function
 * @return {array} the filtered data according to keyword.
 */
export const filterHandler = (
  data: DataElementInterface[] | [],
  keyword: string
): DataElementInterface[] | [] => {
  if (keyword === '') return data;

  const quoteSplittedKeywords: string[] = keyword.toLowerCase().split('"');
  if (quoteSplittedKeywords.length % 2 !== 1) {
    const lastElement: string = quoteSplittedKeywords.pop() ?? '';
    quoteSplittedKeywords[quoteSplittedKeywords.length - 1] += lastElement;
  }
  const searchingKeywords: string[] = quoteSplittedKeywords
    .flatMap((word, index) => (index % 2 === 0 ? word.split(' ') : word))
    .filter((word) => word !== '');

  return data.filter((element) =>
    searchingKeywords.every((word) =>
      Object.values(element).some((value) =>
        value.toString().toLowerCase().includes(word)
      )
    )
  );
};