@sutton-signwriting/core/src/fswquery/fswquery-parse.js

import { re } from './fswquery-re';
import { fsw2coord } from '../convert';

const parsePrefix = (text) => {
  return {
    required: true,
    parts: text == 'T' ? undefined :
      text.match(new RegExp(`(${re.symbol}|${re.range})`, 'g'))
        .map(part => part[0] == 'S' ? part : part.slice(1).split('t'))
  }
}
const parseSignbox = (text) => {
  return text.match(new RegExp(`(${re.symbol}${re.coord}|${re.range}${re.coord})`, 'g'))
    .map(part => {
      let coord, front;
      if (part.includes('x')) {
        coord = fsw2coord(part.slice(-7));
        front = part.slice(0, -7);
      } else {
        front = part;
      }
      if (front.includes('S')) {
        return {
          symbol: front,
          coord: coord
        }
      } else {
        return {
          range: front.slice(1).split('t'),
          coord: coord
        }
      }
    })
}

/**
 * Function to parse FSW query string to object
 * @function fswquery.parse
 * @param {string} fswQueryString - an FSW query string
 * @returns {object} elements of an FSW query string
 * @example
 * fswquery.parse('QAS10000R100t204S20500TS20000R100t105500x500V5-')
 * 
 * return {
 *  query: true,
 *  prefix: {
 *    required: true,
 *    parts: [
 *      'S10000',
 *      ['100', '204'],
 *      'S20500'
 *    ]
 *  },
 *  signbox: [
 *    { symbol: 'S20000' },
 *    {
 *      range: ['100', '105'],
 *      coord: [500, 500]
 *    }
 *  ],
 *  variance: 5,
 *  style: true
 * }
 */
const parse = (fswQueryString) => {
  const query = (typeof fswQueryString === 'string') ? fswQueryString.match(new RegExp(`^${re.full}`)) : undefined;
  return {
    'query': query ? true : undefined,
    'prefix': query && query[1] ? parsePrefix(query[1]) : undefined,
    'signbox': query && query[2] ? parseSignbox(query[2]) : undefined,
    'variance': query && query[3] ? parseInt(query[3].slice(1)) : undefined,
    'style': query && query[4] ? true : undefined
  };
}

export { parse }