'use strict';

const fs = require ('fs-extra');

/**
 * @param str
 */
function get_table_info (str) {
  const lines = str.split (/\n/ug);
  lines.splice (0, 2);
  lines.splice (lines.length - 2, 2);
  const name_line = lines.splice (0);
  const { name } = (/<b>(?<name>\S)<\/b>/u).exec (name_line).groups;
  const columns = [];

  return { name, columns };
}

/**
 * get all tables from a structure file
 *
 * @param {string} file path to the structure file
 * @returns {Array<object>} tables
 */
async function get_tables (file) {
  const lines = (await fs.readFile (file, 'utf-8')).split (/\n/gu);
  const curr = [];
  const tables = [];
  for (const l of lines) {
    if (curr.length > 0 || (/\S+ \[label=</u).test (l))
      curr.push (l);

    if ((/>\]/u).test (l)) {
      tables.push (curr.join ('\n'));
      curr.splice (0, curr.length);
    }
  }

  return tables.map ((val) => get_table_info (val));
}

module.exports = { get_tables };