import globals from '../globals';

export default function flatten (data, keepArray = false) {  // flatten object: {a: {b: true}} -> {a.b: true}
  const result = {};
  function recurse (cur, prop) {
    if (Object(cur) !== cur || Object.keys(cur).length === 0) {
      result[prop] = cur;
    }
    else if (prop === `${globals.spectrum.spectrum}.${globals.spectrum.dpt}`) {
      result[prop + '.labels'] = cur.map(e => e[0]);
      result[prop + '.values'] = cur.map(e => e[1]);
    }
    else if (Array.isArray(cur)) {
      if (keepArray) {
        result[prop] = cur;
      }
      else {  // array to string
        if (cur.length && (Object(cur[0]) !== cur || Object.keys(cur[0]).length === 0)) {  // array of non-objects
          result[prop] = '[' + cur.join(', ') + ']';
        }
        else {
          let l = 0;
          for(let i = 0, l = cur.length; i < l; i++)
            recurse(cur[i], prop + "[" + i + "]");
          if (l == 0)
            result[prop] = [];
        }
      }
    }
    else {
      let isEmpty = true;
      for (let p in cur) {
        isEmpty = false;
        recurse(cur[p], prop ? prop+"."+p : p);
      }
      if (isEmpty && prop)
        result[prop] = {};
    }
  }
  recurse(data, '');
  return result;
}