import {UnpackedData, PackedData, UnpackedZoneData} from './types';

export function pack(data: UnpackedData): PackedData {
  return {
    zones: Object.keys(data.zones).map(zone =>
      [
        zone,
        ...data.zones[zone].map(([ts, ...others]) =>
          [ts === '' ? '' : ts.toString(36), ...others].join(',')
        ),
      ].join('|')
    ),
    abbrvs: data.abbrvs.join('|'),
    offsets: data.offsets.map(o => o.toString(36)).join('|'),
  };
}

export function unpack(data: PackedData): Record<string, UnpackedZoneData[]> {
  const abbrvs = data.abbrvs.split('|');
  const offsets = data.offsets.split('|').map(n => parseInt(n, 36));
  const packedZones = data.zones;
  const zones: Record<string, UnpackedZoneData[]> = {};
  for (const d of packedZones) {
    const [zone, ...zoneData] = d.split('|');

    zones[zone] = zoneData
      .map(z => z.split(','))
      .map(([ts, abbrvIndex, offsetIndex, dst]) => [
        ts === '' ? -Infinity : parseInt(ts, 36),
        abbrvs[+abbrvIndex],
        offsets[+offsetIndex],
        dst === '1',
      ]);
  }
  return zones;
}