import {EpochSlotOpts} from "./interface.js";

/**
 * Formats time as: `EPOCH/SLOT_INDEX SECONDS.MILLISECONDS
 */
export function formatEpochSlotTime(opts: EpochSlotOpts, now = Date.now()): string {
  const nowSec = now / 1000;
  const secSinceGenesis = nowSec - opts.genesisTime;
  const epoch = Math.floor(secSinceGenesis / (opts.slotsPerEpoch * opts.secondsPerSlot));
  const epochStartSec = opts.genesisTime + epoch * opts.slotsPerEpoch * opts.secondsPerSlot;
  const secSinceStartEpoch = nowSec - epochStartSec;
  const slotIndex = Math.floor(secSinceStartEpoch / opts.secondsPerSlot);
  const slotSec = secSinceStartEpoch % opts.secondsPerSlot;
  return `Eph ${epoch}/${slotIndex} ${slotSec.toFixed(3)}`;
}