pojazdownik/src/utils/speedLimitUtils.ts

import speedLimitTable from '../constants/speedLimits.json';
export type LocoType = keyof typeof speedLimitTable;

export const calculateSpeedLimit = (locoType: LocoType, stockMass: number, isTrainPassenger: boolean) => {
  const speedTable = speedLimitTable[locoType][isTrainPassenger ? 'passenger' : 'cargo'];

  if (!speedTable) return undefined;

  let speedLimit = 0;
  for (let mass in speedTable) if (stockMass > Number(mass)) speedLimit = (speedTable as any)[mass];

  return speedLimit;
};