import TickingPromise from '@/util/ticking-promise.js';

export default function delta(object, properties) {
  const deltas = {};
  for (const key in properties) {
    const property = properties[key];
    const delta = {
      duration: Infinity,
      elapsed: 0,
      ...property,
    };
    deltas[key] = delta;
  }
  let stop;
  const promise = new TickingPromise(
    (resolve) => {
      stop = resolve;
    },
    (elapsed, resolve) => {
      for (const key in deltas) {
        deltas[key].elapsed += elapsed;
        if (deltas[key].elapsed >= deltas[key].duration) {
          object[key] += deltas[key].delta * (deltas[key].duration - deltas[key].elapsed);
          resolve();
          return;
        }
        object[key] += deltas[key].delta * elapsed;
      }
    },
  );
  return {stop, deltas, promise};
}