import raf from '../../_util/raf';
import { onBeforeUnmount, ref, shallowRef } from 'vue-demi';
export function useLayoutState(defaultState) {
  const stateRef = shallowRef(defaultState);
  let rafId;
  const updateBatchRef = shallowRef([]);
  function setFrameState(updater) {
    updateBatchRef.value.push(updater);
    raf.cancel(rafId);
    rafId = raf(() => {
      const prevBatch = updateBatchRef.value;
      // const prevState = stateRef.value;
      updateBatchRef.value = [];
      prevBatch.forEach(batchUpdater => {
        stateRef.value = batchUpdater(stateRef.value);
      });
    });
  }
  onBeforeUnmount(() => {
    raf.cancel(rafId);
  });
  return [stateRef, setFrameState];
}
/** Lock frame, when frame pass reset the lock. */
export function useTimeoutLock(defaultState) {
  const frameRef = ref(defaultState || null);
  const timeoutRef = ref();
  function cleanUp() {
    clearTimeout(timeoutRef.value);
  }
  function setState(newState) {
    frameRef.value = newState;
    cleanUp();
    timeoutRef.value = setTimeout(() => {
      frameRef.value = null;
      timeoutRef.value = undefined;
    }, 100);
  }
  function getState() {
    return frameRef.value;
  }
  onBeforeUnmount(() => {
    cleanUp();
  });
  return [setState, getState];
}