tweb-i2p/src/helpers/schedulers.ts

// * Jolly Cobra's schedulers
import { AnyToVoidFunction, NoneToVoidFunction } from "../types";

//type Scheduler = typeof requestAnimationFrame | typeof onTickEnd | typeof runNow;

export function debounce<F extends AnyToVoidFunction>(
  fn: F,
  ms: number,
  shouldRunFirst = true,
  shouldRunLast = true,
) {
  let waitingTimeout: number | null = null;

  return (...args: Parameters<F>) => {
    if(waitingTimeout) {
      clearTimeout(waitingTimeout);
      waitingTimeout = null;
    } else if(shouldRunFirst) {
      // @ts-ignore
      fn(...args);
    }

    waitingTimeout = setTimeout(() => {
      if(shouldRunLast) {
        // @ts-ignore
        fn(...args);
      }

      waitingTimeout = null;
    }, ms) as any;
  };
}

/* export function throttle<F extends AnyToVoidFunction>(
  fn: F,
  ms: number,
  shouldRunFirst = true,
) {
  let interval: number | null = null;
  let isPending: boolean;
  let args: Parameters<F>;

  return (..._args: Parameters<F>) => {
    isPending = true;
    args = _args;

    if (!interval) {
      if (shouldRunFirst) {
        isPending = false;
        // @ts-ignore
        fn(...args);
      }

      interval = window.setInterval(() => {
        if (!isPending) {
          window.clearInterval(interval!);
          interval = null;
          return;
        }

        isPending = false;
        // @ts-ignore
        fn(...args);
      }, ms);
    }
  };
} */

/* export function throttleWithRaf<F extends AnyToVoidFunction>(fn: F) {
  return throttleWith(fastRaf, fn);
}

export function throttleWithTickEnd<F extends AnyToVoidFunction>(fn: F) {
  return throttleWith(onTickEnd, fn);
}

export function throttleWithNow<F extends AnyToVoidFunction>(fn: F) {
  return throttleWith(runNow, fn);
}

export function throttleWith<F extends AnyToVoidFunction>(schedulerFn: Scheduler, fn: F) {
  let waiting = false;
  let args: Parameters<F>;

  return (..._args: Parameters<F>) => {
    args = _args;

    if (!waiting) {
      waiting = true;

      schedulerFn(() => {
        waiting = false;
        // @ts-ignore
        fn(...args);
      });
    }
  };
}

export function onTickEnd(cb: NoneToVoidFunction) {
  Promise.resolve().then(cb);
}

function runNow(fn: NoneToVoidFunction) {
  fn();
} */

export const pause = (ms: number) => new Promise<void>((resolve) => {
  setTimeout(resolve, ms);
});

let fastRafCallbacks: NoneToVoidFunction[] | undefined;
export function fastRaf(callback: NoneToVoidFunction) {
  if(!fastRafCallbacks) {
    fastRafCallbacks = [callback];

    requestAnimationFrame(() => {
      const currentCallbacks = fastRafCallbacks!;
      fastRafCallbacks = undefined;
      currentCallbacks.forEach((cb) => cb());
    });
  } else {
    fastRafCallbacks.push(callback);
  }
}

export function doubleRaf() {
  return new Promise((resolve) => {
    window.requestAnimationFrame(() => {
      window.requestAnimationFrame(resolve);
    });
  });
}