// Adapted from https://gist.github.com/paulirish/1579671#gistcomment-91515
let caf = undefined;
let raf = undefined;
// Ensure window exists.
if ('undefined' !== typeof window) {
  raf = window.requestAnimationFrame;
  caf = window.cancelAnimationFrame;
  // Vendors?
  for (const vendor of ['ms', 'moz', 'webkit', 'o']) {
    if (raf) {
      break;
    }
    raf = window[`${vendor}RequestAnimationFrame`];
    caf = window[`${vendor}CancelAnimationFrame`];
    caf = caf || window[`${vendor}CancelRequestAnimationFrame`];
  }
  // rAF is built in but cAF is not.
  if (raf && !caf) {
    const browserRaf = raf;
    const canceled = {}
    raf = (fn) => {
      const id = browserRaf((time) => {
        if (!(id in canceled)) {
          return fn(time);
        }
        delete canceled[id];
      });
      return id;
    };
    caf = (id) => {
      canceled[id] = true;
    };
  }
}
// Handle legacy browsers and node.
if (!raf) {
  let targetTime = 0;
  raf = (fn) => {
    const currentTime = +new Date;
    targetTime = Math.max(targetTime + 16, currentTime);
    const wfn = () => {
      fn(+new Date);
    }
    return setTimeout(wfn, targetTime - currentTime);
  };
  caf = (id) => {
    clearTimeout(id);
  };
}
// Export what we've scrounged up.
export {caf as cancelAnimationFrame};
export {raf as requestAnimationFrame};
// setInterval, but for animations. :)
let said = 0
const handles = {}
export function setAnimation(fn) {
  const id = ++said;
  const wfn = (time) => {
    if (!handles[id]) {
      return;
    }
    fn(time);
    handles[id] = raf(wfn);
  }
  handles[id] = raf(wfn);
  return id;
}
// clearInterval counterpart.
export function clearAnimation (id) {
  caf(handles[id]);
  delete handles[id];
}