browser.ts

import { Effect as T, pipe } from '@effect-ts/core'

/** Sleeps the specified duration depending on whether the document is hidden or not */
export const sleepBackgroundForegroud = ({
  durationHiddenMs,
  durationVisibleMs,
}: {
  durationHiddenMs: number
  durationVisibleMs: number
}) => {
  const startTimeMs = Date.now()

  const cleanUpFns: (() => void)[] = []

  return pipe(
    T.effectAsync((cb) => {
      const visbilityEventHandler = () => {
        if (document.hidden === false) {
          const elapsedMs = Date.now() - startTimeMs
          if (elapsedMs >= durationHiddenMs) {
            cb(T.unit)
          }
        }
      }

      document.addEventListener('visibilitychange', visbilityEventHandler)
      cleanUpFns.push(() => document.removeEventListener('visibilitychange', visbilityEventHandler))

      const backgroundTimeout = setTimeout(() => {}, durationHiddenMs)
      cleanUpFns.push(() => clearTimeout(backgroundTimeout))

      const foregroundTimeout = setTimeout(() => {
        if (document.hidden === false) {
          cb(T.unit)
        }
      }, durationVisibleMs)

      cleanUpFns.push(() => clearTimeout(foregroundTimeout))
    }),
    T.tap(() =>
      T.succeedWith(() => {
        cleanUpFns.forEach((fn) => fn())
      }),
    ),
  )
}