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import { atom } from 'jotai'import type { Atom, Getter, WritableAtom } from 'jotai'
type Timeout = ReturnType<typeof setTimeout>type AnyError = unknown
declare global {  interface SymbolConstructor {    readonly observable: symbol  }}
type Subscription = {  unsubscribe: () => void}
type Observer<T> = {  next: (value: T) => void  error: (error: AnyError) => void  complete: () => void}
type ObservableLike<T> = {  subscribe(observer: Observer<T>): Subscription  subscribe(    next: (value: T) => void,    error?: (error: AnyError) => void,    complete?: () => void  ): Subscription  [Symbol.observable]?: () => ObservableLike<T> | undefined}
type SubjectLike<T> = ObservableLike<T> & Observer<T>
type Options<Data> = {  initialValue?: Data | (() => Data)  unstable_timeout?: number}
export function atomWithObservable<Data>(  createObservable: (get: Getter) => SubjectLike<Data>,  options?: Options<Data>): WritableAtom<Data, Data>
export function atomWithObservable<Data>(  createObservable: (get: Getter) => ObservableLike<Data>,  options?: Options<Data>): Atom<Data>
export function atomWithObservable<Data>(  createObservable: (get: Getter) => ObservableLike<Data> | SubjectLike<Data>,  options?: Options<Data>) {  const observableResultAtom = atom((get) => {    let observable = createObservable(get)    const itself = observable[Symbol.observable]?.()    if (itself) {      observable = itself    }
    type Result = { d: Data } | { e: AnyError }    let resolve: ((result: Result) => void) | undefined    const makePending = () =>      new Promise<Result>((r) => {        resolve = r      })    const initialResult: Result | Promise<Result> =      options && 'initialValue' in options        ? {            d:              typeof options.initialValue === 'function'                ? (options.initialValue as () => Data)()                : (options.initialValue as Data),          }        : makePending()
    let setResult: ((result: Result) => void) | undefined    let lastResult: Result | undefined    const listener = (result: Result) => {      lastResult = result      resolve?.(result)      setResult?.(result)    }
    let subscription: Subscription | undefined    let timer: Timeout | undefined    const isNotMounted = () => !setResult    const start = () => {      if (subscription) {        clearTimeout(timer)        subscription.unsubscribe()      }      subscription = observable.subscribe(        (d) => listener({ d }),        (e) => listener({ e })      )      if (isNotMounted() && options?.unstable_timeout) {        timer = setTimeout(() => {          if (subscription) {            subscription.unsubscribe()            subscription = undefined          }        }, options.unstable_timeout)      }    }    start()
    const resultAtom = atom(lastResult || initialResult)    resultAtom.onMount = (update) => {      setResult = update      if (lastResult) {        update(lastResult)      }      if (subscription) {        clearTimeout(timer)      } else {        start()      }      return () => {        setResult = undefined        if (subscription) {          subscription.unsubscribe()          subscription = undefined        }      }    }    return [resultAtom, observable, makePending, start, isNotMounted] as const  })
  const observableAtom = atom(    (get) => {      const [resultAtom] = get(observableResultAtom)      const result = get(resultAtom)      if ('e' in result) {        throw result.e      }      return result.d    },    (get, set, data: Data) => {      const [resultAtom, observable, makePending, start, isNotMounted] =        get(observableResultAtom)      if ('next' in observable) {        if (isNotMounted()) {          set(resultAtom, makePending())          start()        }        observable.next(data)      } else {        throw new Error('observable is not subject')      }    }  )
  return observableAtom}