import { ref, watchEffect, Ref } from 'vue'

interface SWROptions {
  fetcher: (...args: any[]) => Promise<any>
  initialData?: any
}

export function useSWR(key: string, options: SWROptions) {
  const data = ref(options.initialData)
  const error = ref<Error | null>(null)
  const isValidating = ref(false)

  watchEffect(async () => {
    isValidating.value = true
    try {
      const result = await options.fetcher(key)
      data.value = result
    } catch (err) {
      error.value = err as Error | null
    } finally {
      isValidating.value = false
    }
  })

  return {
    data,
    error,
    isValidating
  }
}