import { cloneDeep, isEqual } from 'lodash'
import { computed, ComputedGetter, ComputedRef, readonly, Ref, ref, watch, watchEffect } from 'vue'
import { formatISO, parseISO } from 'date-fns'

export function computedIter<T>(fn: ComputedGetter<Iterable<T>>): ComputedRef<T[]> {
  return computed(() => Array.from(fn()))
}

export const useId = (() => {
  let _id = 0
  return function useId(prefix = 'component') {
    return readonly(ref(`${prefix}-${_id++}`))
  }
})()

export function useAsyncFunction<F extends (...args: never[]) => Promise<unknown>>(fn: F) {
  const isProcessing = ref(false)
  async function wrapper(...args: Parameters<F>): Promise<Awaited<ReturnType<F>>> {
    isProcessing.value = true
    try {
      return (await fn(...args)) as Awaited<ReturnType<F>>
    } finally {
      isProcessing.value = false
    }
  }
  return { fn: wrapper, isProcessing }
}

export function useUpdatableState<T>(
  externalStateRef: Ref<T>,
  onUpdate: (value: T) => void,
  clone: (value: T) => T = cloneDeep,
): Ref<T> {
  const localRef = ref()
  watchEffect(() => {
    localRef.value = clone(externalStateRef.value)
  })
  watch(
    localRef,
    (newValue) => {
      if (!isEqual(newValue, externalStateRef.value)) {
        onUpdate(newValue)
      }
    },
    { deep: true },
  )
  return localRef
}

export function useFormattedISODate(date: Ref<Date>) {
  return computed({
    get() {
      return formatISO(date.value, { representation: 'date' })
    },
    set(dateValue: string) {
      date.value = parseISO(dateValue)
    },
  })
}