import React, { PropsWithChildren, useEffect, useRef } from 'react'
import { DefaultLoading } from '../components/page/loading'
import { useChatContext } from '../contexts/chat_context'
import { useApiGet, useOrganization } from '../hooks'
import { currentPersonRequestArgs } from '../hooks/use_current_person'
import { AgeCheckRequiredScreen } from '../screens/age_check/age_check_required_screen'
import { AgeCheckUnderageScreen } from '../screens/age_check/age_check_underage_screen'
import { AgeQualificationStatus, CurrentPersonResource } from '../types'

export function ChatAccessGate({ children }: PropsWithChildren) {
  const { data: person, isFetched } = useApiGet<CurrentPersonResource>(currentPersonRequestArgs)
  const { data: organization } = useOrganization()

  const ageQualificationStatus = person?.ageQualificationStatus
  const contactEmail = organization?.contactEmail

  useAgeDisqualification(ageQualificationStatus, contactEmail)

  if (!isFetched) {
    return <DefaultLoading />
  }

  if (!person) {
    throw new Error('Current person not found')
  }

  if (ageQualificationStatus === AgeQualificationStatus.DISQUALIFIED) {
    return <AgeCheckUnderageScreen contactEmail={contactEmail} />
  }

  if (ageQualificationStatus === AgeQualificationStatus.UNKNOWN) {
    return <AgeCheckRequiredScreen />
  }

  return <>{children}</>
}

/**
 * Helper hook that handles the age disqualification logic.
 *
 * If a host app provides an onAgeDisqualification callback, it will be called
 * when a user is found to be disqualified by their age.
 */
function useAgeDisqualification(
  ageQualificationStatus: CurrentPersonResource['ageQualificationStatus'],
  contactEmail: string | undefined
) {
  const { onAgeDisqualification } = useChatContext()
  const hasCalledCallbackRef = useRef(false)

  useEffect(() => {
    if (
      ageQualificationStatus === AgeQualificationStatus.DISQUALIFIED &&
      !hasCalledCallbackRef.current
    ) {
      hasCalledCallbackRef.current = true
      onAgeDisqualification({ contactEmail: contactEmail || '' })
    }
  }, [ageQualificationStatus, onAgeDisqualification, contactEmail])
}