import { useQuery } from '@apollo/client'
import Item, { ItemSkeleton } from './item'
import ItemJob from './item-job'
import styles from './items.module.css'
import MoreFooter from './more-footer'
import { Fragment, useCallback, useMemo } from 'react'
import { CommentFlat } from './comment'
import { SUB_ITEMS } from '../fragments/subs'
import { LIMIT } from '../lib/cursor'
import ItemFull from './item-full'

export default function Items ({ ssrData, variables = {}, query, destructureData, rank, noMoreText, Footer, filter = () => true }) {
  const { data, fetchMore } = useQuery(query || SUB_ITEMS, { variables })
  const Foooter = Footer || MoreFooter

  const { items, pins, cursor } = useMemo(() => {
    if (!data && !ssrData) return {}
    if (destructureData) {
      return destructureData(data || ssrData)
    } else {
      return data?.items || ssrData?.items
    }
  }, [data, ssrData])

  const pinMap = useMemo(() =>
    pins?.reduce((a, p) => { a[p.position] = p; return a }, {}), [pins])

  const Skeleton = useCallback(() =>
    <ItemsSkeleton rank={rank} startRank={items?.length} limit={variables.limit} />, [rank, items])

  if (!ssrData && !data) {
    return <Skeleton />
  }

  return (
    <>
      <div className={styles.grid}>
        {items.filter(filter).map((item, i) => (
          <Fragment key={item.id}>
            {pinMap && pinMap[i + 1] && <Item item={pinMap[i + 1]} />}
            {item.parentId
              ? <CommentFlat item={item} rank={rank && i + 1} noReply includeParent clickToContext />
              : (item.isJob
                  ? <ItemJob item={item} rank={rank && i + 1} />
                  : (item.searchText
                      ? <ItemFull item={item} rank={rank && i + 1} noReply siblingComments={variables.includeComments} />
                      : <Item item={item} rank={rank && i + 1} siblingComments={variables.includeComments} />))}
          </Fragment>
        ))}
      </div>
      <Foooter
        cursor={cursor} fetchMore={fetchMore} noMoreText={noMoreText}
        count={items?.length}
        Skeleton={Skeleton}
      />
    </>
  )
}

export function ItemsSkeleton ({ rank, startRank = 0, limit = LIMIT }) {
  const items = new Array(limit).fill(null)

  return (
    <div className={styles.grid}>
      {items.map((_, i) => (
        <ItemSkeleton rank={rank && i + startRank + 1} key={i + startRank} />
      ))}
    </div>
  )
}