import { Button } from '@/components/ui/button'
import { Switch } from '@/components/ui/switch'
import { useFetchRelayInfos } from '@/hooks'
import { isReplyNoteEvent } from '@/lib/event'
import { cn } from '@/lib/utils'
import { useNostr } from '@/providers/NostrProvider'
import { useScreenSize } from '@/providers/ScreenSizeProvider'
import client from '@/services/client.service'
import dayjs from 'dayjs'
import { Event, Filter, kinds } from 'nostr-tools'
import { useEffect, useMemo, useRef, useState } from 'react'
import { useTranslation } from 'react-i18next'
import PullToRefresh from 'react-simple-pull-to-refresh'
import NoteCard from '../NoteCard'

const NORMAL_RELAY_LIMIT = 100
const ALGO_RELAY_LIMIT = 500

export default function NoteList({
  relayUrls,
  filter = {},
  className
}: {
  relayUrls: string[]
  filter?: Filter
  className?: string
}) {
  const { t } = useTranslation()
  const { signEvent, checkLogin } = useNostr()
  const { isFetching: isFetchingRelayInfo, areAlgoRelays } = useFetchRelayInfos(relayUrls)
  const [refreshCount, setRefreshCount] = useState(0)
  const [timelineKey, setTimelineKey] = useState<string | undefined>(undefined)
  const [events, setEvents] = useState<Event[]>([])
  const [newEvents, setNewEvents] = useState<Event[]>([])
  const [hasMore, setHasMore] = useState<boolean>(true)
  const [initialized, setInitialized] = useState(false)
  const [displayReplies, setDisplayReplies] = useState(false)
  const bottomRef = useRef<HTMLDivElement | null>(null)
  const noteFilter = useMemo(() => {
    return {
      kinds: [kinds.ShortTextNote, kinds.Repost],
      limit: areAlgoRelays ? ALGO_RELAY_LIMIT : NORMAL_RELAY_LIMIT,
      ...filter
    }
  }, [JSON.stringify(filter), areAlgoRelays])

  useEffect(() => {
    if (isFetchingRelayInfo) return

    async function init() {
      setInitialized(false)
      setEvents([])
      setNewEvents([])
      setHasMore(true)

      const { closer, timelineKey } = await client.subscribeTimeline(
        relayUrls,
        noteFilter,
        {
          onEvents: (events, eosed) => {
            if (events.length > 0) {
              setEvents(events)
            } else {
              setHasMore(false)
            }
            if (areAlgoRelays) {
              setHasMore(false)
            }
            if (eosed) {
              setInitialized(true)
            }
          },
          onNew: (event) => {
            setNewEvents((oldEvents) =>
              [event, ...oldEvents].sort((a, b) => b.created_at - a.created_at)
            )
          }
        },
        {
          signer: async (evt) => {
            const signedEvt = await checkLogin(() => signEvent(evt))
            return signedEvt ?? null
          },
          needSort: !areAlgoRelays
        }
      )
      setTimelineKey(timelineKey)
      return closer
    }

    const promise = init()
    return () => {
      promise.then((closer) => closer())
    }
  }, [
    JSON.stringify(relayUrls),
    JSON.stringify(noteFilter),
    isFetchingRelayInfo,
    areAlgoRelays,
    refreshCount
  ])

  useEffect(() => {
    if (!initialized) return

    const options = {
      root: null,
      rootMargin: '10px',
      threshold: 1
    }

    const observerInstance = new IntersectionObserver((entries) => {
      if (entries[0].isIntersecting && hasMore) {
        loadMore()
      }
    }, options)

    const currentBottomRef = bottomRef.current

    if (currentBottomRef) {
      observerInstance.observe(currentBottomRef)
    }

    return () => {
      if (observerInstance && currentBottomRef) {
        observerInstance.unobserve(currentBottomRef)
      }
    }
  }, [initialized, hasMore, events, timelineKey])

  const loadMore = async () => {
    if (!timelineKey) return

    const newEvents = await client.loadMoreTimeline(
      timelineKey,
      events.length ? events[events.length - 1].created_at - 1 : dayjs().unix(),
      noteFilter.limit
    )
    if (newEvents.length === 0) {
      setHasMore(false)
      return
    }
    setEvents((oldEvents) => [...oldEvents, ...newEvents])
  }

  const showNewEvents = () => {
    setEvents((oldEvents) => [...newEvents, ...oldEvents])
    setNewEvents([])
  }

  return (
    <div className={cn('space-y-2 sm:space-y-4', className)}>
      <DisplayRepliesSwitch displayReplies={displayReplies} setDisplayReplies={setDisplayReplies} />
      <PullToRefresh
        onRefresh={async () =>
          new Promise((resolve) => {
            setRefreshCount((pre) => pre + 1)
            setTimeout(resolve, 1000)
          })
        }
        pullingContent=""
      >
        <>
          {newEvents.filter((event) => displayReplies || !isReplyNoteEvent(event)).length > 0 && (
            <div className="flex justify-center w-full max-sm:mt-2">
              <Button size="lg" onClick={showNewEvents}>
                {t('show new notes')}
              </Button>
            </div>
          )}
          <div className="flex flex-col sm:gap-4">
            {events
              .filter((event) => displayReplies || !isReplyNoteEvent(event))
              .map((event) => (
                <NoteCard key={event.id} className="w-full" event={event} />
              ))}
          </div>
        </>
      </PullToRefresh>
      <div className="text-center text-sm text-muted-foreground">
        {hasMore ? (
          <div ref={bottomRef}>{t('loading...')}</div>
        ) : events.length ? (
          t('no more notes')
        ) : (
          <div className="flex justify-center w-full max-sm:mt-2">
            <Button size="lg" onClick={() => setRefreshCount((pre) => pre + 1)}>
              {t('reload notes')}
            </Button>
          </div>
        )}
      </div>
    </div>
  )
}

function DisplayRepliesSwitch({
  displayReplies,
  setDisplayReplies
}: {
  displayReplies: boolean
  setDisplayReplies: (value: boolean) => void
}) {
  const { t } = useTranslation()
  const { isSmallScreen } = useScreenSize()

  if (isSmallScreen) {
    return (
      <div>
        <div className="flex">
          <div
            className={`w-1/2 text-center py-2 font-semibold hover:bg-muted cursor-pointer rounded-lg ${displayReplies ? 'text-muted-foreground' : ''}`}
            onClick={() => setDisplayReplies(false)}
          >
            {t('Notes')}
          </div>
          <div
            className={`w-1/2 text-center py-2 font-semibold hover:bg-muted cursor-pointer rounded-lg ${displayReplies ? '' : 'text-muted-foreground'}`}
            onClick={() => setDisplayReplies(true)}
          >
            {t('Notes & Replies')}
          </div>
        </div>
        <div
          className={`w-1/2 px-4 transition-transform duration-500 ${displayReplies ? 'translate-x-full' : ''}`}
        >
          <div className="w-full h-1 bg-primary rounded-full" />
        </div>
      </div>
    )
  }

  return (
    <div className="flex justify-end gap-2">
      <div>{t('Display replies')}</div>
      <Switch checked={displayReplies} onCheckedChange={setDisplayReplies} />
    </div>
  )
}