mobile-darmasaba/app/(application)/announcement/index.tsx

import GuideOverlay from "@/components/GuideOverlay";
import BorderBottomItem from "@/components/borderBottomItem";
import InputSearch from "@/components/inputSearch";
import SkeletonContent from "@/components/skeletonContent";
import Text from '@/components/Text';
import Styles from "@/constants/Styles";
import { apiGetAnnouncement } from "@/lib/api";
import { GUIDE_ANNOUNCEMENT } from "@/lib/guideSteps";
import { useGuide } from "@/lib/useGuide";
import { useAuthSession } from "@/providers/AuthProvider";
import { useTheme } from "@/providers/ThemeProvider";
import { MaterialIcons } from "@expo/vector-icons";
import { useInfiniteQuery } from "@tanstack/react-query";
import { router } from "expo-router";
import { useEffect, useMemo, useState } from "react";
import { RefreshControl, View, VirtualizedList } from "react-native";
import { useSelector } from "react-redux";

type Props = {
   id: string,
   title: string,
   desc: string,
   createdAt: string
}

export default function Announcement() {
   const { token, decryptToken } = useAuthSession()
   const { colors } = useTheme();
   const [search, setSearch] = useState('')
   const update = useSelector((state: any) => state.announcementUpdate)
   const { visible: guideVisible, dismiss: dismissGuide } = useGuide('announcement')
   const arrSkeleton = Array.from({ length: 5 }, (_, index) => index)

   // TanStack Query Infinite Query
   const {
      data,
      fetchNextPage,
      hasNextPage,
      isFetchingNextPage,
      isLoading,
      refetch,
      isRefetching
   } = useInfiniteQuery({
      queryKey: ['announcements', search],
      queryFn: async ({ pageParam = 1 }) => {
         const hasil = await decryptToken(String(token?.current))
         const response = await apiGetAnnouncement({
            user: hasil,
            search: search,
            page: pageParam
         })
         return response.data
      },
      initialPageParam: 1,
      getNextPageParam: (lastPage, allPages) => {
         return lastPage.length > 0 ? allPages.length + 1 : undefined
      },
   })

   // Trigger refetch when Redux state 'update' changes
   useEffect(() => {
      refetch()
   }, [update, refetch])

   // Flatten data from pages
   const flattenedData = useMemo(() => {
      return data?.pages.flat() || []
   }, [data])

   const loadMoreData = () => {
      if (hasNextPage && !isFetchingNextPage) {
         fetchNextPage()
      }
   };

   const getItem = (_data: unknown, index: number): Props => ({
      id: flattenedData[index].id,
      title: flattenedData[index].title,
      desc: flattenedData[index].desc,
      createdAt: flattenedData[index].createdAt,
   })

   return (
      <View style={[Styles.p15, Styles.flex1, { backgroundColor: colors.background }]}>
         <GuideOverlay visible={guideVisible} steps={GUIDE_ANNOUNCEMENT} onDismiss={dismissGuide} />
         <View>
            <InputSearch onChange={setSearch} />
         </View>
         <View style={[Styles.flex2, Styles.mt05]}>
            {
               isLoading && !flattenedData.length ?
                  arrSkeleton.map((item, index) => {
                     return (
                        <SkeletonContent key={index} />
                     )
                  })
                  :
                  flattenedData.length > 0
                     ?
                     <VirtualizedList
                        data={flattenedData}
                        getItemCount={() => flattenedData.length}
                        getItem={getItem}
                        renderItem={({ item, index }: { item: Props, index: number }) => {
                           return (
                              <BorderBottomItem
                                 key={index}
                                 onPress={() => { router.push(`/announcement/${item.id}`) }}
                                 borderType="bottom"
                                 bgColor="transparent"
                                 icon={
                                    <MaterialIcons name="campaign" size={25} color={colors.text} />
                                 }
                                 title={item.title}
                                 desc={item.desc.replace(/<[^>]*>?/gm, '').replace(/\r?\n|\r/g, ' ')}
                                 rightTopInfo={item.createdAt}
                              />
                           )
                        }}
                        keyExtractor={(item, index) => String(item.id || index)}
                        onEndReached={loadMoreData}
                        onEndReachedThreshold={0.5}
                        showsVerticalScrollIndicator={false}
                        refreshControl={
                           <RefreshControl
                              refreshing={isRefetching && !isFetchingNextPage}
                              onRefresh={refetch}
                              tintColor={colors.icon}
                           />
                        }
                     />
                     :
                     <Text style={[Styles.textDefault, Styles.textCenter, { color: colors.dimmed }]}>Tidak ada pengumuman</Text>
            }
         </View>
      </View>
   )
}