import { ChangeEvent, useEffect, useState } from 'react';
import { useTranslation } from 'react-i18next';
import { PATHS } from '@/shared/constants/paths';
import { useNavigate } from '@/shared/lib/hooks/use-navigate';
import { useNoticeListMutation } from '@/entities/support/api/use-notice-list-mutation';
import { DEFAULT_PAGE_PARAM } from '@/entities/common/model/constant';
import { InformCl, NoticeItem, NoticeListParams, NoticeListResponse, SearchCl } from '@/entities/support/model/types';
import { SupportNoticeItem } from '@/entities/support/ui/notice-item';
import { DefaultRequestPagination, HeaderType } from '@/entities/common/model/types';
import {
	useSetHeaderTitle,
	useSetHeaderType,
	useSetFooterMode,
  useSetOnBack
} from '@/widgets/sub-layout/use-sub-layout';
import useIntersectionObserver from '@/widgets/intersection-observer';

export const NoticeListPage = () => {
  const { navigate } = useNavigate();
  const { t } = useTranslation();

  const [onActionIntersect, setOnActionIntersect] = useState<boolean>(false);
  const [pageParam, setPageParam] = useState<DefaultRequestPagination>(DEFAULT_PAGE_PARAM);
  const [informCl, setInformCl] = useState<InformCl | string>('');
  const [searchKeyword, setSearchKeyword] = useState<string>('');
  const [resultList, setResultList] = useState<Array<NoticeItem>>([]);

  useSetHeaderTitle(t('support.notice.title'));
  useSetHeaderType(HeaderType.LeftArrow);
  useSetFooterMode(false);
  useSetOnBack(() => {
    navigate(PATHS.home);
  });

  const { mutateAsync: noticeList } = useNoticeListMutation();

  const onIntersect: IntersectionObserverCallback = (entries: Array<IntersectionObserverEntry>) => {
    entries.forEach((entry: IntersectionObserverEntry) => {
      if(entry.isIntersecting){
        if(onActionIntersect && !!pageParam.cursor){
          setOnActionIntersect(false);
          callList('page');
        } 
      }
    });
  };

  const { setTarget } = useIntersectionObserver({ 
    threshold: 1, 
    onIntersect 
  });

  const callList = (type?: string) => {
    setOnActionIntersect(false);
    let listParams: NoticeListParams = {
      informCl: informCl,
      searchCl: (!!searchKeyword)? SearchCl.HEAD: null,
      searchKeyword: searchKeyword,
      page: pageParam
    };
    if(type !== 'page' && listParams.page){
      listParams.page.cursor = null;
    }

    noticeList(listParams).then((rs: NoticeListResponse) => {
      if(type === 'page'){
        setResultList([
          ...resultList,
          ...rs.content
        ]);
      }
      else{
        setResultList(rs.content);
      }
      if(rs.hasNext 
        && rs.nextCursor !== pageParam.cursor
        && rs.content.length === DEFAULT_PAGE_PARAM.size
      ){
        setPageParam({
          ...pageParam,
          ...{ cursor: rs.nextCursor }
        });
      }
      else{
        setPageParam({
          ...pageParam,
          ...{ cursor: null }
        });
      }
      setOnActionIntersect(
        !!rs.hasNext 
        && rs.nextCursor !== pageParam.cursor
        && rs.content.length === DEFAULT_PAGE_PARAM.size
      );
    });
  };

  const onClickToAction = () => {
    // Remove focus from active element
    if (document.activeElement instanceof HTMLElement) {
      document.activeElement.blur();
    }
    callList();
  };

  const getNoticeList = () => {
    let rs = [];
    for(let i=0;i<resultList.length;i++){
      rs.push(
        <SupportNoticeItem
          key={ `key-support-notice-item-${i}` }
          seq={ resultList[i]?.seq }
          title={ resultList[i]?.title }
          informCl={ resultList[i]?.informCl }
          regDt={ resultList[i]?.regDt }
        ></SupportNoticeItem>
      )
    }
    return rs;
  };

  useEffect(() => {
    callList();
  }, [informCl]);

  return (
    <>
      <main>
        <div className="tab-content">
          <div className="tab-pane sub active">
            <div className="notice114">
              <div className="notice-controls">
                <div className="notice-search">
                  <span 
                    className="ic16 search" 
                    aria-hidden="true"
                    onClick={ () => onClickToAction() }
                  ></span>
                  <input
                    type="text"
                    placeholder={ t('support.notice.searchPlaceholder') }
                    value={ searchKeyword }
                    onChange={ (e: ChangeEvent<HTMLInputElement>) => setSearchKeyword(e.target.value) }
                    onKeyDown={ (e: React.KeyboardEvent<HTMLInputElement>) => {
                      if (e.key === 'Enter' && !e.nativeEvent.isComposing) {
                        onClickToAction();
                      }
                    }}
                  />
                </div>
                <div className="notice-filter">
                  <select
                    className="flex-1"
                    value={ informCl }
                    onChange={ (e: ChangeEvent<HTMLSelectElement>) => setInformCl(e.target.value) }
                  >
                    <option value="">{ t('support.notice.categories.all') }</option>
                    <option value="INTEREST_FREE_INSTALLMENT">{ t('support.notice.categories.INTEREST_FREE_INSTALLMENT') }</option>
                    <option value="NEWS">{ t('support.notice.categories.NEWS') }</option>
                    <option value="SERVICE_DISRUPTION_NOTICE">{ t('support.notice.categories.SERVICE_DISRUPTION_NOTICE') }</option>
                    <option value="MAINTENANCE_NOTICE">{ t('support.notice.categories.MAINTENANCE_NOTICE') }</option>
                    <option value="EVENT">{ t('support.notice.categories.EVENT') }</option>
                    <option value="SERVICE_CHANGE_OR_ADDITION">{ t('support.notice.categories.SERVICE_CHANGE_OR_ADDITION') }</option>
                    <option value="IMPORTANT_NOTICE">{ t('support.notice.categories.IMPORTANT_NOTICE') }</option>
                    <option value="ADDITIONAL_SERVICE">{ t('support.notice.categories.ADDITIONAL_SERVICE') }</option>
                  </select>
                </div>
              </div>
              <div className="notice-list-114">
                { getNoticeList() } 
              </div>
              <div ref={ setTarget }></div>
            </div>
          </div>
        </div>
      </main>
    </>
  );
};