import { useState, useCallback } from 'react';
import PropTypes from 'prop-types';
import Button from '@mui/material/Button';
import List from '@mui/material/List';
import Typography from '@mui/material/Typography';
import BackIcon from '@mui/icons-material/ArrowBackSharp';
import { announce } from '@react-aria/live-announcer';
import { useTranslation } from 'react-i18next';
import SearchHit from '../containers/SearchHit';
import { ScrollTo } from './ScrollTo';

/**
 * Return SearchHits for every hit in the response
 * Return SearchHits for every annotation in the response if there are no hits
 */
function SearchHitsAndAnnotations({
  companionWindowId,
  containerRef,
  searchAnnotations,
  searchHits,
  windowId,
  focused,
  toggleFocus,
}) {
  if (searchHits.length === 0 && searchAnnotations.length > 0) {
    return searchAnnotations.map((anno, index) => (
      <SearchHit
        announcer={announce}
        annotationId={anno.id}
        companionWindowId={companionWindowId}
        containerRef={containerRef}
        key={anno.id}
        focused={focused}
        index={index}
        total={searchAnnotations.length}
        windowId={windowId}
        showDetails={toggleFocus}
      />
    ));
  }

  return searchHits.map((hit, index) => (
    <SearchHit
      announcer={announce}
      containerRef={containerRef}
      companionWindowId={companionWindowId}
      key={hit.annotations[0]}
      focused={focused}
      hit={hit}
      index={index}
      total={searchHits.length}
      windowId={windowId}
      showDetails={toggleFocus}
    />
  ));
}

/** */
export function SearchResults({
  companionWindowId,
  containerRef = undefined,
  isFetching = false,
  fetchSearch,
  nextSearch = undefined,
  query = undefined,
  searchAnnotations = [],
  searchHits = [],
  searchNumTotal = undefined,
  windowId,
}) {
  const { t } = useTranslation();
  const [focused, setFocused] = useState(false);

  /** */
  const toggleFocus = useCallback(() => {
    setFocused(!focused);
  }, [setFocused, focused]);

  const noResultsState = (
    query && !isFetching && searchHits.length === 0 && searchAnnotations.length === 0
  );

  return (
    <>
      { focused && (
        <ScrollTo containerRef={containerRef} offsetTop={96} scrollTo>
          <Button onClick={toggleFocus} sx={{ textTransform: 'none' }} size="small">
            <BackIcon />
            {t('backToResults')}
          </Button>
        </ScrollTo>
      )}
      {noResultsState && (
        <Typography sx={{
          padding: 2,
          typography: 'h6',
        }}
        >
          {t('searchNoResults')}
        </Typography>
      )}
      <List disablePadding>
        <SearchHitsAndAnnotations
          companionWindowId={companionWindowId}
          containerRef={containerRef}
          searchAnnotations={searchAnnotations}
          searchHits={searchHits}
          windowId={windowId}
          focused={focused}
          toggleFocus={toggleFocus}
        />
      </List>
      { nextSearch && (
        <Button
          sx={{ width: '100%' }}
          color="secondary"
          onClick={() => fetchSearch(windowId, companionWindowId, nextSearch, query)}
        >
          {t('moreResults')}
          <br />
          {`(${t('searchResultsRemaining', { numLeft: searchNumTotal - searchHits.length })})`}
        </Button>
      )}
    </>
  );
}

SearchResults.propTypes = {
  companionWindowId: PropTypes.string.isRequired,
  containerRef: PropTypes.oneOfType([
    PropTypes.func,
    PropTypes.shape({ current: PropTypes.instanceOf(Element) }),
  ]),
  fetchSearch: PropTypes.func.isRequired,
  isFetching: PropTypes.bool,
  nextSearch: PropTypes.string,
  query: PropTypes.string,
  searchAnnotations: PropTypes.arrayOf(PropTypes.object), // eslint-disable-line react/forbid-prop-types
  searchHits: PropTypes.arrayOf(PropTypes.object), // eslint-disable-line react/forbid-prop-types
  searchNumTotal: PropTypes.number,
  windowId: PropTypes.string.isRequired, // eslint-disable-line react/no-unused-prop-types
};