dify/web/app/components/base/chat/chat/citation/index.tsx

import { useEffect, useMemo, useRef, useState } from 'react'
import type { FC } from 'react'
import { useTranslation } from 'react-i18next'
import { RiArrowDownSLine } from '@remixicon/react'
import type { CitationItem } from '../type'
import Popup from './popup'

export type Resources = {
  documentId: string
  documentName: string
  dataSourceType: string
  sources: CitationItem[]
}

type CitationProps = {
  data: CitationItem[]
  showHitInfo?: boolean
  containerClassName?: string
}
const Citation: FC<CitationProps> = ({
  data,
  showHitInfo,
  containerClassName = 'chat-answer-container',
}) => {
  const { t } = useTranslation()
  const elesRef = useRef<HTMLDivElement[]>([])
  const [limitNumberInOneLine, setlimitNumberInOneLine] = useState(0)
  const [showMore, setShowMore] = useState(false)
  const resources = useMemo(() => data.reduce((prev: Resources[], next) => {
    const documentId = next.document_id
    const documentName = next.document_name
    const dataSourceType = next.data_source_type
    const documentIndex = prev.findIndex(i => i.documentId === documentId)

    if (documentIndex > -1) {
      prev[documentIndex].sources.push(next)
    }
    else {
      prev.push({
        documentId,
        documentName,
        dataSourceType,
        sources: [next],
      })
    }

    return prev
  }, []), [data])

  const handleAdjustResourcesLayout = () => {
    const containerWidth = document.querySelector(`.${containerClassName}`)!.clientWidth - 40
    let totalWidth = 0
    for (let i = 0; i < resources.length; i++) {
      totalWidth += elesRef.current[i].clientWidth

      if (totalWidth + i * 4 > containerWidth!) {
        totalWidth -= elesRef.current[i].clientWidth

        if (totalWidth + 34 > containerWidth!)
          setlimitNumberInOneLine(i - 1)
        else
          setlimitNumberInOneLine(i)

        break
      }
      else {
        setlimitNumberInOneLine(i + 1)
      }
    }
  }

  useEffect(() => {
    handleAdjustResourcesLayout()
  }, [])

  const resourcesLength = resources.length

  return (
    <div className='mt-3 -mb-1'>
      <div className='flex items-center mb-2 text-xs font-medium text-gray-500'>
        {t('common.chat.citation.title')}
        <div className='grow ml-2 h-[1px] bg-black/5' />
      </div>
      <div className='relative flex flex-wrap'>
        {
          resources.map((res, index) => (
            <div
              key={index}
              className='absolute top-0 left-0 w-auto mr-1 mb-1 pl-7 pr-2 max-w-[240px] h-7 text-xs whitespace-nowrap opacity-0 -z-10'
              ref={ele => (elesRef.current[index] = ele!)}
            >
              {res.documentName}
            </div>
          ))
        }
        {
          resources.slice(0, showMore ? resourcesLength : limitNumberInOneLine).map((res, index) => (
            <div key={index} className='mr-1 mb-1 cursor-pointer'>
              <Popup
                data={res}
                showHitInfo={showHitInfo}
              />
            </div>
          ))
        }
        {
          limitNumberInOneLine < resourcesLength && (
            <div
              className='flex items-center px-2 h-7 bg-white rounded-lg text-xs font-medium text-gray-500 cursor-pointer'
              onClick={() => setShowMore(v => !v)}
            >
              {
                !showMore
                  ? `+ ${resourcesLength - limitNumberInOneLine}`
                  : <RiArrowDownSLine className='w-4 h-4 text-gray-600 rotate-180' />
              }
            </div>
          )
        }
      </div>
    </div>
  )
}

export default Citation