dify/web/app/components/workflow/header/online-users.tsx

'use client'
import type { OnlineUser } from '../collaboration/types'
import { ChevronDownIcon } from '@heroicons/react/20/solid'
import { useEffect, useState } from 'react'
import { useReactFlow } from 'reactflow'
import Avatar from '@/app/components/base/avatar'
import Divider from '@/app/components/base/divider'
import {
  PortalToFollowElem,
  PortalToFollowElemContent,
  PortalToFollowElemTrigger,
} from '@/app/components/base/portal-to-follow-elem'
import Tooltip from '@/app/components/base/tooltip'
import { useAppContext } from '@/context/app-context'
import { getAvatar } from '@/service/common'
import { cn } from '@/utils/classnames'
import { useCollaboration } from '../collaboration/hooks/use-collaboration'
import { getUserColor } from '../collaboration/utils/user-color'
import { useStore } from '../store'

const useAvatarUrls = (users: OnlineUser[]) => {
  const [avatarUrls, setAvatarUrls] = useState<Record<string, string>>({})

  useEffect(() => {
    const fetchAvatars = async () => {
      const newAvatarUrls: Record<string, string> = {}

      await Promise.all(
        users.map(async (user) => {
          if (user.avatar) {
            try {
              const response = await getAvatar({ avatar: user.avatar })
              newAvatarUrls[user.sid] = response.avatar_url
            }
            catch (error) {
              console.error('Failed to fetch avatar:', error)
              newAvatarUrls[user.sid] = user.avatar
            }
          }
        }),
      )

      setAvatarUrls(newAvatarUrls)
    }

    if (users.length > 0)
      fetchAvatars()
  }, [users])

  return avatarUrls
}

const OnlineUsers = () => {
  const appId = useStore(s => s.appId)
  const { onlineUsers, cursors, isEnabled: isCollaborationEnabled } = useCollaboration(appId as string)
  const { userProfile } = useAppContext()
  const reactFlow = useReactFlow()
  const [dropdownOpen, setDropdownOpen] = useState(false)
  const avatarUrls = useAvatarUrls(onlineUsers || [])

  const currentUserId = userProfile?.id

  const renderDisplayName = (
    user: OnlineUser,
    baseClassName: string,
    suffixClassName: string,
  ) => {
    const baseName = user.username || 'User'
    const isCurrentUser = user.user_id === currentUserId

    return (
      <span className={cn('inline-flex items-center gap-1', baseClassName)}>
        <span>{baseName}</span>
        {isCurrentUser && (
          <span className={suffixClassName}>
            (You)
          </span>
        )}
      </span>
    )
  }

  // Function to jump to user's cursor position
  const jumpToUserCursor = (userId: string) => {
    const cursor = cursors[userId]
    if (!cursor)
      return

    // Convert world coordinates to center the view on the cursor
    reactFlow.setCenter(cursor.x, cursor.y, { zoom: 1, duration: 800 })
  }

  if (!isCollaborationEnabled || !onlineUsers || onlineUsers.length === 0)
    return null

  // Display logic:
  // 1-3 users: show all avatars
  // 4+ users: show 2 avatars + count + arrow
  const shouldShowCount = onlineUsers.length >= 4
  const maxVisible = shouldShowCount ? 2 : 3
  const visibleUsers = onlineUsers.slice(0, maxVisible)
  const remainingCount = onlineUsers.length - maxVisible

  const getAvatarUrl = (user: OnlineUser) => {
    return avatarUrls[user.sid] || user.avatar
  }

  const hasCounter = remainingCount > 0

  return (
    <>
      <div
        className={cn(
          'flex h-8 items-center rounded-full border-[0.5px] border-components-panel-border',
          'bg-components-panel-bg py-1 shadow-xs shadow-shadow-shadow-3 backdrop-blur-[10px]',
          hasCounter ? 'min-w-[87px] gap-px pl-1 pr-1.5' : 'gap-1 px-1.5',
        )}
      >
        <div className="flex h-6 items-center">
          <div className="flex items-center">
            {visibleUsers.map((user, index) => {
              const isCurrentUser = user.user_id === currentUserId
              const userColor = isCurrentUser ? undefined : getUserColor(user.user_id)
              return (
                <Tooltip
                  key={`${user.sid}-${index}`}
                  popupContent={renderDisplayName(
                    user,
                    'system-xs-medium text-text-secondary',
                    'text-text-quaternary',
                  )}
                  position="bottom"
                  triggerMethod="hover"
                  needsDelay={false}
                  asChild
                  popupClassName="flex h-[28px] items-center justify-center gap-1 rounded-md border-[0.5px] border-components-panel-border bg-components-tooltip-bg px-3 py-[6px] shadow-lg shadow-shadow-shadow-5 backdrop-blur-[10px]"
                  noDecoration
                >
                  <div
                    className={cn(
                      'relative flex size-6 items-center justify-center',
                      index > 0 && '-ml-1.5',
                      !isCurrentUser && 'cursor-pointer transition-transform hover:scale-110',
                    )}
                    style={{ zIndex: visibleUsers.length - index }}
                    onClick={() => !isCurrentUser && jumpToUserCursor(user.user_id)}
                  >
                    <Avatar
                      name={user.username || 'User'}
                      avatar={getAvatarUrl(user)}
                      size={24}
                      className="ring-1 ring-components-panel-bg"
                      backgroundColor={userColor}
                    />
                  </div>
                </Tooltip>
              )
            })}
            {remainingCount > 0 && (
              <PortalToFollowElem
                open={dropdownOpen}
                onOpenChange={setDropdownOpen}
                placement="bottom-start"
                offset={{
                  mainAxis: 8,
                  crossAxis: -48,
                }}
              >
                <PortalToFollowElemTrigger
                  onClick={() => setDropdownOpen(prev => !prev)}
                  asChild
                >
                  <div className="flex items-center gap-1">
                    <div
                      className={cn(
                        'flex h-6 w-6 cursor-pointer select-none items-center justify-center rounded-full bg-components-icon-bg-midnight-solid text-[10px] font-semibold uppercase leading-[12px] text-white ring-1 ring-components-panel-bg',
                        visibleUsers.length > 0 && '-ml-1',
                      )}
                    >
                      +
                      {remainingCount}
                    </div>
                    <ChevronDownIcon className="h-3 w-3 cursor-pointer text-gray-500" />
                  </div>
                </PortalToFollowElemTrigger>
                <PortalToFollowElemContent
                  className="z-[9999]"
                >
                  <div
                    className={cn(
                      'mt-1.5',
                      'flex flex-col',
                      'max-h-[200px] w-[240px] overflow-y-auto',
                      'rounded-xl border-[0.5px] border-components-panel-border',
                      'bg-components-panel-bg-blur p-1',
                      'shadow-lg shadow-shadow-shadow-5',
                      'backdrop-blur-[10px]',
                    )}
                  >
                    {onlineUsers.map((user) => {
                      const isCurrentUser = user.user_id === currentUserId
                      const userColor = isCurrentUser ? undefined : getUserColor(user.user_id)
                      return (
                        <div
                          key={user.sid}
                          className={cn(
                            'flex items-center gap-2 rounded-lg px-3 py-1.5',
                            !isCurrentUser && 'cursor-pointer hover:bg-components-panel-on-panel-item-bg-hover',
                          )}
                          onClick={() => {
                            if (!isCurrentUser) {
                              jumpToUserCursor(user.user_id)
                              setDropdownOpen(false)
                            }
                          }}
                        >
                          <div className="relative">
                            <Avatar
                              name={user.username || 'User'}
                              avatar={getAvatarUrl(user)}
                              size={24}
                              backgroundColor={userColor}
                            />
                          </div>
                          {renderDisplayName(
                            user,
                            'system-xs-medium text-text-secondary',
                            'text-text-tertiary',
                          )}
                        </div>
                      )
                    })}
                  </div>
                </PortalToFollowElemContent>
              </PortalToFollowElem>
            )}
          </div>
        </div>
      </div>
      <Divider type="vertical" className="mx-auto h-3.5" />
    </>
  )
}

export default OnlineUsers