'use client'

import type { AppListQuery, AppListSortBy } from '@/contract/console/apps'
import { cn } from '@langgenius/dify-ui/cn'
import { keepPreviousData, useInfiniteQuery, useQuery, useSuspenseQuery } from '@tanstack/react-query'
import { useDebounce } from 'ahooks'
import { useLocalStorage } from 'foxact/use-local-storage'
import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
import { useTranslation } from 'react-i18next'
import { NEED_REFRESH_APP_LIST_KEY } from '@/config'
import { useAppContext } from '@/context/app-context'
import { useProviderContext } from '@/context/provider-context'
import { systemFeaturesQueryOptions } from '@/features/system-features/client'
import { CheckModal } from '@/hooks/use-pay'
import { usePathname, useRouter, useSearchParams } from '@/next/navigation'
import { consoleQuery } from '@/service/client'
import { AppModeEnum } from '@/types/app'
import AppCard from './app-card'
import { AppCardSkeleton } from './app-card-skeleton'
import { AppListCreationModals } from './app-list-creation-modals'
import { AppListHeaderFilters } from './app-list-header-filters'
import { AppListTagManagementModal } from './app-list-tag-management-modal'
import { APP_LIST_GRID_CLASS_NAME, APP_LIST_SEARCH_DEBOUNCE_MS } from './constants'
import Empty from './empty'
import FirstEmptyState from './first-empty-state'
import { useAppsQueryState } from './hooks/use-apps-query-state'
import { useDSLDragDrop } from './hooks/use-dsl-drag-drop'
import { useWorkflowOnlineUsers } from './hooks/use-workflow-online-users'
import { StarredAppList } from './starred-app-list'
import { StudioListHeader } from './studio-list-header'

const STARRED_APP_LIMIT = 100

type Props = Readonly<{
  controlRefreshList?: number
}>

function List({
  controlRefreshList = 0,
}: Props) {
  const { t } = useTranslation()
  const { data: systemFeatures } = useSuspenseQuery(systemFeaturesQueryOptions())
  const { isCurrentWorkspaceEditor, isCurrentWorkspaceDatasetOperator } = useAppContext()
  const { onPlanInfoChanged } = useProviderContext()
  const searchParams = useSearchParams()
  const pathname = usePathname()
  const { replace } = useRouter()

  // eslint-disable-next-line react/use-state -- custom URL query hook, not React.useState
  const {
    query: { category, keywords, creatorIDs },
    setCategory,
    setKeywords,
    setCreatorIDs,
  } = useAppsQueryState()
  const [tagIDs, setTagIDs] = useState<string[]>([])
  const [sortBy, setSortBy] = useState<AppListSortBy>('last_modified')
  const debouncedKeywords = useDebounce(keywords, { wait: APP_LIST_SEARCH_DEBOUNCE_MS })
  const containerRef = useRef<HTMLDivElement>(null)
  const [showTagManagementModal, setShowTagManagementModal] = useState(false)
  const [showNewAppTemplateDialog, setShowNewAppTemplateDialog] = useState(false)
  const [showNewAppModal, setShowNewAppModal] = useState(false)
  const [showCreateFromDSLModal, setShowCreateFromDSLModal] = useState(false)
  const [droppedDSLFile, setDroppedDSLFile] = useState<File | undefined>()
  const [needsRefreshAppList, setNeedsRefreshAppList] = useLocalStorage<string>(NEED_REFRESH_APP_LIST_KEY, '0', { raw: true })

  const handleDSLFileDropped = useCallback((file: File) => {
    setDroppedDSLFile(file)
    setShowCreateFromDSLModal(true)
  }, [])

  const { dragging } = useDSLDragDrop({
    onDSLFileDropped: handleDSLFileDropped,
    containerRef,
    enabled: isCurrentWorkspaceEditor,
  })

  useEffect(() => {
    if (!searchParams.has('tagIDs'))
      return

    const params = new URLSearchParams(searchParams.toString())
    params.delete('tagIDs')
    const query = params.toString()
    replace(query ? `${pathname}?${query}` : pathname, { scroll: false })
  }, [pathname, replace, searchParams])

  const appListQuery = useMemo<AppListQuery>(() => ({
    page: 1,
    limit: 30,
    name: debouncedKeywords,
    sort_by: sortBy,
    ...(tagIDs.length ? { tag_ids: tagIDs } : {}),
    ...(creatorIDs.length ? { creator_ids: creatorIDs } : {}),
    ...(category !== 'all' ? { mode: category } : {}),
  }), [category, creatorIDs, debouncedKeywords, sortBy, tagIDs])

  const {
    data,
    isLoading,
    isFetching,
    isFetchingNextPage,
    fetchNextPage,
    hasNextPage,
    error,
    refetch,
  } = useInfiniteQuery({
    ...consoleQuery.apps.list.infiniteOptions({
      input: pageParam => ({
        query: {
          ...appListQuery,
          page: Number(pageParam),
        },
      }),
      getNextPageParam: lastPage => lastPage.has_more ? lastPage.page + 1 : undefined,
      initialPageParam: 1,
      placeholderData: keepPreviousData,
    }),
    enabled: !isCurrentWorkspaceDatasetOperator,
    refetchInterval: systemFeatures.enable_collaboration_mode ? 10000 : false,
  })

  const starredAppListQuery = useMemo<AppListQuery>(() => ({
    ...appListQuery,
    page: 1,
    limit: STARRED_APP_LIMIT,
  }), [appListQuery])

  const {
    data: starredAppList,
    refetch: refetchStarredAppList,
  } = useQuery({
    ...consoleQuery.apps.starredList.queryOptions({
      input: {
        query: starredAppListQuery,
      },
    }),
    enabled: !isCurrentWorkspaceDatasetOperator,
  })

  const refreshAppLists = useCallback(() => {
    void refetch()
    void refetchStarredAppList()
  }, [refetch, refetchStarredAppList])

  useEffect(() => {
    if (controlRefreshList > 0)
      refetch()
  }, [controlRefreshList, refetch])

  const anchorRef = useRef<HTMLDivElement>(null)

  useEffect(() => {
    if (needsRefreshAppList === '1') {
      setNeedsRefreshAppList(null)
      refetch()
    }
  }, [needsRefreshAppList, refetch, setNeedsRefreshAppList])

  useEffect(() => {
    if (isCurrentWorkspaceDatasetOperator)
      return
    const hasMore = hasNextPage ?? true
    let observer: IntersectionObserver | undefined

    if (error) {
      if (observer)
        observer.disconnect()
      return
    }

    if (anchorRef.current && containerRef.current) {
      const containerHeight = containerRef.current.clientHeight
      const dynamicMargin = Math.max(100, Math.min(containerHeight * 0.2, 200))

      observer = new IntersectionObserver((entries) => {
        if (entries[0]!.isIntersecting && !isLoading && !isFetchingNextPage && !error && hasMore)
          fetchNextPage()
      }, {
        root: containerRef.current,
        rootMargin: `${dynamicMargin}px`,
        threshold: 0.1,
      })
      observer.observe(anchorRef.current)
    }
    return () => observer?.disconnect()
  }, [isLoading, isFetchingNextPage, fetchNextPage, error, hasNextPage, isCurrentWorkspaceDatasetOperator])

  const pages = useMemo(() => data?.pages ?? [], [data?.pages])
  const apps = useMemo(() => pages.flatMap(({ data: pageApps }) => pageApps), [pages])
  const starredApps = useMemo(() => starredAppList?.data ?? [], [starredAppList?.data])

  const workflowOnlineUserAppIds = useMemo(() => {
    const appIds = new Set<string>()
    apps.forEach((app) => {
      if (app.mode === AppModeEnum.WORKFLOW || app.mode === AppModeEnum.ADVANCED_CHAT)
        appIds.add(app.id)
    })
    return Array.from(appIds)
  }, [apps])

  const {
    onlineUsersMap: workflowOnlineUsersMap,
  } = useWorkflowOnlineUsers({
    appIds: workflowOnlineUserAppIds,
    enabled: systemFeatures.enable_collaboration_mode,
  })

  const hasResolvedFirstPage = pages.length > 0
  const hasAnyApp = (pages[0]?.total ?? 0) > 0
  const hasActiveFilters = category !== 'all' || tagIDs.length > 0 || keywords.trim().length > 0 || debouncedKeywords.trim().length > 0 || creatorIDs.length > 0
  const showSkeleton = isLoading || (isFetching && pages.length === 0)
  const showFirstEmptyState = !showSkeleton && !hasAnyApp && isCurrentWorkspaceEditor && hasResolvedFirstPage && !hasActiveFilters

  return (
    <>
      <div ref={containerRef} className="relative flex h-0 shrink-0 grow flex-col overflow-y-auto bg-background-body">
        {dragging && (
          <div className="absolute inset-0 z-50 m-0.5 rounded-2xl border-2 border-dashed border-components-dropzone-border-accent bg-[rgba(21,90,239,0.14)] p-2">
          </div>
        )}

        <StudioListHeader
          title={(
            <div className="flex items-center">
              <h1 className="text-[18px]/[21.6px] font-semibold text-text-primary">{t('menus.apps', { ns: 'common' })}</h1>
            </div>
          )}
        >
          <AppListHeaderFilters
            category={category}
            tagIDs={tagIDs}
            keywords={keywords}
            creatorIDs={creatorIDs}
            sortBy={sortBy}
            onCategoryChange={setCategory}
            onTagIDsChange={setTagIDs}
            onKeywordsChange={setKeywords}
            onCreatorIDsChange={setCreatorIDs}
            onSortByChange={setSortBy}
            onCreateBlank={() => setShowNewAppModal(true)}
            onCreateTemplate={() => setShowNewAppTemplateDialog(true)}
            onImportDSL={() => setShowCreateFromDSLModal(true)}
            onOpenTagManagement={() => setShowTagManagementModal(true)}
            showCreateButton={isCurrentWorkspaceEditor}
          />
        </StudioListHeader>
        {showFirstEmptyState
          ? (
              <FirstEmptyState
                onCreateBlank={() => setShowNewAppModal(true)}
                onCreateTemplate={() => setShowNewAppTemplateDialog(true)}
                onImportDSL={() => setShowCreateFromDSLModal(true)}
              />
            )
          : (
              <>
                {starredApps.length > 0 && (
                  <StarredAppList
                    apps={starredApps}
                    isCurrentWorkspaceEditor={isCurrentWorkspaceEditor}
                    onRefresh={refreshAppLists}
                  />
                )}
                <div className={cn(
                  `relative grow content-start ${APP_LIST_GRID_CLASS_NAME}`,
                  !hasAnyApp && 'overflow-hidden',
                )}
                >
                  {showSkeleton
                    ? <AppCardSkeleton count={6} />
                    : hasAnyApp
                      ? apps.map(app => (
                          <AppCard
                            key={app.id}
                            app={app}
                            onlineUsers={workflowOnlineUsersMap[app.id] ?? []}
                            onRefresh={refreshAppLists}
                            onOpenTagManagement={() => setShowTagManagementModal(true)}
                          />
                        ))
                      : <Empty />}
                  {isFetchingNextPage && (
                    <AppCardSkeleton count={3} />
                  )}
                </div>
              </>
            )}

        {isCurrentWorkspaceEditor && !showFirstEmptyState && (
          <div
            className={`flex items-center justify-center gap-2 py-4 ${dragging ? 'text-text-accent' : 'text-text-quaternary'}`}
            role="region"
            aria-label={t('newApp.dropDSLToCreateApp', { ns: 'app' })}
          >
            <span className="i-ri-drag-drop-line size-4" />
            <span className="system-xs-regular">{t('newApp.dropDSLToCreateApp', { ns: 'app' })}</span>
          </div>
        )}
        <CheckModal />
        <div ref={anchorRef} className="h-0"> </div>
        <AppListTagManagementModal
          show={showTagManagementModal}
          onClose={() => setShowTagManagementModal(false)}
          onTagsChange={refreshAppLists}
        />
      </div>

      <AppListCreationModals
        category={category}
        droppedDSLFile={droppedDSLFile}
        showCreateFromDSLModal={showCreateFromDSLModal}
        showNewAppModal={showNewAppModal}
        showNewAppTemplateDialog={showNewAppTemplateDialog}
        onPlanInfoChanged={onPlanInfoChanged}
        onRefetch={refreshAppLists}
        onSetDroppedDSLFile={setDroppedDSLFile}
        onSetShowCreateFromDSLModal={setShowCreateFromDSLModal}
        onSetShowNewAppModal={setShowNewAppModal}
        onSetShowNewAppTemplateDialog={setShowNewAppTemplateDialog}
      />
    </>
  )
}

export default List