btrc-hub/frontend/src/components/TopNav.tsx

import { useQuery } from '@tanstack/react-query'
import { AnimatePresence, motion } from 'framer-motion'
import { Fragment, useEffect, useLayoutEffect, useRef, useState } from 'react'
import { useLocation } from 'react-router-dom'

import Separator from '@/components/MenuSeparator'
import PrefetchLink from '@/components/PrefetchLink'
import TopNavUser from '@/components/TopNavUser'
import { WikiIdBus } from '@/lib/eventBus/WikiIdBus'
import { tagsKeys, wikiKeys } from '@/lib/queryKeys'
import { fetchTag, fetchTagByName } from '@/lib/tags'
import { cn } from '@/lib/utils'
import { fetchWikiPage } from '@/lib/wiki'

import type { FC, MouseEvent } from 'react'

import type { Menu, MenuVisibleItem, Tag, User } from '@/types'

type Props = { user: User | null }


export const menuOutline = ({ tag, wikiId, user, pathName }: { 
    tag?: Tag | null
    wikiId: number | null
    user: User | null,
    pathName: string }): Menu => {
  const postCount = tag?.postCount ?? 0

  const wikiPageFlg = Boolean (/^\/wiki\/(?!new|changes)[^\/]+/.test (pathName) && wikiId)
  const wikiTitle = pathName.split ('/')[2] ?? ''

  const tagFlg = /^\/tags\/\d+/.test (pathName)

  return [
      { name: '広場', to: '/posts', subMenu: [
	  { name: '一覧', to: '/posts' },
	  { name: '検索', to: '/posts/search' },
	  { name: '追加', to: '/posts/new' },
	  { name: '履歴', to: '/posts/changes' },
	  { name: 'ヘルプ', to: '/wiki/ヘルプ:広場' }] },
      { name: 'タグ', to: '/tags', subMenu: [
	  { name: 'マスタ', to: '/tags' },
	  { name: 'ニコニコ連携', to: '/tags/nico' },
	  { name: '履歴', to: '/tags/changes' },
	  { name: 'ヘルプ', to: '/wiki/ヘルプ:タグ' },
	  { component: <Separator/>, visible: tagFlg },
	  { name: `広場 (${ postCount || 0 })`,
	    to: `/posts?tags=${ encodeURIComponent (tag?.name ?? '') }`,
	    visible: tagFlg },
	  { name: '履歴', to: `/tags/changes?id=${ tag?.id }`,
	    visible: tagFlg && tag?.category !== 'nico' }] },
      { name: '素材', to: '/materials', visible: false, subMenu: [
	  { name: '一覧', to: '/materials' },
	  { name: '検索', to: '/materials/search', visible: false }, 
	  { name: '追加', to: '/materials/new' },
	  { name: '履歴', to: '/materials/changes', visible: false },
	  { name: 'ヘルプ', to: '/wiki/ヘルプ:素材集' }] },
      { name: '上映会', to: '/theatres/1', base: '/theatres', subMenu: [
	  { name: <>第&thinsp;1&thinsp;会場</>, to: '/theatres/1' },
	  { name: 'CyTube', to: '//cytube.mm428.net/r/deernijika' },
	  { name: <>ニジカ放送局第&thinsp;1&thinsp;チャンネル</>,
	    to: '//www.youtube.com/watch?v=DCU3hL4Uu6A' },
	  { name: 'ヘルプ', to: '/wiki/ヘルプ:上映会' }] },
      { name: 'Wiki', to: '/wiki/ヘルプ:ホーム', base: '/wiki', subMenu: [
	  { name: '検索', to: '/wiki' },
	  { name: '新規', to: '/wiki/new' },
	  { name: '全体履歴', to: '/wiki/changes' },
	  { name: 'ヘルプ', to: '/wiki/ヘルプ:Wiki' },
	  { component: <Separator/>, visible: wikiPageFlg },
	  { name: `広場 (${ postCount || 0 })`, to: `/posts?tags=${ wikiTitle }`,
	    visible: wikiPageFlg },
	  { name: '履歴', to: `/wiki/changes?id=${ wikiId }`, visible: wikiPageFlg },
	  { name: '編輯', to: `/wiki/${ wikiId || wikiTitle }/edit`, visible: wikiPageFlg }] },
      { name: 'ユーザ', to: '/users/settings', visible: false, subMenu: [
	  { name: '一覧', to: '/users', visible: false },
	  { name: 'お前', to: `/users/${ user?.id }`, visible: false },
	  { name: '設定', to: '/users/settings', visible: Boolean (user) }] },
      { name: '法規', visible: false, subMenu: [
	  { name: '利用規約', to: '/tos' }] }]
}


export default (({ user }: Props) => {
  const location = useLocation ()

  const dirRef = useRef<(-1) | 1> (1)
  const itemsRef = useRef<(HTMLAnchorElement | null)[]> ([])
  const navRef = useRef<HTMLDivElement | null> (null)

  const measure = (idx: number) => {
    const nav = navRef.current
    const el = itemsRef.current[idx < 0 ? visibleMenu.length : idx]

    if (!(nav) || !(el))
      {
	setHL ({ left: 0, width: 0, visible: true })
	return
      }

    const navRect = nav.getBoundingClientRect ()
    const elRect = el.getBoundingClientRect ()

    setHL ({ left:    elRect.left - navRect.left,
	     width:   elRect.width,
	     visible: true })
  }

  const [hl, setHL] = useState<{ left: number; width: number; visible: boolean }> ({
      left:     0,
      width:    0,
      visible:  false })
  const [menuOpen, setMenuOpen] = useState (false)
  const [moreVsbl, setMoreVsbl] = useState (false)
  const [openItemIdx, setOpenItemIdx] = useState (-1)
  const [wikiId, setWikiId] = useState<number | null> (WikiIdBus.get ())

  const wikiIdStr = String (wikiId ?? '')

  const { data: wikiPage } = useQuery ({
      enabled: Boolean (wikiIdStr),
      queryKey: wikiKeys.show (wikiIdStr, { }),
      queryFn: () => fetchWikiPage (wikiIdStr, { }) })

  const tagFlg = /^\/tags\/\d+/.test (location.pathname)
  const effectiveTitle = (tagFlg ? location.pathname.split ('/')[2] : wikiPage?.title) ?? ''

  const { data: tag } = useQuery ({
      enabled: Boolean (effectiveTitle),
      queryKey: tagsKeys.show (effectiveTitle),
      queryFn: () => (tagFlg ? fetchTag : fetchTagByName) (effectiveTitle) })


  const menu = menuOutline ({ tag, wikiId, user, pathName: location.pathname })
  const visibleMenu = menu.filter ((item): item is MenuVisibleItem => item.visible ?? true)
  const activeIdx =
      visibleMenu.findIndex (item => location.pathname.startsWith (item.base || item.to))

  const prevActiveIdxRef = useRef<number> (activeIdx)

  if (activeIdx !== prevActiveIdxRef.current)
    {
      dirRef.current = activeIdx > prevActiveIdxRef.current ? 1 : -1
      prevActiveIdxRef.current = activeIdx
    }

  const dir = dirRef.current

  useLayoutEffect (() => {
    const raf = requestAnimationFrame (() => measure (moreVsbl ? -1 : activeIdx))
    const onResize = () => requestAnimationFrame (() => measure (moreVsbl ? -1 : activeIdx))

    addEventListener ('resize', onResize)
    return () => {
      cancelAnimationFrame (raf)
      removeEventListener ('resize', onResize)
    }
  })

  useEffect (() => {
    const unsubscribe = WikiIdBus.subscribe (setWikiId)
    return () => unsubscribe ()
  }, [activeIdx])

  useEffect (() => {
    setMenuOpen (false)
    setOpenItemIdx (activeIdx)
  }, [location])

  return (
      <>
	<nav className="px-3 flex justify-between items-center w-full
			bg-yellow-200 dark:bg-red-975 md:bg-yellow-50">
	  <div className="flex items-center gap-2 h-12">
	    <PrefetchLink
		to="/posts"
		className="mx-4 text-xl font-bold text-pink-600 hover:text-pink-400
			   dark:text-pink-300 dark:hover:text-pink-100"
		onClick={() => {
		  scroll (0, 0)
		}}>
	      ぼざクリ タグ広場
	    </PrefetchLink>

	    <div ref={navRef} className="relative hidden md:flex h-12 items-center">
	      <div aria-hidden
		   className={cn ('absolute inset-y-0 h-12',
				  'bg-yellow-200 dark:bg-red-950',
				  'transition-[transform,width] duration-200 ease-out')}
		   style={{ width:      hl.width,
			    transform:  `translateX(${ hl.left }px)`,
			    opacity:    hl.visible ? 1 : 0 }}/>

	      {visibleMenu.map ((item, i) => (
		  <motion.div
		      key={item.to}
		      layoutId={`menu-${ item.name }`}
		      animate={{ opacity: moreVsbl ? 0 : 1 }}
		      transition={{ opacity: { duration: .12 },
				    layout: { duration: .2, ease: 'easeOut' } }}
		      style={{ pointerEvents: moreVsbl ? 'none' : 'auto' }}
		      onMouseEnter={() => setMoreVsbl (false)}>
		    <PrefetchLink
			to={item.to}
			ref={(el: (HTMLAnchorElement | null)) => {
			  itemsRef.current[i] = el
			}}
			className={cn ('relative z-10 flex h-full items-center px-5',
				       (i === openItemIdx) && 'font-bold')}>
		      {item.name}
		    </PrefetchLink>
		  </motion.div>))}
	      <PrefetchLink
		  to="/more"
		  ref={(el: (HTMLAnchorElement | null)) => {
		    itemsRef.current[visibleMenu.length] = el
		  }}
		  onClick={() => setMoreVsbl (false)}
		  onMouseEnter={() => {
		    setMoreVsbl (true)
		    measure (-1)
		  }}
		  className={cn ('relative z-10 flex h-full items-center px-5',
				 (openItemIdx < 0 || moreVsbl) && 'font-bold')}>
		その他 &raquo;
	      </PrefetchLink>
	    </div>
	  </div>

	  <TopNavUser user={user}/>

	  <a href="#"
	     className="md:hidden ml-auto pr-4
			text-pink-600 hover:text-pink-400
			dark:text-pink-300 dark:hover:text-pink-100"
	     onClick={ev => {
	       ev.preventDefault ()
	       setMenuOpen (!(menuOpen))
	     }}>
	    {menuOpen ? '×' : 'Menu'}
	  </a>
	</nav>

	<AnimatePresence initial={false}>
	  <motion.div
	      key="submenu-shell"
	      layout
	      className="relative hidden md:block overflow-hidden
			 bg-yellow-200 dark:bg-red-950"
	      style={{ height: moreVsbl ? 40 * menu.length : (activeIdx < 0 ? 0 : 40) }}
	      onMouseLeave={() => {
		if (moreVsbl)
		  setMoreVsbl (false)
	      }}
	      transition={{ layout: { duration: .2, ease: 'easeOut' } }}
	      onAnimationComplete={() => {
		measure (moreVsbl ? -1 : activeIdx)
	      }}>
	  {moreVsbl
	   ? (
	      menu.map ((item, i) => (
		  <div key={i} className="relative h-[40px]">
		    <div className="absolute inset-0 flex items-center px-3">
		      <motion.div
			  transition={{ duration: .2, ease: 'easeOut' }}
			  {...((item.visible ?? true)
			       ? { layoutId: `menu-${ item.name }` }
			       : { initial: { x: 40, y: -40, opacity: 0 },
				   animate: { x: 0, y: 0, opacity: 1 },
				   exit: { x: 40, y: -40, opacity: 0 } })}
			  className="z-10 h-full flex items-center px-3 font-bold w-24">
			<h2>{item.name}</h2>
		      </motion.div>
		      {item.subMenu
		       .filter (subItem => subItem.visible ?? true)
		       .map ((subItem, j) => (
			  'component' in subItem
			  ? (
			      <motion.div
				  key={`c-${ i }-${ j }`}
				  transition={{ duration: .2, ease: 'easeOut' }}
				  {...((visibleMenu[activeIdx]?.name
					=== item.name)
				       ? { layoutId: `submenu-${ item.name }-${ j }` }
				       : { initial: { y: -40, opacity: 0 },
					   animate: { y: 0, opacity: 1 },
					   exit: { y: -40, opacity: 0 } })}>
				{subItem.component}
			      </motion.div>)
			  : (
			      <motion.div
				  key={`l-${ i }-${ j }`}
				  transition={{ duration: .2, ease: 'easeOut' }}
				  {...((visibleMenu[activeIdx]?.name
					=== item.name)
				       ? { layoutId: `submenu-${ item.name }-${ j }` }
				       : { initial: { y: -40, opacity: 0 },
					   animate: { y: 0, opacity: 1 },
					   exit: { y: -40, opacity: 0 } })}>
				<PrefetchLink
				    to={subItem.to}
				    target={subItem.to.slice (0, 2) === '//' ? '_blank' : undefined}
				    onClick={() => setMoreVsbl (false)}
				    className="h-full flex items-center px-3">
				  {subItem.name}
				</PrefetchLink>
			      </motion.div>)))}
		    </div>
		  </div>)))
	   : ((visibleMenu[activeIdx]?.subMenu ?? []).length > 0
	      && (
		  <div className="relative h-[40px]">
		    <AnimatePresence initial={false} custom={dir}>
		      <motion.div
			  key={activeIdx}
			  custom={dir}
			  variants={{ enter: (d: -1 | 1) => ({ y: d * 24, opacity: 0 }),
				      centre: { y: 0, opacity: 1 },
				      exit: (d: -1 | 1) => ({ y: (-d) * 24, opacity: 0 }) }}
			  className="absolute inset-0 flex items-center px-3"
			  initial="enter"
			  animate="centre"
			  exit="exit"
			  transition={{ duration: .2, ease: 'easeOut' }}>
			{(visibleMenu[activeIdx]?.subMenu ?? [])
			 .filter (item => item.visible ?? true)
			 .map ((item, i) => (
			    'component' in item
			    ? (
				<motion.div
				    key={`c-${ i }`}
				    transition={{ layout: { duration: .2, ease: 'easeOut' } }}
				    layoutId={`submenu-${ visibleMenu[activeIdx].name }-${ i }`}>
				  {item.component}
				</motion.div>)
			    : (
				<motion.div
				    key={`l-${ i }`}
				    transition={{ layout: { duration: .2, ease: 'easeOut' } }}
				    layoutId={`submenu-${ visibleMenu[activeIdx].name }-${ i }`}>
				  <PrefetchLink
				      to={item.to}
				      target={item.to.slice (0, 2) === '//' ? '_blank' : undefined}
				      className="h-full flex items-center px-3">
				    {item.name}
				  </PrefetchLink>
				</motion.div>)))}
		      </motion.div>
		    </AnimatePresence>
		  </div>))}
	  </motion.div>
	</AnimatePresence>

	<AnimatePresence initial={false}>
	  {menuOpen && (
	      <motion.div
		  key="spmenu"
		  className={cn ('flex flex-col md:hidden',
				 'bg-yellow-200 dark:bg-red-975 items-start')}
		  variants={{ closed: { clipPath: 'inset(0 0 100% 0)',
					height:   0 },
			      open:   { clipPath: 'inset(0 0 0% 0)',
					height:   'auto' } }}
		  initial="closed"
		  animate="open"
		  exit="closed"
		  transition={{ duration: .2, ease: 'easeOut' }}>
		<Separator/>
		{visibleMenu.map ((item, i) => (
		    <Fragment key={i}>
		      <PrefetchLink
			  to={i === openItemIdx ? item.to : '#'}
			  className={cn ('w-full min-h-[40px] flex items-center pl-8',
				     ((i === openItemIdx)
				      && 'font-bold bg-yellow-50 dark:bg-red-950'))}
			  onClick={(ev: MouseEvent<HTMLAnchorElement>) => {
			    if (i !== openItemIdx)
			      {
				ev.preventDefault ()
				setOpenItemIdx (i)
			      }
			  }}>
			{item.name}
		      </PrefetchLink>

		      <AnimatePresence initial={false}>
			{i === openItemIdx && (
			    <motion.div
				key={`sp-sub-${ i }`}
				className="w-full bg-yellow-50 dark:bg-red-950"
				variants={{ closed: { clipPath: 'inset(0 0 100% 0)',
						      height:   0,
						      opacity:  0 },
					    open:   { clipPath: 'inset(0 0 0% 0)',
						      height:   'auto',
						      opacity:  1 } }}
				initial="closed"
				animate="open"
				exit="closed"
				transition={{ duration: .2, ease: 'easeOut' }}>
			      {item.subMenu
			       .filter (subItem => subItem.visible ?? true)
			       .map ((subItem, j) => (
				  'component' in subItem
				  ? (
				      <Fragment key={`sp-c-${ i }-${ j }`}>
					{subItem.component}
				      </Fragment>)
				  : (
				      <PrefetchLink
					  key={`sp-l-${ i }-${ j }`}
					  to={subItem.to}
					  target={subItem.to.slice (0, 2) === '//'
						  ? '_blank'
						  : undefined}
					  className="w-full min-h-[36px] flex items-center pl-12">
					{subItem.name}
				      </PrefetchLink>)))}
			    </motion.div>)}
		      </AnimatePresence>
		    </Fragment>))}
		<PrefetchLink
		    to="/more"
		    ref={(el: (HTMLAnchorElement | null)) => {
		      itemsRef.current[visibleMenu.length] = el
		    }}
		    className={cn ('w-full min-h-[40px] flex items-center pl-8',
				   ((openItemIdx < 0)
				    && 'font-bold bg-yellow-50 dark:bg-red-950'))}>
		  その他 &raquo;
		</PrefetchLink>
		<TopNavUser user={user} sp/>
		<Separator/>
	      </motion.div>)}
	</AnimatePresence>
      </>)
}) satisfies FC<Props>