'use client'
import {useMemo, useState, PointerEvent, ComponentProps, useSyncExternalStore, use, Suspense} from 'react'
import Link from 'next/link'
import Image from 'next/image'
import {HeaderContext} from './_components/header/common'
import SolutionMenu from './_components/header/menu-solution'
import ProductMenu from './_components/header/menu-product'
import HelpMenu from './_components/header/menu-help'
import MobileMenu from './_components/header/menu-mobile'
import Wrap from '@/components/wrap'
import logo from '@/assets/logo.webp'
import {Button} from '@/components/ui/button'
import {useProfileStore} from '@/components/stores/profile'
import UserCenter from '@/components/composites/user-center'
import {MenuIcon} from 'lucide-react'
import down from '@/assets/header/down.svg'
import {merge} from '@/lib/utils'

export type HeaderProps = {}

export default function Header(props: HeaderProps) {
  // ======================
  // 滚动条状态
  // ======================

  const scroll = useSyncExternalStore((callback) => {
    window.addEventListener('scroll', callback)
    return () => {
      window.removeEventListener('scroll', callback)
    }
  }, () => window.scrollY > 48, () => false)

  // ======================
  // 菜单状态
  // ======================

  const [menu, setMenu] = useState(false)
  const [page, setPage] = useState(0)
  const pages = useMemo(() => [
    <ProductMenu key="product"/>,
    <SolutionMenu key="solution"/>,
    <HelpMenu key="help"/>,
    <MobileMenu key="mobile"/>,
  ], [])

  const enterMenu = (i: number) => {
    return (e: PointerEvent) => {
      setPage(i)
      if (e.pointerType === 'mouse' || page !== i) {
        setMenu(true)
      }
      else {
        setMenu(!menu)
      }
    }
  }

  const exitMenu = (e: PointerEvent) => {
    if (e.pointerType === 'mouse') {
      setMenu(false)
    }
  }

  const enterMenuContent = (e: PointerEvent) => {
    setMenu(true)
  }

  const exitMenuContent = (e: PointerEvent) => {
    if (e.pointerType === 'mouse') {
      setMenu(false)
    }
  }

  const enterMenuMask = (e: PointerEvent) => {
    if (e.pointerType !== 'mouse') {
      setMenu(false)
    }
  }

  // ======================
  // 用户信息
  // ======================

  const profile = useProfileStore(store => store.profile)

  // ======================
  // render
  // ======================

  return (
    <header
      className={merge(
        'fixed top-0 left-0 w-screen z-10 flex flex-col ',
        menu ? 'h-screen' : 'pointer-events-none',
      )}>
      <HeaderContext.Provider value={{setMenu}}>

        {/* 菜单栏 */}
        <div className={merge(
          `flex-none pointer-events-auto`,
          `transition-[background,shadow] duration-200 ease-in-out`,
          menu
            ? `bg-[#fffe] backdrop-blur-sm`
            : scroll
              ? `bg-[#fffe] backdrop-blur-sm shadow-lg`
              : `bg-transparent shadow-none`,
        )}>
          <Wrap className="h-20 max-md:h-16 flex justify-between">
            <nav className="flex items-center justify-between lg:flex-row-reverse gap-4 lg:gap-8">

              {/* 桌面端菜单 */}
              <ul className="h-full items-stretch hidden lg:flex">
                <LinkItem text="首页" href="/"/>
                <MenuItem
                  text="产品订购"
                  active={menu && page === 0}
                  onPointerEnter={enterMenu(0)}
                  onPointerLeave={exitMenu}
                />
                <MenuItem
                  text="业务场景"
                  active={menu && page === 1}
                  onPointerEnter={enterMenu(1)}
                  onPointerLeave={exitMenu}
                />
                <MenuItem
                  text="帮助中心"
                  active={menu && page === 2}
                  onPointerEnter={enterMenu(2)}
                  onPointerLeave={exitMenu}
                />
                <LinkItem
                  text="业务定制"
                  href="/customized"/>
              </ul>

              {/* 移动端菜单 */}
              <Button
                theme="ghost"
                className="lg:hidden size-10"
                onPointerEnter={enterMenu(3)}
                onPointerLeave={exitMenu}
              >
                <MenuIcon/>
              </Button>

              {/* logo */}
              <Link href="/" className="flex items-center">
                <Image src={logo} alt="logo" height={40} className="translate-y-0.5"/>
              </Link>
            </nav>

            {/* 登录 */}
            <Suspense>
              <ProfileOrLogin/>
            </Suspense>
          </Wrap>
        </div>

        {/* 下拉菜单 */}
        <div
          className={merge(
            `flex-auto overflow-auto lg:flex-none lg:basis-72 shadow-lg box-content`,
            `bg-[#fffe] backdrop-blur-sm`,
            `transition-[opacity,padding] transition-discrete duration-200 ease-in-out`,
            menu
              ? `delay-[0s,0s] opacity-100 py-4`
              : `delay-[0s,0s] opacity-0 py-0 pointer-events-none`,
          )}
          onPointerEnter={enterMenuContent}
          onPointerLeave={exitMenuContent}
        >
          {pages[page]}
        </div>

        {/* 遮罩层 */}
        <div className="flex-auto" onPointerEnter={enterMenuMask}/>

      </HeaderContext.Provider>
    </header>
  )
}

function LinkItem(props: {
  text: string
  href: string
}) {
  return (
    <li className="group relative">
      <Link
        href={props.href}
        className={[
          `h-full px-4 flex items-center text-lg`,
          `transition-colors duration-200 ease-in-out`,
          `hover:text-blue-500`,
        ].join(' ')}
      >
        {props.text}
      </Link>
      <div className={[
        `absolute bottom-0 w-full h-0.5 bg-transparent `,
        `transition-colors duration-200`,
        `group-hover:bg-blue-500`,
      ].join(' ')}>
      </div>
    </li>
  )
}

function MenuItem(props: {
  text: string
  active: boolean
} & ComponentProps<'button'>) {
  return (
    <li className="group relative">
      <button
        onPointerEnter={props.onPointerEnter}
        onPointerLeave={props.onPointerLeave}
        className={[
          `h-full px-4 flex gap-3 items-center cursor-pointer text-lg`,
          `transition-colors duration-200 ease-in-out`,
          props.active
            ? `text-blue-500`
            : ``,
        ].join(' ')}
      >
        <span>{props.text}</span>
        <Image
          src={down}
          alt="drop_menu"
          className={[
            `transition-transform duration-200 ease-in-out`,
            props.active
              ? `rotate-180`
              : ``,
          ].join(' ')}
        />
      </button>
      <div
        className={[
          `absolute bottom-0 w-full h-0.5 pointer-events-none`,
          `transition-colors duration-200`,
          props.active
            ? `bg-blue-500`
            : 'bg-transparent',
        ].join(' ')}/>
    </li>
  )
}

function ProfileOrLogin() {
  const profile = use(useProfileStore(store => store.profile))
  return (
    <div className="flex items-center">
      {profile == null
        ? (
          <>
            <Link
              href="/login"
              className="w-24 h-12 flex items-center justify-center lg:text-lg"
            >
              <span>登录</span>
            </Link>
            <Link
              href="/login"
              className={[
                `w-20 lg:w-24 h-10 lg:h-12 bg-linear-to-r rounded-sm flex items-center justify-center lg:text-lg text-white`,
                `transition-colors duration-200 ease-in-out`,
                `from-blue-500 to-cyan-400 hover:from-blue-500 hover:to-cyan-300`,
              ].join(' ')}
            >
              <span>注册</span>
            </Link>
          </>
        )
        : (
          <UserCenter profile={profile}/>
        )
      }
    </div>
  )
}