"use client"

import Link from '../LocalizedLink'
import Image from 'next/image'
import { useState, useRef, useEffect } from 'react'
import {
  ArrowRight,
  ChevronRight,
  Star,
  Sparkles,
  Box,
} from 'lucide-react'
import type { MegaMenuPayload, MenuColumn } from './menuTypes'
import { getLocalizedMenuText } from './menuTypes'
import { ICON_REGISTRY, type AvailableIcons } from './iconRegistry'

function DynamicIcon({ iconName, defaultIcon: DefaultIcon, className, strokeWidth }: { iconName?: string, defaultIcon: any, className?: string, strokeWidth?: number }) {
  const IconComponent = (iconName && ICON_REGISTRY[iconName as AvailableIcons])
    ? ICON_REGISTRY[iconName as AvailableIcons]
    : DefaultIcon;
  
  return <IconComponent className={className} strokeWidth={strokeWidth} />;
}



interface DesktopMegaMenuProps {
  items: MegaMenuPayload[]
  lang: string
  currentPath: string
}



const MAX_TOP_LEVEL_LINKS = 5
const MAX_INLINE_CHILD_LINKS = 3

const getMoreLabel = (count: number, lang: string) => {
  if (lang === 'th') return `+ อีก ${count} รายการ`
  if (lang === 'ja') return `+ 他${count}件`
  if (lang === 'zh') return `+ 还有 ${count} 项`
  if (lang === 'vi') return `+ ${count} mục khác`
  if (lang === 'ko') return `+ ${count}개 더`
  return `+ ${count} more`
}

// Render a 1:1 image using next/image for optimization (website uses CDN images)
function MenuImage({
  src,
  alt,
  placeholder,
  className = '',
  style,
}: {
  src?: string | null
  alt: string
  placeholder?: string
  className?: string
  style?: React.CSSProperties
}) {
  const [loaded, setLoaded] = useState(false)

  if (!src) {
    if (!placeholder) return null
    return (
      <span className="text-text-main/30 text-xs text-center px-3 leading-relaxed">{placeholder}</span>
    )
  }

  return (
    <Image
      src={src}
      alt={alt}
      fill
      sizes="(max-width: 1024px) 0px, 224px"
      className={`object-cover transition-opacity duration-300 ${loaded ? 'opacity-100' : 'opacity-0'} ${className}`}
      style={style}
      onLoad={() => setLoaded(true)}
      loading="lazy"
    />
  )
}

export function DesktopMegaMenu({ items, lang, currentPath }: DesktopMegaMenuProps) {
  const [openId, setOpenId] = useState<string | null>(null)
  const [hoveredLinkImage, setHoveredLinkImage] = useState<string | null>(null)
  const closeTimer = useRef<ReturnType<typeof setTimeout> | null>(null)

  // Automatically close mega menu when route changes
  useEffect(() => {
    if (closeTimer.current) clearTimeout(closeTimer.current)
    setOpenId(null)
    setHoveredLinkImage(null)
  }, [currentPath])

  const handleOpen = (id: string) => {
    if (closeTimer.current) clearTimeout(closeTimer.current)
    if (openId !== id) setHoveredLinkImage(null)
    setOpenId(id)
  }

  const handleClose = () => {
    closeTimer.current = setTimeout(() => {
      setOpenId(null)
      setHoveredLinkImage(null)
    }, 150)
  }

  const handleLinkClick = () => {
    if (closeTimer.current) clearTimeout(closeTimer.current)
    setOpenId(null)
    setHoveredLinkImage(null)
  }

  const getFirstImageLink = (columns: MenuColumn[] = []) => {
    for (const column of columns) {
      const found = column.links.find((link) => link.imageUrl)
      if (found) return found
    }
    return columns[0]?.links[0]
  }

  return (
    <div className="hidden space-x-7 text-sm font-medium uppercase tracking-wide md:flex">
      {items.map((item, index) => {
        const uniqueId = item.nodeId || item.id || `menu-${item.url || index}`
        const isOpen = openId === uniqueId
        const hasColumns = !!item.columns?.length
        const isActive = item.url ? currentPath === item.url : false

        const visibleColumns = item.columns?.slice(0, 2) ?? []
        const featuredLink = getFirstImageLink(item.columns)
        const featuredConfig = item.featured
        const showFeatured = featuredConfig?.enabled !== false
        const configuredImage = featuredConfig?.imageUrl || null
        const featuredImage = hoveredLinkImage ?? configuredImage ?? featuredLink?.imageUrl ?? item.rootImageUrl
        const focalPoint = featuredConfig?.focalPoint
        const objectPosition = focalPoint ? `${focalPoint.x} ${focalPoint.y}` : 'center'
        const featuredHeading = getLocalizedMenuText(featuredConfig?.sectionTitle, lang) || 'Featured'
        const featuredBadge = getLocalizedMenuText(featuredConfig?.badge, lang) || 'Recommended'
        const featuredTitle = getLocalizedMenuText(featuredConfig?.title, lang)
          || getLocalizedMenuText(featuredLink?.label, lang)
          || getLocalizedMenuText(item.label, lang)
        const featuredSubtitle = getLocalizedMenuText(featuredConfig?.subtitle, lang) || (item.columns?.[0]
          ? getLocalizedMenuText(item.columns[0].title, lang)
          : getLocalizedMenuText(item.label, lang))
        const featuredHref = featuredConfig?.url || featuredLink?.url || item.url || '#'
        const featuredCta = getLocalizedMenuText(featuredConfig?.ctaLabel, lang) || 'View details'

        return (
          <div
            key={uniqueId}
            className="relative"
            onMouseEnter={() => handleOpen(uniqueId)}
            onMouseLeave={handleClose}
          >
            <Link
              href={item.url || '#'}
              onClick={handleLinkClick}
              className={`flex items-center gap-1 border-b py-2 transition-colors ${
                isOpen || isActive
                  ? 'border-brand-primary text-text-main'
                  : 'border-transparent text-text-main hover:border-brand-primary hover:text-text-main'
              }`}
            >
              {getLocalizedMenuText(item.label, lang)}
              {hasColumns && (
                <svg
                  className={`h-3 w-3 opacity-50 transition-transform duration-300 ${isOpen ? 'rotate-180' : ''}`}
                  fill="none"
                  viewBox="0 0 24 24"
                  stroke="currentColor"
                >
                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" />
                </svg>
              )}
            </Link>

            {hasColumns && (
              <div
                className={`fixed left-1/2 z-50 w-[min(100vw-2rem,980px)] -translate-x-1/2 transition-all duration-200 ${
                  isOpen ? 'pointer-events-auto translate-y-0 opacity-100' : 'pointer-events-none -translate-y-1 opacity-0'
                }`}
                style={{ top: 'var(--navbar-bottom, 64px)' }}
                onMouseEnter={() => handleOpen(uniqueId)}
                onMouseLeave={handleClose}
              >
                <div className="mx-auto h-3 w-20 overflow-hidden">
                  <div className="mx-auto mt-2 h-5 w-5 rotate-45 rounded-sm border-l border-t border-line-primary/15 bg-surface-card/95" />
                </div>
                <div className="w-full cursor-default overflow-hidden rounded-lg border border-line-primary/15 bg-surface-card/95 shadow-card backdrop-blur-xl">
                  <div className={`grid gap-0 px-8 py-8 ${showFeatured ? 'grid-cols-[1fr_1fr_270px]' : 'grid-cols-2'}`}>
                    {visibleColumns.map((column, columnIndex) => (
                      <div
                        key={columnIndex}
                        className={`pr-8 ${columnIndex > 0 ? 'border-l border-line-primary/15 pl-8' : ''}`}
                      >
                        <h4 className="mb-5 flex items-center gap-3 text-xs font-bold normal-case tracking-normal text-text-main">
                          <DynamicIcon 
                            iconName={column.icon} 
                            defaultIcon={Sparkles} 
                            className="h-4 w-4 text-brand-primary" 
                            strokeWidth={1.5} 
                          />
                          {getLocalizedMenuText(column.title, lang)}
                        </h4>
                        <ul className="space-y-2">
                          {column.links.slice(0, MAX_TOP_LEVEL_LINKS).map((link, linkIndex) => {
                            const hasNestedLinks = !!link.links?.length
                            const visibleChildLinks = link.links?.slice(0, MAX_INLINE_CHILD_LINKS) ?? []
                            const hiddenChildCount = Math.max((link.links?.length ?? 0) - MAX_INLINE_CHILD_LINKS, 0)
                            const moreChildHref = link.url || link.links?.[MAX_INLINE_CHILD_LINKS]?.url || link.links?.[0]?.url || '#'

                            return (
                              <li key={linkIndex}>
                                <div
                                  className="rounded-md"
                                  onMouseEnter={() => setHoveredLinkImage(link.imageUrl || null)}
                                  onMouseLeave={() => setHoveredLinkImage(null)}
                                >
                                  <Link
                                    href={link.url || link.links?.[0]?.url || '#'}
                                    onClick={handleLinkClick}
                                    className="group flex items-center gap-4 rounded-md px-1 py-2.5 text-left transition-colors hover:bg-surface-muted"
                                  >
                                    <span className="flex h-9 w-9 shrink-0 items-center justify-center rounded-md border border-line-primary/20 bg-surface-page text-brand-primary transition-colors group-hover:border-brand-primary/40">
                                      <DynamicIcon 
                                        iconName={link.icon} 
                                        defaultIcon={Box} 
                                        className="h-5 w-5" 
                                        strokeWidth={1.35} 
                                      />
                                    </span>
                                    <span className="min-w-0 flex-1">
                                      <span className="block text-sm font-bold normal-case tracking-normal text-text-main">
                                        {getLocalizedMenuText(link.label, lang)}
                                      </span>
                                      <span className="mt-0.5 block truncate text-xs font-normal normal-case tracking-normal text-muted-text">
                                        {getLocalizedMenuText(column.title, lang)}
                                      </span>
                                    </span>
                                    <ChevronRight className="h-4 w-4 shrink-0 text-text-main/40 transition-colors group-hover:text-brand-primary" />
                                  </Link>

                                  {hasNestedLinks && (
                                    <ul className="ml-[3.25rem] mt-1 space-y-1 border-l border-line-primary/15 pl-3">
                                      {visibleChildLinks.map((childLink, childIndex) => (
                                        <li key={childIndex}>
                                          <Link
                                            href={childLink.url || '#'}
                                            onClick={handleLinkClick}
                                            className="block rounded-sm px-2 py-1.5 text-xs font-normal normal-case tracking-normal text-muted-text transition-colors hover:bg-surface-muted hover:text-brand-primary"
                                            onMouseEnter={() => setHoveredLinkImage(childLink.imageUrl || link.imageUrl || null)}
                                          >
                                            {getLocalizedMenuText(childLink.label, lang)}
                                          </Link>
                                        </li>
                                      ))}
                                      {hiddenChildCount > 0 && (
                                        <li>
                                          <Link
                                            href={moreChildHref}
                                            onClick={handleLinkClick}
                                            className="block rounded-sm px-2 py-1.5 text-xs font-semibold normal-case tracking-normal text-brand-primary transition-colors hover:bg-surface-muted"
                                          >
                                            {getMoreLabel(hiddenChildCount, lang)}
                                          </Link>
                                        </li>
                                      )}
                                    </ul>
                                  )}
                                </div>
                              </li>
                            )
                          })}
                        </ul>
                        <Link
                          href={item.url || '#'}
                          onClick={handleLinkClick}
                          className="mt-7 flex items-center justify-between text-xs font-medium normal-case tracking-normal text-text-main/65 transition-colors hover:text-brand-primary"
                        >
                          <span>{getLocalizedMenuText(item.label, lang)}</span>
                          <ArrowRight className="h-4 w-4" />
                        </Link>
                      </div>
                    ))}

                    {showFeatured && (
                      <div className="border-l border-line-primary/15 pl-8">
                        <h4 className="mb-5 flex items-center gap-3 text-xs font-bold normal-case tracking-normal text-text-main">
                          <Star className="h-4 w-4 text-brand-primary" strokeWidth={1.5} />
                          {featuredHeading}
                        </h4>
                        <Link
                          href={featuredHref}
                          onClick={handleLinkClick}
                          className="group block overflow-hidden rounded-lg border border-line-primary/20 bg-surface-page transition-colors hover:border-brand-primary/40"
                          onMouseEnter={() => setHoveredLinkImage(configuredImage ?? featuredLink?.imageUrl ?? null)}
                          onMouseLeave={() => setHoveredLinkImage(null)}
                        >
                          <div className="relative h-40 w-full overflow-hidden bg-surface-muted">
                            <MenuImage
                              src={featuredImage}
                              alt={featuredTitle}
                              placeholder={getLocalizedMenuText(item.label, lang)}
                              className="h-full w-full object-cover transition-transform duration-700 group-hover:scale-105"
                              style={{ objectPosition }}
                            />
                          </div>
                          <div className="space-y-2 p-4">
                            {featuredBadge && (
                              <span className="inline-flex rounded-full bg-surface-card px-2.5 py-1 text-[10px] font-bold normal-case tracking-normal text-brand-primary">
                                {featuredBadge}
                              </span>
                            )}
                            <div>
                              <p className="line-clamp-2 text-sm font-bold normal-case tracking-normal text-text-main">
                                {featuredTitle}
                              </p>
                              {featuredSubtitle && (
                                <p className="mt-1 line-clamp-1 text-xs font-normal normal-case tracking-normal text-muted-text">
                                  {featuredSubtitle}
                                </p>
                              )}
                              {featuredConfig?.price && (
                                <p className="mt-2 text-sm font-bold normal-case tracking-normal text-text-main">
                                  {featuredConfig.price}
                                </p>
                              )}
                            </div>
                            <span className="flex w-full items-center justify-center rounded-full border border-brand-primary/40 px-4 py-2 text-xs font-bold normal-case tracking-normal text-text-main transition-colors group-hover:bg-brand-primary group-hover:text-surface-card">
                              {featuredCta}
                            </span>
                          </div>
                        </Link>
                      </div>
                    )}
                  </div>
                </div>
              </div>
            )}
          </div>
        )
      })}
    </div>
  )
}