"use client"

import { useEffect, useMemo, useState } from 'react'
import Image from 'next/image'
import Link from './LocalizedLink'
import { Heart, Search, ShoppingBag, Star, User } from 'lucide-react'
import { formatPrice, getCategoryImage, type Product, type StoreSettings } from '@homaroma/types'
import { useCartStore } from '../store/cartStore'
import { resolveCategoryName, resolveLocalized } from '../lib/localization'
import { useLang } from '../hooks/useLang'

function resolveOptionValue(val: string, options: Product['options'], lang: string): string {
  if (!val || !options || !Array.isArray(options)) return val

  for (const option of options) {
    if (!Array.isArray(option.values)) continue
    for (const item of option.values) {
      const base = typeof item === 'string' ? item : item.th || item.en || Object.values(item)[0] || ''
      if (base === val) {
        if (typeof item === 'string') return item
        return item[lang] ?? item[lang.slice(0, 2)] ?? item.th ?? item.en ?? Object.values(item)[0] ?? base
      }
    }
  }

  return val
}

export default function ProductStickyPurchaseBar({
  product,
  triggerId,
  settings = null,
}: {
  product: Product
  triggerId: string
  settings?: StoreSettings | null
}) {
  const lang = useLang()
  const [isVisible, setIsVisible] = useState(false)
  const { addToCart, toggleCart } = useCartStore()
  const productName = resolveLocalized(product.name, lang) || product.brand.name
  const categoryName = resolveCategoryName(product.category, lang)
  const brandName = settings?.brandName || 'HomAroma'
  const variant = product.variants?.[0]
  const imageUrl = product.images?.[0]?.url || product.category.imageUrl || getCategoryImage(categoryName)

  const variantName = useMemo(() => {
    if (!variant) return ''
    return [variant.option1, variant.option2, variant.option3]
      .filter(Boolean)
      .map((option) => resolveOptionValue(option, product.options, lang))
      .join(' / ')
  }, [lang, product.options, variant])

  const handleAddToCart = () => {
    if (!variant) return

    addToCart({
      productId: product.id,
      variantId: variant.id,
      quantity: 1,
      price: variant.price || 0,
      productName,
      variantName: variantName || undefined,
      productImage: imageUrl,
    })
    toggleCart(true)
  }

  useEffect(() => {
    const updateVisibility = () => {
      const trigger = document.getElementById(triggerId)
      if (!trigger) {
        setIsVisible(false)
        if (document.documentElement.dataset.productStickyVisible !== 'false') {
          document.documentElement.dataset.productStickyVisible = 'false'
          window.dispatchEvent(new CustomEvent('product-sticky-change', { detail: false }))
        }
        return
      }

      const nextVisible = trigger.getBoundingClientRect().top <= 0
      setIsVisible(nextVisible)
      const nextStr = nextVisible ? 'true' : 'false'
      if (document.documentElement.dataset.productStickyVisible !== nextStr) {
        document.documentElement.dataset.productStickyVisible = nextStr
        window.dispatchEvent(new CustomEvent('product-sticky-change', { detail: nextVisible }))
      }
    }

    updateVisibility()
    window.addEventListener('scroll', updateVisibility, { passive: true })
    window.addEventListener('resize', updateVisibility)

    return () => {
      document.documentElement.dataset.productStickyVisible = 'false'
      window.dispatchEvent(new CustomEvent('product-sticky-change', { detail: false }))
      window.removeEventListener('scroll', updateVisibility)
      window.removeEventListener('resize', updateVisibility)
    }
  }, [triggerId])

  return (
    <div className={`fixed left-0 right-0 top-0 z-50 hidden border-b border-line-primary/15 bg-surface-page/98 px-6 py-3 backdrop-blur transition duration-300 md:block ${
      isVisible ? 'translate-y-0 opacity-100' : 'pointer-events-none -translate-y-full opacity-0'
    }`}>
      <div className="relative mx-auto flex max-w-7xl items-start justify-between gap-6">
        <div className="absolute left-1/2 top-0 hidden -translate-x-1/2 md:block">
          <Link href="/" className="flex h-10 items-center justify-center">
            {settings?.logoUrl ? (
              <Image
                src={settings.logoUrl}
                alt={brandName}
                width={180}
                height={44}
                unoptimized
                className="max-h-10 w-auto object-contain"
              />
            ) : (
              <span className="text-3xl font-bold uppercase tracking-[0.22em] text-text-main">{brandName}</span>
            )}
          </Link>
        </div>

        <div className="flex min-w-0 items-center gap-5 pt-9 md:max-w-[48%]">
          <div className="relative h-12 w-12 shrink-0 overflow-hidden bg-surface-card">
            <Image src={imageUrl} alt={productName} fill className="object-cover" sizes="56px" />
          </div>
          <div className="min-w-0">
            <p className="truncate text-base font-semibold uppercase tracking-[0.18em] text-text-main">{productName}</p>
            <p className="mt-1 truncate text-sm text-muted-text">
              {variantName || categoryName}
            </p>
          </div>
        </div>

        <div className="flex shrink-0 flex-col items-end gap-6">
          <div className="hidden items-center gap-5 text-text-main md:flex">
            <button type="button" aria-label="Search" className="transition hover:text-brand-primary">
              <Search className="h-5 w-5" strokeWidth={1.6} />
            </button>
            <Link href="/profile" aria-label="Account" className="transition hover:text-brand-primary">
              <User className="h-5 w-5" strokeWidth={1.6} />
            </Link>
            <Link href="/wishlist" aria-label="Wishlist" className="transition hover:text-brand-primary">
              <Star className="h-5 w-5" strokeWidth={1.6} />
            </Link>
            <Link href="/wishlist" aria-label="Favorites" className="transition hover:text-brand-primary">
              <Heart className="h-5 w-5" strokeWidth={1.6} />
            </Link>
            <button type="button" aria-label="Cart" onClick={() => toggleCart(true)} className="transition hover:text-brand-primary">
              <ShoppingBag className="h-5 w-5" strokeWidth={1.6} />
            </button>
          </div>

          <div className="flex items-center gap-8">
            <p className="hidden text-base font-semibold uppercase tracking-[0.16em] text-text-main sm:block">{formatPrice(variant?.price ?? 0)}</p>
          <button
            type="button"
            onClick={handleAddToCart}
            disabled={!variant}
              className="bg-text-main px-8 py-4 text-xs font-bold uppercase tracking-widest text-surface-page transition hover:bg-brand-primary disabled:cursor-not-allowed disabled:opacity-50 md:min-w-32"
          >
            {variant ? 'Add to Cart' : 'Unavailable'}
          </button>
          </div>
        </div>
      </div>
    </div>
  )
}