<script setup lang="ts">
/**
 * Product Detail Page
 *
 * Displays full details for a single product with large image and description.
 * Includes functional "Add to Cart" functionality with notifications and cart UI integration.
 */

import { ArrowLeft, ArrowLeftIcon, CheckCircle, ChevronLeftIcon, Loader2, ShoppingCartIcon } from 'lucide-vue-next'
import { toast } from 'vue-sonner'

// Page metadata
definePageMeta({
  layout: 'default',
})

// Get product ID from route
const route = useRoute()
const productId = route.params.id as string

// Type definition for product
interface Product {
  id: string
  navProductId: string
  name: string
  description: string
  price: string
  stockQuantity: number
  category: string
  active: boolean
  createdAt: Date
  updatedAt: Date
}

// Fetch product from API
const { data: product, error, pending } = await useFetch<Product>(`/api/products/${productId}`)

// Format price in EUR
const formattedPrice = computed(() => {
  if (!product.value) return ''
  return new Intl.NumberFormat('de-DE', {
    style: 'currency',
    currency: 'EUR',
  }).format(Number(product.value.price))
})

// Cart composables
const { addItem, loading: cartLoading, items } = useCart()
const { open: openCart } = useCartUI()

// Local loading state for this specific button
const isAddingToCart = ref(false)

// Check if product is already in cart
const isInCart = computed(() => {
  if (!product.value) return false
  return items.value.some((item) => item.productId === product.value.id)
})

// Handle "Add to Cart" action
const handleAddToCart = async () => {
  if (!product.value) return

  // Prevent adding if out of stock
  if (product.value.stockQuantity === 0) {
    toast.error('Nicht verfügbar', {
      description: 'Dieses Produkt ist derzeit nicht auf Lager.',
    })
    return
  }

  isAddingToCart.value = true

  try {
    // Add item to cart (quantity: 1)
    await addItem(product.value.id, 1)

    // Show success notification
    toast.success('In den Warenkorb gelegt', {
      description: `${product.value.name} wurde zu deinem Warenkorb hinzugefügt.`,
    })

    // Open cart sidebar/sheet to show added item
    openCart()
  } catch (error) {
    console.error('Failed to add item to cart:', error)

    // Show error notification
    toast.error('Fehler beim Hinzufügen', {
      description: 'Das Produkt konnte nicht in den Warenkorb gelegt werden. Bitte versuche es erneut.',
    })
  } finally {
    isAddingToCart.value = false
  }
}
</script>

<template>
  <NuxtLayout name="default">
    <div class="min-h-screen px-4 py-12 md:px-6 lg:px-8">
      <!-- Back Button -->
      <div class="mx-auto mb-8 max-w-container-narrow">
        <NuxtLink to="/products"
          class="inline-flex items-center gap-2 text-white/80 transition-colors hover:text-white">
          <ArrowLeft :size="20" />
          <span>Zurück zur Übersicht</span>
        </NuxtLink>
      </div>

      <!-- Loading State -->
      <div v-if="pending" class="mx-auto max-w-container-narrow text-center">
        <div class="card-glass inline-block">
          <p class="text-white/80">Produkt wird geladen...</p>
        </div>
      </div>

      <!-- Error State (404 or other errors) -->
      <div v-else-if="error" class="mx-auto max-w-container-narrow">
        <div class="card-glass border-red/50 bg-red/10">
          <h2 class="mb-2 text-2xl font-semibold text-red">
            {{ error.statusCode === 404 ? 'Produkt nicht gefunden' : 'Fehler beim Laden' }}
          </h2>
          <p class="mb-6 text-white/80">
            {{
              error.statusCode === 404
                ? 'Das angeforderte Produkt existiert nicht oder ist nicht verfügbar.'
                : error.message || 'Ein unbekannter Fehler ist aufgetreten.'
            }}
          </p>
          <NuxtLink to="/products">
            <Button variant="experimenta" size="experimenta">
              Zur Produktübersicht
            </Button>
          </NuxtLink>
        </div>
      </div>

      <!-- Product Detail -->
      <div v-else-if="product" class="mx-auto max-w-container-narrow">
        <div class="overflow-hidden rounded-2xl border border-white/20 bg-white/10 shadow-glass backdrop-blur-lg">
          <!-- Product Image (no padding, flush with top) -->
          <div class="relative aspect-[16/9] w-full overflow-hidden bg-purple-dark">
            <img src="/img/makerspace-jk-2025.jpg" :alt="product.name" class="h-full w-full object-cover" />
            <!-- Gradient overlay -->
            <div class="absolute inset-0 bg-gradient-to-t from-purple-darkest/80 via-transparent to-transparent" />
          </div>

          <!-- Product Content -->
          <div class="space-y-6 p-8">
            <!-- Title -->
            <h1 class="text-3xl font-bold text-white md:text-4xl">
              {{ product.name }}
            </h1>

            <!-- Description -->
            <p class="text-lg leading-relaxed text-white/90">
              {{ product.description }}
            </p>

            <!-- Product Details -->
            <div class="grid gap-4 sm:grid-cols-2">
              <!-- Price Card -->
              <div class="rounded-xl bg-white/5 p-4 backdrop-blur-sm">
                <span class="mb-1 block text-xs uppercase tracking-wide text-white/60">Preis</span>
                <span class="text-3xl font-bold text-experimenta-accent">
                  {{ formattedPrice }}
                </span>
              </div>

              <!-- Availability Card -->
              <div class="rounded-xl bg-white/5 p-4 backdrop-blur-sm">
                <span class="mb-1 block text-xs uppercase tracking-wide text-white/60">Verfügbarkeit</span>
                <div :class="[
                  'flex items-center gap-2 text-xl font-semibold',
                  product.stockQuantity > 0 ? 'text-green' : 'text-red',
                ]">
                  <CheckCircle v-if="product.stockQuantity > 0" :size="24" />
                  <span>{{ product.stockQuantity > 0 ? 'Sofort' : 'Nicht verfügbar' }}</span>
                </div>
              </div>
            </div>

            <!-- Features / Benefits -->
            <div class="rounded-xl border border-white/20 bg-white/5 p-6 backdrop-blur-sm">
              <h2 class="mb-4 text-xl font-semibold text-white">
                Was du mit dieser Karte bekommst:
              </h2>
              <ul class="space-y-3 text-white/90">
                <li class="flex items-start gap-2">
                  <span class="mt-1 text-experimenta-accent">✓</span>
                  <span>365 Tage unbegrenzter Zugang</span>
                </li>
                <li class="flex items-start gap-2">
                  <span class="mt-1 text-experimenta-accent">✓</span>
                  <span>Keine versteckten Kosten</span>
                </li>
                <li class="flex items-start gap-2">
                  <span class="mt-1 text-experimenta-accent">✓</span>
                  <span>Sofort einsatzbereit nach Kauf</span>
                </li>
                <li class="flex items-start gap-2">
                  <span class="mt-1 text-experimenta-accent">✓</span>
                  <span>Flexible Nutzung – komme so oft du möchtest</span>
                </li>
              </ul>
            </div>

            <!-- Action Buttons -->
            <div class="flex flex-col gap-4 sm:flex-row">
              <NuxtLink to="/products" class="btn-secondary flex-1 text-center">
                <ArrowLeftIcon class="w-5 h-5 mr-2 inline-block" />
                Weitere Produkte ansehen
              </NuxtLink>
              <Button variant="experimenta" size="experimenta" class="flex-1 relative"
                :disabled="product.stockQuantity === 0 || isAddingToCart" @click="handleAddToCart">
                <!-- Loading spinner -->
                <Loader2 v-if="isAddingToCart" :size="20" class="mr-2 animate-spin" />

                <!-- Button text -->
                <span v-if="isAddingToCart">Wird hinzugefügt...</span>
                <span v-else-if="product.stockQuantity === 0">Nicht verfügbar</span>
                <span v-else>
                  <ShoppingCartIcon class="mr-3 inline-flex" />
                  In den Warenkorb
                </span>
              </Button>

            </div>

            <!-- Already in cart hint -->
            <div v-if="isInCart && product.stockQuantity > 0" class="mt-2 text-center text-sm text-white/70">
              Dieses Produkt befindet sich bereits in deinem Warenkorb.
            </div>
          </div>
        </div>
      </div>
    </div>
  </NuxtLayout>
</template>
