import { computed, ref } from 'vue'
import { showToast, useDidShow } from '@tarojs/taro'
import { pinia, useAppStore, useCartStore } from '@/stores'
import type {
  MiniCategory,
  MiniMenuSection,
  MiniProductDetail
} from '@/shared'
import { openRoute } from '@/utils/router'
import { createMenuDataActions } from './menu-page/data-actions'
import { createMenuDetailActions } from './menu-page/detail-actions'
import {
  getSelectedIds,
  resolveSelectionError
} from './menu-page/selection-helpers'

export function useMenuPage () {
  const appStore = useAppStore(pinia)
  const cartStore = useCartStore(pinia)
  const loading = ref(true)
  const errorMessage = ref('')
  const categories = ref<MiniCategory[]>([])
  const sections = ref<MiniMenuSection[]>([])
  const detailVisible = ref(false)
  const cartVisible = ref(false)
  const activeDetail = ref<MiniProductDetail | null>(null)
  const currentSkuId = ref('')
  const detailQuantity = ref(1)
  const specSelections = ref<Record<string, string[]>>({})
  const addonSelections = ref<Record<string, string[]>>({})

  const currentStore = computed(() => appStore.currentStore)
  const cartCount = computed(() => cartStore.itemCount)
  const totalAmountText = computed(() => cartStore.totalAmountText)
  const lineList = computed(() => cartStore.lineList)
  const currentSku = computed(() =>
    activeDetail.value?.skus.find((sku) => sku.id === currentSkuId.value) || null
  )
  const currentDetailPrice = computed(() => {
    if (!activeDetail.value) return 0

    const basePrice = currentSku.value?.price ?? activeDetail.value.basePrice
    const addonPrice = activeDetail.value.optionGroups
      .filter((group) => group.groupType === 'addon')
      .flatMap((group) =>
        group.options.filter((option) => (addonSelections.value[group.id] || []).includes(option.id))
      )
      .reduce((amount, option) => amount + option.extraPrice, 0)

    return (basePrice + addonPrice) * detailQuantity.value
  })
  const displayUnitPrice = computed(() =>
    detailQuantity.value > 0 ? currentDetailPrice.value / detailQuantity.value : 0
  )
  const currentDetailPriceText = computed(() => currentDetailPrice.value.toFixed(2))
  const canAddCurrentDetail = computed(() => {
    if (!activeDetail.value) return false
    if (activeDetail.value.skus.length && !currentSkuId.value) return false

    return !resolveSelectionError({
      activeDetail: activeDetail.value,
      addonSelections: addonSelections.value,
      currentSkuId: currentSkuId.value,
      specSelections: specSelections.value
    })
  })
  const summaryText = computed(() => {
    if (!activeDetail.value) return ''

    const parts: string[] = []
    activeDetail.value.optionGroups.forEach((group) => {
      const selected = getSelectedIds(addonSelections.value, specSelections.value, group.id)
      group.options
        .filter((option) => selected.includes(option.id))
        .forEach((option) => parts.push(option.name))
    })

    return parts.join(' · ') || '请选择规格'
  })
  const disabledButtonText = computed(() =>
    resolveSelectionError({
      activeDetail: activeDetail.value,
      addonSelections: addonSelections.value,
      currentSkuId: currentSkuId.value,
      specSelections: specSelections.value
    }) || '请选择规格'
  )

  function isOptionSelected (groupId: string, optionId: string) {
    return getSelectedIds(addonSelections.value, specSelections.value, groupId).includes(optionId)
  }

  function closeDetail () {
    detailVisible.value = false
    activeDetail.value = null
    currentSkuId.value = ''
    detailQuantity.value = 1
    specSelections.value = {}
    addonSelections.value = {}
  }

  const { handleSceneChange, loadMenu } = createMenuDataActions({
    appStore,
    categories,
    errorMessage,
    loading,
    sections
  })

  const {
    changeDetailQuantity,
    confirmAddCurrentDetail,
    handleProductAction,
    toggleOption
  } = createMenuDetailActions({
    activeDetail,
    addonSelections,
    appStore,
    canAddCurrentDetail,
    cartStore,
    closeDetail,
    currentDetailPrice,
    currentSkuId,
    detailQuantity,
    detailVisible,
    specSelections
  })

  function goStoreSelect () {
    void openRoute('/pages/store/select/index')
  }

  async function goCheckout () {
    if (!cartStore.itemCount) {
      await showToast({ title: '请先加购商品', icon: 'none' })
      return
    }

    void openRoute('/pages/trade/checkout/index')
  }

  useDidShow(() => {
    void loadMenu()
  })

  return {
    activeDetail,
    appStore,
    canAddCurrentDetail,
    cartCount,
    cartStore,
    cartVisible,
    categories,
    changeDetailQuantity,
    closeDetail,
    confirmAddCurrentDetail,
    currentDetailPriceText,
    currentStore,
    detailQuantity,
    detailVisible,
    disabledButtonText,
    displayUnitPrice,
    errorMessage,
    goCheckout,
    goStoreSelect,
    handleProductAction,
    handleSceneChange,
    isOptionSelected,
    lineList,
    loadMenu,
    loading,
    sections,
    summaryText,
    toggleOption,
    totalAmountText
  }
}