import { computed, inject, onMounted, provide, reactive, ref, watch, type InjectionKey } from 'vue'
import { useRoute, useRouter } from 'vue-router'
import { companiesApi, customersApi, mapAdminOrder, ordersApi } from '@/services/api'
import { ApiError } from '@/services/http'
import type { Company, Customer, Order, RawOrderStatus, SettlementMethod } from '@/types'
import { rawStatusLabel } from '@/utils/orderStatus'

import { useToast } from '@/composables/useToast'

export function useOrdersPage() {
  const route = useRoute()
  const router = useRouter()
  const toast = useToast()

  const companies = ref<Company[]>([])
  const customers = ref<Customer[]>([])
  const orderList = ref<Order[]>([])
  const activeTab = ref(typeof route.query.tab === 'string' && route.query.tab.trim() ? route.query.tab.trim() : 'all')
  const selectedOrderId = ref<string>('')
  const searchQuery = ref('')
  const showAddModal = ref(false)
  const showDetailPanel = ref(false)
  const showDetailModal = ref(false)
  const formError = ref('')
  const saving = ref(false)

  const emptyForm = () => ({
    customerId: '',
    customerName: '',
    companyId: companies.value[0]?.id ?? '',
    settlementMethod: 'check' as SettlementMethod,
    meterage: 1000,
    customerPhone: '',
  })

  const form = reactive(emptyForm())

  const isFormValid = computed(
    () => form.customerId.length > 0 && form.companyId.length > 0,
  )

  const activeCustomers = computed(() => {
    const list = [...customers.value]
    list.sort((a, b) => Number(b.isActive) - Number(a.isActive) || a.name.localeCompare(b.name, 'fa'))
    return list
  })

  function applyCustomer(customerId: string) {
    const customer = customers.value.find((c) => c.id === customerId)
    form.customerId = customerId
    form.customerName = customer?.name ?? ''
    form.customerPhone = customer?.phone ?? ''
  }

  async function loadCustomers() {
    try {
      customers.value = await customersApi.list()
    } catch (err) {
      toast.error(err instanceof ApiError ? err.message : 'بارگذاری مشتریان انجام نشد.')
    }
  }

  const filteredOrders = computed(() => {
    let list = orderList.value
    if (activeTab.value !== 'all') {
      list = list.filter((o) => o.status === activeTab.value)
    }
    if (searchQuery.value.trim()) {
      const q = searchQuery.value.trim()
      list = list.filter(
        (o) => o.orderNumber.includes(q) || o.customerName.includes(q),
      )
    }
    return list
  })

  const selectedOrder = computed(() =>
    orderList.value.find((o) => o.id === selectedOrderId.value) ?? null,
  )

  function findOrderByRef(ref: string): Order | undefined {
    const key = ref.trim()
    if (!key) return undefined
    return orderList.value.find(
      (o) => o.id === key || o.orderNumber.toUpperCase() === key.toUpperCase(),
    )
  }

  async function applyOrderDeepLink() {
    const orderRef = typeof route.query.order === 'string' ? route.query.order : ''
    if (!orderRef || !orderList.value.length) return

    const order = findOrderByRef(orderRef)
    if (!order) {
      searchQuery.value = orderRef
      return
    }

    const focus = typeof route.query.focus === 'string' ? route.query.focus : ''
    if (focus === 'pricing') {
      await router.replace(`/orders/${order.id}/pricing`)
      return
    }
    if (focus === 'checks') {
      await router.replace(`/orders/${order.id}/checks`)
      return
    }

    openOrderDetail(order)
    searchQuery.value = order.orderNumber
  }

  async function loadData() {
    try {
      const [ordersData, companiesData, customersData] = await Promise.all([
        ordersApi.list(),
        companiesApi.list(),
        customersApi.list(),
      ])
      orderList.value = ordersData.map((o) => mapAdminOrder(o) as Order)
      companies.value = companiesData
      customers.value = customersData
      if (!form.companyId && companiesData[0]) {
        form.companyId = companiesData[0].id
      }
      await applyOrderDeepLink()
    } catch (err) {
      toast.error(err instanceof ApiError ? err.message : 'بارگذاری سفارش‌ها انجام نشد.')
    }
  }

  onMounted(() => {
    void loadData()
  })

  watch(
    () => [route.query.order, route.query.focus] as const,
    () => {
      void applyOrderDeepLink()
    },
  )

  watch(
    () => route.query.tab,
    (tab) => {
      if (typeof tab === 'string' && tab.trim()) {
        activeTab.value = tab.trim()
      }
    },
  )

  function selectOrder(order: Order, openDetail = false) {
    selectedOrderId.value = order.id
    if (openDetail) {
      showDetailPanel.value = true
    }
  }

  function openOrderDetail(order: Order) {
    selectedOrderId.value = order.id
    showDetailModal.value = true
  }

  function closeDetailPanel() {
    showDetailPanel.value = false
  }

  function closeDetailModal() {
    showDetailModal.value = false
  }

  function settlementLabel(method?: string | null) {
    if (!method) return 'انتخاب‌نشده'
    return method === 'check' ? 'چکی' : 'نقدی'
  }

  const statusSaving = ref(false)

  async function changeStatus(payload: {
    orderId: string
    status: RawOrderStatus
    note?: string
    reason?: string
    force?: boolean
  }) {
    if (statusSaving.value) return null
    statusSaving.value = true
    try {
      const updated = await ordersApi.updateStatus(payload.orderId, {
        status: payload.status,
        note: payload.note,
        reason: payload.reason,
        force: payload.force,
      })
      const mapped = mapAdminOrder(updated) as Order
      const index = orderList.value.findIndex((o) => o.id === payload.orderId)
      if (index >= 0) orderList.value[index] = { ...orderList.value[index]!, ...mapped }
      toast.success(`وضعیت سفارش به «${rawStatusLabel(payload.status)}» تغییر کرد.`)
      return mapped
    } catch (err) {
      toast.error(err instanceof ApiError ? err.message : 'تغییر وضعیت انجام نشد.')
      return null
    } finally {
      statusSaving.value = false
    }
  }

  function goPricing(order: Order) {
    router.push(`/orders/${order.id}/pricing`)
  }

  function goChecks(order: Order) {
    router.push(`/orders/${order.id}/checks`)
  }

  function goCashReceipt(order: Order) {
    router.push({ path: '/cash-payments', query: { order: order.orderNumber } })
  }

  function openAddModal() {
    Object.assign(form, emptyForm())
    formError.value = ''
    showAddModal.value = true
    void loadCustomers()
  }

  function closeAddModal() {
    showAddModal.value = false
    formError.value = ''
  }

  async function submitAddOrder() {
    if (!isFormValid.value) {
      formError.value = 'انتخاب مشتری و شرکت الزامی است.'
      return
    }

    saving.value = true
    try {
      const created = await ordersApi.create({
        companyId: form.companyId,
        customerId: form.customerId || undefined,
        userId: form.customerId || undefined,
        customerName: form.customerName.trim(),
        customerPhone: form.customerPhone.trim() || undefined,
        settlementMethod: form.settlementMethod,
        meterage: form.meterage,
      })
      const mapped = mapAdminOrder(created) as Order
      orderList.value.unshift(mapped)
      selectedOrderId.value = mapped.id
      toast.success('سفارش جدید ثبت شد.')
      closeAddModal()
    } catch (err) {
      toast.error(err instanceof ApiError ? err.message : 'ثبت سفارش انجام نشد.')
    } finally {
      saving.value = false
    }
  }

  return {
    companies,
    customers,
    activeCustomers,
    applyCustomer,
    loadCustomers,
    orderList,
    activeTab,
    selectedOrderId,
    searchQuery,
    showAddModal,
    showDetailPanel,
    showDetailModal,
    formError,
    form,
    isFormValid,
    filteredOrders,
    selectedOrder,
    selectOrder,
    openOrderDetail,
    closeDetailPanel,
    closeDetailModal,
    settlementLabel,
    changeStatus,
    statusSaving,
    goPricing,
    goChecks,
    goCashReceipt,
    openAddModal,
    closeAddModal,
    submitAddOrder,
    saving,
  }
}

export type OrdersPageContext = ReturnType<typeof useOrdersPage>

export const ORDERS_PAGE_KEY: InjectionKey<OrdersPageContext> = Symbol('orders-page')

export function provideOrdersPage() {
  const ctx = useOrdersPage()
  provide(ORDERS_PAGE_KEY, ctx)
  return ctx
}

export function useOrdersPageContext() {
  const ctx = inject(ORDERS_PAGE_KEY)
  if (!ctx) throw new Error('Orders page context is missing')
  return ctx
}