import { defineStore } from 'pinia'
import { ref, reactive, computed } from 'vue'
import type { ChangeOrderFormData, ForecastChangeOrder } from '@/types/forecast-order'
import type { ForecastOrder } from '@/types/forecast-order'
import { getById } from '@/api/forecast/forecast-order'
import { saveChangeDraft, submitChange, approveChange, rejectChange, withdrawChangeOrder, findChangeOrdersByForecastId } from '@/api/forecast/forecast-order'
import { useI18n } from 'vue-i18n'
import { reqIsSucceed } from '@/utils'
import { handleApiError } from '@/utils/errorHandler'
import { ElMessage } from 'element-plus'

export const useChangeOrderFormStore = defineStore('changeOrderForm', () => {
  const { t } = useI18n()
  // State
  const changeFcId = ref<number | undefined>(undefined)
  const changeId = ref<number | undefined>(undefined)
  const snapshot = ref<{
    originalCustomerCode?: string
    originalCustomerName?: string
    originalDeliveryDate?: string
    originalCustomsManualNo?: string
    remainingQty?: number
    standardization?: string
    foStatus?: string
  }>({})
  const changeForm = reactive<ChangeOrderFormData>({
    forecastOrderId: 0,
  })
  const errors = ref<Record<string, string>>({})
  const submitting = ref(false)
  const actionLoading = ref(false)
  const modalVisible = ref(false)
  const approveModalVisible = ref(false)
  const changeList = ref<ForecastChangeOrder[]>([])
  const forecastOrder = ref<ForecastOrder | null>(null)

  // Getters
  const canRelease = computed(() => {
    if (!snapshot.value.standardization || !snapshot.value.foStatus) return false
    return snapshot.value.standardization === 'STANDARD' &&
      (snapshot.value.foStatus === 'SCHEDULED' || snapshot.value.foStatus === 'PARTIAL_CONVERTED')
  })

  /**
   * 是否有未完成的变更单（草稿/已提交状态）
   */
  const hasPendingChange = computed(() => {
    return changeList.value.some(
      (ch) => ch.coStatus === 'DRAFT' || ch.coStatus === 'SUBMITTED',
    )
  })

  // Actions
  async function initCreate(forecastOrderId: number) {
    changeFcId.value = forecastOrderId
    changeId.value = undefined
    Object.assign(changeForm, {
      changeOrderId: undefined,
      forecastOrderId,
      newCustomerCode: '',
      newCustomerName: '',
      newDeliveryDate: '',
      newCustomsManualNo: '',
      releaseQty: undefined,
      rejectReason: '',
      versionNum: undefined,
    })
    errors.value = {}

    // 加载预测单详情作为快照
    try {
      const res = await getById(forecastOrderId)
      if (reqIsSucceed(res)) {
        const fo = res.data
        forecastOrder.value = fo
        snapshot.value = {
          originalCustomerCode: fo.customerCode,
          originalCustomerName: fo.customerName,
          originalDeliveryDate: fo.expectedDeliveryDate,
          originalCustomsManualNo: fo.customsManualNo || '',
          remainingQty: (fo.actualScheduleQty || 0) - (fo.convertedQty || 0) - (fo.releasedQty || 0),
          standardization: fo.standardization,
          foStatus: fo.foStatus,
          productCode: fo.productCode,
        }
      }
    } catch (error: unknown) {
      const err = error as { code?: string; message?: string }
      handleApiError(err?.code || 'unknown', err?.message)
    }
    modalVisible.value = true
  }

  function updateField<K extends keyof ChangeOrderFormData>(field: K, value: ChangeOrderFormData[K]) {
    changeForm[field] = value
    if (errors.value[field]) {
      delete errors.value[field]
    }
  }

  function validateForm(): boolean {
    errors.value = {}
    if (changeForm.releaseQty !== undefined && changeForm.releaseQty !== null) {
      const remaining = snapshot.value.remainingQty || 0
      if (changeForm.releaseQty > remaining) {
        errors.value.releaseQty = t('forecast-order.validation.releaseQtyExceeded', { remaining })
      }
      if (changeForm.releaseQty <= 0) {
        errors.value.releaseQty = t('forecast-order.validation.releaseQtyPositive')
      }
    }
    // 至少填写一个变更字段
    if (!changeForm.newCustomerCode && !changeForm.newDeliveryDate && !changeForm.newCustomsManualNo && !changeForm.releaseQty) {
      errors.value.general = t('forecast-order.validation.noChangeField')
    }
    return Object.keys(errors.value).length === 0
  }

  async function saveDraftAction() {
    if (submitting.value) return
    submitting.value = true
    try {
      const res = await saveChangeDraft({ params: { ...changeForm } })
      if (reqIsSucceed(res)) {
        ElMessage.success(t('forecast-order.toast.changeDraftSaved'))
        modalVisible.value = false
        return res.data
      } else {
        handleApiError(res.code, res.msg)
      }
    } catch (error: unknown) {
      const err = error as { code?: string; message?: string }
      handleApiError(err?.code || 'unknown', err?.message)
    } finally {
      submitting.value = false
    }
  }

  async function submitAction() {
    if (!validateForm()) return
    if (submitting.value) return
    submitting.value = true
    try {
      const res = await submitChange({ params: { ...changeForm } })
      if (reqIsSucceed(res)) {
        ElMessage.success(t('forecast-order.toast.changeSubmitted'))
        modalVisible.value = false
        return res.data
      } else {
        handleApiError(res.code, res.msg)
      }
    } catch (error: unknown) {
      const err = error as { code?: string; message?: string }
      handleApiError(err?.code || 'unknown', err?.message)
    } finally {
      submitting.value = false
    }
  }

  async function doApprove(changeOrderId: number) {
    actionLoading.value = true
    try {
      const res = await approveChange(changeOrderId)
      if (reqIsSucceed(res)) {
        ElMessage.success(t('forecast-order.toast.approveSuccess'))
        approveModalVisible.value = false
        return res.data
      } else {
        handleApiError(res.code, res.msg)
      }
    } catch (error: unknown) {
      const err = error as { code?: string; message?: string }
      handleApiError(err?.code || 'unknown', err?.message)
    } finally {
      actionLoading.value = false
    }
  }

  async function doReject(changeOrderId: number, rejectReason?: string) {
    actionLoading.value = true
    try {
      const res = await rejectChange({ params: { changeOrderId, rejectReason } })
      if (reqIsSucceed(res)) {
        ElMessage.success(t('forecast-order.toast.rejectSuccess'))
        approveModalVisible.value = false
        return res.data
      } else {
        handleApiError(res.code, res.msg)
      }
    } catch (error: unknown) {
      const err = error as { code?: string; message?: string }
      handleApiError(err?.code || 'unknown', err?.message)
    } finally {
      actionLoading.value = false
    }
  }

  async function doWithdraw(changeOrderId: number) {
    actionLoading.value = true
    try {
      const res = await withdrawChangeOrder(changeOrderId)
      if (reqIsSucceed(res)) {
        ElMessage.success(t('forecast-order.toast.withdrawSuccess'))
      } else {
        handleApiError(res.code, res.msg)
      }
    } catch (error: unknown) {
      const err = error as { code?: string; message?: string }
      handleApiError(err?.code || 'unknown', err?.message)
    } finally {
      actionLoading.value = false
    }
  }

  async function fetchChangeList(forecastOrderId: number) {
    try {
      const res = await findChangeOrdersByForecastId(forecastOrderId)
      if (reqIsSucceed(res)) {
        changeList.value = res.data || []
      }
    } catch (error: unknown) {
      const err = error as { code?: string; message?: string }
      handleApiError(err?.code || 'unknown', err?.message)
    }
  }

  function reset() {
    changeFcId.value = undefined
    changeId.value = undefined
    snapshot.value = {}
    errors.value = {}
    submitting.value = false
    modalVisible.value = false
    approveModalVisible.value = false
    changeList.value = []
  }

  return {
    changeFcId, changeId, snapshot, changeForm, errors, submitting, actionLoading,
    modalVisible, approveModalVisible, changeList, forecastOrder,
    canRelease, hasPendingChange,
    initCreate, updateField, validateForm, saveDraftAction, submitAction,
    doApprove, doReject, doWithdraw, fetchChangeList, reset,
  }
})