import _ from 'lodash'
import calculateBatchItem from './calculateBatchItem'

export default function calculateOrder (order: IAppOrder, promoDiscount: number = 0, riceCoinDiscount: number = 0): IAppOrder {
  // * 餐點原價
  let originalTotal = 0
  // * 餐點折扣
  let calculatedDiscountTotal = 0
  // * 餐點服務費
  let surchargeTotal = 0
  // * 餐點總價
  let total = 0
  order.batches.forEach(batch => {
    const calculatedItems = batch.items.map(item => calculateBatchItem(item, order))
    originalTotal += _.sumBy(calculatedItems, 'originalTotal')
    calculatedDiscountTotal += _.sumBy(calculatedItems, 'totalDiscount')
    surchargeTotal += _.sumBy(calculatedItems, 'surcharge')
    total += _.sumBy(calculatedItems, 'total')
  })

  // * 運費原價
  let originalShippingFee = 0
  if (order.shipping != null && order.deliveryType === 'storeDelivery') {
    if (order.shipping.totalFee != null) {
      originalShippingFee = order.shipping.totalFee
    }
    if (order.originalShippingFee != null) {
      originalShippingFee = order.originalShippingFee
    }
  }
  // * 運費折扣
  let calculatedShippingFeeDiscount = 0
  // * 運費總價
  let shippingFeeTotal = originalShippingFee

  // 運費折扣
  if (order.deliveryType === 'storeDelivery' && order.shipping != null && total > order.shipping.minAmount && order.shipping.discounts[0] != null) {
    const shippingDiscount = order.shipping.discounts[0]
    calculatedShippingFeeDiscount += shippingDiscount.amount
    shippingFeeTotal -= shippingDiscount.amount
  }

  // 折扣碼
  if (promoDiscount > 0) {
    const newTotal = total -= promoDiscount
    // 實際折扣金額
    const diffTotal = total - newTotal
    // 累計折扣金額
    calculatedDiscountTotal += diffTotal
    // 更新 total
    total = newTotal
  }

  // calculate order level modifiers
  order.modifiers.forEach(modifier => {
    let newTotal = total
    let newShippingFeeTotal = shippingFeeTotal

    // 全單折扣或 RiceCoin
    if (modifier.applyTo === 'ALL' || modifier.type === 'RICECOIN') {
      // 將 total 及 shippingFeeTotal 計算 percent 折扣
      newTotal = total * (100 + modifier.percent) / 100
      newShippingFeeTotal = shippingFeeTotal * (100 + modifier.percent) / 100

      // modifier amount 優先折在運費
      if (modifier.amount > shippingFeeTotal) {
        // 折扣金額大於運費，折完運費繼續折餐點
        shippingFeeTotal -= modifier.amount
        newTotal -= (modifier.amount - newShippingFeeTotal)
      } else {
        // 只折在運費
        newShippingFeeTotal -= modifier.amount
      }
    }

    // 餐點折扣或優惠碼和店家給的折扣
    if (modifier.applyTo === 'PRODUCT' || modifier.type === 'PROMOCODE' || modifier.type === 'MERCHANT') {
      // 計算折價後總計運費
      newTotal = total * (100 + modifier.percent) / 100 + modifier.amount
    }

    // 運費折扣
    if (modifier.applyTo === 'SHIPPING' || modifier.type === 'SHIPPING_DISCOUNT') {
      // 計算折價後總計運費
      newShippingFeeTotal = shippingFeeTotal * (100 + modifier.percent) / 100 + modifier.amount
    }

    // 計算折了多少
    const diffTotal = total - newTotal
    const diffShippingFee = shippingFeeTotal - newShippingFeeTotal

    // 累計折了多少
    if (diffTotal > 0) {
      // 折扣
      calculatedDiscountTotal += diffTotal
    } else {
      // 費用
      surchargeTotal += Math.abs(diffTotal)
    }
    calculatedShippingFeeDiscount += diffShippingFee

    // 更新總計金額
    total = newTotal
    shippingFeeTotal = newShippingFeeTotal
  })

  // RiceCoin
  if (riceCoinDiscount > 0) {
    let newTotal = total
    let newShippingFeeTotal = shippingFeeTotal

    // 優先折在運費
    if (riceCoinDiscount > shippingFeeTotal) {
      // 折扣金額大於運費，折完運費繼續折餐點
      shippingFeeTotal -= riceCoinDiscount
      newTotal -= (riceCoinDiscount - newShippingFeeTotal)
    } else {
      // 只折在運費
      newShippingFeeTotal -= riceCoinDiscount
    }

    // 計算折了多少
    const diffTotal = total - newTotal
    const diffShippingFee = shippingFeeTotal - newShippingFeeTotal

    // 累計折了多少
    calculatedDiscountTotal += diffTotal
    calculatedShippingFeeDiscount += diffShippingFee

    // 更新總計金額
    total = newTotal
    shippingFeeTotal = newShippingFeeTotal
  }

  order.originalTotal = originalTotal
  order.calculatedDiscountTotal = calculatedDiscountTotal
  order.surchargeTotal = surchargeTotal
  order.total = total
  order.originalShippingFee = originalShippingFee
  order.discountShippingFee = calculatedShippingFeeDiscount
  order.shippingFee = shippingFeeTotal

  return order
}