優惠結果說明
讓我們用 2 個簡單的例子說明。
假設商品資料為：
ts
const a30: Commodity = {
key: '1',
name: 'A-30ml',
price: 6000
}
const a50: Commodity = {
key: '2',
name: 'A-50ml',
price: 9000
}優惠為「A 商品 30ml、50ml，任兩件 85 折」
ts
const promotionAnyTwoA15Off: Promotion = {
key: '5',
type: 'commodity-offer',
name: 'A 商品優惠',
description: '30ml、50ml，任兩件 85 折',
contents: [
{
condition: [
{
list: [ a50, a30 ],
comparison: {
logic: 'equal',
target: 'purchase-quantity',
value: 2
}
}
],
result: {
operator: 'mul',
value: 0.85
}
}
]
}一般結果
2 個 A 30ml
可以預期一定符合優惠，這時候得到的結果為：
ts
const result = [
{
"giveawayList": [],
"offsetList": [],
"originalItems": [
{
"commodity": a30,
"quantity": 2
}
],
"remainingItems": [],
"promotedList": [
{
"appliedList": [
{
"item": {
"commodity": a30,
"quantity": 2
}
}
],
"promotedContent": {
"condition": [
{
"list": [
{
"key": "1",
"name": "A",
"specifications": [
"30ml"
],
"price": 6000
},
{
"key": "2",
"name": "A",
"specifications": [
"50ml"
],
"price": 9000
}
],
"comparison": {
"logic": "equal",
"target": "purchase-quantity",
"value": 2
}
}
],
"result": {
"operator": "mul",
"value": 0.85
}
},
"promotion": {
"key": "5",
"type": "commodity-offer",
"name": "A 商品優惠",
"description": "30ml、50ml，任兩件 85 折",
"contents": [
{
"condition": [
{
"list": [
{
"key": "1",
"name": "A",
"specifications": [
"30ml"
],
"price": 6000
},
{
"key": "2",
"name": "A",
"specifications": [
"50ml"
],
"price": 9000
}
],
"comparison": {
"logic": "equal",
"target": "purchase-quantity",
"value": 2
}
}
],
"result": {
"operator": "mul",
"value": 0.85
}
}
]
}
}
]
}
]很長很長，讓我們一項一項看。
由於沒有贈品，所以 giveawayList 和 offsetList 都是空矩陣，所以這兩者先跳過不看。
originalItems
此欄位等於原始購買內容，所以就是 2 個 A 30ml。
json
"originalItems": [
{
"commodity": a30,
"quantity": 2
}
],remainingItems
此欄位表示沒有套用優惠，被剩下來的商品。
由於 2 個 A 30ml 都被加入優惠，沒有剩下任何商品，所以會得到空矩陣。
json
"remainingItems": [],promotedList
此欄位表示被套用優惠的商品與詳細商品細節。
其中 appliedList 為被套用的商品，也就是 2 個 A 30ml。
json
{
"appliedList": [
{
"item": {
"commodity": a30,
"quantity": 2
}
}
],
...
}剩下的欄位其實很單純：
- promotedContent 表示實際上符合的 contents
- promotion 則是優惠本體
所以那個很長的結果其實完全效於以下內容：
json
{
"promotedContent": promotionAnyTwoA15Off.contents[0],
"promotion": promotionAnyTwoA15Off
}3 個 A 30ml
和剛剛的例子只差在多了 1 個 A，可以預期 2 個 A 有套用優惠，最後剩下 1 個 A。
讓我們來看看結果：
ts
const result = [
{
"giveawayList": [],
"offsetList": [],
"originalItems": [
{
"commodity": a30,
"quantity": 3
}
],
"remainingItems": [
{
"commodity": a30,
"quantity": 1
}
],
"promotedList": [
{
"appliedList": [
{
"item": {
"commodity": a30,
"quantity": 2
}
}
],
"promotedContent": promotionAnyTwoA15Off.contents[0],
"promotion": promotionAnyTwoA15Off
}
]
}
]originalItems
3 個 A 30ml 沒錯。
json
"originalItems": [
{
"commodity": a30,
"quantity": 3
}
],remainingItems
由於 2 個 A 30ml 都被加入優惠，剩下 1 個 A
json
"remainingItems": [
{
"commodity": a30,
"quantity": 1
}
],promotedList
一樣套用了 2 個 A，所以會與上一個例子相同。
json
{
"appliedList": [
{
"item": {
"commodity": a30,
"quantity": 2
}
}
],
"promotedContent": promotionAnyTwoA15Off.contents[0],
"promotion": promotionAnyTwoA15Off
}贈品自動抵銷
autoOffsetMode 有以下模式：
single-type：
贈品種類只有一種時，自動抵銷商品。超過一種則不抵銷，同一般贈品。
multiple-types-from-highest：
不管種類多寡，都從價值最高的贈品開始抵銷。
使用範例
ts
const offsetPromotions = getPromotionsRanking({
items,
promotions,
autoOffsetMode: 'multiple-types-from-highest',
});假設有以下優惠：
ts
const promotion01: Promotion = {
key: '5',
type: 'commodity-offer',
name: 'A 商品優惠',
description: '買 A 系列 50ml 2 瓶，送 1 瓶 30ml',
contents: [
{
condition: [
{
list: [ a50 ],
comparison: {
logic: 'equal',
target: 'purchase-quantity',
value: 2
}
}
],
result: {
commodities: [ a30 ],
quantity: 1,
}
}
]
}
const promotion02: Promotion = {
key: '6',
type: 'commodity-offer',
name: 'A 商品優惠',
description: '買 A 系列任 5 瓶，送 A 系列任選 1 瓶',
contents: [
{
condition: [
{
list: [ a50, a30 ],
comparison: {
logic: 'equal',
target: 'purchase-quantity',
value: 5
}
}
],
result: {
commodities: [ a30, a50 ],
quantity: 1,
}
}
]
}2 瓶 A 50ml、1 瓶 A 30ml
這裡使用 promotion01 優惠，不難看出 1 瓶 A 30ml 會被自動抵銷。
由於贈品只有 1 種，所以不管是哪一種模式結果都會相同。
ts
const result: PromotionResult = {
giveawayList: [],
offsetList: [
{
item: { commodity: a30, quantity: 1 },
promotedContent: promotion01.contents[0],
promotion: promotion01,
},
],
originalItems: [
{ commodity: a50, quantity: 2 },
{ commodity: a30, quantity: 1 },
],
remainingItems: [],
promotedList: [
{
appliedList: [
{ item: { commodity: a50, quantity: 2 } }
],
promotedContent: promotion01.contents[0],
promotion: promotion01,
}
]
}可以看到 a30 跑到 offsetList 裡面去了。ლ(╹◡╹ლ)
6 瓶 A 50ml、1 瓶 A 30ml
這裡使用 promotion02 優惠，由於贈品有 2 種，所以這次不同模式結果會不同。
single-type
由於贈品有 2 種，所以不會自動抵銷。
ts
const result: PromotionResult = {
giveawayList: [
{
item: {
commodities: [ a30, a50 ], quantity: 1,
},
promotedContent: promotion01.contents[0],
promotion: promotion01,
},
],
offsetList: [],
originalItems: [
{ commodity: a50, quantity: 6 },
{ commodity: a30, quantity: 1 },
],
remainingItems: [
{ commodity: a50, quantity: 1 },
{ commodity: a30, quantity: 1 },
],
promotedList: [
{
appliedList: [
{
item: { commodity: a50, quantity: 5 }
}
],
promotedContent: promotion02.contents[0],
promotion: promotion02,
}
]
}可以看到 giveawayList 裡有東西了。(｡･∀･)ﾉﾞ
multiple-types-from-highest
此模式會從最貴的商品開始抵銷，所以會抵銷 a50，而非 a30。
ts
const result: PromotionResult = {
giveawayList: [],
offsetList: [
{
item: { commodity: a50, quantity: 1 },
promotedContent: promotion02.contents[0],
promotion: promotion02,
}
],
originalItems: [
{ commodity: a50, quantity: 6 },
{ commodity: a30, quantity: 1 },
],
remainingItems: [
{ commodity: a30, quantity: 1 },
],
promotedList: [
{
appliedList: [
{
item: { commodity: a50, quantity: 5 }
}
],
promotedContent: promotion02.contents[0],
promotion: promotion02,
}
]
}可以看到剩下的那一個 a50 跑到 offsetList 了。