//: Playground - noun: a place where people can play
protocol CashSuper {
func acceptCash(_ money: Double) -> Double
}
struct CashNormal: CashSuper {
func acceptCash(_ money: Double) -> Double {
return money
}
}
struct CashRebate: CashSuper {
let monenyRebate: Double
init(_ moneyRebate: Double) {
self.monenyRebate = moneyRebate
}
func acceptCash(_ money: Double) -> Double {
return money * monenyRebate
}
}
struct CashReturn: CashSuper {
let moneyCondition: Double
let moneyReturn: Double
init(_ moneyCondition: Double, _ moneyReturn: Double) {
self.moneyCondition = moneyCondition
self.moneyReturn = moneyReturn
}
func acceptCash(_ money: Double) -> Double {
var result = money
if result >= moneyCondition {
result = money - Double(Int(money / moneyCondition)) * moneyReturn
}
return result
}
}
enum DiscountWays {
case byDefault, twentyPersentOff, every300Get100Return
}
struct CashContext {
private let cs: CashSuper
init(_ cs: CashSuper) {
self.cs = cs
}
func getResult(_ money: Double) -> Double {
return cs.acceptCash(money)
}
}
struct CashContextWithSimpleFactoryPattern {
private let cs: CashSuper
init(_ type: DiscountWays) {
switch type {
case .twentyPersentOff:
cs = CashRebate(0.8)
case .every300Get100Return:
cs = CashReturn(300, 100)
default:
cs = CashNormal()
}
}
func getResult(_ money: Double) -> Double {
return cs.acceptCash(money)
}
}
// 策略模式
var type = DiscountWays.twentyPersentOff
var cc: CashContext
switch type {
case .twentyPersentOff:
cc = CashContext(CashRebate(0.8))
case .every300Get100Return:
cc = CashContext(CashReturn(300, 100))
default:
cc = CashContext(CashNormal())
}
print(cc.getResult(200))
var cs = CashContextWithSimpleFactoryPattern(.byDefault)
print(cs.getResult(100))
cs = CashContextWithSimpleFactoryPattern(.twentyPersentOff)
print(cs.getResult(200.5))
cs = CashContextWithSimpleFactoryPattern(.every300Get100Return)
print(cs.getResult(650))
