memento.go

package main

import (
	"fmt"
	"time"
	"strings"
)

type CarType int
const (
	Kawasaki CarType = iota
	Honda
	Suzuki
	Ducati
)

type ServiceData struct{
	Id int
	PersonalName string
	Model CarType
	Price float32
	Date time.Time
}

var counter *int
var dataHistoryList map[int]ServiceData

func UpdateDataChange(model *ServiceData,counter *int) {
	*counter++
	model.Id=*counter
	dataHistoryList[*counter] = *model
}

func Undo() ServiceData{
	index := *counter -1
	if index >=1 {
		*counter=index
		return dataHistoryList[index]
	}
	return dataHistoryList[*counter]
}

func Redo() ServiceData{
	index := *counter +1
	if index <= len(dataHistoryList)-1{
		*counter=index
		return dataHistoryList[index]
	}
	return dataHistoryList[*counter +1]
}

func main() {
	counter = new(int)
	dataHistoryList = make(map[int]ServiceData)
	mainData := ServiceData{PersonalName: "Bora Kasmer", Model: Honda, Price: 385.50, Date: time.Now()}

	UpdateDataChange(&mainData,counter)
	fmt.Println(mainData)

	mainData = ServiceData{PersonalName: "Kent Back", Model: Kawasaki, Price: 1650.50, Date: time.Now()}
	UpdateDataChange(&mainData,counter)
	fmt.Println(mainData)

	mainData = ServiceData{PersonalName: "Martin Fowler", Model: Ducati, Price: 2350.50, Date: time.Now()}
	UpdateDataChange(&mainData,counter)
	fmt.Println(mainData)
	fmt.Println(strings.Repeat("-",100))

	mainData= Undo()
	fmt.Println("1 Geri Git: ",mainData)

	fmt.Println(strings.Repeat("-",100))

	mainData= Undo()
	fmt.Println("1 Geri Git: ",mainData)

	fmt.Println(strings.Repeat("-",100))

	mainData= Redo()
	fmt.Println("1 İleri Git: ",mainData)

	fmt.Println(strings.Repeat("-",100))

	mainData= Redo()
	fmt.Println("1 İleri Git: ",mainData)
}