progress on the input reading

inputHandler.go

+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+)
+
+func getFormatVersionIndex() int{
+	fmt.Println("\n\nThe available format Versions are:")
+
+	for i := 0; i < len(supportedVersions); i++ {
+		fmt.Printf("[%d] -> {%d.%d.%d}\n",i, supportedVersions[i].Major,supportedVersions[i].Minor,supportedVersions[i].Patch)
+	}
+
+	fmt.Println("Inside of the brackets [] are the indices, which are needed to select the version.")
+
+	var input int = 0
+	scanner := bufio.NewScanner(os.Stdin)
+	var err error = nil
+
+	for ok := true; ok; {
+		fmt.Println("Please enter the index of the version you want to use:")
+		scanner.Scan()
+		input, err = strconv.Atoi(scanner.Text())
+
+		if err != nil || input < 0 || input >= len(supportedVersions) {
+			// handle invalid input
+			fmt.Println("please enter a valid value")
+			continue
+		}
+
+		ok = false
+		fmt.Printf("\n\n")
+	}
+
+	return input
+}
+
+func readTrainName() string{
+	fmt.Println("Enter the name of the train:")
+
+	scanner := bufio.NewScanner(os.Stdin)
+	scanner.Scan()
+
+	fmt.Printf("\n\n")
+	return scanner.Text()
+}
+
+func readTrainMass() float64{
+	var input float64 = 0
+	scanner := bufio.NewScanner(os.Stdin)
+	var err error = nil
+
+	for ok := true; ok; {
+		fmt.Println("Please enter the mass of the train:")
+		scanner.Scan()
+		input, err = strconv.ParseFloat(scanner.Text(),64)
+
+		if err != nil || input < 0 {
+			// handle invalid input
+			fmt.Println("please enter a valid value")
+			continue
+		}
+
+		ok = false
+		fmt.Printf("\n\n")
+	}
+
+	return input
+}
+
+func readMaxVelocity() float64{
+	var input float64 = 0
+	scanner := bufio.NewScanner(os.Stdin)
+	var err error = nil
+
+	for ok := true; ok; {
+		fmt.Println("Please enter the maximum velocity of the train:")
+		scanner.Scan()
+		input, err = strconv.ParseFloat(scanner.Text(),64)
+
+		if err != nil || input < 0 {
+			// handle invalid input
+			fmt.Println("please enter a valid value")
+			continue
+		}
+
+		ok = false
+		fmt.Printf("\n\n")
+	}
+
+	return input
+}
+
+func readMaxAcceleration() float64{
+	var input float64 = 0
+	scanner := bufio.NewScanner(os.Stdin)
+	var err error = nil
+
+	for ok := true; ok; {
+		fmt.Println("Please enter the maximum acceleration of the train:")
+		scanner.Scan()
+		input, err = strconv.ParseFloat(scanner.Text(),64)
+
+		if err != nil || input < 0 {
+			// handle invalid input
+			fmt.Println("please enter a valid value")
+			continue
+		}
+
+		ok = false
+		fmt.Printf("\n\n")
+	}
+
+	return input
+}
\ No newline at end of file

main.go

 package main
 
-import "fmt"
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"log"
+)
+
+var supportedVersions = [...]versionStruct { {0,4,0} }
 
 func main(){
-	fmt.Println("Hello World!")
+
+	fmt.Println("Welcome to the train creator.")
+	fmt.Println("\nFirst you will have to select which format version you want to target.")
+	fmt.Println("The format version determines the features that can be used.")
+	fmt.Println("It is recommended to use the latest version if possible.")
+
+	selectedVersion := supportedVersions[getFormatVersionIndex()]
+	fmt.Printf("You have selected the format Version {%d.%d.%d}\n",selectedVersion.Major,selectedVersion.Minor,selectedVersion.Patch)
+	create(selectedVersion)
+}
+
+func create(version versionStruct){
+	var trainConfig trainProperties
+
+	switch version {
+	case versionStruct{0,4,0}:
+		tmp := createTrainProperties040()
+		trainConfig = tmp.cast()
+	default:
+		trainConfig = createTrainProperties()
+	}
+
+	filename := trainConfig.Name + ".json"
+	jOutput, err := json.MarshalIndent(trainConfig, "", "")
+	if err != nil {
+		log.Fatalln(err.Error())
+		return
+	}
+
+	err = ioutil.WriteFile(filename, jOutput, 0644)
+
+	if err != nil {
+		log.Fatalln(err.Error())
+		return
+	}
+
+	fmt.Println("Created the train file " + filename)
 }

train_properties.go

+package main
+
+type versionStruct struct {
+	Major int64
+	Minor int64
+	Patch int64
+}
+
+type trainProperties struct{
+	trainProperties040
+}
+
+type trainProperties040 struct {
+	Name    string   `json:"name"`
+	Mass	float64   `json:"mass"`
+	MaxVelocity	float64   `json:"maxVelocity"`
+	MaxAcceleration	float64   `json:"maxAcceleration"`
+	FormatVersion    string   `json:"formatVersion"`
+	TrackDrag	float64   `json:"trackDrag"`
+	AirDrag	float64   `json:"airDrag"`
+	VelocityUnit    string   `json:"velocityUnit"`
+}
+
+func (b *trainProperties040) cast() trainProperties{
+	var retval trainProperties
+	retval.Name = b.Name
+	retval.Mass = b.Mass
+	retval.MaxVelocity = b.MaxVelocity
+	retval.MaxAcceleration = b.MaxAcceleration
+	retval.FormatVersion = b.FormatVersion
+	retval.TrackDrag = b.TrackDrag
+	retval.AirDrag = b.AirDrag
+	retval.VelocityUnit = b.VelocityUnit
+	return retval
+}
+
+func createTrainProperties() trainProperties{
+	tmp := createTrainProperties040()
+	return tmp.cast()
+}
+
+func createTrainProperties040() trainProperties040{
+	var retVal trainProperties040
+	retVal.FormatVersion = "0.4.0"
+	retVal.Name = readTrainName()
+	retVal.Mass = readTrainMass()
+
+	return retVal
+}