Merge pull request #4 from dominikwinter/3-add-flags-to-make-the-app-…

…flexible

add the possibility to change the behavior via flags to make the app …

Makefile

@@ -1,23 +1,26 @@
-.PHONY: default t test b build i install c clean r release
+.PHONY: default test build install clean release
 
 default: build
 
-t test:
-	go test -v
+run:
+	go run cmd/genpno/main.go
 
-b build:
-	go build
+test:
+	go test -v --race -cpu 2 -cover -shuffle on -vet '' ./...
 
-i install:
-	go install
+build:
+	go build -o bin/genpno cmd/genpno/main.go
 
-c clean:
+install:
+	go install bin/genpno
+
+clean:
 	go mod tidy
 
-r release:
+release:
 	mkdir -p bin
-	CGO_ENABLED=0 GOOS=darwin GOARCH=arm64 go build -o bin/genpno-macos-arm64
-	CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o bin/genpno-linux-amd64
-	CGO_ENABLED=0 GOOS=linux GOARCH=386 go build -o bin/genpno-linux-386
-	CGO_ENABLED=0 GOOS=windows GOARCH=amd64 go build -o bin/genpno-windows-amd64.exe
-	CGO_ENABLED=0 GOOS=windows GOARCH=386 go build -o bin/genpno-windows-386.exe
+	CGO_ENABLED=0 GOOS=darwin GOARCH=arm64 go build -o bin/genpno-macos-arm64 cmd/genpno/main.go
+	CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o bin/genpno-linux-amd64 cmd/genpno/main.go
+	CGO_ENABLED=0 GOOS=linux GOARCH=386 go build -o bin/genpno-linux-386 cmd/genpno/main.go
+	CGO_ENABLED=0 GOOS=windows GOARCH=amd64 go build -o bin/genpno-windows-amd64.exe cmd/genpno/main.go
+	CGO_ENABLED=0 GOOS=windows GOARCH=386 go build -o bin/genpno-windows-386.exe cmd/genpno/main.go

cmd/genpno/main.go

@@ -0,0 +1,42 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+
+	"github.com/dominikwinter/genpno/internal/generator"
+)
+
+func main() {
+	helpFlag := flag.Bool("h", false, "Help")
+	verboseFlag := flag.Bool("v", false, "Verbose")
+
+	dateFlag := flag.String("d", "", "Date (format: yyyymmdd) (default random)")
+	countryFlag := flag.String("c", "", "Country code (default random)")
+	genderFlag := flag.String("g", "", "Gender (m/f) (default random)")
+	formatFlag := flag.String("f", "", `Output forma (default 3):
+	1. yymmddccgn
+	2. yymmdd-ccgn
+	3. yyyymmddccgn
+	4. yyyymmdd-ccgn`)
+
+	flag.Parse()
+
+	if *helpFlag {
+		flag.Usage()
+		return
+	}
+
+	pno, err := generator.GeneratePno(*dateFlag, *countryFlag, *genderFlag, *formatFlag)
+
+	if err != nil {
+		if *verboseFlag {
+			panic(err)
+		} else {
+			fmt.Println(err)
+			return
+		}
+	}
+
+	fmt.Println(pno)
+}

internal/generator/checksum.go

@@ -0,0 +1,39 @@
+package generator
+
+import (
+	"fmt"
+	"strconv"
+)
+
+func GetShortDate(date string) string {
+	return date[2:]
+}
+
+func GetChecksum(date, country, gender string) (string, error) {
+	if l := len(date); l != 8 {
+		return "", fmt.Errorf("date is not 8 characters long, but '%d'", l)
+	}
+
+	shortDate := GetShortDate(date)
+	num := shortDate + country + gender
+	numLen := len(num)
+
+	var checksum int
+
+	for i := numLen - 2; i >= 0; i -= 2 {
+		n := num[i] - '0'
+		checksum += int(n)
+	}
+
+	for i := numLen - 1; i >= 0; i -= 2 {
+		n := (num[i] - '0') * 2
+
+		if n > 9 {
+			n -= 9
+		}
+
+		checksum += int(n)
+	}
+
+	return strconv.Itoa(checksum * 9 % 10), nil
+}

internal/generator/country.go

@@ -0,0 +1,26 @@
+package generator
+
+import (
+	"fmt"
+	"math/rand"
+	"strconv"
+)
+
+func GetCountry(country string) (string, error) {
+	if l := len(country); l != 2 {
+		return "", fmt.Errorf("country is not 2 characters long, but '%d'", l)
+	}
+
+	c, err := strconv.Atoi(country)
+	if err != nil {
+		return "", fmt.Errorf("could not parse country '%s': %w", country, err)
+	}
+
+	return fmt.Sprintf("%02d", c), nil
+}
+
+func GetRandomCountry() (string, error) {
+	country := rand.Intn(99)
+
+	return fmt.Sprintf("%02d", country), nil
+}

internal/generator/date.go

@@ -0,0 +1,32 @@
+package generator
+
+import (
+	"fmt"
+	"math/rand"
+	"time"
+)
+
+const DATE_FORMAT = "20060102"
+
+func GetRandomDate() (string, error) {
+	now := time.Now()
+
+	min := now.AddDate(-100, 0, 0).Unix()
+	max := now.AddDate(-18, 0, 0).Unix()
+
+	delta := max - min
+	sec := rand.Int63n(delta) + min
+
+	return time.Unix(sec, 0).Format(DATE_FORMAT), nil
+}
+
+func GetDate(date string) (string, error) {
+	d, err := time.Parse(DATE_FORMAT, date)
+	if err != nil {
+		return "", fmt.Errorf("could not parse date: '%s': %w", date, err)
+	}
+
+	sec := d.Unix()
+
+	return time.Unix(sec, 0).Format(DATE_FORMAT), nil
+}

internal/generator/format.go

@@ -0,0 +1,22 @@
+package generator
+
+import "fmt"
+
+func GetFormat(formatFlag, date, country, gender, checksum string) (string, error) {
+	switch formatFlag {
+	case "1", "yymmddccgn":
+		return GetShortDate(date) + country + gender + checksum, nil
+
+	case "2", "yymmdd-ccgn":
+		return GetShortDate(date) + "-" + country + gender + checksum, nil
+
+	case "3", "yyyymmddccgn", "":
+		return date + country + gender + checksum, nil
+
+	case "4", "yyyymmdd-ccgn":
+		return date + "-" + country + gender + checksum, nil
+
+	default:
+		return "", fmt.Errorf("unknown format '%s'", formatFlag)
+	}
+}

internal/generator/gender.go

@@ -0,0 +1,35 @@
+package generator
+
+import (
+	"fmt"
+	"math/rand"
+	"strconv"
+)
+
+func GetGenderNumber(gender string) (string, error) {
+	var num int
+
+	switch gender {
+	case "m":
+		// generate random single digit odd number
+		num = rand.Intn(10) | 1 // force last bit to 1
+
+	case "f":
+		// generate random single digit even number
+		num = rand.Intn(8)
+		num += num & 1 // force last bit to 0
+
+	default:
+		return "", fmt.Errorf("unknown gender '%s'", gender)
+	}
+
+	return strconv.Itoa(num), nil
+}
+
+func GetRandomGenderNumber() (string, error) {
+	if n := rand.Intn(2); n == 0 {
+		return GetGenderNumber("m")
+	} else {
+		return GetGenderNumber("f")
+	}
+}

internal/generator/generate.go

@@ -0,0 +1,39 @@
+package generator
+
+import "fmt"
+
+func GeneratePno(dateFlag, countryFlag, genderFlag, formatFlag string) (string, error) {
+	date, err := GenerateStr(dateFlag, GetDate, GetRandomDate)
+	if err != nil {
+		return "", fmt.Errorf("failed to get date: %w", err)
+	}
+
+	country, err := GenerateStr(countryFlag, GetCountry, GetRandomCountry)
+	if err != nil {
+		return "", fmt.Errorf("failed to get country: %w", err)
+	}
+
+	gender, err := GenerateStr(genderFlag, GetGenderNumber, GetRandomGenderNumber)
+	if err != nil {
+		return "", fmt.Errorf("failed to get gender: %w", err)
+	}
+
+	checksum, err := GetChecksum(date, country, gender)
+	if err != nil {
+		return "", fmt.Errorf("failed to get checksum: %w", err)
+	}
+
+	return GetFormat(formatFlag, date, country, gender, checksum)
+}
+
+func GenerateStr[I string, O string](
+	flag I,
+	getFunc func(I) (O, error),
+	getRandomFunc func() (O, error),
+) (O, error) {
+	if len(flag) > 0 {
+		return getFunc(flag)
+	}
+
+	return getRandomFunc()
+}

internal/generator/generate_test.go

@@ -0,0 +1,98 @@
+package generator
+
+import (
+	"strconv"
+	"testing"
+)
+
+func Test_GetRandomDate(t *testing.T) {
+	for i := 0; i < 1000; i++ {
+		date, err := GetRandomDate()
+		if err != nil {
+			t.Error(err)
+		}
+
+		if l := len(date); l != 8 {
+			t.Errorf("Date is not 8 characters long, but %d", l)
+		}
+	}
+}
+
+func Test_getRandomBirthCountry(t *testing.T) {
+	for i := 0; i < 1000; i++ {
+		country, err := GetRandomCountry()
+		if err != nil {
+			t.Error(err)
+		}
+
+		if l := len(country); l != 2 {
+			t.Errorf("Country is not 2 characters long, but %d", l)
+		}
+	}
+}
+
+func Test_getRandomGenderNumber(t *testing.T) {
+	for i := 0; i < 1000; i++ {
+		gender, err := GetRandomGenderNumber()
+		if err != nil {
+			t.Error(err)
+		}
+
+		if l := len(gender); l != 1 {
+			t.Errorf("Gender is not 1 characters long, but %d", l)
+		}
+	}
+}
+
+func Test_GetChecksum(t *testing.T) {
+	date := "19800101"
+	country := "12"
+	gender := "1"
+
+	checksum, err := GetChecksum(date, country, gender)
+	if err != nil {
+		t.Error(err)
+	}
+
+	if l := len(checksum); l != 1 {
+		t.Errorf("Checksum is not 1 characters long, but %d", l)
+	}
+}
+
+func Test_GetGenderNumber(t *testing.T) {
+	t.Run("male", func(t *testing.T) {
+		for i := 0; i < 1000; i++ {
+			str, err := GetGenderNumber("m")
+			if err != nil {
+				t.Error(err)
+			}
+
+			num, err := strconv.Atoi(str)
+			if err != nil {
+				t.Error(err)
+			}
+
+			if num%2 == 0 {
+				t.Errorf("%d is not a male random number", num)
+			}
+		}
+	})
+
+	t.Run("female", func(t *testing.T) {
+		for i := 0; i < 1000; i++ {
+			str, err := GetGenderNumber("f")
+			if err != nil {
+				t.Error(err)
+			}
+
+			num, err := strconv.Atoi(str)
+			if err != nil {
+				t.Error(err)
+			}
+
+			if num%2 != 0 {
+				t.Errorf("%d is not a female random number", num)
+			}
+		}
+	})
+}