Merge pull request #9 from dominikwinter/8-add-validation

add validation feature

README.md

@@ -2,7 +2,7 @@
 
 # Swedish Personnummer Generator
 
-A simple command-line interface (CLI) application written in Go that generates valid [Swedish "Personnummer" (personal identification numbers)](https://en.wikipedia.org/wiki/Personal_identity_number_(Sweden)).
+A simple command-line interface (CLI) application written in Go that generates or validates [Swedish "Personnummer" (personal identification numbers)](https://en.wikipedia.org/wiki/Personal_identity_number_(Sweden)).
 
 ## Install
 
@@ -13,24 +13,35 @@ A simple command-line interface (CLI) application written in Go that generates v
   go install github.com/dominikwinter/pno@latest
   ```
 ## Usage
+generate a personnummer:
 ```bash
 pno gen -h
 
 Usage of pno gen:
   -c string
-      Country code (default random)
+        Country code (default random)
   -d string
-      Date (format: yyyymmdd) (default random)
+        Date (format: yyyymmdd) (default random)
   -f string
-      Output forma (default 3):
-        1. yymmddccgn
-        2. yymmdd-ccgn
-        3. yyyymmddccgn
-        4. yyyymmdd-ccgn
+        Output forma (default 3):
+                1. yymmddccgn
+                2. yymmdd-ccgn
+                3. yyyymmddccgn
+                4. yyyymmdd-ccgn
   -g string
-      Gender (m/f) (default random)
-  -h	Help
-  -v	Verbose
+        Gender (m/f) (default random)
+  -h    Help
+  -v    Verbose
+```
+
+validate a personnummer:
+```bash
+pno val -h
+
+Usage of pno val <pno>:
+  -e    Return exit code 1 if not valid
+  -h    Help
+  -v    Verbose
 ```
 
 ## Development

cmd/gen.go

@@ -7,7 +7,7 @@ import (
 	"github.com/dominikwinter/pno/internal/gen"
 )
 
-func Run(args []string) {
+func Gen(args []string) {
 	fs := flag.NewFlagSet("pno gen", flag.ExitOnError)
 
 	helpFlag := fs.Bool("h", false, "Help")

cmd/val.go

@@ -0,0 +1,49 @@
+package cmd
+
+import (
+	"flag"
+	"fmt"
+	"os"
+
+	"github.com/dominikwinter/pno/internal/val"
+)
+
+func Val(args []string) {
+	fs := flag.NewFlagSet("pno val <pno>", flag.ExitOnError)
+
+	helpFlag := fs.Bool("h", false, "Help")
+	verboseFlag := fs.Bool("v", false, "Verbose")
+	exitFlag := fs.Bool("e", false, "Return exit code 1 if not valid")
+
+	fs.Parse(args)
+
+	if *helpFlag || len(args) == 0 {
+		fs.Usage()
+		return
+	}
+
+	pno := args[len(args)-1]
+	valid, _, err := val.ValidatePno(pno)
+
+	if *verboseFlag {
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	if *exitFlag {
+		if valid {
+			os.Exit(0)
+		} else {
+			os.Exit(1)
+		}
+		return
+	} else {
+		if valid {
+			fmt.Println("valid")
+		} else {
+			fmt.Println("invalid")
+		}
+		return
+	}
+}

internal/val/validate.go

@@ -0,0 +1,67 @@
+package val
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+	"strconv"
+	"time"
+
+	"github.com/dominikwinter/pno/internal/gen"
+)
+
+var re = regexp.MustCompile(`(\d{2,4})(\d{2})(\d{2})-?(\d{2})(\d)(\d)`)
+
+func ValidatePno(pno string) (bool, string, error) {
+	results := re.FindAllStringSubmatch(pno, -1)
+
+	if len(results) != 1 {
+		return false, "", errors.New("invalid format")
+	}
+
+	matches := results[0]
+
+	if len(matches) != 7 {
+		return false, "", errors.New("invalid format")
+	}
+
+	year, err := fillYear(matches[1])
+
+	if err != nil {
+		return false, "", err
+	}
+
+	date := year + matches[2] + matches[3]
+	country := matches[4]
+	gender := matches[5]
+	checksum := matches[6]
+
+	genChecksum, err := gen.GetChecksum(date, country, gender)
+
+	if err != nil {
+		return false, "", err
+	}
+
+	return genChecksum == checksum, genChecksum, nil
+}
+
+func fillYear(year string) (string, error) {
+	if len(year) == 2 {
+		currentYear := time.Now().Year()
+		year, err := strconv.Atoi(year)
+
+		if err != nil {
+			return "", fmt.Errorf("invalid year input: %w", err)
+		}
+
+		century := currentYear / 100
+
+		if year < (currentYear % 100) {
+			century++
+		}
+
+		return strconv.Itoa(century*100 + year), nil
+	}
+
+	return year, nil
+}

internal/val/validate_test.go

@@ -0,0 +1,87 @@
+package val
+
+import (
+	"testing"
+)
+
+func Test_ValidatePno(t *testing.T) {
+	t.Run("valid", func(t *testing.T) {
+		tests := [...]string{
+			"4112098357",
+			"3311305498",
+			"7112050112",
+			"7412188927",
+			"3812145997",
+			"6701203199",
+			"8004113877",
+			"9806275906",
+			"2802107041",
+			"0007060833",
+			"991227-0171",
+			"720813-5637",
+			"370123-4878",
+			"350717-7297",
+			"871010-5225",
+			"651214-3329",
+			"041008-1400",
+			"750930-7117",
+			"821010-9701",
+			"200303178578",
+			"193902179021",
+			"198801266217",
+			"197511269453",
+			"200505206169",
+			"199304288872",
+			"195012150594",
+			"200003170933",
+			"196908054858",
+			"199702051559",
+			"200010201317",
+			"196106122234",
+			"19410308-0778",
+			"19341028-8843",
+			"19840928-9744",
+			"19340815-3322",
+			"19921220-7667",
+			"20000104-6416",
+			"19721218-8754",
+			"20020226-3695",
+		}
+
+		for _, pno := range tests {
+			valid, checksum, err := ValidatePno(pno)
+			if err != nil {
+				t.Error(err)
+			}
+
+			if !valid {
+				t.Errorf("'%s' should be a valid PNO. checksum is '%s'", pno, checksum)
+			}
+		}
+	})
+
+	t.Run("invalid", func(t *testing.T) {
+		tests := [...]string{
+			"198003257629",
+			"19800325762",
+			"1980032576",
+			"198003257",
+			"19800325",
+			"1980032",
+			"198003",
+			"19800",
+			"1980",
+			"198",
+			"19",
+			"1",
+		}
+
+		for _, pno := range tests {
+			valid, checksum, _ := ValidatePno(pno)
+
+			if valid {
+				t.Errorf("'%s' should be a invalid PNO. checksum is '%s'", pno, checksum)
+			}
+		}
+	})
+}

main.go

@@ -8,10 +8,11 @@ import (
 )
 
 func main() {
-	const usage = `Usage of pno <command> [<args>]:
+	const usage = `Usage of pno <command> [<args>]
 
   commands:
     gen     Generate a personal number
+    val     Validate a personal number
 
   args:
     -h      Help`
@@ -26,7 +27,11 @@ func main() {
 
 	switch command {
 	case "gen":
-		cmd.Run(args)
+		cmd.Gen(args)
+
+	case "val":
+		cmd.Val(args)
+
 	default:
 		fmt.Fprintf(os.Stderr, "Unrecognized command %s.\n\n%s\n", command, usage)
 		os.Exit(1)