first commit

internal/pkg/rand/rand.go

@@ -0,0 +1,53 @@
+package rand
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"fmt"
+	randv2 "math/rand/v2"
+	"strings"
+)
+
+const alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+
+func Bytes(n int) ([]byte, error) {
+	b := make([]byte, n)
+	nRead, err := rand.Read(b)
+	if err != nil {
+		return nil, fmt.Errorf("bytes: %w", err)
+	}
+	if nRead < n {
+		return nil, fmt.Errorf("bytes: didn't read enough random bytes")
+	}
+	return b, nil
+}
+
+func String(n int) (string, error) {
+	b, err := Bytes(n)
+	if err != nil {
+		return "", fmt.Errorf("string: %w", err)
+	}
+	return base64.URLEncoding.EncodeToString(b), nil
+}
+
+func RandomInt(n int) string {
+	letters := []byte("0123456789")
+	l := len(letters)
+	result := make([]byte, n)
+	for i := range result {
+		result[i] = letters[randv2.IntN(l)]
+	}
+	return string(result)
+}
+
+func RandomString(n int) string {
+	var sb strings.Builder
+	k := len(alphabet)
+
+	for i := 0; i < n; i++ {
+		c := alphabet[randv2.IntN(k)]
+		sb.WriteByte(c)
+	}
+
+	return sb.String()
+}