Add onboard command

internal/util/util.go

@@ -1,8 +1,13 @@
 package util
 
 import (
+	"bytes"
 	"fmt"
 	"os"
+	"regexp"
+	"strings"
+	"unicode"
+	"unicode/utf8"
 
 	"github.com/ooni/probe-cli/internal/colors"
 )
@@ -17,3 +22,86 @@ func Fatal(err error) {
 	fmt.Fprintf(os.Stderr, "\n     %s %s\n\n", colors.Red("Error:"), err)
 	os.Exit(1)
 }
+
+// Finds the control character sequences (like colors)
+var ctrlFinder = regexp.MustCompile("\x1b\x5b[0-9]+\x6d")
+
+func EscapeAwareRuneCountInString(s string) int {
+	n := utf8.RuneCountInString(s)
+	for _, sm := range ctrlFinder.FindAllString(s, -1) {
+		n -= utf8.RuneCountInString(sm)
+	}
+	return n
+}
+
+func RightPad(str string, length int) string {
+	return str + strings.Repeat(" ", length-EscapeAwareRuneCountInString(str))
+}
+
+// WrapString wraps the given string within lim width in characters.
+//
+// Wrapping is currently naive and only happens at white-space. A future
+// version of the library will implement smarter wrapping. This means that
+// pathological cases can dramatically reach past the limit, such as a very
+// long word.
+// This is taken from: https://github.com/mitchellh/go-wordwrap/tree/f253961a26562056904822f2a52d4692347db1bd
+func WrapString(s string, lim uint) string {
+	// Initialize a buffer with a slightly larger size to account for breaks
+	init := make([]byte, 0, len(s))
+	buf := bytes.NewBuffer(init)
+
+	var current uint
+	var wordBuf, spaceBuf bytes.Buffer
+
+	for _, char := range s {
+		if char == '\n' {
+			if wordBuf.Len() == 0 {
+				if current+uint(spaceBuf.Len()) > lim {
+					current = 0
+				} else {
+					current += uint(spaceBuf.Len())
+					spaceBuf.WriteTo(buf)
+				}
+				spaceBuf.Reset()
+			} else {
+				current += uint(spaceBuf.Len() + wordBuf.Len())
+				spaceBuf.WriteTo(buf)
+				spaceBuf.Reset()
+				wordBuf.WriteTo(buf)
+				wordBuf.Reset()
+			}
+			buf.WriteRune(char)
+			current = 0
+		} else if unicode.IsSpace(char) {
+			if spaceBuf.Len() == 0 || wordBuf.Len() > 0 {
+				current += uint(spaceBuf.Len() + wordBuf.Len())
+				spaceBuf.WriteTo(buf)
+				spaceBuf.Reset()
+				wordBuf.WriteTo(buf)
+				wordBuf.Reset()
+			}
+
+			spaceBuf.WriteRune(char)
+		} else {
+
+			wordBuf.WriteRune(char)
+
+			if current+uint(spaceBuf.Len()+wordBuf.Len()) > lim && uint(wordBuf.Len()) < lim {
+				buf.WriteRune('\n')
+				current = 0
+				spaceBuf.Reset()
+			}
+		}
+	}
+
+	if wordBuf.Len() == 0 {
+		if current+uint(spaceBuf.Len()) <= lim {
+			spaceBuf.WriteTo(buf)
+		}
+	} else {
+		spaceBuf.WriteTo(buf)
+		wordBuf.WriteTo(buf)
+	}
+
+	return buf.String()
+}