nix-amer/internal/clifmt/symbols.go

package clifmt

import (
	"fmt"
	"regexp"
	"strings"
)

var titleIndex = 0
var alignOffset = 40
var defaultPrinter = fmt.Printf

// Warn returns a red warning ASCII sign. If a string is given
// as argument, it will print it after the warning sign
func Warn(s ...string) string {
	if len(s) == 0 {
		return Color(31, "/!\\")
	}

	return fmt.Sprintf("%s  %s", Warn(), s[0])
}

// Info returns a blue info ASCII sign. If a string is given
// as argument, it will print it after the info sign
func Info(s ...string) string {
	if len(s) == 0 {
		return Color(34, "(!)")
	}

	return fmt.Sprintf("%s  %s", Info(), s[0])
}

// Title prints a formatted title (auto-indexed from local counted)
func Title(s string) {
	titleIndex++
	defaultPrinter("\n%s |%d| %s %s\n", Color(33, ">>", false), titleIndex, s, Color(33, "<<", false))

}

// Align prints strings with space padding to align line ends (fixed width)
// also crops the content to add '...' at the end if too long (must have a space
// at the end)
func Align(s string) {

	// 1. replace tabs with 4 spaces
	tabs := strings.Split(strings.Trim(s, " \t"), "\t")
	s = strings.Join(tabs, "    ")

	// 2. get real size
	size := DisplaySize(s)
	offset := alignOffset

	if size > alignOffset-2 {

		for i := len(s) - 1; i > 0; i-- { // find when real size is right under
			next := fmt.Sprintf("%s\033[0m… ", s[0:i])

			if DisplaySize(next) <= alignOffset {
				s = next
				size = DisplaySize(s)
				break
			}

		}
	}

	// 3. print string
	defaultPrinter("%s", s)

	// 4. print trailing spaces
	for i := size; i < offset; i++ {
		defaultPrinter(" ")
	}
}

var re = regexp.MustCompile(`(?m)\[(?:\d+;)*\d+m`)
var reDots = regexp.MustCompile(`(?m)…`)

// DisplaySize returns the real size escaping special characters
func DisplaySize(s string) int {

	// 1. get actual size
	size := len(s)

	// 2. get all terminal coloring matches
	matches := re.FindAllString(s, -1)
	for _, m := range matches {
		size -= len(m)
	}

	// 3. Remove unicode character (len of 3 instead of 1)
	matches = reDots.FindAllString(s, -1)
	for _, m := range matches {
		size -= len(m)
		size++
	}

	return size
}