package textfmt

import (
	"bytes"
	"fmt"
	"strings"
	"unicode"
)

func timesn(s string, n int) string {
	if n < 0 {
		return ""
	}

	ss := make([]string, n+1)
	return strings.Join(ss, s)
}

// non-negative numbers only
func numDigits(n int) int {
	if n == 0 {
		return 1
	}

	var d int
	for n > 0 {
		d++
		n /= 10
	}

	return d
}

func maxLength(names []string) int {
	var m int
	for _, n := range names {
		if len([]rune(n)) > m {
			m = len([]rune(n))
		}
	}

	return m
}

func padRight(s string, n int) string {
	if len([]rune(s)) >= n {
		return s
	}

	n -= len([]rune(s))
	return s + timesn("\u00a0", n)
}

func trim(s string) string {
	return strings.TrimFunc(
		s,
		func(r rune) bool { return r != '\u00a0' && unicode.IsSpace(r) },
	)
}

func singleLine(text string) string {
	var l []string
	p := strings.Split(text, "\n")
	for _, part := range p {
		part = trim(part)
		if part == "" {
			continue
		}

		l = append(l, part)
	}

	return strings.Join(l, " ")
}

func textToString(t Txt) string {
	if len(t.cat) == 0 && t.link == "" {
		return trim(t.text)
	}

	if len(t.cat) == 0 && t.text == "" {
		return trim(t.link)
	}

	if len(t.cat) == 0 {
		return fmt.Sprintf("%s (%s)", t.text, t.link)
	}

	b := bytes.NewBuffer(nil)
	for i := range t.cat {
		if i > 0 {
			b.WriteRune(' ')
		}

		b.WriteString(textToString(t.cat[i]))
	}

	return singleLine(b.String())
}