package golanghelper

import "strings"

const (
	EMPTY = ""
	SPACE = " "
)

type StringUtils struct {
}

// IsEmpty 會檢查 str 是否為空值
func (s *StringUtils) IsEmpty(str string) bool {
	return len(str) == 0
}

// LeftPad 將 padStr 以 size 做為長度，向左填滿 str
func (s *StringUtils) LeftPad(str string, size int, padStr string) string {
	if s.IsEmpty(padStr) {
		padStr = SPACE
	}

	padStrLen := len(padStr)
	padCount := size - len(str)

	if padCount <= 0 || padCount < padStrLen {
		return str
	}
	if padCount == padStrLen {
		return padStr + str
	}

	return strings.Repeat(padStr, padCount) + str
}