Challenge QuintoAndar

phoneparse.go

package main

import (
	"fmt"
	"regexp"
)

const SEPARATOR = "-"

func main() {
	case1 := "00-44  48 5555 8361"
	case2 := "0 - 22 1985--324"
	case3 := "555372654"
	fmt.Println("case1: ", parse(case1)) //case1: 004-448-555-583-61
	fmt.Println("case2: ", parse(case2)) //case2: 022-198-53-24
	fmt.Println("case3: ", parse(case3)) //case3: 555-372-654
}

func parse(input string) string {

	reg, err := regexp.Compile("[^0-9]+")
	if err != nil {
		panic(err)
	}
	input = reg.ReplaceAllString(input, "")

	inputLength := len(input)
	if inputLength <= 3 {
		return input
	} else {
		mod := inputLength % 3
		if mod == 0 {
			return split3(input)
		} else if mod == 1 {
			baseEnd := inputLength - 4
			base := split3(input[0:baseEnd])
			suffix := split2(input[baseEnd:inputLength])
			return base + "-" + suffix
		} else {
			baseEnd := inputLength - 2
			base := split3(input[0:baseEnd])
			suffix := input[baseEnd:inputLength]
			return base + "-" + suffix
		}
	}
}

func split2(input string) string {
	return splitTemplate(input, 2)
}

func split3(input string) string {
	return splitTemplate(input, 3)
}

func splitTemplate(input string, splitSize int) string {
	result := ""
	for i := 0; i < len(input); i += splitSize {
		sub := input[i : i+splitSize]
		result += sub
		if i != (len(input) - splitSize) {
			result += SEPARATOR
		}
	}
	return result
}