package utils

import (
	"strconv"
	"strings"
)

//return 0 if they are equal,and 1 if v1>2,and 2 if v1<v2
func Compare(v1, v2 string) int {
	replaceMap := map[string]string{"V": "", "v": "", "-": "."}
	for k, v := range replaceMap {
		if strings.Contains(v1, k) {
			v1 = strings.Replace(v1, k, v, -1)
		}
		if strings.Contains(v2, k) {
			v2 = strings.Replace(v2, k, v, -1)
		}
	}
	verStr1 := strings.Split(v1, ".")
	verStr2 := strings.Split(v2, ".")

	ver1 := strSlice2IntSlice(verStr1)
	ver2 := strSlice2IntSlice(verStr2)

	var shorter int
	if len(ver1) > len(ver2) {
		shorter = len(ver2)
	} else {
		shorter = len(ver1)
	}

	for i := 0; i < shorter; i++ {
		if ver1[i] == ver2[i] {
			if shorter-1 == i {
				if len(ver1) == len(ver2) {
					return 0
				} else {
					if len(ver1) > len(ver2) {
						return 1
					} else {
						return 2
					}
				}
			}
		} else if ver1[i] > ver2[i] {
			return 1
		} else {
			return 2
		}
	}
	return -1
}

func strSlice2IntSlice(strs []string) []int64 {
	if len(strs) == 0 {
		return []int64{}
	}
	retInt := make([]int64, 0, len(strs))
	for _, str := range strs {
		i, err := strconv.ParseInt(str, 10, 64)
		if err == nil {
			retInt = append(retInt, i)
		}
	}
	return retInt
}

//operator compare returns true if the first field and the third field  equation holds else false
func CompareVersions(v1, operator, v2 string) bool {
	com := Compare(v1, v2)
	switch operator {
	case "==":
		if com == 0 {
			return true
		}
	case "<":
		if com == 2 {
			return true
		}
	case ">":
		if com == 1 {
			return true
		}
	case "<=":
		if com == 0 || com == 2 {
			return true
		}
	case ">=":
		if com == 0 || com == 1 {
			return true
		}
	}
	return false
}