package util

import (
	"math/rand"
	"regexp"
	"strings"
)

func FindInSlice(slice []string, val string) bool {
	for _, item := range slice {
		if item == val {
			return true
		}
	}
	return false
}

func ValuesString(m map[string]string) string {
	values := make([]string, 0, len(m))
	for _, v := range m {
		values = append(values, v)
	}
	return strings.Join(values, ", ")
}

var matchFirstCap = regexp.MustCompile("(.)([A-Z][a-z]+)")
var matchAllCap = regexp.MustCompile("([a-z0-9])([A-Z])")

func ToSnakeCase(str string) string {
	snake := matchFirstCap.ReplaceAllString(str, "${1}_${2}")
	snake = matchAllCap.ReplaceAllString(snake, "${1}_${2}")
	return strings.ToLower(snake)
}

const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
const (
	letterIdxBits = 6                    // 6 bits to represent a letter index
	letterIdxMask = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits
)

func RandomString(n int) string {
	if n <= 0 {
		return ""
	}
	b := make([]byte, n)
	for i := 0; i < n; {
		if idx := int(rand.Int63() & letterIdxMask); idx < len(letterBytes) {
			b[i] = letterBytes[idx]
			i++
		}
	}
	return string(b)
}