password.go

package goutils

import (
	"math/rand"
	"strings"
)

var (
	lowerCharSet = "abcdedfghijklmnopqrst"
	upperCharSet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
	numberSet    = "0123456789"
	allCharSet   = lowerCharSet + upperCharSet + numberSet
)

/*
	 rand.Seed(time.Now().Unix())
Exemplo: GeneratePassword(32, 2, 2)
*/
func GeneratePassword(passwordLength, minNum, minUpperCase int) string {
	var password strings.Builder

	//Set numeric
	for i := 0; i < minNum; i++ {
		random := rand.Intn(len(numberSet))
		password.WriteString(string(numberSet[random]))
	}

	//Set uppercase
	for i := 0; i < minUpperCase; i++ {
		random := rand.Intn(len(upperCharSet))
		password.WriteString(string(upperCharSet[random]))
	}

	remainingLength := passwordLength - minNum - minUpperCase
	for i := 0; i < remainingLength; i++ {
		random := rand.Intn(len(allCharSet))
		password.WriteString(string(allCharSet[random]))
	}
	inRune := []rune(password.String())
	rand.Shuffle(len(inRune), func(i, j int) {
		inRune[i], inRune[j] = inRune[j], inRune[i]
	})
	return string(inRune)
}