package acl

import (
	"errors"
	"strconv"
)

const (
	NullAttr string = ""
	AllAttr  string = "*"
)

type AclBit struct {
	Acl uint64
	Atr string
}

// Initialize acl bits and atributes
func NewAclBit(def uint64, atr string) *AclBit {
	acl := new(AclBit)

	acl.Acl = def
	acl.Atr = atr

	return acl
}

// Set acl bits and atributes
func (a *AclBit) Set(acl uint64, atr string) {
	a.Acl = acl
	a.Atr = atr
}

// Set array acl bits and atributes
func (a *AclBit) SetArray(acl []AclBit) {
	var endacl uint64
	var endatr string
	lenacl := len(acl)
	for _, a0 := range acl {
		endacl = endacl | a0.Acl
		if a0.Atr != NullAttr {
			endatr = endatr + a0.Atr
			if lenacl > 1 {
				endatr = endatr + ","
			}
		}
		lenacl--
	}
	a.Acl = endacl
	a.Atr = endatr
}

// set acl bits
func (a *AclBit) SetAcl(acl uint64) {
	a.Acl = acl
}

// set acl atributes
func (a *AclBit) SetAtr(atr string) {
	a.Atr = atr
}

// get current acl
func (a *AclBit) Get() *AclBit {
	return a
}

// set acl bit in true
func (a *AclBit) SetBitTrue(n int) {
	a.Acl = a.Acl | (1 << n)
}

// set acl bit in false
func (a *AclBit) SetBitFalse(n int) {
	a.Acl = a.Acl &^ (1 << n)
}

// get acl bit return true or false
func (a *AclBit) GetBit(n int) bool {
	var msk uint64 = 1 << n
	if (a.Acl & msk) == msk {
		return true
	} else {
		return false
	}

}

// converting acl bits in string
func (a *AclBit) StringAcl() string {
	return strconv.FormatUint(uint64(a.Acl), 2)
}

// converting string bits to uint64
func Uint64(str string) (uint64, error) {
	u64, err := strconv.ParseUint(str, 2, 64)
	if err != nil {
		return 0, errors.New("string not bit formats")
	}
	return u64, nil
}