package main

import (
	"errors"
)

func (s *OpenVpnMgt) isFree(ip string) bool {
	for _, remote := range s.clients {
		for _, c := range remote {
			if c.PrivIP == ip {
				return false
			}
		}
	}
	return true
}

// internal DHCP
func (s *OpenVpnMgt) getIP(c *vpnSession) (string, error) {
	s.m.Lock()
	defer s.m.Unlock()

	ipmax := nextIP(s.ldap[c.Profile].ipMax).String()

	sip := s.ldap[c.Profile].ipMin.String()
	for ip := s.ldap[c.Profile].ipMin; sip != ipmax; ip = nextIP(ip) {
		sip = ip.String()
		if s.isFree(sip) {
			return sip, nil
		}
	}

	return "", errors.New("no more IP")
}