package cidr

import (
	"net"

	"git.loafle.net/commons_go/util/net/converter"
)

type cidrRangeIPv4 struct {
	cidrNet *net.IPNet
}

func (cr *cidrRangeIPv4) Contains(ip net.IP) bool {
	return cr.cidrNet.Contains(ip)
}

func (cr *cidrRangeIPv4) First() net.IP {
	nIP := cr.Network()
	return cr.Next(nIP)
}

func (cr *cidrRangeIPv4) Last() net.IP {
	bIP := cr.Broadcast()
	return cr.Previous(bIP)
}

func (cr *cidrRangeIPv4) Range(exclude []net.IP) []net.IP {
	fIP := cr.First()
	if nil == fIP {
		return nil
	}
	lIP := cr.Last()
	if nil == lIP {
		return nil
	}
	fNum := converter.IPv4ToInt(fIP.To4())
	lNum := converter.IPv4ToInt(lIP.To4())

	exs := make([]int32, 0)
	if nil != exclude {
		for _, ex := range exclude {
			exs = append(exs, converter.IPv4ToInt(ex.To4()))
		}
	}

	r := make([]net.IP, 0)
Loop:
	for i := fNum; i <= lNum; i++ {
		for _, exN := range exs {
			if exN == i {
				continue Loop
			}
		}
		r = append(r, converter.IntToIPv4(i))
	}
	return r
}

func (cr *cidrRangeIPv4) Broadcast() net.IP {
	ip := cr.cidrNet.IP.To4()
	bIP := net.IPv4(0, 0, 0, 0).To4()
	for i := 0; i < len(bIP); i++ {
		bIP[i] = ip[i] | ^cr.cidrNet.Mask[i]
	}
	return bIP
}

func (cr *cidrRangeIPv4) Network() net.IP {
	ip := cr.cidrNet.IP.To4()
	return ip.Mask(cr.cidrNet.Mask)
}

func (cr *cidrRangeIPv4) Next(ip net.IP) net.IP {
	nNum := converter.IPv4ToInt(ip.To4()) + 1
	nIP := converter.IntToIPv4(nNum)
	if cr.Contains(nIP) {
		return nIP
	}
	return nil
}

func (cr *cidrRangeIPv4) Previous(ip net.IP) net.IP {
	nNum := converter.IPv4ToInt(ip.To4()) - 1
	nIP := converter.IntToIPv4(nNum)
	if cr.Contains(nIP) {
		return nIP
	}
	return nil
}