/*

 * Copyright 2011 Tomas Zeman <tzeman@volny.cz>

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package net.tz.ip

import net.liftweb.common._

import net.liftweb.util.Helpers._

case class IpNetwork(from: IpAddress, to: IpAddress) {

  require(from.v == to.v, "IpAddresses must be of the same version")

  lazy val v = from.v

  lazy val mask = from.v.ones ^ from.toBigInt ^ to.toBigInt

  lazy val size = to.toBigInt - from.toBigInt + 1

  lazy val maskLen = mask bitCount

  lazy val maskIp = IpAddress(v, mask)

  override def toString = maskIp map { _ => from + "/" + maskLen } openOr

    (from + "-" + to)

}

object IpNetwork {

  def apply(net: String, maskLen: Int): Box[IpNetwork] = for {

    ip <- IpAddress(net)

    n <- apply(ip, maskLen)

  } yield { n }

  def apply(net: IpAddress, maskLen: Int): Box[IpNetwork] = {

    require(net.v.bits >= maskLen,

      "MaskLen must be less or equal to IP length")

    val hm = BigInt(2).pow(net.v.bits - maskLen) - 1 // host mask

    val m = net.v.ones &~ hm // net mask

    val f = net.toBigInt & m

    val t = net.toBigInt | hm

    for {

      from <- IpAddress(net.v, f)

      to <- IpAddress(net.v, t)

    } yield { IpNetwork(from, to) }

  }

}

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