/*
 * 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) }
  }
}

// vim: set ts=2 sw=2 et: