//****************************************************
//         Copyright (c) 2009 Cisco Systems, Inc.     
//         All rights reserved.                       
//****************************************************

package com.sheer.types.ipaddrfactory;

import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;

import com.sheer.framework.DataVersion;
import com.sheer.types.IPAddress;
import com.sheer.types.IPAddress.IpPart2String;

public class InternalIPv4Address implements InternalIPAddress {


	private static final long serialVersionUID = DataVersion.CURRENT_VERSION;

	private static transient IpPart2String[] ipPart2StringMap = loadIpPart2String();
	private static transient int type = IPAddress.IP_ADDR_TYPE_v4;

	int address = 0;

	//no need to serialize, is reconstructed upon first call to toString()
	private transient String strAddress = null;

	public InternalIPv4Address() {
		this(0);
	}

	public InternalIPv4Address(int address) {
		this.address = address;
	}

	public InternalIPv4Address(String addressString) {
		// check addressString on null
		if (addressString == null) {
			return;
		}

		if (addressString.equalsIgnoreCase("localhost")) {
			throw new IllegalArgumentException("IPAddress cannot resolve localhost. use IPAddressFactory instead");
		}

		this.address = IPAddress.nameToInt(addressString);
	}

	public int getAddressAsInt() throws UnsupportedOperationException {
		return this.getAddress();
	}

	public byte[] getHexAddress() {
		int temp = address;
		byte[] hex = new byte[4];
		int i = 3;
		while (i >= 0) {
			hex[i] = (byte) (temp & 0xFF);
			i--;
			temp >>= 8;
		}
		return hex;
	}

	public int getType() {
		return type;
	}

	@Override
	public boolean equals(Object obj) {
		if (obj == null) {
			return false;
		}

		InternalIPv4Address otherInternal = (InternalIPv4Address)obj;

		return otherInternal.getAddress() == this.getAddress();
	}

	protected int getAddress() {
		return address;
	}

	@Override
	public int hashCode() {
		return this.getAddress();
	}

	@Override
	public int compareTo(InternalIPAddress addr) {
		return compare(address, ((InternalIPv4Address)addr).getAddress());
	}

	/**
	 * @author Guy_Aloni 
	 * @param address1
	 *            first IP address
	 * @param address2
	 *            second IP address
	 * @return 0 if equal, 1 if address1 is greater then address2, -1 if address1
	 *         is lower then address2
	 */
	public static int compare(int address1, int address2) {
		if (address1 == address2)
			return 0;// equality
		if (((address1 ^ address2) >>> 31) == 0) {
			// both numbers have the same sign
			return (address1 > address2) ? 1 : -1;
		}
		// different sign
		return (address1 > address2) ? -1 : 1;
	}

	public static int compare(Object address1, Object address2) {
		return compare(((InternalIPv4Address)address1).getAddress(), ((InternalIPv4Address)address2).getAddress());
	}

	public String toString() {
		if (strAddress == null) {// the first toString -> calc the string and hold it in strAddress
			strAddress = ipPart2StringMap[address >>> 24].first + // First octet
			ipPart2StringMap[(address >> 16) & 0xff].rest + // Second octet
			ipPart2StringMap[(address >> 8) & 0xff].rest + // Third octet
			ipPart2StringMap[address & 0xff].rest;// Fourth octet

			//brussabr - removing call to intern() - this call was found to badly hit performance
			//strAddress = strAddress.intern();
		}

		return strAddress;
	}

	private static IpPart2String[] loadIpPart2String() {
		IpPart2String[] map = new IpPart2String[256];
		for (int i = 0; i < 256; i++)
			map[i] = new IpPart2String(Integer.toString(i));
		return map;
	}


	@Override
	public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
		this.address = in.readInt();
	}

	@Override
	public void writeExternal(ObjectOutput out) throws IOException {
		out.writeInt(address);
	}

}