// NOTE! This code contains minor bits taken from Sun's JDK 1.1.7 sources,
// in particular java.lang.Integer and java.net.InetAddress.

import edu.mit.media.hive.support.Debug;
import java.net.UnknownHostException;

/** Simple data structure to store host info. **/
public class Host {
    public int ipAddress;
    
    public Host(String s) throws UnknownHostException {
        ipAddress = quadToInt(s);
    }
    
    public String toString() {
        return this.intToQuad(ipAddress);
    }

    // taken from JDK 117 java.lang.Integer
    public boolean equals(Object obj) {
	if ((obj != null) && (obj instanceof Host)) {
	    return ipAddress == ((Host)obj).ipAddress;
	}
	return false;
    }

    public int hashCode() {
	return ipAddress;
    }

    public static int quadToInt(String host) throws UnknownHostException {
        // this code taken from JDK 117 sources for java.net.InetAddress
        int IP = 0x00;
        int hitDots = 0;
        char[] data = host.toCharArray();

        for(int i = 0; i < data.length; i++) {    // loop over dots
            char c = data[i];
            if (c < 48 || c > 57) { // !digit
                throw new UnknownHostException(host);
            }
            int b = 0x00;
            while(c != '.') {                     // grab all numbers to .
                if (c < 48 || c > 57) { // !digit
                    throw new UnknownHostException(host);
                }
                b = b*10 + c - '0';
                
                if (++i >= data.length)
                    break;
                c = data[i];
            }
            if(b > 0xFF) { /* bogus - bigger than a byte */
                throw new UnknownHostException(host);
            }
            IP = (IP << 8) + b;
            hitDots++;
        }
        
        if(hitDots != 4 || host.endsWith(".")) {
            throw new UnknownHostException(host);
        }
        return IP;
    }

    public static String intToQuad(int n) {
        // This code taken from java.net.InetAddress.
        return ((n >>> 24) & 0xFF) + "." +
            ((n >>> 16) & 0xFF) + "." +
            ((n >>>  8) & 0xFF) + "." +
            ((n >>>  0) & 0xFF);
    }

    public static void main(String args[]) {
        int n;
        try {
            n = Host.quadToInt(args[0]);
            String s = Host.intToQuad(n);
            if (!s.equals(args[0]))
                System.out.println("Couldn't parse " + args[0]);
            System.out.println("Parsed: " + new Host(args[0]));
        } catch (UnknownHostException ex) {
            Debug.error(ex);
        }
        
    }
}