/src/java/com/shadowolf/protocol/AnnounceResponse.java

package com.shadowolf.protocol;



import com.google.common.base.Charsets;



/**

 * This isnt done!

 * @author Jon

 *

 */

public class AnnounceResponse {

	private int seeders;

	private int leechers;

	private Peer[] peers;

	private int interval;

	private int minInterval;

	private String error;

	

	public AnnounceResponse(int seeders, int leechers, Peer[] peers, int interval, int minInterval) {

		super();

		this.seeders = seeders;

		this.leechers = leechers;

		this.peers = peers;

		this.interval = interval;

		this.minInterval = minInterval;

		this.error = "";

	}

	

	/**

	 * @return the error

	 */

	public String getError() {

		return error;

	}



	/**

	 * If this is set, all other data in the announce will be

	 * discarded, and the error message will be sent to the client. 

	 * <strong>The empty string is not a valid error and will be 

	 * treated as if no error exists!</strong>

	 * @param error the error to set

	 */

	public void setError(String error) {

		this.error = error;

	}



	/**

	 * @return the seeders

	 */

	public int getSeeders() {

		return seeders;

	}

	

	/**

	 * @param seeders the seeders to set

	 */

	public void setSeeders(int seeders) {

		this.seeders = seeders;

	}

	

	/**

	 * @return the leechers

	 */

	public int getLeechers() {

		return leechers;

	}

	

	/**

	 * @param leechers the leechers to set

	 */

	public void setLeechers(int leechers) {

		this.leechers = leechers;

	}

	

	/**

	 * @return the peers

	 */

	public Peer[] getPeers() {

		return peers;

	}

	

	/**

	 * @param peers the peers to set

	 */

	public void setPeers(Peer[] peers) {

		this.peers = peers;

	}

	

	/**

	 * @return the interval

	 */

	public int getInterval() {

		return interval;

	}

	

	/**

	 * @param interval the interval to set

	 */

	public void setInterval(int interval) {

		this.interval = interval;

	}

	

	/**

	 * @return the minInterval

	 */

	public int getMinInterval() {

		return minInterval;

	}

	

	/**

	 * @param minInterval the minInterval to set

	 */

	public void setMinInterval(int minInterval) {

		this.minInterval = minInterval;

	}

	

	public String bencode() {

		if(error.length() > 0) {

			return "d14:failure reason"+error.length()+":"+error+"e\r\n"; // size 

		}

		StringBuilder sb = new StringBuilder();

		

		String s = "d8:intervali" + interval + "e" + "12:min intervali" + minInterval + "e10:incompletei" + leechers + "e8:completei" + seeders + "e"; //length 14+18+16+13=66

		sb.append(s);

		//sb.append(s.getBytes(Charsets.UTF_8));

		sb.append(new String(encodePeers()));

		sb.append("\r\n"/*.getBytes(Charsets.UTF_8)*/); // length2

		

		return sb.toString();

	}

	

	private byte[] encodePeers() {

		//This is required to know how big of an array to allocate.

		int ipv4Count = 0;

		int ipv6Count = 0;

		

		for(Peer p : peers) {

			if(p.getAddress().getAddress().getAddress().length > 4) {

				ipv6Count++;

			} else {

				ipv4Count++;

			}

		}

		

		//These may not be defined here because we want to omit them if size = 0 for ipv4 or ipv6

		byte[] ipv4start = new byte[0]; // length 0

		byte[] ipv6start = new byte[0]; // length 0

		

		if(ipv4Count > 0) {

			ipv4start = ("5:peers"+(ipv4Count*6)+":").getBytes(Charsets.UTF_8); // length 10

			//System.out.println(ipv4start.length);

		}

		

		if(ipv6Count > 0) {

			ipv6start = ("6:peers6"+(ipv6Count*18)+":").getBytes(Charsets.UTF_8); // length 10

		}

		

		int size = ipv6start.length + ipv4start.length + (ipv6Count * 18) + (ipv4Count * 6)+1;

		

		byte[] result = new byte[size];

		

		result[size-1] = 'e';

		

		int ipv4Index = 0;

		int ipv6Index = ipv4start.length+(6*ipv4Count);

		

		System.arraycopy(ipv4start, 0, result, ipv4Index, ipv4start.length);

		System.arraycopy(ipv6start, 0, result, ipv6Index, ipv6start.length);

		

		ipv4Index += ipv4start.length;

		ipv6Index += ipv6start.length;

		

		for(Peer p : peers) {

			int index;

			int portIndex;

			byte[] b = p.getAddress().getAddress().getAddress();

			byte[] port = intToByte(p.getAddress().getPort());

			if(b.length > 4) {

				index = ipv6Index;

				portIndex = index+16;

				ipv6Index += 18;

			} else {

				index = ipv4Index;

				portIndex = index+4;

				ipv4Index += 6;

			}



			System.arraycopy(b, 0, result, index, b.length);

			System.arraycopy(port, 0, result, portIndex, port.length);

			

		}

		

		return result;

	}

	

	private static byte[] intToByte(int i) {

		return new byte[] { (byte)(i >>> 8), (byte) i};

	}

}