// hello.java 
// -----------------------
// part of the AnomicHTTPD caching proxy
// (C) by Michael Peter Christen; mc@anomic.de
// first published on http://www.anomic.de
// Frankfurt, Germany, 2004
//
// $LastChangedDate$
// $LastChangedRevision$
// $LastChangedBy$
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
// Using this software in any meaning (reading, learning, copying, compiling,
// running) means that you agree that the Author(s) is (are) not responsible
// for cost, loss of data or any harm that may be caused directly or indirectly
// by usage of this softare or this documentation. The usage of this software
// is on your own risk. The installation and usage (starting/running) of this
// software may allow other people or application to access your computer and
// any attached devices and is highly dependent on the configuration of the
// software which must be done by the user of the software; the author(s) is
// (are) also not responsible for proper configuration and usage of the
// software, even if provoked by documentation provided together with
// the software.
//
// Any changes to this file according to the GPL as documented in the file
// gpl.txt aside this file in the shipment you received can be done to the
// lines that follows this copyright notice here, but changes must not be
// done inside the copyright notive above. A re-distribution must contain
// the intact and unchanged copyright notice.
// Contributions and changes to the program code must be marked as such.
//
// You must compile this file with
// javac -classpath .:../../classes hello.java
// if the shell's current path is HTROOT

import java.net.InetAddress;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.Map;

import de.anomic.http.httpHeader;
import de.anomic.plasma.plasmaSwitchboard;
import de.anomic.server.serverCore;
import de.anomic.server.serverDomains;
import de.anomic.server.serverObjects;
import de.anomic.server.serverSwitch;
import de.anomic.yacy.yacyClient;
import de.anomic.yacy.yacyCore;
import de.anomic.yacy.yacyNetwork;
import de.anomic.yacy.yacySeed;
import de.anomic.yacy.yacyVersion;

public final class hello {

    public static serverObjects respond(httpHeader header, serverObjects post, serverSwitch<?> env) throws InterruptedException {
        plasmaSwitchboard sb = (plasmaSwitchboard) env;
        serverObjects prop = new serverObjects();
        prop.put("message", "none");
        if ((post == null) || (env == null)) {
            prop.put("message", "no post or no enviroment");
            return prop;
        }
        if (!yacyNetwork.authentifyRequest(post, env)) {
            prop.put("message", "not in my network");
            return prop;
        }
        
//      final String iam      = (String) post.get("iam", "");      // complete seed of the requesting peer
//      final String mytime   = (String) post.get(MYTIME, ""); //
        final String key      = post.get("key", "");      // transmission key for response
        final String seed     = post.get("seed", "");
        final String countStr = post.get("count", "0");
        int  count = 0;
        try {count = (countStr == null) ? 0 : Integer.parseInt(countStr);} catch (NumberFormatException e) {count = 0;}
//      final Date remoteTime = yacyCore.parseUniversalDate((String) post.get(MYTIME)); // read remote time
        if (seed.length() > yacySeed.maxsize) {
        	yacyCore.log.logInfo("hello/server: rejected contacting seed; too large (" + seed.length() + " > " + yacySeed.maxsize + ")");
            prop.put("message", "your seed is too long (" + seed.length() + ")");
            return prop;
        }
        final yacySeed remoteSeed = yacySeed.genRemoteSeed(seed, key);

//      System.out.println("YACYHELLO: REMOTESEED=" + ((remoteSeed == null) ? "NULL" : remoteSeed.toString()));
        if ((remoteSeed == null) || (remoteSeed.hash == null)) {
            prop.put("message", "cannot parse your seed");
            return prop;
        }
        
//      final String properTest = remoteSeed.isProper();
        // The remote peer might not know its IP yet, so don't abort if the IP check fails
//      if ((properTest != null) && (! properTest.substring(0,1).equals("IP"))) { return null; }

        // we easily know the caller's IP:
        final String clientip = (String) header.get(httpHeader.CONNECTION_PROP_CLIENTIP, "<unknown>"); // read an artificial header addendum
        InetAddress ias = serverDomains.dnsResolve(clientip);
        if (ias == null) {
            prop.put("message", "cannot resolve your IP from your reported location " + clientip);
            return prop;
        }
        final String userAgent = (String) header.get(httpHeader.USER_AGENT, "<unknown>");
        final String reportedip = remoteSeed.get(yacySeed.IP, "");
        final String reportedPeerType = remoteSeed.get(yacySeed.PEERTYPE, yacySeed.PEERTYPE_JUNIOR);
        final float clientversion = remoteSeed.getVersion();

        if ((sb.isRobinsonMode()) && (!sb.isPublicRobinson())) {
        	// if we are a robinson cluster, answer only if this client is known by our network definition
            prop.put("message", "I am robinson, I do not answer");
            return prop;
        }
        
        int urls = -1;
        if (sb.clusterhashes != null) remoteSeed.setAlternativeAddress((String) sb.clusterhashes.get(remoteSeed.hash));
        
        // if the remote client has reported its own IP address and the client supports
        // the port forwarding feature (if client version >= 0.383) then we try to 
        // connect to the reported IP address first
        if (reportedip.length() > 0 && !clientip.equals(reportedip) && clientversion >= yacyVersion.YACY_SUPPORTS_PORT_FORWARDING) {            
            serverCore.checkInterruption();
            
            // try first the reportedip, since this may be a connect from a port-forwarding host
            prop.put("yourip", reportedip);
            remoteSeed.put(yacySeed.IP, reportedip);
            urls = yacyClient.queryUrlCount(remoteSeed);
        } else {
            prop.put("yourip", "unknown");
        }

        // if the previous attempt (using the reported ip address) was not successful, try the ip where 
        // the request came from
        if (urls < 0) {
        	boolean isNotLocal = true;
        	
        	// we are only allowed to connect to the client IP address if it's not our own address
        	if (serverCore.useStaticIP) {
        		isNotLocal = !ias.isSiteLocalAddress();
            }
        	if (isNotLocal) {
        		serverCore.checkInterruption();
                
                prop.put("yourip", clientip);
                remoteSeed.put(yacySeed.IP, clientip);
                urls = yacyClient.queryUrlCount(remoteSeed);
        	}
        }

//      System.out.println("YACYHELLO: YOUR IP=" + clientip);
        // set lastseen value (we have seen that peer, it contacted us!)
        remoteSeed.setLastSeenUTC();
        
        // assign status
        if (urls >= 0) {
            if (remoteSeed.get(yacySeed.PEERTYPE, yacySeed.PEERTYPE_SENIOR) == null) {
                prop.put(yacySeed.YOURTYPE, yacySeed.PEERTYPE_SENIOR);
                remoteSeed.put(yacySeed.PEERTYPE, yacySeed.PEERTYPE_SENIOR);
            } else if (remoteSeed.get(yacySeed.PEERTYPE, yacySeed.PEERTYPE_PRINCIPAL).equals(yacySeed.PEERTYPE_PRINCIPAL)) {
                prop.put(yacySeed.YOURTYPE, yacySeed.PEERTYPE_PRINCIPAL);
            } else {
                prop.put(yacySeed.YOURTYPE, yacySeed.PEERTYPE_SENIOR);
                remoteSeed.put(yacySeed.PEERTYPE, yacySeed.PEERTYPE_SENIOR);
            }
            // connect the seed
            yacyCore.peerActions.peerArrival(remoteSeed, true);
        } else {
            prop.put(yacySeed.YOURTYPE, yacySeed.PEERTYPE_JUNIOR);
            yacyCore.peerActions.juniorConnects++; // update statistics
            remoteSeed.put(yacySeed.PEERTYPE, yacySeed.PEERTYPE_JUNIOR);
            yacyCore.log.logInfo("hello: responded remote junior peer '" + remoteSeed.getName() + "' from " + reportedip);
            // no connection here, instead store junior in connection cache
            if ((remoteSeed.hash != null) && (remoteSeed.isProper() == null)) {
                yacyCore.peerActions.peerPing(remoteSeed);
            }
        }
        yacyCore.peerActions.setUserAgent(clientip, userAgent);
        if (!((String)prop.get(yacySeed.YOURTYPE)).equals(reportedPeerType)) {
            yacyCore.log.logInfo("hello: changing remote peer '" + remoteSeed.getName() +
                                                           "' [" + reportedip +
                                             "] peerType from '" + reportedPeerType +
                                                        "' to '" + prop.get(yacySeed.YOURTYPE) + "'.");
        }

        serverCore.checkInterruption();
        final StringBuffer seeds = new StringBuffer(768);
        // attach some more seeds, as requested
        if ((sb.webIndex.seedDB != null) && (sb.webIndex.seedDB.sizeConnected() > 0)) {
            if (count > sb.webIndex.seedDB.sizeConnected()) { count = sb.webIndex.seedDB.sizeConnected(); }
            if (count > 100) { count = 100; }
            
            // latest seeds
            final Map<String, yacySeed> ySeeds = sb.webIndex.seedDB.seedsByAge(true, count); // peerhash/yacySeed relation
            
            // attach also my own seed
            seeds.append("seed0=").append(sb.webIndex.seedDB.mySeed().genSeedStr(key)).append(serverCore.CRLF_STRING);
            count = 1;            
            
            // attach other seeds
            if (ySeeds != null) {
                seeds.ensureCapacity((ySeeds.size() + 1) * 768);
                Iterator<yacySeed> si = ySeeds.values().iterator();
                yacySeed s;
                String seedString;
                while (si.hasNext()) {
                	s = si.next();
                    if ((s != null) && (s.isProper() == null)) try {
                        seedString = s.genSeedStr(key);
                        if (seedString != null) {
                            seeds.append("seed").append(count).append('=').append(seedString).append(serverCore.CRLF_STRING);
                            count++;
                        }
                    } catch (ConcurrentModificationException e) {
                        e.printStackTrace();
                    }
                }
            }
        } else {
            // attach also my own seed
            seeds.append("seed0=").append(sb.webIndex.seedDB.mySeed().genSeedStr(key)).append(serverCore.CRLF_STRING);
        }

        prop.put("seedlist", seeds.toString());
        // return rewrite properties
        prop.put("message", "ok " + seed.length());
        return prop;
    }

}