// yacySearch.java 
// -------------------------------------
// (C) by Michael Peter Christen; mc@yacy.net
// 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 notice above. A re-distribution must contain
// the intact and unchanged copyright notice.
// Contributions and changes to the program code must be marked as such.

package de.anomic.yacy;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

import de.anomic.crawler.ResultURLs;
import de.anomic.index.indexReferenceBlacklist;
import de.anomic.kelondro.kelondroBitfield;
import de.anomic.kelondro.kelondroMScoreCluster;
import de.anomic.plasma.plasmaSearchQuery;
import de.anomic.plasma.plasmaSearchRankingProcess;
import de.anomic.plasma.plasmaSearchRankingProfile;
import de.anomic.plasma.plasmaWordIndex;
import de.anomic.server.logging.serverLog;

public class yacySearch extends Thread {

    final private String wordhashes, excludehashes, urlhashes;
    final private boolean global;
    final private int partitions;
    final private plasmaWordIndex wordIndex;
    final private plasmaSearchRankingProcess containerCache;
    final private Map<String, TreeMap<String, String>> abstractCache;
    final private indexReferenceBlacklist blacklist;
    final private yacySeed targetPeer;
    private String[] urls;
    private int count, maxDistance;
    final private plasmaSearchRankingProfile rankingProfile;
    final private String prefer, filter;
    final private kelondroBitfield constraint;
    ResultURLs crawlResults;
    
    public yacySearch(String wordhashes, String excludehashes, String urlhashes, String prefer, String filter, int count, int maxDistance, 
                      boolean global, int partitions, yacySeed targetPeer, plasmaWordIndex wordIndex,
                      ResultURLs crawlResults,
                      plasmaSearchRankingProcess containerCache,
                      Map<String, TreeMap<String, String>> abstractCache,
                      indexReferenceBlacklist blacklist,
                      plasmaSearchRankingProfile rankingProfile,
                      kelondroBitfield constraint) {
        super("yacySearch_" + targetPeer.getName());
        //System.out.println("DEBUG - yacySearch thread " + this.getName() + " initialized " + ((urlhashes.length() == 0) ? "(primary)" : "(secondary)"));
        this.wordhashes = wordhashes;
        this.excludehashes = excludehashes;
        this.urlhashes = urlhashes;
        this.prefer = prefer;
        this.filter = filter;
        this.global = global;
        this.partitions = partitions;
        this.wordIndex = wordIndex;
        this.crawlResults = crawlResults;
        this.containerCache = containerCache;
        this.abstractCache = abstractCache;
        this.blacklist = blacklist;
        this.targetPeer = targetPeer;
        this.urls = null;
        this.count = count;
        this.maxDistance = maxDistance;
        this.rankingProfile = rankingProfile;
        this.constraint = constraint;
    }

    public void run() {
        this.urls = yacyClient.search(
                    wordIndex.seedDB.mySeed(),
                    wordhashes, excludehashes, urlhashes, prefer, filter, count, maxDistance, global, partitions,
                    targetPeer, wordIndex, crawlResults, containerCache, abstractCache,
                    blacklist, rankingProfile, constraint);
        if (urls != null) {
            // urls is an array of url hashes. this is only used for log output
            StringBuffer urllist = new StringBuffer(this.urls.length * 13);
            for (int i = 0; i < this.urls.length; i++) urllist.append(this.urls[i]).append(' ');
            yacyCore.log.logInfo("REMOTE SEARCH - remote peer " + targetPeer.hash + ":" + targetPeer.getName() + " contributed " + urls.length + " links for word hash " + wordhashes + ": " + new String(urllist));
            wordIndex.seedDB.mySeed().incRI(urls.length);
            wordIndex.seedDB.mySeed().incRU(urls.length);
        } else {
            yacyCore.log.logInfo("REMOTE SEARCH - no answer from remote peer " + targetPeer.hash + ":" + targetPeer.getName());
        }
    }

    public static String set2string(Set<String> hashes) {
        String wh = "";
        final Iterator<String> iter = hashes.iterator();
        while (iter.hasNext()) { wh = wh + iter.next(); }
        return wh;
    }

    public int links() {
        return this.urls.length;
    }
    
    public int count() {
        return this.count;
    }
    
    public yacySeed target() {
        return targetPeer;
    }

    private static yacySeed[] selectClusterPeers(yacySeedDB seedDB, TreeMap<String, String> peerhashes) {
    	Iterator<Map.Entry<String, String>> i = peerhashes.entrySet().iterator();
    	ArrayList<yacySeed> l = new ArrayList<yacySeed>();
    	Map.Entry<String, String> entry;
    	yacySeed s;
    	while (i.hasNext()) {
    		entry = i.next();
    		s = seedDB.get(entry.getKey()); // should be getConnected; get only during testing time
    		if (s != null) {
    			s.setAlternativeAddress(entry.getValue());
    			l.add(s);
    		}
    	}
    	yacySeed[] result = new yacySeed[l.size()];
    	for (int j = 0; j < l.size(); j++) {
    		result[j] = l.get(j);
    	}
    	return result;
    	//return (yacySeed[]) l.toArray();
    }
    
    private static yacySeed[] selectSearchTargets(yacySeedDB seedDB, yacyPeerActions peerActions, Set<String> wordhashes, int seedcount) {
        // find out a specific number of seeds, that would be relevant for the given word hash(es)
        // the result is ordered by relevance: [0] is most relevant
        // the seedcount is the maximum number of wanted results
        if (seedDB == null) { return null; }
        if ((seedcount >= seedDB.sizeConnected()) || (seedDB.noDHTActivity())) {
            seedcount = seedDB.sizeConnected();
        }
        
        // put in seeds according to dht
        final kelondroMScoreCluster<String> ranking = new kelondroMScoreCluster<String>();
        final HashMap<String, yacySeed> regularSeeds = new HashMap<String, yacySeed>();
        final HashMap<String, yacySeed> matchingSeeds = new HashMap<String, yacySeed>();
        final HashMap<String, yacySeed> robinsonSeeds = new HashMap<String, yacySeed>();
        yacySeed seed;
        Iterator<yacySeed> dhtEnum;         
        int c;
        String wordhash;
        double distance;
        Iterator<String> iter = wordhashes.iterator();
        while (iter.hasNext()) {
            wordhash = iter.next();
            dhtEnum = peerActions.dhtAction.getDHTSeeds(true, wordhash, (float) 0.0);
            c = seedcount;
            while (dhtEnum.hasNext() && c > 0) {
                seed = dhtEnum.next();
                if (seed == null) continue;
                distance = yacyDHTAction.dhtDistance(seed.hash, wordhash);
                if (distance > 0.2) continue; // catch bug in peer selection
                if (!seed.getFlagAcceptRemoteIndex()) continue; // probably a robinson peer
                serverLog.logFine("PLASMA", "selectPeers/DHTorder: " + seed.hash + ":" + seed.getName() + "/" + distance + " for wordhash " + wordhash + ", score " + c);
                ranking.addScore(seed.hash, c--);
                regularSeeds.put(seed.hash, seed);
            }
        }

        // put in seeds according to size of peer
        dhtEnum = seedDB.seedsSortedConnected(false, yacySeed.ICOUNT);
        c = Math.min(seedDB.sizeConnected(), seedcount);
        int score;
        while (dhtEnum.hasNext() && c > 0) {
            seed = dhtEnum.next();
            if (seed == null) continue;
            if (!seed.getFlagAcceptRemoteIndex()) continue; // probably a robinson peer
            score = (int) Math.round(Math.random() * ((c / 3) + 3));
            serverLog.logFine("PLASMA", "selectPeers/RWIcount: " + seed.hash + ":" + seed.getName() + ", RWIcount=" + seed.get(yacySeed.ICOUNT,"") + ", score " + score);
            ranking.addScore(seed.hash, score);
            regularSeeds.put(seed.hash, seed);
            c--;
        }

        // put in seeds that are public robinson peers and where the peer tags match with query
        // or seeds that are newbies to ensure that public demonstrations always work
        dhtEnum = seedDB.seedsConnected(true, false, null, (float) 0.50);
        while (dhtEnum.hasNext()) {
        	seed = dhtEnum.next();
            if (seed == null) continue;
            if (seed.getFlagAcceptRemoteIndex()) {
                // enhance ranking for regular peers
                if (seed.matchPeerTags(wordhashes)) { // access robinson peers with matching tag
                    serverLog.logInfo("PLASMA", "selectPeers/PeerTags: " + seed.hash + ":" + seed.getName() + ", is specialized peer for " + seed.getPeerTags().toString());
                    regularSeeds.remove(seed.hash);
                    ranking.deleteScore(seed.hash);
                    matchingSeeds.put(seed.hash, seed);
                }
                if (seed.getAge() < 1) { // the 'workshop feature'
                    serverLog.logInfo("PLASMA", "selectPeers/Age: " + seed.hash + ":" + seed.getName() + ", is newbie, age = " + seed.getAge());
                    regularSeeds.remove(seed.hash);
                    ranking.deleteScore(seed.hash);
                    matchingSeeds.put(seed.hash, seed);
                }
            } else {
                // this is a robinson peer
                // in case the peer has more than a million urls, take it as search target
                if (seed.getLinkCount() > 1000000 || seed.matchPeerTags(wordhashes)) {
                    regularSeeds.remove(seed.hash);
                    ranking.deleteScore(seed.hash);
                    if (seed.matchPeerTags(wordhashes))
                        matchingSeeds.put(seed.hash, seed);
                    else
                        robinsonSeeds.put(seed.hash, seed);
                }
            }
        }
        
        // evaluate the ranking score and select seeds
        seedcount = Math.min(ranking.size(), seedcount);
        yacySeed[] result = new yacySeed[seedcount + robinsonSeeds.size() + matchingSeeds.size()];
        c = 0;
        iter = ranking.scores(false); // higher are better
        while (iter.hasNext() && c < seedcount) {
            seed = regularSeeds.get(iter.next());
            seed.selectscore = c;
            serverLog.logInfo("PLASMA", "selectPeers/_dht_: " + seed.hash + ":" + seed.getName() + " is choice " + c);
            result[c++] = seed;
        }
        for (yacySeed s: robinsonSeeds.values()) {
            serverLog.logInfo("PLASMA", "selectPeers/_robinson_: " + s.hash + ":" + s.getName() + " is choice " + c);
            result[c++] = s;
        }
        for (yacySeed s: matchingSeeds.values()) {
            serverLog.logInfo("PLASMA", "selectPeers/_match_: " + s.hash + ":" + s.getName() + " is choice " + c);
            result[c++] = s;
        }

//      System.out.println("DEBUG yacySearch.selectPeers = " + seedcount + " seeds:"); for (int i = 0; i < seedcount; i++) System.out.println(" #" + i + ":" + result[i]); // debug
        return result;
    }

    public static yacySearch[] primaryRemoteSearches(
            String wordhashes, String excludehashes, String urlhashes,
            String prefer, String filter, int count, int maxDist,
            plasmaWordIndex wordIndex,
            ResultURLs crawlResults,
            plasmaSearchRankingProcess containerCache,
            Map<String, TreeMap<String, String>> abstractCache,
            int targets,
            indexReferenceBlacklist blacklist,
            plasmaSearchRankingProfile rankingProfile,
            kelondroBitfield constraint,
            TreeMap<String, String> clusterselection) {
        // check own peer status
        //if (wordIndex.seedDB.mySeed() == null || wordIndex.seedDB.mySeed().getPublicAddress() == null) { return null; }

        // prepare seed targets and threads
        final yacySeed[] targetPeers = (clusterselection == null) ? selectSearchTargets(wordIndex.seedDB, wordIndex.peerActions, plasmaSearchQuery.hashes2Set(wordhashes), targets) : selectClusterPeers(wordIndex.seedDB, clusterselection);
        if (targetPeers == null) return new yacySearch[0];
        targets = targetPeers.length;
        if (targets == 0) return new yacySearch[0];
        yacySearch[] searchThreads = new yacySearch[targets];
        for (int i = 0; i < targets; i++) {
            searchThreads[i] = new yacySearch(wordhashes, excludehashes, urlhashes, prefer, filter, count, maxDist, true, targets, targetPeers[i],
                    wordIndex, crawlResults, containerCache, abstractCache, blacklist, rankingProfile, constraint);
            searchThreads[i].start();
            //try {Thread.sleep(20);} catch (InterruptedException e) {}
        }
        return searchThreads;
    }
    
    public static yacySearch secondaryRemoteSearch(String wordhashes, String excludehashes, String urlhashes,
            plasmaWordIndex wordIndex,
            ResultURLs crawlResults,
            plasmaSearchRankingProcess containerCache,
            String targethash, indexReferenceBlacklist blacklist,
            plasmaSearchRankingProfile rankingProfile,
            kelondroBitfield constraint, TreeMap<String, String> clusterselection) {
        // check own peer status
        if (wordIndex.seedDB.mySeed() == null || wordIndex.seedDB.mySeed().getPublicAddress() == null) { return null; }

        // prepare seed targets and threads
        final yacySeed targetPeer = wordIndex.seedDB.getConnected(targethash);
        if (targetPeer == null) return null;
        if (clusterselection != null) targetPeer.setAlternativeAddress(clusterselection.get(targetPeer.hash));
        yacySearch searchThread = new yacySearch(wordhashes, excludehashes, urlhashes, "", "", 0, 9999, true, 0, targetPeer,
                                             wordIndex, crawlResults, containerCache, new TreeMap<String, TreeMap<String, String>>(), blacklist, rankingProfile, constraint);
        searchThread.start();
        return searchThread;
    }
    
    public static int remainingWaiting(yacySearch[] searchThreads) {
        if (searchThreads == null) return 0;
        int alive = 0;
        for (int i = 0; i < searchThreads.length; i++) {
            if (searchThreads == null) break; // may occur
            if (searchThreads[i].isAlive()) alive++;
        }
        return alive;
    }
    
    public static int collectedLinks(yacySearch[] searchThreads) {
        int links = 0;
        for (int i = 0; i < searchThreads.length; i++) {
            if (!(searchThreads[i].isAlive())) links += searchThreads[i].urls.length;
        }
        return links;
    }
    
    public static void interruptAlive(yacySearch[] searchThreads) {
        for (int i = 0; i < searchThreads.length; i++) {
            if (searchThreads[i].isAlive()) searchThreads[i].interrupt();
        }
    }
    
}