// plasmaWordIndex.java
// (C) 2005, 2006 by Michael Peter Christen; mc@yacy.net, Frankfurt a. M., Germany
// first published 2005 on http://www.anomic.de
//
// This is a part of YaCy, a peer-to-peer based web search engine
//
// $LastChangedDate$
// $LastChangedRevision$
// $LastChangedBy$
//
// LICENSE
//
// 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

package de.anomic.plasma;

import java.io.File;
import java.io.IOException;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;

import de.anomic.crawler.CrawlProfile;
import de.anomic.crawler.IndexingStack;
import de.anomic.data.Blacklist;
import de.anomic.htmlFilter.htmlFilterContentScraper;
import de.anomic.http.httpdProxyCacheEntry;
import de.anomic.kelondro.blob.BLOBArray;
import de.anomic.kelondro.order.Base64Order;
import de.anomic.kelondro.order.ByteOrder;
import de.anomic.kelondro.text.BufferedIndex;
import de.anomic.kelondro.text.IndexCell;
import de.anomic.kelondro.text.IndexCollectionMigration;
import de.anomic.kelondro.text.ReferenceContainer;
import de.anomic.kelondro.text.IODispatcher;
import de.anomic.kelondro.text.MetadataRepository;
import de.anomic.kelondro.text.ReferenceFactory;
import de.anomic.kelondro.text.metadataPrototype.URLMetadataRow;
import de.anomic.kelondro.text.referencePrototype.WordReference;
import de.anomic.kelondro.text.referencePrototype.WordReferenceFactory;
import de.anomic.kelondro.text.referencePrototype.WordReferenceRow;
import de.anomic.kelondro.util.FileUtils;
import de.anomic.kelondro.util.kelondroException;
import de.anomic.kelondro.util.Log;
import de.anomic.plasma.parser.Word;
import de.anomic.plasma.parser.Condenser;
import de.anomic.tools.iso639;
import de.anomic.xml.RSSFeed;
import de.anomic.xml.RSSMessage;
import de.anomic.yacy.yacySeedDB;
import de.anomic.yacy.yacyURL;

public final class plasmaWordIndex {

    // environment constants
    public static final long wCacheMaxAge    = 1000 * 60 * 30; // milliseconds; 30 minutes
    public static final int  wCacheMaxChunk  =  800;           // maximum number of references for each urlhash
    public static final int  lowcachedivisor =  900;
    public static final int  maxCollectionPartition = 7;       // should be 7
    public static final long targetFileSize  = 100 * 1024 * 1024; // 100 MB
    public static final long maxFileSize     = BLOBArray.oneGigabyte; // 1GB
    public static final int  writeBufferSize = 4 * 1024 * 1024;
    
    // the reference factory
    public static final ReferenceFactory<WordReference> wordReferenceFactory = new WordReferenceFactory();
    
    public static final String CRAWL_PROFILE_PROXY                 = "proxy";
    public static final String CRAWL_PROFILE_REMOTE                = "remote";
    public static final String CRAWL_PROFILE_SNIPPET_LOCAL_TEXT    = "snippetLocalText";
    public static final String CRAWL_PROFILE_SNIPPET_GLOBAL_TEXT   = "snippetGlobalText";
    public static final String CRAWL_PROFILE_SNIPPET_LOCAL_MEDIA   = "snippetLocalMedia";
    public static final String CRAWL_PROFILE_SNIPPET_GLOBAL_MEDIA  = "snippetGlobalMedia";
    public static final String CRAWL_PROFILE_SURROGATE             = "surrogates";
    
    public static final String DBFILE_ACTIVE_CRAWL_PROFILES        = "crawlProfilesActive.heap";
    public static final String DBFILE_PASSIVE_CRAWL_PROFILES       = "crawlProfilesPassive.heap";
    
    public static final long CRAWL_PROFILE_PROXY_RECRAWL_CYCLE = 60L * 24L;
    public static final long CRAWL_PROFILE_SNIPPET_LOCAL_TEXT_RECRAWL_CYCLE = 60L * 24L * 30L;
    public static final long CRAWL_PROFILE_SNIPPET_GLOBAL_TEXT_RECRAWL_CYCLE = 60L * 24L * 30L;
    public static final long CRAWL_PROFILE_SNIPPET_LOCAL_MEDIA_RECRAWL_CYCLE = 60L * 24L * 30L;
    public static final long CRAWL_PROFILE_SNIPPET_GLOBAL_MEDIA_RECRAWL_CYCLE = 60L * 24L * 30L;
    public static final long CRAWL_PROFILE_SURROGATE_RECRAWL_CYCLE = 60L * 24L * 30L;
    
    public static final ByteOrder wordOrder = Base64Order.enhancedCoder;
    
    private final BufferedIndex<WordReference> index;
    private final Log             log;
    private MetadataRepository    metadata;
    private final yacySeedDB      peers;
    private final File            primaryRoot, secondaryRoot;
    public        IndexingStack   queuePreStack;
    public        CrawlProfile    profilesActiveCrawls, profilesPassiveCrawls;
    public  CrawlProfile.entry    defaultProxyProfile;
    public  CrawlProfile.entry    defaultRemoteProfile;
    public  CrawlProfile.entry    defaultTextSnippetLocalProfile, defaultTextSnippetGlobalProfile;
    public  CrawlProfile.entry    defaultMediaSnippetLocalProfile, defaultMediaSnippetGlobalProfile;
    public  CrawlProfile.entry    defaultSurrogateProfile;
    private final File            queuesRoot;
    private IODispatcher<WordReference> merger;
    
    public plasmaWordIndex(
            final String networkName,
            final Log log,
            final File indexPrimaryRoot,
            final File indexSecondaryRoot,
            final int entityCacheMaxSize,
            final boolean useCommons,
            final int redundancy,
            final int partitionExponent) throws IOException {
        
        log.logInfo("Initializing Word Index for the network '" + networkName + "', word hash cache size is " + Word.hashCacheSize + ".");
                        
        if (networkName == null || networkName.length() == 0) {
            log.logSevere("no network name given - shutting down");
            System.exit(0);
        }
        this.log = log;
        this.primaryRoot = new File(indexPrimaryRoot, networkName);
        this.secondaryRoot = new File(indexSecondaryRoot, networkName);
        File indexPrimaryTextLocation = new File(this.primaryRoot, "TEXT");
        if (!indexPrimaryTextLocation.exists()) {
            // patch old index locations; the secondary path is patched in plasmaCrawlLURL
            final File oldPrimaryPath = new File(new File(indexPrimaryRoot, "PUBLIC"), "TEXT");
            final File oldPrimaryTextLocation = new File(new File(indexPrimaryRoot, "PUBLIC"), "TEXT");
            if (oldPrimaryPath.exists() && oldPrimaryTextLocation.exists()) {
                // move the text folder from the old location to the new location
                assert !indexPrimaryTextLocation.exists();
                indexPrimaryTextLocation.mkdirs();
                if (oldPrimaryTextLocation.renameTo(indexPrimaryTextLocation)) {
                    FileUtils.deletedelete(oldPrimaryPath);
                } else {
                    indexPrimaryTextLocation = oldPrimaryTextLocation; // emergency case: stay with old directory
                }
            }
        }
        
        // check if the peer has migrated the index
        if (new File(indexPrimaryTextLocation, "RICOLLECTION").exists()) {
            this.merger = new IODispatcher<WordReference>(plasmaWordIndex.wordReferenceFactory, 1, 1, writeBufferSize);
            if (this.merger != null) this.merger.start();
            this.index = new IndexCollectionMigration<WordReference>(
                                    indexPrimaryTextLocation,
                                    wordReferenceFactory,
                                    wordOrder,
                                    WordReferenceRow.urlEntryRow,
                                    entityCacheMaxSize,
                                    targetFileSize,
                                    maxFileSize,
                                    this.merger,
                                    writeBufferSize,
                                    log);
        } else {
            this.merger = new IODispatcher<WordReference>(plasmaWordIndex.wordReferenceFactory, 1, 1, writeBufferSize);
            this.merger.start();
            this.index = new IndexCell<WordReference>(
                                    new File(indexPrimaryTextLocation, "RICELL"),
                                    wordReferenceFactory,
                                    wordOrder,
                                    WordReferenceRow.urlEntryRow,
                                    entityCacheMaxSize,
                                    targetFileSize,
                                    maxFileSize,
                                    this.merger,
                                    writeBufferSize);
        }
        
        
            
        // migrate LURL-db files into new subdirectory METADATA
        File textdir = new File(this.secondaryRoot, "TEXT");
        File metadatadir = new File(textdir, "METADATA");
        if (!metadatadir.exists()) metadatadir.mkdirs();
        String[] l = textdir.list();
        for (int i = 0; i < l.length; i++) {
            if (l[i].startsWith("urls.")) (new File(textdir, l[i])).renameTo(new File(metadatadir, l[i]));
        }
        // create LURL-db
        metadata = new MetadataRepository(metadatadir);
        
        // make crawl profiles database and default profiles
        this.queuesRoot = new File(this.primaryRoot, "QUEUES");
        this.queuesRoot.mkdirs();
        this.log.logConfig("Initializing Crawl Profiles");
        final File profilesActiveFile = new File(queuesRoot, DBFILE_ACTIVE_CRAWL_PROFILES);
        if (!profilesActiveFile.exists()) {
            // migrate old file
            final File oldFile = new File(new File(queuesRoot.getParentFile().getParentFile().getParentFile(), "PLASMADB"), "crawlProfilesActive1.db");
            if (oldFile.exists()) oldFile.renameTo(profilesActiveFile);
        }
        try {
            this.profilesActiveCrawls = new CrawlProfile(profilesActiveFile);
        } catch (IOException e) {
            FileUtils.deletedelete(profilesActiveFile);
            try {
                this.profilesActiveCrawls = new CrawlProfile(profilesActiveFile);
            } catch (IOException e1) {
                e1.printStackTrace();
                this.profilesActiveCrawls = null;
            }
        }
        initActiveCrawlProfiles();
        log.logInfo("Loaded active crawl profiles from file " + profilesActiveFile.getName() +
                ", " + this.profilesActiveCrawls.size() + " entries" +
                ", " + profilesActiveFile.length()/1024);
        final File profilesPassiveFile = new File(queuesRoot, DBFILE_PASSIVE_CRAWL_PROFILES);
        if (!profilesPassiveFile.exists()) {
            // migrate old file
            final File oldFile = new File(new File(queuesRoot.getParentFile().getParentFile().getParentFile(), "PLASMADB"), "crawlProfilesPassive1.db");
            if (oldFile.exists()) oldFile.renameTo(profilesPassiveFile);
        }
        try {
            this.profilesPassiveCrawls = new CrawlProfile(profilesPassiveFile);
        } catch (IOException e) {
            FileUtils.deletedelete(profilesPassiveFile);
            try {
                this.profilesPassiveCrawls = new CrawlProfile(profilesPassiveFile);
            } catch (IOException e1) {
                e1.printStackTrace();
                this.profilesPassiveCrawls = null;
            }
        }
        log.logInfo("Loaded passive crawl profiles from file " + profilesPassiveFile.getName() +
                ", " + this.profilesPassiveCrawls.size() + " entries" +
                ", " + profilesPassiveFile.length()/1024);
        
        // init queues
        final File preStackFile = new File(queuesRoot, "urlNoticePreStack");
        if (!preStackFile.exists()) {
            // migrate old file
            final File oldFile = new File(new File(queuesRoot.getParentFile().getParentFile().getParentFile(), "PLASMADB"), "switchboardQueue.stack");
            if (oldFile.exists()) oldFile.renameTo(preStackFile);
        }
        this.queuePreStack = new IndexingStack(this, preStackFile, this.profilesActiveCrawls);
        
        // create or init seed cache
        final File networkRoot = new File(this.primaryRoot, "NETWORK");
        networkRoot.mkdirs();
        final File mySeedFile = new File(networkRoot, yacySeedDB.DBFILE_OWN_SEED);
        final File oldSeedFile = new File(new File(indexPrimaryRoot.getParentFile(), "YACYDB"), "mySeed.txt");
        if (oldSeedFile.exists()) oldSeedFile.renameTo(mySeedFile);
        peers = new yacySeedDB(
                networkRoot,
                "seed.new.heap",
                "seed.old.heap",
                "seed.pot.heap",
                mySeedFile,
                redundancy,
                partitionExponent);
    }
    
    public MetadataRepository metadata() {
        return this.metadata;
    }

    public yacySeedDB peers() {
        return this.peers;
    }

    public BufferedIndex<WordReference> index() {
        return this.index;
    }
    
    public void clear() {
        try {
            index.clear();
            metadata.clear();
        } catch (final IOException e) {
            e.printStackTrace();
        }
        queuePreStack.clear();
    }
    
    private void initActiveCrawlProfiles() {
        this.defaultProxyProfile = null;
        this.defaultRemoteProfile = null;
        this.defaultTextSnippetLocalProfile = null;
        this.defaultTextSnippetGlobalProfile = null;
        this.defaultMediaSnippetLocalProfile = null;
        this.defaultMediaSnippetGlobalProfile = null;
        this.defaultSurrogateProfile = null;
        final Iterator<CrawlProfile.entry> i = this.profilesActiveCrawls.profiles(true);
        CrawlProfile.entry profile;
        String name;
        try {
            while (i.hasNext()) {
                profile = i.next();
                name = profile.name();
                if (name.equals(CRAWL_PROFILE_PROXY)) this.defaultProxyProfile = profile;
                if (name.equals(CRAWL_PROFILE_REMOTE)) this.defaultRemoteProfile = profile;
                if (name.equals(CRAWL_PROFILE_SNIPPET_LOCAL_TEXT)) this.defaultTextSnippetLocalProfile = profile;
                if (name.equals(CRAWL_PROFILE_SNIPPET_GLOBAL_TEXT)) this.defaultTextSnippetGlobalProfile = profile;
                if (name.equals(CRAWL_PROFILE_SNIPPET_LOCAL_MEDIA)) this.defaultMediaSnippetLocalProfile = profile;
                if (name.equals(CRAWL_PROFILE_SNIPPET_GLOBAL_MEDIA)) this.defaultMediaSnippetGlobalProfile = profile;
                if (name.equals(CRAWL_PROFILE_SURROGATE)) this.defaultSurrogateProfile = profile;
            }
        } catch (final Exception e) {
            this.profilesActiveCrawls.clear();
            this.defaultProxyProfile = null;
            this.defaultRemoteProfile = null;
            this.defaultTextSnippetLocalProfile = null;
            this.defaultTextSnippetGlobalProfile = null;
            this.defaultMediaSnippetLocalProfile = null;
            this.defaultMediaSnippetGlobalProfile = null;
            this.defaultSurrogateProfile = null;
        }
        
        if (this.defaultProxyProfile == null) {
            // generate new default entry for proxy crawling
            this.defaultProxyProfile = this.profilesActiveCrawls.newEntry("proxy", null, CrawlProfile.KEYWORDS_PROXY, CrawlProfile.MATCH_ALL, CrawlProfile.MATCH_NEVER,
                    0 /*Integer.parseInt(getConfig(PROXY_PREFETCH_DEPTH, "0"))*/,
                    this.profilesActiveCrawls.getRecrawlDate(CRAWL_PROFILE_PROXY_RECRAWL_CYCLE), -1, -1, false,
                    true /*getConfigBool(PROXY_INDEXING_LOCAL_TEXT, true)*/,
                    true /*getConfigBool(PROXY_INDEXING_LOCAL_MEDIA, true)*/,
                    true, true,
                    false /*getConfigBool(PROXY_INDEXING_REMOTE, false)*/, true, true, true);
        }
        if (this.defaultRemoteProfile == null) {
            // generate new default entry for remote crawling
            defaultRemoteProfile = this.profilesActiveCrawls.newEntry(CRAWL_PROFILE_REMOTE, null, CrawlProfile.KEYWORDS_REMOTE, CrawlProfile.MATCH_ALL, CrawlProfile.MATCH_NEVER, 0,
                    -1, -1, -1, true, true, true, false, true, false, true, true, false);
        }
        if (this.defaultTextSnippetLocalProfile == null) {
            // generate new default entry for snippet fetch and optional crawling
            defaultTextSnippetLocalProfile = this.profilesActiveCrawls.newEntry(CRAWL_PROFILE_SNIPPET_LOCAL_TEXT, null, CrawlProfile.KEYWORDS_SNIPPET, CrawlProfile.MATCH_ALL, CrawlProfile.MATCH_NEVER, 0,
            		this.profilesActiveCrawls.getRecrawlDate(CRAWL_PROFILE_SNIPPET_LOCAL_TEXT_RECRAWL_CYCLE), -1, -1, true, false, false, false, false, false, true, true, false);
        }
        if (this.defaultTextSnippetGlobalProfile == null) {
            // generate new default entry for snippet fetch and optional crawling
            defaultTextSnippetGlobalProfile = this.profilesActiveCrawls.newEntry(CRAWL_PROFILE_SNIPPET_GLOBAL_TEXT, null, CrawlProfile.KEYWORDS_SNIPPET, CrawlProfile.MATCH_ALL, CrawlProfile.MATCH_NEVER, 0,
            		this.profilesActiveCrawls.getRecrawlDate(CRAWL_PROFILE_SNIPPET_GLOBAL_TEXT_RECRAWL_CYCLE), -1, -1, true, true, true, true, true, false, true, true, false);
        }
        if (this.defaultMediaSnippetLocalProfile == null) {
            // generate new default entry for snippet fetch and optional crawling
            defaultMediaSnippetLocalProfile = this.profilesActiveCrawls.newEntry(CRAWL_PROFILE_SNIPPET_LOCAL_MEDIA, null, CrawlProfile.KEYWORDS_SNIPPET, CrawlProfile.MATCH_ALL, CrawlProfile.MATCH_NEVER, 0,
            		this.profilesActiveCrawls.getRecrawlDate(CRAWL_PROFILE_SNIPPET_LOCAL_MEDIA_RECRAWL_CYCLE), -1, -1, true, false, false, false, false, false, true, true, false);
        }
        if (this.defaultMediaSnippetGlobalProfile == null) {
            // generate new default entry for snippet fetch and optional crawling
            defaultMediaSnippetGlobalProfile = this.profilesActiveCrawls.newEntry(CRAWL_PROFILE_SNIPPET_GLOBAL_MEDIA, null, CrawlProfile.KEYWORDS_SNIPPET, CrawlProfile.MATCH_ALL, CrawlProfile.MATCH_NEVER, 0,
            		this.profilesActiveCrawls.getRecrawlDate(CRAWL_PROFILE_SNIPPET_GLOBAL_MEDIA_RECRAWL_CYCLE), -1, -1, true, false, true, true, true, false, true, true, false);
        }
        if (this.defaultSurrogateProfile == null) {
            // generate new default entry for surrogate parsing
            defaultSurrogateProfile = this.profilesActiveCrawls.newEntry(CRAWL_PROFILE_SURROGATE, null, CrawlProfile.KEYWORDS_SNIPPET, CrawlProfile.MATCH_ALL, CrawlProfile.MATCH_NEVER, 0,
                    this.profilesActiveCrawls.getRecrawlDate(CRAWL_PROFILE_SURROGATE_RECRAWL_CYCLE), -1, -1, true, true, false, false, false, false, true, true, false);
        }
    }
    
    private void resetProfiles() {
        final File pdb = new File(this.queuesRoot, DBFILE_ACTIVE_CRAWL_PROFILES);
        if (pdb.exists()) FileUtils.deletedelete(pdb);
        try {
            profilesActiveCrawls = new CrawlProfile(pdb);
        } catch (IOException e) {
            e.printStackTrace();
        }
        initActiveCrawlProfiles();
    }
    
    
    public boolean cleanProfiles() throws InterruptedException {
        if (queuePreStack.size() > 0) return false;
        final Iterator<CrawlProfile.entry> iter = profilesActiveCrawls.profiles(true);
        CrawlProfile.entry entry;
        boolean hasDoneSomething = false;
        try {
            while (iter.hasNext()) {
                // check for interruption
                if (Thread.currentThread().isInterrupted()) throw new InterruptedException("Shutdown in progress");
                
                // getting next profile
                entry = iter.next();
                if (!((entry.name().equals(CRAWL_PROFILE_PROXY))  ||
                      (entry.name().equals(CRAWL_PROFILE_REMOTE)) ||
                      (entry.name().equals(CRAWL_PROFILE_SNIPPET_LOCAL_TEXT))  ||
                      (entry.name().equals(CRAWL_PROFILE_SNIPPET_GLOBAL_TEXT)) ||
                      (entry.name().equals(CRAWL_PROFILE_SNIPPET_LOCAL_MEDIA)) ||
                      (entry.name().equals(CRAWL_PROFILE_SNIPPET_GLOBAL_MEDIA)) ||
                      (entry.name().equals(CRAWL_PROFILE_SURROGATE)))) {
                    profilesPassiveCrawls.newEntry(entry.map());
                    iter.remove();
                    hasDoneSomething = true;
                }
            }
        } catch (final kelondroException e) {
            resetProfiles();
            hasDoneSomething = true;
        }
        return hasDoneSomething;
    }
    
    public File getLocation(final boolean primary) {
        return (primary) ? this.primaryRoot : this.secondaryRoot;
    }

    /**
     * this is called by the switchboard to put in a new page into the index
     * use all the words in one condenser object to simultanous create index entries
     * 
     * @param url
     * @param urlModified
     * @param document
     * @param condenser
     * @param language
     * @param doctype
     * @param outlinksSame
     * @param outlinksOther
     * @return
     */
    public int addPageIndex(final yacyURL url, final Date urlModified, final plasmaParserDocument document, final Condenser condenser, final String language, final char doctype, final int outlinksSame, final int outlinksOther) {
        int wordCount = 0;
        final int urlLength = url.toNormalform(true, true).length();
        final int urlComps = htmlFilterContentScraper.urlComps(url.toString()).length;
        
        // iterate over all words of context text
        final Iterator<Map.Entry<String, Word>> i = condenser.words().entrySet().iterator();
        Map.Entry<String, Word> wentry;
        String word;
        int len = (document == null) ? urlLength : document.dc_title().length();
        WordReferenceRow ientry = new WordReferenceRow(url.hash(),
                                urlLength, urlComps, len,
                                condenser.RESULT_NUMB_WORDS,
                                condenser.RESULT_NUMB_SENTENCES,
                                urlModified.getTime(),
                                System.currentTimeMillis(),
                                language,
                                doctype,
                                outlinksSame, outlinksOther);
        Word wprop;
        while (i.hasNext()) {
            wentry = i.next();
            word = wentry.getKey();
            wprop = wentry.getValue();
            assert (wprop.flags != null);
            ientry.setWord(wprop);
            try {
                this.index.add(Word.word2hash(word), ientry);
            } catch (IOException e) {
                e.printStackTrace();
            }
            wordCount++;
        }
        
        return wordCount;
    }

    public void close() {
        if (this.merger != null) this.merger.terminate();
        index.close();
        metadata.close();
        peers.close();
        profilesActiveCrawls.close();
        queuePreStack.close();
    }

    public URLMetadataRow storeDocument(final IndexingStack.QueueEntry entry, final plasmaParserDocument document, final Condenser condenser) throws IOException {
        final long startTime = System.currentTimeMillis();

        // CREATE INDEX
        
        // load some document metadata
        final String dc_title = document.dc_title();
        final yacyURL referrerURL = entry.referrerURL();
        final Date docDate = entry.getModificationDate();
        
        // do a identification of the language
        String language = condenser.language(); // this is a statistical analysation of the content: will be compared with other attributes
        String bymetadata = document.dc_language(); // the languageByMetadata may return null if there was no declaration
        if (language == null) {
            // no statistics available, we take either the metadata (if given) or the TLD
            language = (bymetadata == null) ? entry.url().language() : bymetadata;
            System.out.println("*** DEBUG LANGUAGE-BY-STATISTICS: " + entry.url() + " FAILED, taking " + ((bymetadata == null) ? "TLD" : "metadata") + ": " + language);
        } else {
            if (bymetadata == null) {
                // two possible results: compare and report conflicts
                if (language.equals(entry.url().language()))
                    System.out.println("*** DEBUG LANGUAGE-BY-STATISTICS: " + entry.url() + " CONFIRMED - TLD IDENTICAL: " + language);
                else {
                    String error = "*** DEBUG LANGUAGE-BY-STATISTICS: " + entry.url() + " CONFLICTING: " + language + " (the language given by the TLD is " + entry.url().language() + ")";
                    // see if we have a hint in the url that the statistic was right
                    String u = entry.url().toNormalform(true, false).toLowerCase();
                    if (!u.contains("/" + language + "/") && !u.contains("/" + iso639.country(language).toLowerCase() + "/")) {
                        // no confirmation using the url, use the TLD
                        language = entry.url().language();
                        System.out.println(error + ", corrected using the TLD");
                    } else {
                        // this is a strong hint that the statistics was in fact correct
                        System.out.println(error + ", but the url proves that the statistic is correct");
                    }
                }
            } else {
                // here we have three results: we can do a voting
                if (language.equals(bymetadata)) {
                    System.out.println("*** DEBUG LANGUAGE-BY-STATISTICS: " + entry.url() + " CONFIRMED - METADATA IDENTICAL: " + language);
                } else if (language.equals(entry.url().language())) {
                    System.out.println("*** DEBUG LANGUAGE-BY-STATISTICS: " + entry.url() + " CONFIRMED - TLD IS IDENTICAL: " + language);
                } else if (bymetadata.equals(entry.url().language())) {
                    System.out.println("*** DEBUG LANGUAGE-BY-STATISTICS: " + entry.url() + " CONFLICTING: " + language + " BUT METADATA AND TLD ARE IDENTICAL: " + bymetadata + ")");
                    language = bymetadata;
                } else {
                    System.out.println("*** DEBUG LANGUAGE-BY-STATISTICS: " + entry.url() + " CONFLICTING: ALL DIFFERENT! statistic: " + language + ", metadata: " + bymetadata + ", TLD: + " + entry.url().language() + ". taking metadata.");
                    language = bymetadata;
                }
            }
        }
        
        // create a new loaded URL db entry
        final long ldate = System.currentTimeMillis();
        final URLMetadataRow newEntry = new URLMetadataRow(
                entry.url(),                               // URL
                dc_title,                                  // document description
                document.dc_creator(),                     // author
                document.dc_subject(' '),                  // tags
                "",                                        // ETag
                docDate,                                   // modification date
                new Date(),                                // loaded date
                new Date(ldate + Math.max(0, ldate - docDate.getTime()) / 2), // freshdate, computed with Proxy-TTL formula 
                (referrerURL == null) ? null : referrerURL.hash(),            // referer hash
                new byte[0],                               // md5
                (int) entry.size(),                        // size
                condenser.RESULT_NUMB_WORDS,               // word count
                httpdProxyCacheEntry.docType(document.dc_format()), // doctype
                condenser.RESULT_FLAGS,                    // flags
                language,                                  // language
                document.inboundLinks(),                   // inbound links
                document.outboundLinks(),                  // outbound links
                document.getAudiolinks().size(),           // laudio
                document.getImages().size(),               // limage
                document.getVideolinks().size(),           // lvideo
                document.getApplinks().size()              // lapp
        );
        
        // STORE URL TO LOADED-URL-DB
        metadata.store(newEntry); // TODO: should be serialized; integrated in IODispatcher
        
        final long storageEndTime = System.currentTimeMillis();
        
        // STORE PAGE INDEX INTO WORD INDEX DB
        final int words = addPageIndex(
                entry.url(),                                  // document url
                docDate,                                      // document mod date
                document,                                     // document content
                condenser,                                    // document condenser
                language,                                     // document language
                httpdProxyCacheEntry.docType(document.dc_format()),  // document type
                document.inboundLinks(),                      // inbound links
                document.outboundLinks()                      // outbound links
        );
            
        final long indexingEndTime = System.currentTimeMillis();
        
        if (log.isInfo()) {
            // TODO: UTF-8 docDescription seems not to be displayed correctly because
            // of string concatenation
            log.logInfo("*Indexed " + words + " words in URL " + entry.url() +
                    " [" + entry.urlHash() + "]" +
                    "\n\tDescription:  " + dc_title +
                    "\n\tMimeType: "  + document.dc_format() + " | Charset: " + document.getCharset() + " | " +
                    "Size: " + document.getTextLength() + " bytes | " +
                    "Anchors: " + ((document.getAnchors() == null) ? 0 : document.getAnchors().size()) +
                    "\n\tLinkStorageTime: " + (storageEndTime - startTime) + " ms | " +
                    "indexStorageTime: " + (indexingEndTime - storageEndTime) + " ms");
            RSSFeed.channels((entry.initiator().equals(peers.mySeed().hash)) ? RSSFeed.LOCALINDEXING : RSSFeed.REMOTEINDEXING).addMessage(new RSSMessage("Indexed web page", dc_title, entry.url().toNormalform(true, false)));
        }
        
        // finished
        return newEntry;
    }
    
    @SuppressWarnings("unchecked")
    public HashMap<byte[], ReferenceContainer<WordReference>>[] localSearchContainers(
                            final TreeSet<byte[]> queryHashes, 
                            final TreeSet<byte[]> excludeHashes, 
                            final Set<String> urlselection) {
        // search for the set of hashes and return a map of of wordhash:indexContainer containing the seach result

        // retrieve entities that belong to the hashes
        HashMap<byte[], ReferenceContainer<WordReference>> inclusionContainers =
            (queryHashes.size() == 0) ?
                    new HashMap<byte[], ReferenceContainer<WordReference>>(0) :
                    getContainers(queryHashes, urlselection);
        if ((inclusionContainers.size() != 0) && (inclusionContainers.size() < queryHashes.size())) inclusionContainers = new HashMap<byte[], ReferenceContainer<WordReference>>(0); // prevent that only a subset is returned
        final HashMap<byte[], ReferenceContainer<WordReference>> exclusionContainers =
            (inclusionContainers.size() == 0) ?
                    new HashMap<byte[], ReferenceContainer<WordReference>>(0) :
                    getContainers(excludeHashes, urlselection);
        return new HashMap[]{inclusionContainers, exclusionContainers};
    }

    /**
     * collect containers for given word hashes. This collection stops if a single container does not contain any references.
     * In that case only a empty result is returned.
     * @param wordHashes
     * @param urlselection
     * @return map of wordhash:indexContainer
     */
    private HashMap<byte[], ReferenceContainer<WordReference>> getContainers(final TreeSet<byte[]> wordHashes, final Set<String> urlselection) {
        // retrieve entities that belong to the hashes
        final HashMap<byte[], ReferenceContainer<WordReference>> containers = new HashMap<byte[], ReferenceContainer<WordReference>>(wordHashes.size());
        byte[] singleHash;
        ReferenceContainer<WordReference> singleContainer;
            final Iterator<byte[]> i = wordHashes.iterator();
            while (i.hasNext()) {
            
                // get next word hash:
                singleHash = i.next();
            
                // retrieve index
                try {
                    singleContainer = index.get(singleHash, urlselection);
                } catch (IOException e) {
                    e.printStackTrace();
                    continue;
                }
            
                // check result
                if ((singleContainer == null || singleContainer.size() == 0)) return new HashMap<byte[], ReferenceContainer<WordReference>>(0);
            
                containers.put(singleHash, singleContainer);
            }
        return containers;
    }
    
    //  The Cleaner class was provided as "UrldbCleaner" by Hydrox
    public synchronized ReferenceCleaner getReferenceCleaner(final byte[] startHash) {
        return new ReferenceCleaner(startHash);
    }
    
    public class ReferenceCleaner extends Thread {
        
        private final byte[] startHash;
        private boolean run = true;
        private boolean pause = false;
        public int rwiCountAtStart = 0;
        public byte[] wordHashNow = null;
        public byte[] lastWordHash = null;
        public int lastDeletionCounter = 0;
        
        public ReferenceCleaner(final byte[] startHash) {
            this.startHash = startHash;
            this.rwiCountAtStart = index().size();
        }
        
        public void run() {
            Log.logInfo("INDEXCLEANER", "IndexCleaner-Thread started");
            ReferenceContainer<WordReference> container = null;
            WordReference entry = null;
            yacyURL url = null;
            final HashSet<String> urlHashs = new HashSet<String>();
            try {
                Iterator<ReferenceContainer<WordReference>> indexContainerIterator = index.references(startHash, false, 100, false).iterator();
                while (indexContainerIterator.hasNext() && run) {
                    waiter();
                    container = indexContainerIterator.next();
                    final Iterator<WordReference> containerIterator = container.entries();
                    wordHashNow = container.getTermHash();
                    while (containerIterator.hasNext() && run) {
                        waiter();
                        entry = containerIterator.next();
                        // System.out.println("Wordhash: "+wordHash+" UrlHash:
                        // "+entry.getUrlHash());
                        final URLMetadataRow ue = metadata.load(entry.metadataHash(), entry, 0);
                        if (ue == null) {
                            urlHashs.add(entry.metadataHash());
                        } else {
                            url = ue.metadata().url();
                            if ((url == null) || (plasmaSwitchboard.urlBlacklist.isListed(Blacklist.BLACKLIST_CRAWLER, url) == true)) {
                                urlHashs.add(entry.metadataHash());
                            }
                        }
                    }
                    if (urlHashs.size() > 0) try {
                        final int removed = index.remove(container.getTermHash(), urlHashs);
                        Log.logFine("INDEXCLEANER", container.getTermHashAsString() + ": " + removed + " of " + container.size() + " URL-entries deleted");
                        lastWordHash = container.getTermHash();
                        lastDeletionCounter = urlHashs.size();
                        urlHashs.clear();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    
                    if (!containerIterator.hasNext()) {
                        // We may not be finished yet, try to get the next chunk of wordHashes
                        final TreeSet<ReferenceContainer<WordReference>> containers = index.references(container.getTermHash(), false, 100, false);
                        indexContainerIterator = containers.iterator();
                        // Make sure we don't get the same wordhash twice, but don't skip a word
                        if ((indexContainerIterator.hasNext()) && (!container.getTermHash().equals(indexContainerIterator.next().getTermHash()))) {
                            indexContainerIterator = containers.iterator();
                        }
                    }
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            Log.logInfo("INDEXCLEANER", "IndexCleaner-Thread stopped");
        }
        
        public void abort() {
            synchronized(this) {
                run = false;
                this.notifyAll();
            }
        }

        public void pause() {
            synchronized (this) {
                if (!pause) {
                    pause = true;
                    Log.logInfo("INDEXCLEANER", "IndexCleaner-Thread paused");
                }
            }
        }

        public void endPause() {
            synchronized (this) {
                if (pause) {
                    pause = false;
                    this.notifyAll();
                    Log.logInfo("INDEXCLEANER", "IndexCleaner-Thread resumed");
                }
            }
        }

        public void waiter() {
            synchronized (this) {
                if (this.pause) {
                    try {
                        this.wait();
                    } catch (final InterruptedException e) {
                        this.run = false;
                        return;
                    }
                }
            }
        }
    }
}