// list.java 
// -----------------------
// part of YaCy
// (C) by Michael Peter Christen; mc@anomic.de
// first published on http://www.anomic.de
// Frankfurt, Germany, 2004
//
// This File is contributed by Alexander Schier
//
// $LastChangedDate$
// $LastChangedRevision$
// $LastChangedBy$
//
// 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 list.java
// if the shell's current path is HTROOT

// contains contributions by [FB] to support listing URLs for URL Fetcher

import java.io.File;

import de.anomic.data.URLFetcherStack;
import de.anomic.data.htmlTools;
import de.anomic.data.listManager;
import de.anomic.http.httpHeader;
import de.anomic.net.URL;
import de.anomic.plasma.plasmaSwitchboard;
import de.anomic.server.serverCore;
import de.anomic.server.serverObjects;
import de.anomic.server.serverSwitch;
import de.anomic.server.logging.serverLog;
import de.anomic.yacy.yacyCore;
import de.anomic.yacy.yacySeed;

public final class list {

    public static serverObjects respond(httpHeader header, serverObjects post, serverSwitch ss) {
        if (post == null || ss == null)
            throw new NullPointerException("post: " + post + ", sb: " + ss);
        plasmaSwitchboard sb = (plasmaSwitchboard) ss;
        
        // return variable that accumulates replacements
        final serverObjects prop = new serverObjects();
        
        final String col = post.get("col", "");
        final File listsPath = new File(ss.getRootPath(),ss.getConfig("listsPath", "DATA/LISTS"));
        
        String otherPeerName = null;
        if (post.containsKey("iam")) {
            yacySeed bla = yacyCore.seedDB.get(post.get("iam", ""));
            if (bla != null) otherPeerName = bla.getName();
        }
        if (otherPeerName == null) otherPeerName = (String)header.get(httpHeader.CONNECTION_PROP_CLIENTIP);
        
        if ((sb.isRobinsonMode()) && (!sb.isInMyCluster(otherPeerName))) {
            // if we are a robinson cluster, answer only if this client is known by our network definition
            return null;
        }
        
        if (col.equals("black")) {
            final StringBuffer out = new StringBuffer();

            final String filenames=ss.getConfig("BlackLists.Shared", "");
            final String[] filenamesarray = filenames.split(",");

            if(filenamesarray.length > 0){
                for(int i = 0;i < filenamesarray.length; i++){
                    String filename = filenamesarray[i];
                    File fileObj = new File(listsPath,filename);
                    out.append(listManager.getListString(fileObj, false))
                       .append(serverCore.crlfString);
                }
            } // if filenamesarray.length > 0

            prop.put("list",out);
        }
        // start contrib by [FB]
        else if (col.length() == 0 && post.get("list", "").equals("queueUrls")) {
            final URLFetcherStack db = CrawlURLFetchStack_p.getURLFetcherStack(ss);
            final String display = post.get("display", "list");
            if (display.equals("list")) {
                // list urls from remote crawler queue for other peers
                final int count = Math.min(post.getInt("count", 50), CrawlURLFetchStack_p.maxURLsPerFetch);
                
                if (count > 0 && db.size() > 0) {
                    final StringBuffer b = new StringBuffer();
                    
                    URL url;
                    int cnt = 0;
                    for (int i=0; i<count; i++) {
                        if ((url = db.pop()) == null) continue;
                        b.append(htmlTools.deReplaceHTMLEntities(url.toNormalform())).append("\n");
                        cnt++;
                    }
                    prop.put("list", b);
                    CrawlURLFetchStack_p.fetchMap.put(
                            otherPeerName,
                            new Integer(((CrawlURLFetchStack_p.fetchMap.get(otherPeerName) == null)
                                    ? 0
                                    : ((Integer)CrawlURLFetchStack_p.fetchMap.get(otherPeerName)).intValue()) + cnt));
                    serverLog.logInfo("URLFETCHER", "sent " + cnt + " URLs to " + otherPeerName);
                } else {
                    prop.put("list", "");
                    serverLog.logInfo("URLFETCHER", "couldn't satisfy URL request from " + otherPeerName + ": stack is empty");
                }
            } else if (display.equals("count")) {
                prop.put("list", db.size());
            }
        // end contrib by [FB]
        } else {
            prop.putASIS("list","");
        }
        
        return prop;
    }
}