// indexURLEntry.java
// (C) 2006 by Michael Peter Christen; mc@anomic.de, Frankfurt a. M., Germany
// first published 2006 on http://www.anomic.de
//
// This is a part of YaCy, a peer-to-peer based web search engine
//
// $LastChangedDate: 2006-04-02 22:40:07 +0200 (So, 02 Apr 2006) $
// $LastChangedRevision: 1986 $
// $LastChangedBy: orbiter $
//
// 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.index;

import java.io.IOException;
import java.net.MalformedURLException;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.Date;
import java.util.Properties;

import de.anomic.kelondro.kelondroBase64Order;
import de.anomic.kelondro.kelondroBitfield;
import de.anomic.kelondro.kelondroException;
import de.anomic.kelondro.kelondroNaturalOrder;
import de.anomic.kelondro.kelondroRow;
import de.anomic.net.URL;
import de.anomic.plasma.plasmaCrawlEntry;
import de.anomic.plasma.plasmaSearchQuery;
import de.anomic.plasma.plasmaURL;
import de.anomic.server.serverCharBuffer;
import de.anomic.server.serverCodings;
import de.anomic.tools.crypt;
import de.anomic.tools.nxTools;
import de.anomic.index.indexRWIEntry;

public class indexURLEntry {

    // this object stores attributes for URL entries
    
    public static final kelondroRow rowdef = new kelondroRow(
        "String hash-12, " +            // the url's hash
        "String comp-360, " +           // components: the url, description, author and tags. As 5th element, an ETag is possible
        "Cardinal mod-4 {b256}, " +     // last-modified from the httpd
        "Cardinal load-4 {b256}, " +    // time when the url was loaded
        "Cardinal fresh-4 {b256}, " +   // time until this url is fresh
        "String referrer-12, " +        // (one of) the url's referrer hash(es)
        "byte[] md5-8, " +              // the md5 of the url content (to identify changes)
        "Cardinal size-6 {b256}, " +    // size of file in bytes
        "Cardinal wc-3 {b256}, " +      // size of file by number of words; for video and audio: seconds
        "byte[] dt-1, " +               // doctype, taken from extension or any other heuristic
        "Bitfield flags-4, " +          // flags; any stuff (see Word-Entity definition)
        "String lang-2, " +             // language
        "Cardinal llocal-2 {b256}, " +  // # of outlinks to same domain; for video and image: width 
        "Cardinal lother-2 {b256}, " +  // # of outlinks to outside domain; for video and image: height
        "Cardinal limage-2 {b256}, " +  // # of embedded image links
        "Cardinal laudio-2 {b256}, " +  // # of embedded audio links; for audio: track number; for video: number of audio tracks
        "Cardinal lvideo-2 {b256}, " +  // # of embedded video links
        "Cardinal lapp-2 {b256}",       // # of embedded links to applications
        kelondroBase64Order.enhancedCoder,
        0);      
    
    /* ===========================================================================
     * Constants to access the various columns of an URL entry
     * =========================================================================== */
    /** the url's hash */
    private static final int col_hash     =  0;
    /** components: the url, description, author and tags. As 5th element, an ETag is possible */
    private static final int col_comp     =  1;
    /** components: the url, description, author and tags. As 5th element, an ETag is possible */
    private static final int col_mod      =  2;
    /** time when the url was loaded */
    private static final int col_load     =  3;
    /** time until this url is fresh */
    private static final int col_fresh    =  4;
    /** time when the url was loaded */
    private static final int col_referrer =  5;
    /** the md5 of the url content (to identify changes) */
    private static final int col_md5      =  6;
    /** size of file in bytes */
    private static final int col_size     =  7;
    /** size of file by number of words; for video and audio: seconds */
    private static final int col_wc       =  8;
    /** doctype, taken from extension or any other heuristic */
    private static final int col_dt       =  9;
    /** flags; any stuff (see Word-Entity definition) */
    private static final int col_flags    = 10;
    /** language */
    private static final int col_lang     = 11;
    /** of outlinks to same domain; for video and image: width */
    private static final int col_llocal   = 12;
    /** of outlinks to outside domain; for video and image: height */
    private static final int col_lother   = 13;
    /** of embedded image links */
    private static final int col_limage   = 14;
    /** of embedded audio links; for audio: track number; for video: number of audio tracks */
    private static final int col_laudio   = 15;
    /** of embedded video links */
    private static final int col_lvideo   = 16;
    /** of embedded links to applications */
    private static final int col_lapp     = 17;
    
    private kelondroRow.Entry entry;
    private String snippet;
    private indexRWIEntry word; // this is only used if the url is transported via remote search requests

    public indexURLEntry(
            URL url,
            String descr,
            String author,
            String tags,
            String ETag,
            Date mod,
            Date load,
            Date fresh,
            String referrer,
            byte[] md5,
            long size,
            int wc,
            char dt,
            kelondroBitfield flags,
            String lang,
            int llocal,
            int lother,
            int laudio,
            int limage,
            int lvideo,
            int lapp) {
        // create new entry and store it into database
        this.entry = rowdef.newEntry();
        this.entry.setCol(col_hash, plasmaURL.urlHash(url), null);
        this.entry.setCol(col_comp, encodeComp(url, descr, author, tags, ETag));
        this.entry.setCol(col_mod, encodeDate(mod));
        this.entry.setCol(col_load, encodeDate(load));
        this.entry.setCol(col_fresh, encodeDate(fresh));
        this.entry.setCol(col_referrer, referrer.getBytes());
        this.entry.setCol(col_md5, md5);
        this.entry.setCol(col_size, size);
        this.entry.setCol(col_wc, wc);
        this.entry.setCol(col_dt, new byte[]{(byte) dt});
        this.entry.setCol(col_flags, flags.bytes());
        this.entry.setCol(col_lang, lang.getBytes());
        this.entry.setCol(col_llocal, llocal);
        this.entry.setCol(col_lother, lother);
        this.entry.setCol(col_limage, limage);
        this.entry.setCol(col_laudio, laudio);
        this.entry.setCol(col_lvideo, lvideo);
        this.entry.setCol(col_lapp, lapp);
        this.snippet = null;
        this.word = null;
    }

    public static byte[] encodeDate(Date d) {
        // calculates the number of days since 1.1.1970 and returns this as 4-byte array
        return kelondroNaturalOrder.encodeLong(d.getTime() / 86400000, 4);
    }
    
    public static byte[] encodeComp(URL url, String descr, String author, String tags, String ETag) {
        serverCharBuffer s = new serverCharBuffer(200);
        s.append(url.toNormalform()).append(10);
        s.append(descr).append(10);
        s.append(author).append(10);
        s.append(tags).append(10);
        s.append(ETag).append(10);
        return s.toString().getBytes();
    }
    
    public indexURLEntry(kelondroRow.Entry entry, indexRWIEntry searchedWord) {
        this.entry = entry;
        this.snippet = null;
        this.word = searchedWord;
    }

    public indexURLEntry(Properties prop){
        // generates an plasmaLURLEntry using the properties from the argument
        // the property names must correspond to the one from toString
        //System.out.println("DEBUG-ENTRY: prop=" + prop.toString());
        URL url;
        try {
            url = new URL(crypt.simpleDecode(prop.getProperty("url", ""), null));
        } catch (MalformedURLException e) {
            url = null;
        }
        String descr = crypt.simpleDecode(prop.getProperty("descr", ""), null); if (descr == null) descr = "";
        String author = crypt.simpleDecode(prop.getProperty("author", ""), null); if (author == null) author = "";
        String tags = crypt.simpleDecode(prop.getProperty("tags", ""), null); if (tags == null) tags = "";
        String ETag = crypt.simpleDecode(prop.getProperty("ETag", ""), null); if (ETag == null) ETag = "";
        
        this.entry = rowdef.newEntry();
        this.entry.setCol(col_hash, plasmaURL.urlHash(url), null);
        this.entry.setCol(col_comp, encodeComp(url, descr, author, tags, ETag));
        try {
            this.entry.setCol(col_mod, encodeDate(plasmaURL.shortDayFormatter.parse(prop.getProperty("mod", "20000101"))));
        } catch (ParseException e) {
            this.entry.setCol(col_mod, encodeDate(new Date()));
        }
        try {
            this.entry.setCol(col_load, encodeDate(plasmaURL.shortDayFormatter.parse(prop.getProperty("load", "20000101"))));
        } catch (ParseException e) {
            this.entry.setCol(col_load, encodeDate(new Date()));
        }
        try {
            this.entry.setCol(col_fresh, encodeDate(plasmaURL.shortDayFormatter.parse(prop.getProperty("fresh", "20000101"))));
        } catch (ParseException e) {
            this.entry.setCol(col_fresh, encodeDate(new Date()));
        }
        this.entry.setCol(col_referrer, prop.getProperty("referrer", plasmaURL.dummyHash).getBytes());
        this.entry.setCol(col_md5, serverCodings.decodeHex(prop.getProperty("md5", "")));
        this.entry.setCol(col_size, Integer.parseInt(prop.getProperty("size", "0")));
        this.entry.setCol(col_wc, Integer.parseInt(prop.getProperty("wc", "0")));
        this.entry.setCol(col_dt, new byte[]{(byte) prop.getProperty("dt", "t").charAt(0)});
        String flags = prop.getProperty("flags", "AAAAAA");
        this.entry.setCol(col_flags, (flags.length() > 6) ? plasmaSearchQuery.empty_constraint.bytes() : (new kelondroBitfield(4, flags)).bytes());
        this.entry.setCol(col_lang, prop.getProperty("lang", "uk").getBytes());
        this.entry.setCol(col_llocal, Integer.parseInt(prop.getProperty("llocal", "0")));
        this.entry.setCol(col_lother, Integer.parseInt(prop.getProperty("lother", "0")));
        this.entry.setCol(col_limage, Integer.parseInt(prop.getProperty("limage", "0")));
        this.entry.setCol(col_laudio, Integer.parseInt(prop.getProperty("laudio", "0")));
        this.entry.setCol(col_lvideo, Integer.parseInt(prop.getProperty("lvideo", "0")));
        this.entry.setCol(col_lapp, Integer.parseInt(prop.getProperty("lapp", "0")));
        this.snippet = crypt.simpleDecode(prop.getProperty("snippet", ""), null);
        this.word = null;
        if (prop.containsKey("word")) throw new kelondroException("old database structure is not supported");
        if (prop.containsKey("wi")) {
            this.word = new indexRWIEntry(kelondroBase64Order.enhancedCoder.decodeString(prop.getProperty("wi", "")));
        }
    }

    private StringBuffer corePropList() {
        // generate a parseable string; this is a simple property-list
        indexURLEntry.Components comp = this.comp();
        final StringBuffer s = new StringBuffer(300);
        //System.out.println("author=" + comp.author());
        try {
            s.append("hash=").append(hash());
            s.append(",url=").append(crypt.simpleEncode(comp.url().toNormalform()));
            s.append(",descr=").append(crypt.simpleEncode(comp.title()));
            s.append(",author=").append(crypt.simpleEncode(comp.author()));
            s.append(",tags=").append(crypt.simpleEncode(comp.tags()));
            s.append(",ETag=").append(crypt.simpleEncode(comp.ETag()));
            s.append(",mod=").append(plasmaURL.shortDayFormatter.format(moddate()));
            s.append(",load=").append(plasmaURL.shortDayFormatter.format(loaddate()));
            s.append(",fresh=").append(plasmaURL.shortDayFormatter.format(freshdate()));
            s.append(",referrer=").append(referrerHash());
            s.append(",md5=").append(md5());
            s.append(",size=").append(size());
            s.append(",wc=").append(wordCount());
            s.append(",dt=").append(doctype());
            s.append(",flags=").append(flags().exportB64());
            s.append(",lang=").append(language());
            s.append(",llocal=").append(llocal());
            s.append(",lother=").append(lother());
            s.append(",limage=").append(limage());
            s.append(",laudio=").append(laudio());
            s.append(",lvideo=").append(lvideo());
            s.append(",lapp=").append(lapp());
            
            if (this.word != null) {
                // append also word properties
                s.append(",wi=").append(kelondroBase64Order.enhancedCoder.encodeString(word.toPropertyForm()));
            }
            return s;

        } catch (Exception e) {
            //          serverLog.logFailure("plasmaLURL.corePropList", e.getMessage());
            //          if (moddate == null) serverLog.logFailure("plasmaLURL.corePropList", "moddate=null");
            //          if (loaddate == null) serverLog.logFailure("plasmaLURL.corePropList", "loaddate=null");
            //          e.printStackTrace();
            return null;
        }
    }

    public kelondroRow.Entry toRowEntry() throws IOException {
        return this.entry;
    }

    public String hash() {
        // return a url-hash, based on the md5 algorithm
        // the result is a String of 12 bytes within a 72-bit space
        // (each byte has an 6-bit range)
        // that should be enough for all web pages on the world
        return this.entry.getColString(col_hash, null);
    }

    public indexURLEntry.Components comp() {
        ArrayList cl = nxTools.strings(this.entry.getCol("comp", null), "UTF-8");
        return new indexURLEntry.Components(
                (cl.size() > 0) ? ((String) cl.get(0)).trim() : "",
                (cl.size() > 1) ? ((String) cl.get(1)).trim() : "",
                (cl.size() > 2) ? ((String) cl.get(2)).trim() : "",
                (cl.size() > 3) ? ((String) cl.get(3)).trim() : "",
                (cl.size() > 4) ? ((String) cl.get(4)).trim() : "");
    }
    
    public Date moddate() {
        return new Date(86400000 * entry.getColLong(col_mod));
    }

    public Date loaddate() {
        return new Date(86400000 * entry.getColLong(col_load));
    }

    public Date freshdate() {
        return new Date(86400000 * entry.getColLong(col_fresh));
    }

    public String referrerHash() {
        // return the creator's hash
        return entry.getColString(col_referrer, null);
    }

    public String md5() {
        // returns the md5 in hex representation
        return serverCodings.encodeHex(entry.getColBytes(col_md5));
    }

    public char doctype() {
        return (char) entry.getColByte(col_dt);
    }

    public String language() {
        return this.entry.getColString(col_lang, null);
    }

    public int size() {
        return (int) this.entry.getColLong(col_size);
    }

    public kelondroBitfield flags() {
        return new kelondroBitfield(this.entry.getColBytes(col_flags));
    }

    public int wordCount() {
        return (int) this.entry.getColLong(col_wc);
    }

    public int llocal() {
        return (int) this.entry.getColLong(col_llocal);
    }

    public int lother() {
        return (int) this.entry.getColLong(col_lother);
    }

    public int limage() {
        return (int) this.entry.getColLong(col_limage);
    }

    public int laudio() {
        return (int) this.entry.getColLong(col_laudio);
    }

    public int lvideo() {
        return (int) this.entry.getColLong(col_lvideo);
    }

    public int lapp() {
        return (int) this.entry.getColLong(col_lapp);
    }
    
    public String snippet() {
        // the snippet may appear here if the url was transported in a remote search
        // it will not be saved anywhere, but can only be requested here
        return snippet;
    }

    public indexRWIEntry word() {
        return word;
    }

    public boolean isOlder(indexURLEntry other) {
        if (other == null) return false;
        Date tmoddate = moddate();
        Date omoddate = other.moddate();
        if (tmoddate.before(omoddate)) return true;
        if (tmoddate.equals(omoddate)) {
            Date tloaddate = loaddate();
            Date oloaddate = other.loaddate();
            if (tloaddate.before(oloaddate)) return true;
            if (tloaddate.equals(oloaddate)) return true;
        }
        return false;
    }

    public String toString(String snippet) {
        // add information needed for remote transport
        final StringBuffer core = corePropList();
        if (core == null)
            return null;

        core.ensureCapacity(core.length() + snippet.length() * 2);
        core.insert(0, "{");
        core.append(",snippet=").append(crypt.simpleEncode(snippet));
        core.append("}");

        return new String(core);
        //return "{" + core + ",snippet=" + crypt.simpleEncode(snippet) + "}";
    }

    public plasmaCrawlEntry toBalancerEntry() {
        return new plasmaCrawlEntry(
                null, 
                comp().url(), 
                referrerHash(), 
                comp().title(),
                loaddate(), 
                null,
                0, 
                0, 
                0);
    }
    
    /**
     * @return the object as String.<br> 
     * This e.g. looks like this:
     * <pre>{hash=jmqfMk7Y3NKw,referrer=------------,mod=20050610,load=20051003,size=51666,wc=1392,cc=0,local=true,q=AEn,dt=h,lang=uk,url=b|aHR0cDovL3d3dy50cmFuc3BhcmVuY3kub3JnL3N1cnZleXMv,descr=b|S25vd2xlZGdlIENlbnRyZTogQ29ycnVwdGlvbiBTdXJ2ZXlzIGFuZCBJbmRpY2Vz}</pre>
     */
    public String toString() {
        final StringBuffer core = corePropList();
        if (core == null) return null;

        core.insert(0, "{");
        core.append("}");

        return new String(core);
        //return "{" + core + "}";
    }

    public class Components {
        private URL url;
        private String title, author, tags, ETag;
        
        public Components(String url, String title, String author, String tags, String ETag) {
            try {
                this.url = new URL(url);
            } catch (MalformedURLException e) {
                this.url = null;
            }
            this.title = title;
            this.author = author;
            this.tags = tags;
            this.ETag = ETag;
        }
        public Components(URL url, String descr, String author, String tags, String ETag) {
            this.url = url;
            this.title = descr;
            this.author = author;
            this.tags = tags;
            this.ETag = ETag;
        }
        public URL    url()    { return this.url; }
        public String title()  { return this.title; }
        public String author() { return this.author; }
        public String tags()   { return this.tags; }
        public String ETag()   { return this.ETag; }
    }
    
}