package com.laoer.bbscs.lucene;

/**
 * Copyright 2004 The Apache Software Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.TermEnum;
import java.io.File;
import java.util.Date;
import java.util.Arrays;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import com.laoer.bbscs.sys.*;

public class IndexHTML {

  private static final Log logger = LogFactory.getLog(IndexHTML.class);

  private static boolean deleting = false; // true during deletion pass
  private static IndexReader reader; // existing index
  private static IndexWriter writer; // new index being built
  private static TermEnum uidIter; // document id iterator

  public synchronized static void doIndex(boolean iscreate) {
    try {
      //String index = Sys.SYSINFO.FILEPATH + "index/";
      String index = SysUtil.getIndexPath();
      boolean create = iscreate;
      File root = new File(SysUtil.getPostFilePath());
      //File root = new File(Sys.SYSINFO.FILEPATH + "postfile");

      //String usage = "IndexHTML [-create] [-index <index>] <root_directory>";

      Date start = new Date();

      if (!create) { // delete stale docs
        deleting = true;
        indexDocs(root, index, create);
      }

      writer = new IndexWriter(index, new StandardAnalyzer(), create);
      writer.maxFieldLength = 100000000;

      indexDocs(root, index, create); // add new docs

      //System.out.println("Optimizing index...");
      logger.info("Optimizing index...");
      writer.optimize();
      writer.close();

      Date end = new Date();

      logger.info(end.getTime() - start.getTime() + " total milliseconds");
      //System.out.print(end.getTime() - start.getTime());
      //System.out.println(" total milliseconds");

    }
    catch (Exception e) {
      System.out.println(" caught a " + e.getClass() +
                         "\n with message: " + e.getMessage());
      logger.error(e);
    }

  }

  public static void main(String[] argv) {
    try {
      String index = "index";
      boolean create = false;
      File root = null;

      String usage = "IndexHTML [-create] [-index <index>] <root_directory>";

      if (argv.length == 0) {
        System.err.println("Usage: " + usage);
        return;
      }

      for (int i = 0; i < argv.length; i++) {
        if (argv[i].equals("-index")) { // parse -index option
          index = argv[++i];
        }
        else if (argv[i].equals("-create")) { // parse -create option
          create = true;
        }
        else if (i != argv.length - 1) {
          System.err.println("Usage: " + usage);
          return;
        }
        else {
          root = new File(argv[i]);
        }
      }

      Date start = new Date();

      if (!create) { // delete stale docs
        deleting = true;
        indexDocs(root, index, create);
      }

      writer = new IndexWriter(index, new StandardAnalyzer(), create);
      writer.maxFieldLength = 1000000;

      indexDocs(root, index, create); // add new docs

      System.out.println("Optimizing index...");
      writer.optimize();
      writer.close();

      Date end = new Date();

      System.out.print(end.getTime() - start.getTime());
      System.out.println(" total milliseconds");

    }
    catch (Exception e) {
      System.out.println(" caught a " + e.getClass() +
                         "\n with message: " + e.getMessage());
    }
  }

  private static void indexDocs(File file, String index, boolean create) throws
      Exception {
    if (!create) { // incrementally update

      reader = IndexReader.open(index); // open existing index
      uidIter = reader.terms(new Term("uid", "")); // init uid iterator

      indexDocs(file);

      if (deleting) { // delete rest of stale docs
        while (uidIter.term() != null && uidIter.term().field() == "uid") {
          //System.out.println("deleting " + HTMLDocument.uid2url(uidIter.term().text()));
          reader.delete(uidIter.term());
          uidIter.next();
        }
        deleting = false;
      }

      uidIter.close(); // close uid iterator
      reader.close(); // close existing index

    }
    else { // don't have exisiting
      indexDocs(file);
    }
  }

  private static void indexDocs(File file) throws Exception {
    if (file.isDirectory()) { // if a directory
      String[] files = file.list(); // list its files
      Arrays.sort(files); // sort the files
      for (int i = 0; i < files.length; i++) { // recursively index them
        indexDocs(new File(file, files[i]));

      }
    }
    else if (file.getPath().endsWith(".html") || // index .html files
             file.getPath().endsWith(".htm") || // index .htm files
             file.getPath().endsWith(".txt")) { // index .txt files

      if (uidIter != null) {
        String uid = HTMLDocument.uid(file); // construct uid for doc

        while (uidIter.term() != null && uidIter.term().field() == "uid" &&
               uidIter.term().text().compareTo(uid) < 0) {
          if (deleting) { // delete stale docs
            //System.out.println("deleting " + HTMLDocument.uid2url(uidIter.term().text()));
            reader.delete(uidIter.term());
          }
          uidIter.next();
        }
        if (uidIter.term() != null && uidIter.term().field() == "uid" &&
            uidIter.term().text().compareTo(uid) == 0) {
          uidIter.next(); // keep matching docs
        }
        else if (!deleting) { // add new docs
          Document doc = HTMLDocument.Document(file);
          //System.out.println("adding " + doc.get("url"));
          writer.addDocument(doc);
        }
      }
      else { // creating a new index
        Document doc = HTMLDocument.Document(file);
        //System.out.println("adding " + doc.get("url"));
        writer.addDocument(doc); // add docs unconditionally
      }
    }
  }
}