libkiwix/src/searcher.cpp

/*
 * Copyright 2011 Emmanuel Engelhart <kelson@kiwix.org>
 *
 * 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 3 of the License, or
 * 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., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 */

#include "searcher.h"


namespace kiwix {

  /* Constructor */
  Searcher::Searcher() :
    searchPattern(""),
    protocolPrefix("zim://"),
    searchProtocolPrefix("search://?"),
    resultCountPerPage(0),
    estimatedResultCount(0),
    resultStart(0),
    resultEnd(0)
  {
    template_ct2 = getResourceAsString("results.ct2");
    loadICUExternalTables();
  }
  
  /* Destructor */
  Searcher::~Searcher() {}
  
  /* Search strings in the database */
  void Searcher::search(std::string &search, unsigned int resultStart,
			unsigned int resultEnd, const bool verbose) {
    this->reset();

    if (verbose == true) {
      cout << "Performing query `" << search << "'" << endl;
    }

    /* If resultEnd & resultStart inverted */
    if (resultStart > resultEnd) {
      resultEnd += resultStart;
      resultStart = resultEnd - resultStart;
      resultEnd -= resultStart; 
    }

    /* Try to find results */
    if (resultStart != resultEnd) {

      /* Avoid big researches */
      this->resultCountPerPage = resultEnd - resultStart;
      if (this->resultCountPerPage > 70) {
	resultEnd = resultStart + 70;
	this->resultCountPerPage = 70;
      }

      /* Perform the search */
      this->searchPattern = search;
      this->resultStart = resultStart;
      this->resultEnd = resultEnd;
      string unaccentedSearch = removeAccents(search);
      searchInIndex(unaccentedSearch, resultStart, resultEnd, verbose);
      this->resultOffset = this->results.begin();
    }

    return;
  }

  /* Reset the results */
  void Searcher::reset() {
    this->results.clear();
    this->resultOffset = this->results.begin();
    this->estimatedResultCount = 0;
    this->searchPattern = "";
    return;
  }

  /* Return the result count estimation */
  unsigned int Searcher::getEstimatedResultCount() {
    return this->estimatedResultCount;
  }

  /* Get next result */
  bool Searcher::getNextResult(string &url, string &title, unsigned int &score) {
    bool retVal = false;

    if (this->resultOffset != this->results.end()) {

      /* url */
      url = this->resultOffset->url;

      /* title */
      title = this->resultOffset->title;

      /* score */
      score =  this->resultOffset->score;

      /* increment the cursor for the next call */
      this->resultOffset++;

      retVal = true;
    }

    return retVal;
  }

  bool Searcher::setProtocolPrefix(const std::string prefix) {
    this->protocolPrefix = prefix;
    return true;
  }

  bool Searcher::setSearchProtocolPrefix(const std::string prefix) {
    this->searchProtocolPrefix = prefix;
    return true;
  }

  void Searcher::setContentHumanReadableId(const string &contentHumanReadableId) {
    this->contentHumanReadableId = contentHumanReadableId;
  }

#ifndef __ANDROID__
  
  string Searcher::getHtml() {

    SimpleVM oSimpleVM;

    // Fill data
    CDT oData;
    CDT resultsCDT(CDT::ARRAY_VAL);

    this->resultOffset = this->results.begin();
    while (this->resultOffset != this->results.end()) {
      CDT result;
      result["title"] = this->resultOffset->title;
      result["url"] = this->resultOffset->url;
      result["snippet"] = this->resultOffset->snippet;

      if (this->resultOffset->size >= 0)
    result["size"] = kiwix::beautifyInteger(this->resultOffset->size);

      if (this->resultOffset->wordCount >= 0)
    result["wordCount"] = kiwix::beautifyInteger(this->resultOffset->wordCount);

      resultsCDT.PushBack(result);
      this->resultOffset++;
    }
    this->resultOffset = this->results.begin();
    oData["results"] = resultsCDT;

    // pages
    CDT pagesCDT(CDT::ARRAY_VAL);

    unsigned int pageStart = this->resultStart / this->resultCountPerPage >= 5 ? this->resultStart / this->resultCountPerPage - 4 : 0;
    unsigned int pageCount = this->estimatedResultCount / this->resultCountPerPage + 1 - pageStart;

    if (pageCount > 10)
      pageCount = 10;
    else if (pageCount == 1)
      pageCount = 0;

    for (unsigned int i=pageStart; i<pageStart+pageCount; i++) {
      CDT page;
      page["label"] = i + 1;
      page["start"] = i * this->resultCountPerPage;
      page["end"] = (i+1) * this->resultCountPerPage;

      if (i * this->resultCountPerPage == this->resultStart)
    page["selected"] = true;

      pagesCDT.PushBack(page);
    }
    oData["pages"] = pagesCDT;

    oData["count"] = kiwix::beautifyInteger(this->estimatedResultCount);
    oData["searchPattern"] = kiwix::encodeDiples(this->searchPattern);
    oData["searchPatternEncoded"] = urlEncode(this->searchPattern);
    oData["resultStart"] = this->resultStart + 1;
    oData["resultEnd"] = (this->resultEnd > this->estimatedResultCount ? this->estimatedResultCount : this->resultEnd);
    oData["resultRange"] = this->resultCountPerPage;
    oData["resultLastPageStart"] = this->estimatedResultCount > this->resultCountPerPage ? this->estimatedResultCount - this->resultCountPerPage : 0;
    oData["protocolPrefix"] = this->protocolPrefix;
    oData["searchProtocolPrefix"] = this->searchProtocolPrefix;
    oData["contentId"] = this->contentHumanReadableId;

    VMStringLoader oLoader(template_ct2.c_str(), template_ct2.size());

    FileLogger oLogger(stderr);

    // DEBUG only (write output to stdout)
    // oSimpleVM.Run(oData, oLoader, stdout, oLogger);

    std::string sResult;
    oSimpleVM.Run(oData, oLoader, sResult, oLogger);

    return sResult;

  }

#endif

}