/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * Version: MPL 1.1 / GPLv3+ / LGPLv3+
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License or as specified alternatively below. You may obtain a copy of
 * the License at http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * Major Contributor(s):
 * Copyright (C) 2012 Gert van Valkenhoef <g.h.m.van.valkenhoef@rug.nl>
 *  (initial developer)
 *
 * All Rights Reserved.
 *
 * For minor contributions see the git repository.
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 3 or later (the "GPLv3+"), or
 * the GNU Lesser General Public License Version 3 or later (the "LGPLv3+"),
 * in which case the provisions of the GPLv3+ or the LGPLv3+ are applicable
 * instead of those above.
 */

#include <l10ntools/HelpIndexer.hxx>
#include "LuceneHelper.hxx"
#include <CLucene/analysis/LanguageBasedAnalyzer.h>

#include <rtl/string.hxx>
#include <rtl/uri.hxx>
#include <rtl/ustrbuf.hxx>
#include <osl/file.hxx>
#include <osl/thread.h>

#include <algorithm>

using namespace lucene::document;

HelpIndexer::HelpIndexer(rtl::OUString const &lang, rtl::OUString const &module,
    rtl::OUString const &srcDir, rtl::OUString const &outDir)
    : d_lang(lang), d_module(module)
{
    d_indexDir = rtl::OUStringBuffer(outDir).append('/').
        append(module).appendAscii(RTL_CONSTASCII_STRINGPARAM(".idxl")).toString();
    d_captionDir = srcDir + rtl::OUString(RTL_CONSTASCII_USTRINGPARAM("/caption"));
    d_contentDir = srcDir + rtl::OUString(RTL_CONSTASCII_USTRINGPARAM("/content"));
}

bool HelpIndexer::indexDocuments() {
    if (!scanForFiles()) {
        return false;
    }

    rtl::OUString sLang = d_lang.getToken(0, '-');
    bool bUseCJK =
        sLang.equalsAsciiL(RTL_CONSTASCII_STRINGPARAM("ja")) ||
        sLang.equalsAsciiL(RTL_CONSTASCII_STRINGPARAM("ko")) ||
        sLang.equalsAsciiL(RTL_CONSTASCII_STRINGPARAM("zh"));

    // Construct the analyzer appropriate for the given language
    lucene::analysis::Analyzer *analyzer;
    if (bUseCJK)
        analyzer = new lucene::analysis::LanguageBasedAnalyzer(L"cjk");
    else
        analyzer = new lucene::analysis::standard::StandardAnalyzer();

    rtl::OUString ustrSystemPath;
    osl::File::getSystemPathFromFileURL(d_indexDir, ustrSystemPath);

    rtl::OString indexDirStr = rtl::OUStringToOString(ustrSystemPath, osl_getThreadTextEncoding());
    lucene::index::IndexWriter writer(indexDirStr.getStr(), analyzer, true);
    //Double limit of tokens allowed, otherwise we'll get a too-many-tokens
    //exception for ja help. Could alternative ignore the exception and get
    //truncated results as per java-Lucene apparently
    writer.setMaxFieldLength(lucene::index::IndexWriter::DEFAULT_MAX_FIELD_LENGTH*2);

    // Index the identified help files
    Document doc;
    for (std::set<rtl::OUString>::iterator i = d_files.begin(); i != d_files.end(); ++i) {
        helpDocument(*i, &doc);
        writer.addDocument(&doc);
        doc.clear();
    }
    writer.optimize();

    // Optimize the index
    writer.optimize();

    delete analyzer;
    return true;
}

rtl::OUString const & HelpIndexer::getErrorMessage() {
    return d_error;
}

bool HelpIndexer::scanForFiles() {
    if (!scanForFiles(d_contentDir)) {
        return false;
    }
    if (!scanForFiles(d_captionDir)) {
        return false;
    }
    return true;
}

bool HelpIndexer::scanForFiles(rtl::OUString const & path) {

    osl::Directory dir(path);
    if (osl::FileBase::E_None != dir.open()) {
        d_error = rtl::OUString(RTL_CONSTASCII_USTRINGPARAM("Error reading directory ")) + path;
        return true;
    }

    osl::DirectoryItem item;
    osl::FileStatus fileStatus(osl_FileStatus_Mask_FileName | osl_FileStatus_Mask_Type);
    while (dir.getNextItem(item) == osl::FileBase::E_None) {
        item.getFileStatus(fileStatus);
        if (fileStatus.getFileType() == osl::FileStatus::Regular) {
            d_files.insert(fileStatus.getFileName());
        }
    }

    return true;
}

bool HelpIndexer::helpDocument(rtl::OUString const & fileName, Document *doc) {
    // Add the help path as an indexed, untokenized field.

    rtl::OUString path = rtl::OUString(RTL_CONSTASCII_USTRINGPARAM("#HLP#")) +
        d_module + rtl::OUString(RTL_CONSTASCII_USTRINGPARAM("/")) + fileName;
    std::vector<TCHAR> aPath(OUStringToTCHARVec(path));
    doc->add(*_CLNEW Field(_T("path"), &aPath[0], Field::STORE_YES | Field::INDEX_UNTOKENIZED));

    rtl::OUString sEscapedFileName =
        rtl::Uri::encode(fileName,
        rtl_UriCharClassUric, rtl_UriEncodeIgnoreEscapes, RTL_TEXTENCODING_UTF8);

    // Add the caption as a field.
    rtl::OUString captionPath = d_captionDir + rtl::OUString(RTL_CONSTASCII_USTRINGPARAM("/")) + sEscapedFileName;
    doc->add(*_CLNEW Field(_T("caption"), helpFileReader(captionPath), Field::STORE_NO | Field::INDEX_TOKENIZED));

    // Add the content as a field.
    rtl::OUString contentPath = d_contentDir + rtl::OUString(RTL_CONSTASCII_USTRINGPARAM("/")) + sEscapedFileName;
    doc->add(*_CLNEW Field(_T("content"), helpFileReader(contentPath), Field::STORE_NO | Field::INDEX_TOKENIZED));

    return true;
}

lucene::util::Reader *HelpIndexer::helpFileReader(rtl::OUString const & path) {
    osl::File file(path);
    if (osl::FileBase::E_None == file.open(osl_File_OpenFlag_Read)) {
        file.close();
        rtl::OUString ustrSystemPath;
        osl::File::getSystemPathFromFileURL(path, ustrSystemPath);
        rtl::OString pathStr = rtl::OUStringToOString(ustrSystemPath, osl_getThreadTextEncoding());
        return _CLNEW lucene::util::FileReader(pathStr.getStr(), "UTF-8");
    } else {
        return _CLNEW lucene::util::StringReader(L"");
    }
}

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