#include <sstream>
#include <boost/foreach.hpp>

#include "concordia/concordia.hpp"
#include "concordia/common/config.hpp"
#include "concordia/common/utils.hpp"

// ===========================================

std::string _createLibraryVersion();

// ===========================================

std::string Concordia::_libraryVersion = _createLibraryVersion();

// ===========================================

Concordia::Concordia() {
}

Concordia::Concordia(const std::string & indexPath,
                     const std::string & configFilePath)
                                         throw(ConcordiaException) :
    _indexPath(indexPath) {
    _config = boost::shared_ptr<ConcordiaConfig> (
                                new ConcordiaConfig(configFilePath));
    _index = boost::shared_ptr<ConcordiaIndex>(
                                new ConcordiaIndex(_getHashedIndexFilePath(),
                                                   _getMarkersFilePath()));
    _searcher = boost::shared_ptr<IndexSearcher>(new IndexSearcher());
    _initializeIndex();
}

Concordia::~Concordia() {
}

std::string & Concordia::getVersion() {
    return _libraryVersion;
}

std::string _createLibraryVersion() {
    std::stringstream version;

    version << CONCORDIA_VERSION_MAJOR
            << "."
            << CONCORDIA_VERSION_MINOR;

    return version.str();
}

TokenizedSentence
            Concordia::tokenize(const std::string & sentence,
                                bool byWhitespace,
                                bool generateCodes)
                                  throw(ConcordiaException) {
    if (generateCodes) {
        TokenizedSentence result =
                    _hashGenerator->generateHash(sentence, byWhitespace);
        _hashGenerator->serializeWordMap();
        return result;
    } else {
        return _hashGenerator->generateTokens(sentence, byWhitespace);
    }
}

std::vector<TokenizedSentence> Concordia::tokenizeAll(
                     const std::vector<std::string> & sentences,
                     bool byWhitespace,
                     bool generateCodes)
                                     throw(ConcordiaException) {
    std::vector<TokenizedSentence> result;

    if (generateCodes) {
        BOOST_FOREACH(std::string sentence, sentences) {
            result.push_back(_hashGenerator->generateHash(sentence,
                                                          byWhitespace));
        }

        _hashGenerator->serializeWordMap();
    } else {
        BOOST_FOREACH(std::string sentence, sentences) {
            result.push_back(_hashGenerator->generateTokens(sentence,
                                                            byWhitespace));
        }
    }
    return result;
}


// Sentences are written to disk and added to T.
// SA is generated on command by other methods.
TokenizedSentence Concordia::addExample(
                                      const Example & example)
                                      throw(ConcordiaException) {
    return _index->addExample(_hashGenerator, _T, _markers, example);
}

// Sentences are written to disk and added to T.
// SA is generated on command by other methods.
void Concordia::addTokenizedExample(
                    const TokenizedSentence & tokenizedSentence,
                    const SUFFIX_MARKER_TYPE id)
                                              throw(ConcordiaException) {
    _index->addTokenizedExample(_hashGenerator, _T,
                                _markers, tokenizedSentence, id);
}

void Concordia::addAllTokenizedExamples(
                const std::vector<TokenizedSentence> & tokenizedSentences,
                const std::vector<SUFFIX_MARKER_TYPE> & ids)
                                              throw(ConcordiaException) {
    _index->addAllTokenizedExamples(_hashGenerator, _T,
                                _markers, tokenizedSentences, ids);
}


// Sentences are written to disk and added to T.
// SA is generated on command by other methods.
std::vector<TokenizedSentence> Concordia::addAllExamples(
                                         const std::vector<Example> & examples)
                                         throw(ConcordiaException) {
    return _index->addAllExamples(_hashGenerator, _T, _markers, examples);
}

void Concordia::loadRAMIndexFromDisk() throw(ConcordiaException) {
    if (boost::filesystem::exists(_getWordMapFilePath())
      && boost::filesystem::exists(_getHashedIndexFilePath())
      && boost::filesystem::exists(_getMarkersFilePath())) {
        // reading index from file
        _T->clear();
        std::ifstream hashedIndexFile;
        hashedIndexFile.open(
            _getHashedIndexFilePath().c_str(), std::ios::in
                                | std::ios::ate | std::ios::binary);
        saidx_t hiFileSize = hashedIndexFile.tellg();
        if (hiFileSize > 0) {
            hashedIndexFile.seekg(0, std::ios::beg);

            while (!hashedIndexFile.eof()) {
                INDEX_CHARACTER_TYPE character =
                                 Utils::readIndexCharacter(hashedIndexFile);
                Utils::appendCharToSaucharVector(_T, character);
            }
            hashedIndexFile.close();
        } else {
            hashedIndexFile.close();
            throw ConcordiaException("Index corrupt: empty hash index file");
        }

        // reading markers from file
        _markers->clear();
        std::ifstream markersFile;
        markersFile.open(_getMarkersFilePath().c_str(), std::ios::in
                                         | std::ios::ate | std::ios::binary);
        saidx_t maFileSize = markersFile.tellg();
        if (maFileSize > 0) {
            markersFile.seekg(0, std::ios::beg);

            while (!markersFile.eof()) {
                SUFFIX_MARKER_TYPE marker =
                                 Utils::readMarker(markersFile);
                _markers->push_back(marker);
            }
            markersFile.close();
        } else {
            markersFile.close();
            throw ConcordiaException("Index corrupt: empty markers file");
        }
        // generating suffix array
        _SA = _index->generateSuffixArray(_T);
    } else {
        throw ConcordiaException("Index corrupt: missing files");
    }
}

void Concordia::refreshSAfromRAM() throw(ConcordiaException) {
    _SA = _index->generateSuffixArray(_T);
}


void Concordia::_initializeIndex() throw(ConcordiaException) {
    _hashGenerator = boost::shared_ptr<HashGenerator>(
                            new HashGenerator(_indexPath,
                                              _config));
    _T = boost::shared_ptr<std::vector<sauchar_t> >(
                                                  new std::vector<sauchar_t>);
    _markers = boost::shared_ptr<std::vector<SUFFIX_MARKER_TYPE> >(
                                         new std::vector<SUFFIX_MARKER_TYPE>);
    if (boost::filesystem::exists(_getWordMapFilePath())
      && boost::filesystem::exists(_getHashedIndexFilePath())) {
        loadRAMIndexFromDisk();
    } else if (!boost::filesystem::exists(_getWordMapFilePath())
      && !boost::filesystem::exists(_getHashedIndexFilePath())) {
        // empty index
        _SA = boost::shared_ptr<std::vector<saidx_t> >(
                                                new std::vector<saidx_t>);
    } else {
        throw ConcordiaException("Index corrupt: missing files");
    }
}

SUFFIX_MARKER_TYPE Concordia::countOccurences(const std::string & pattern)
                                                 throw(ConcordiaException) {
    if (_T->size() > 0) {
        return _searcher->countOccurences(_hashGenerator, _T,
                                         _markers, _SA, pattern);
    } else {
        return 0;
    }
}


MatchedPatternFragment Concordia::simpleSearch(
                                  const std::string & pattern,
                                  bool byWhitespace)
                                  throw(ConcordiaException) {
    if (_T->size() > 0 && pattern.size() > 0) {
        return _searcher->simpleSearch(_hashGenerator, _T,
                                         _markers, _SA, pattern, byWhitespace);
    } else {
        // If the index or search pattern are empty, return an empty result.
        MatchedPatternFragment result(0, 0);
        return result;
    }
}

OccurencesList Concordia::fullSearch(
                                  const std::string & pattern,
                                  SUFFIX_MARKER_TYPE limit,
                                  SUFFIX_MARKER_TYPE offset,
                                  bool byWhitespace)
                                  throw(ConcordiaException) {
    if (_T->size() > 0 && pattern.size() > 0) {
        return _searcher->fullSearch(_hashGenerator, _T,
                                         _markers, _SA, pattern, limit, offset, byWhitespace);
    } else {
        // If the index or search pattern are empty, return an empty result.
        OccurencesList result(0);
        return result;
    }
}


MatchedPatternFragment Concordia::lexiconSearch(
                                  const std::string & pattern,
                                  bool byWhitespace)
                                  throw(ConcordiaException) {
    if (_T->size() > 0 && pattern.size() > 0) {
        return _searcher->lexiconSearch(_hashGenerator, _T,
                                         _markers, _SA, pattern, byWhitespace);
    } else {
        // If the index or search pattern are empty, return an empty result.
        // Especially performing the lexicon search with an empty pattern
        // would not be funny, as it would effectively search for double EOS,
        // which is very frequent in the index.
        MatchedPatternFragment result(0, 0);
        return result;
    }
}

std::vector<AnubisSearchResult> Concordia::anubisSearch(
                                          const std::string & pattern)
                                  throw(ConcordiaException) {
    if (_T->size() > 0) {
        return _searcher->anubisSearch(_config, _hashGenerator, _T,
                                       _markers, _SA, pattern);
    } else {
        std::vector<AnubisSearchResult> result;
        return result;
    }
}

boost::shared_ptr<ConcordiaSearchResult> Concordia::concordiaSearch(
                                             const std::string & pattern,
                                             bool byWhitespace)
                                             throw(ConcordiaException) {
    if (_T->size() > 0) {
        return _searcher->concordiaSearch(_hashGenerator, _T,
                                       _markers, _SA, pattern, byWhitespace);
    } else {
        std::string empty;
        return boost::shared_ptr<ConcordiaSearchResult>(
            new ConcordiaSearchResult(TokenizedSentence(empty)));
    }
}

void Concordia::clearIndex() throw(ConcordiaException) {
    _hashGenerator->clearWordMap();
    _T = boost::shared_ptr<std::vector<sauchar_t> >(
                                                  new std::vector<sauchar_t>);
    _markers = boost::shared_ptr<std::vector<SUFFIX_MARKER_TYPE> >(
                                         new std::vector<SUFFIX_MARKER_TYPE>);
    _SA = boost::shared_ptr<std::vector<saidx_t> >(
                                            new std::vector<saidx_t>);

    boost::filesystem::remove(_getHashedIndexFilePath());
    boost::filesystem::remove(_getMarkersFilePath());
}

std::string Concordia::_getWordMapFilePath() {
    return _indexPath+"/"+WORD_MAP_FILE_NAME;
}

std::string Concordia::_getHashedIndexFilePath() {
    return _indexPath+"/"+HASHED_INDEX_FILE_NAME;
}

std::string Concordia::_getMarkersFilePath() {
    return _indexPath+"/"+MARKERS_FILE_NAME;
}