// $Id$
// vim:tabstop=2
/***********************************************************************
Moses - factored phrase-based language decoder
Copyright (C) 2006 University of Edinburgh

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library 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
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
***********************************************************************/

#include <fstream>
#include <string>
#include <iterator>
#include <queue>
#include <algorithm>
#include <sys/stat.h>

#include "PhraseDictionaryCompact.h"
#include "moses/FactorCollection.h"
#include "moses/Word.h"
#include "moses/Util.h"
#include "moses/InputFileStream.h"
#include "moses/StaticData.h"
#include "moses/WordsRange.h"
#include "moses/UserMessage.h"
#include "moses/ThreadPool.h"

using namespace std;

namespace Moses
{

void PhraseDictionaryCompact::Load()
{
  const StaticData &staticData = StaticData::Instance();

  m_weight = staticData.GetWeights(this);

  std::string tFilePath = m_filePath;

  std::string suffix = ".minphr";
  if(tFilePath.substr(tFilePath.length() - suffix.length(), suffix.length()) == suffix) {
    if(!FileExists(tFilePath)) {
      throw runtime_error("Error: File " + tFilePath + " does not exit.");
      exit(1);
    }
  } else {
    if(FileExists(tFilePath + suffix)) {
      tFilePath += suffix;
    } else {
      throw runtime_error("Error: File " + tFilePath + ".minphr does not exit.");
    }
  }

  m_phraseDecoder = new PhraseDecoder(*this, &m_input, &m_output,
                                      m_numScoreComponents, &m_weight);

  std::FILE* pFile = std::fopen(tFilePath.c_str() , "r");

  size_t indexSize;
  if(m_inMemory)
    // Load source phrase index into memory
    indexSize = m_hash.Load(pFile);
  else
    // Keep source phrase index on disk
    indexSize = m_hash.LoadIndex(pFile);

  size_t coderSize = m_phraseDecoder->Load(pFile);

  size_t phraseSize;
  if(m_inMemory)
    // Load target phrase collections into memory
    phraseSize = m_targetPhrasesMemory.load(pFile, false);
  else
    // Keep target phrase collections on disk
    phraseSize = m_targetPhrasesMapped.load(pFile, true);

  CHECK(indexSize && coderSize && phraseSize);
}

struct CompareTargetPhrase {
  bool operator() (const TargetPhrase &a, const TargetPhrase &b) {
    return a.GetFutureScore() > b.GetFutureScore();
  }
};

const TargetPhraseCollection*
PhraseDictionaryCompact::GetTargetPhraseCollection(const Phrase &sourcePhrase) const
{

  // There is no souch source phrase if source phrase is longer than longest
  // observed source phrase during compilation
  if(sourcePhrase.GetSize() > m_phraseDecoder->GetMaxSourcePhraseLength())
    return NULL;

  // Retrieve target phrase collection from phrase table
  TargetPhraseVectorPtr decodedPhraseColl
    = m_phraseDecoder->CreateTargetPhraseCollection(sourcePhrase, true);

  if(decodedPhraseColl != NULL && decodedPhraseColl->size()) {
    TargetPhraseVectorPtr tpv(new TargetPhraseVector(*decodedPhraseColl));
    TargetPhraseCollection* phraseColl = new TargetPhraseCollection();

    // Score phrases and if possible apply ttable_limit
    TargetPhraseVector::iterator nth =
      (m_tableLimit == 0 || tpv->size() < m_tableLimit) ?
      tpv->end() : tpv->begin() + m_tableLimit;
    std::nth_element(tpv->begin(), nth, tpv->end(), CompareTargetPhrase());
    for(TargetPhraseVector::iterator it = tpv->begin(); it != nth; it++) {
      TargetPhrase *tp = new TargetPhrase(*it);
      cerr << *tp << endl;
      phraseColl->Add(tp);
    }

    // Cache phrase pair for for clean-up or retrieval with PREnc
    const_cast<PhraseDictionaryCompact*>(this)->CacheForCleanup(phraseColl);

    return phraseColl;
  } else
    return NULL;
}

TargetPhraseVectorPtr
PhraseDictionaryCompact::GetTargetPhraseCollectionRaw(const Phrase &sourcePhrase) const
{

  // There is no souch source phrase if source phrase is longer than longest
  // observed source phrase during compilation
  if(sourcePhrase.GetSize() > m_phraseDecoder->GetMaxSourcePhraseLength())
    return TargetPhraseVectorPtr();

  // Retrieve target phrase collection from phrase table
  return m_phraseDecoder->CreateTargetPhraseCollection(sourcePhrase, true);
}

PhraseDictionaryCompact::~PhraseDictionaryCompact()
{
  if(m_phraseDecoder)
    delete m_phraseDecoder;
}

//TO_STRING_BODY(PhraseDictionaryCompact)

void PhraseDictionaryCompact::CacheForCleanup(TargetPhraseCollection* tpc)
{
#ifdef WITH_THREADS
  boost::mutex::scoped_lock lock(m_sentenceMutex);
  PhraseCache &ref = m_sentenceCache[boost::this_thread::get_id()];
#else
  PhraseCache &ref = m_sentenceCache;
#endif
  ref.push_back(tpc);
}

void PhraseDictionaryCompact::AddEquivPhrase(const Phrase &source,
    const TargetPhrase &targetPhrase) { }

void PhraseDictionaryCompact::CleanUpAfterSentenceProcessing(const InputType &source)
{
  if(!m_inMemory)
    m_hash.KeepNLastRanges(0.01, 0.2);

  m_phraseDecoder->PruneCache();

#ifdef WITH_THREADS
  boost::mutex::scoped_lock lock(m_sentenceMutex);
  PhraseCache &ref = m_sentenceCache[boost::this_thread::get_id()];
#else
  PhraseCache &ref = m_sentenceCache;
#endif

  for(PhraseCache::iterator it = ref.begin(); it != ref.end(); it++)
    delete *it;

  PhraseCache temp;
  temp.swap(ref);
}

}