#include "retrieval.hpp"

#include "search/cancel_exception.hpp"
#include "search/feature_offset_match.hpp"
#include "search/interval_set.hpp"
#include "search/mwm_context.hpp"
#include "search/search_index_values.hpp"
#include "search/search_trie.hpp"
#include "search/token_slice.hpp"

#include "indexer/classificator.hpp"
#include "indexer/feature.hpp"
#include "indexer/feature_algo.hpp"
#include "indexer/feature_data.hpp"
#include "indexer/index.hpp"
#include "indexer/osm_editor.hpp"
#include "indexer/scales.hpp"
#include "indexer/search_delimiters.hpp"
#include "indexer/search_string_utils.hpp"
#include "indexer/trie_reader.hpp"

#include "platform/mwm_version.hpp"

#include "coding/compressed_bit_vector.hpp"
#include "coding/reader_wrapper.hpp"

#include "base/checked_cast.hpp"

#include "std/algorithm.hpp"
#include "std/utility.hpp"

using namespace strings;
using osm::Editor;

namespace search
{
namespace
{
class FeaturesCollector
{
public:
  FeaturesCollector(my::Cancellable const & cancellable, vector<uint64_t> & features)
    : m_cancellable(cancellable), m_features(features), m_counter(0)
  {
  }

  template <typename Value>
  void operator()(Value const & value)
  {
    if ((++m_counter & 0xFF) == 0)
      BailIfCancelled(m_cancellable);
    m_features.push_back(value.m_featureId);
  }

  inline void operator()(uint32_t feature) { m_features.push_back(feature); }

  inline void operator()(uint64_t feature) { m_features.push_back(feature); }

private:
  my::Cancellable const & m_cancellable;
  vector<uint64_t> & m_features;
  uint32_t m_counter;
};

class EditedFeaturesHolder
{
public:
  EditedFeaturesHolder(MwmSet::MwmId const & id) : m_id(id)
  {
    auto & editor = Editor::Instance();
    m_deleted = editor.GetFeaturesByStatus(id, Editor::FeatureStatus::Deleted);
    m_modified = editor.GetFeaturesByStatus(id, Editor::FeatureStatus::Modified);
    m_created = editor.GetFeaturesByStatus(id, Editor::FeatureStatus::Created);
  }

  bool ModifiedOrDeleted(uint32_t featureIndex) const
  {
    return binary_search(m_deleted.begin(), m_deleted.end(), featureIndex) ||
           binary_search(m_modified.begin(), m_modified.end(), featureIndex);
  }

  template <typename Fn>
  void ForEachModifiedOrCreated(Fn && fn)
  {
    ForEach(m_modified, fn);
    ForEach(m_created, fn);
  }

private:
  template <typename Fn>
  void ForEach(vector<uint32_t> const & features, Fn & fn)
  {
    auto & editor = Editor::Instance();
    for (auto const index : features)
    {
      FeatureType ft;
      VERIFY(editor.GetEditedFeature(m_id, index, ft), ());
      fn(ft, index);
    }
  }

  MwmSet::MwmId const & m_id;
  vector<uint32_t> m_deleted;
  vector<uint32_t> m_modified;
  vector<uint32_t> m_created;
};

unique_ptr<coding::CompressedBitVector> SortFeaturesAndBuildCBV(vector<uint64_t> && features)
{
  my::SortUnique(features);
  return coding::CompressedBitVectorBuilder::FromBitPositions(move(features));
}

template <typename DFA>
bool MatchesByName(vector<UniString> const & tokens, vector<DFA> const & dfas)
{
  for (auto const & dfa : dfas)
  {
    for (auto const & token : tokens)
    {
      auto it = dfa.Begin();
      DFAMove(it, token);
      if (it.Accepts())
        return true;
    }
  }

  return false;
}

template <typename DFA>
bool MatchesByType(feature::TypesHolder const & types, vector<DFA> const & dfas)
{
  if (dfas.empty())
    return false;

  auto const & c = classif();

  for (auto const & type : types)
  {
    UniString const s = FeatureTypeToString(c.GetIndexForType(type));

    for (auto const & dfa : dfas)
    {
      auto it = dfa.Begin();
      DFAMove(it, s);
      if (it.Accepts())
        return true;
    }
  }

  return false;
}

template <typename DFA>
bool MatchFeatureByNameAndType(FeatureType const & ft, SearchTrieRequest<DFA> const & request)
{
  feature::TypesHolder th(ft);

  bool matched = false;
  ft.ForEachName([&](int8_t lang, string const & name) {
    if (name.empty() || !request.IsLangExist(lang))
      return true /* continue ForEachName */;

    vector<UniString> tokens;
    NormalizeAndTokenizeString(name, tokens, Delimiters());
    if (!MatchesByName(tokens, request.m_names) && !MatchesByType(th, request.m_categories))
      return true /* continue ForEachName */;

    matched = true;
    return false /* break ForEachName */;
  });

  return matched;
}

bool MatchFeatureByPostcode(FeatureType const & ft, TokenSlice const & slice)
{
  string const postcode = ft.GetMetadata().Get(feature::Metadata::FMD_POSTCODE);
  vector<UniString> tokens;
  NormalizeAndTokenizeString(postcode, tokens, Delimiters());
  if (slice.Size() > tokens.size())
    return false;
  for (size_t i = 0; i < slice.Size(); ++i)
  {
    if (slice.IsPrefix(i))
    {
      if (!StartsWith(tokens[i], slice.Get(i).m_original))
        return false;
    }
    else if (tokens[i] != slice.Get(i).m_original)
    {
      return false;
    }
  }
  return true;
}

template <typename Value, typename DFA>
unique_ptr<coding::CompressedBitVector> RetrieveAddressFeaturesImpl(
    Retrieval::TrieRoot<Value> const & root, MwmContext const & context,
    my::Cancellable const & cancellable, SearchTrieRequest<DFA> const & request)
{
  EditedFeaturesHolder holder(context.GetId());
  vector<uint64_t> features;
  FeaturesCollector collector(cancellable, features);

  MatchFeaturesInTrie(
      request, root,
      [&holder](uint64_t featureIndex) {
        return !holder.ModifiedOrDeleted(base::asserted_cast<uint32_t>(featureIndex));
      },
      collector);

  holder.ForEachModifiedOrCreated([&](FeatureType & ft, uint64_t index) {
    if (MatchFeatureByNameAndType(ft, request))
      features.push_back(index);
  });

  return SortFeaturesAndBuildCBV(move(features));
}

template <typename Value>
unique_ptr<coding::CompressedBitVector> RetrievePostcodeFeaturesImpl(
    Retrieval::TrieRoot<Value> const & root, MwmContext const & context,
    my::Cancellable const & cancellable, TokenSlice const & slice)
{
  EditedFeaturesHolder holder(context.GetId());
  vector<uint64_t> features;
  FeaturesCollector collector(cancellable, features);

  MatchPostcodesInTrie(
      slice, root,
      [&holder](uint64_t featureIndex) {
        return !holder.ModifiedOrDeleted(base::asserted_cast<uint32_t>(featureIndex));
      },
      collector);

  holder.ForEachModifiedOrCreated([&](FeatureType & ft, uint64_t index) {
    if (MatchFeatureByPostcode(ft, slice))
      features.push_back(index);
  });

  return SortFeaturesAndBuildCBV(move(features));
}

unique_ptr<coding::CompressedBitVector> RetrieveGeometryFeaturesImpl(
    MwmContext const & context, my::Cancellable const & cancellable, m2::RectD const & rect,
    int scale)
{
  EditedFeaturesHolder holder(context.GetId());

  covering::IntervalsT coverage;
  CoverRect(rect, scale, coverage);

  vector<uint64_t> features;

  FeaturesCollector collector(cancellable, features);

  context.ForEachIndex(coverage, scale, collector);

  holder.ForEachModifiedOrCreated([&](FeatureType & ft, uint64_t index) {
    auto const center = feature::GetCenter(ft);
    if (rect.IsPointInside(center))
      features.push_back(index);
  });
  return SortFeaturesAndBuildCBV(move(features));
}

template <typename T>
struct RetrieveAddressFeaturesAdaptor
{
  template <typename... Args>
  unique_ptr<coding::CompressedBitVector> operator()(Args &&... args)
  {
    return RetrieveAddressFeaturesImpl<T>(forward<Args>(args)...);
  }
};

template <typename T>
struct RetrievePostcodeFeaturesAdaptor
{
  template <typename... Args>
  unique_ptr<coding::CompressedBitVector> operator()(Args &&... args)
  {
    return RetrievePostcodeFeaturesImpl<T>(forward<Args>(args)...);
  }
};

template <typename Value>
unique_ptr<Retrieval::TrieRoot<Value>> ReadTrie(MwmValue & value, ModelReaderPtr & reader)
{
  serial::CodingParams params(trie::GetCodingParams(value.GetHeader().GetDefCodingParams()));
  return trie::ReadTrie<SubReaderWrapper<Reader>, ValueList<Value>>(
      SubReaderWrapper<Reader>(reader.GetPtr()), SingleValueSerializer<Value>(params));
}
}  // namespace

Retrieval::Retrieval(MwmContext const & context, my::Cancellable const & cancellable)
  : m_context(context)
  , m_cancellable(cancellable)
  , m_reader(context.m_value.m_cont.GetReader(SEARCH_INDEX_FILE_TAG))
{
  auto & value = context.m_value;

  version::MwmTraits mwmTraits(value.GetMwmVersion());
  m_format = mwmTraits.GetSearchIndexFormat();

  switch (m_format)
  {
  case version::MwmTraits::SearchIndexFormat::FeaturesWithRankAndCenter:
    m_root0 = ReadTrie<FeatureWithRankAndCenter>(value, m_reader);
    break;
  case version::MwmTraits::SearchIndexFormat::CompressedBitVector:
    m_root1 = ReadTrie<FeatureIndexValue>(value, m_reader);
    break;
  }
}

unique_ptr<coding::CompressedBitVector> Retrieval::RetrieveAddressFeatures(
    SearchTrieRequest<LevenshteinDFA> const & request)
{
  return Retrieve<RetrieveAddressFeaturesAdaptor>(request);
}

unique_ptr<coding::CompressedBitVector> Retrieval::RetrieveAddressFeatures(
    SearchTrieRequest<PrefixDFAModifier<LevenshteinDFA>> const & request)
{
  return Retrieve<RetrieveAddressFeaturesAdaptor>(request);
}

unique_ptr<coding::CompressedBitVector> Retrieval::RetrievePostcodeFeatures(
    TokenSlice const & slice)
{
  return Retrieve<RetrievePostcodeFeaturesAdaptor>(slice);
}

unique_ptr<coding::CompressedBitVector> Retrieval::RetrieveGeometryFeatures(m2::RectD const & rect,
                                                                            int scale)
{
  return RetrieveGeometryFeaturesImpl(m_context, m_cancellable, rect, scale);
}

template <template <typename> class R, typename... Args>
unique_ptr<coding::CompressedBitVector> Retrieval::Retrieve(Args &&... args)
{
  switch (m_format)
  {
  case version::MwmTraits::SearchIndexFormat::FeaturesWithRankAndCenter:
  {
    R<FeatureWithRankAndCenter> r;
    ASSERT(m_root0, ());
    return r(*m_root0, m_context, m_cancellable, forward<Args>(args)...);
  }
  break;
  case version::MwmTraits::SearchIndexFormat::CompressedBitVector:
  {
    R<FeatureIndexValue> r;
    ASSERT(m_root1, ());
    return r(*m_root1, m_context, m_cancellable, forward<Args>(args)...);
  }
  break;
  }
}
}  // namespace search