#include "map/search_api.hpp"

#include "map/bookmarks_search_params.hpp"
#include "map/discovery/discovery_search_params.hpp"
#include "map/everywhere_search_params.hpp"
#include "map/viewport_search_params.hpp"

#include "search/bookmarks/processor.hpp"
#include "search/geometry_utils.hpp"
#include "search/hotels_filter.hpp"

#include "storage/downloader_search_params.hpp"

#include "platform/preferred_languages.hpp"
#include "platform/safe_callback.hpp"

#include "geometry/mercator.hpp"

#include "base/string_utils.hpp"

#include <algorithm>
#include <iterator>
#include <string>
#include <type_traits>

using namespace search;
using namespace std;

namespace
{
using BookmarkIdDoc = pair<bookmarks::Id, bookmarks::Doc>;

double const kDistEqualQueryMeters = 100.0;

// Cancels search query by |handle|.
void CancelQuery(weak_ptr<ProcessorHandle> & handle)
{
  if (auto queryHandle = handle.lock())
    queryHandle->Cancel();
  handle.reset();
}

bookmarks::Id MarkIDToBookmarkId(kml::MarkId id)
{
  static_assert(is_integral<kml::MarkId>::value, "");
  static_assert(is_integral<bookmarks::Id>::value, "");

  static_assert(is_unsigned<kml::MarkId>::value, "");
  static_assert(is_unsigned<bookmarks::Id>::value, "");

  static_assert(sizeof(bookmarks::Id) >= sizeof(kml::MarkId), "");

  return static_cast<bookmarks::Id>(id);
}

kml::MarkId BookmarkIdToMarkID(bookmarks::Id id) { return static_cast<kml::MarkId>(id); }

void AppendBookmarkIdDocs(vector<pair<kml::MarkId, kml::BookmarkData>> const & marks,
                          vector<BookmarkIdDoc> & result)
{
  result.reserve(result.size() + marks.size());

  for (auto const & mark : marks)
  {
    auto const & id = mark.first;
    auto const & data = mark.second;
    result.emplace_back(MarkIDToBookmarkId(id), bookmarks::Doc(data));
  }
}

void AppendBookmarkIds(vector<kml::MarkId> const & marks, vector<bookmarks::Id> & result)
{
  result.reserve(result.size() + marks.size());
  transform(marks.begin(), marks.end(), back_inserter(result), MarkIDToBookmarkId);
}

class BookmarksSearchCallback
{
public:
  using OnResults = BookmarksSearchParams::OnResults;

  explicit BookmarksSearchCallback(OnResults const & onResults) : m_onResults(onResults) {}

  void operator()(Results const & results)
  {
    if (results.IsEndMarker())
    {
      if (results.IsEndedNormal())
      {
        m_status = BookmarksSearchParams::Status::Completed;
      }
      else
      {
        ASSERT(results.IsEndedCancelled(), ());
        m_status = BookmarksSearchParams::Status::Cancelled;
      }
    }
    else
    {
      ASSERT_EQUAL(m_status, BookmarksSearchParams::Status::InProgress, ());
    }

    auto const & rs = results.GetBookmarksResults();
    ASSERT_LESS_OR_EQUAL(m_results.size(), rs.size(), ());

    for (size_t i = m_results.size(); i < rs.size(); ++i)
      m_results.emplace_back(BookmarkIdToMarkID(rs[i].m_id));
    if (m_onResults)
      m_onResults(m_results, m_status);
  }

private:
  BookmarksSearchParams::Results m_results;
  BookmarksSearchParams::Status m_status = BookmarksSearchParams::Status::InProgress;
  OnResults m_onResults;
};
}  // namespace

SearchAPI::SearchAPI(DataSource & dataSource, storage::Storage const & storage,
                     storage::CountryInfoGetter const & infoGetter, Delegate & delegate)
  : m_dataSource(dataSource)
  , m_storage(storage)
  , m_infoGetter(infoGetter)
  , m_delegate(delegate)
  , m_engine(m_dataSource, GetDefaultCategories(), m_infoGetter,
             Engine::Params(languages::GetCurrentTwine() /* locale */, 1 /* params.m_numThreads */))
{
}

void SearchAPI::OnViewportChanged(m2::RectD const & viewport)
{
  m_viewport = viewport;

  auto const forceSearchInViewport = !m_isViewportInitialized;
  if (!m_isViewportInitialized)
  {
    m_isViewportInitialized = true;
    for (size_t i = 0; i < static_cast<size_t>(Mode::Count); i++)
    {
      auto & intent = m_searchIntents[i];
      // Viewport search will be triggered below, in PokeSearchInViewport().
      if (!intent.m_isDelayed || static_cast<Mode>(i) == Mode::Viewport)
        continue;
      intent.m_params.m_viewport = m_viewport;
      intent.m_params.m_position = m_delegate.GetCurrentPosition();
      Search(intent);
    }
  }

  PokeSearchInViewport(forceSearchInViewport);
}

bool SearchAPI::SearchEverywhere(EverywhereSearchParams const & params)
{
  SearchParams p;
  p.m_query = params.m_query;
  p.m_inputLocale = params.m_inputLocale;
  p.m_mode = Mode::Everywhere;
  p.m_position = m_delegate.GetCurrentPosition();
  SetViewportIfPossible(p);  // Search request will be delayed if viewport is not available.
  p.m_maxNumResults = SearchParams::kDefaultNumResultsEverywhere;
  p.m_suggestsEnabled = true;
  p.m_needAddress = true;
  p.m_needHighlighting = true;
  p.m_hotelsFilter = params.m_hotelsFilter;

  p.m_onResults = EverywhereSearchCallback(
      static_cast<EverywhereSearchCallback::Delegate &>(*this),
      params.m_bookingFilterTasks,
      [this, params](Results const & results, std::vector<ProductInfo> const & productInfo) {
        if (params.m_onResults)
          RunUITask([params, results, productInfo] {
            params.m_onResults(results, productInfo);
          });
      });

  m_delegate.OnBookingFilterParamsUpdate(params.m_bookingFilterTasks);

  return Search(p, true /* forceSearch */);
}

bool SearchAPI::SearchInViewport(ViewportSearchParams const & params)
{
  SearchParams p;
  p.m_query = params.m_query;
  p.m_inputLocale = params.m_inputLocale;
  p.m_position = m_delegate.GetCurrentPosition();
  SetViewportIfPossible(p);  // Search request will be delayed if viewport is not available.
  p.m_maxNumResults = SearchParams::kDefaultNumResultsInViewport;
  p.m_mode = Mode::Viewport;
  p.m_suggestsEnabled = false;
  p.m_needAddress = false;
  p.m_needHighlighting = false;
  p.m_hotelsFilter = params.m_hotelsFilter;

  p.m_onStarted = [this, params] {
    if (params.m_onStarted)
      RunUITask([params]() { params.m_onStarted(); });
  };

  p.m_onResults = ViewportSearchCallback(
      static_cast<ViewportSearchCallback::Delegate &>(*this),
      params.m_bookingFilterTasks,
      [this, params](Results const & results) {
        if (results.IsEndMarker() && params.m_onCompleted)
          RunUITask([params, results] { params.m_onCompleted(results); });
      });

  m_delegate.OnBookingFilterParamsUpdate(params.m_bookingFilterTasks);

  return Search(p, false /* forceSearch */);
}

void SearchAPI::SearchForDiscovery(DiscoverySearchParams const & params)
{
  CHECK(params.m_onResults, ());
  CHECK(!params.m_query.empty(), ());
  CHECK_GREATER(params.m_itemsCount, 0, ());

  SearchParams p;
  p.m_query = params.m_query;
  p.m_inputLocale = "en";
  p.m_viewport = params.m_viewport;
  p.m_position = params.m_position;
  p.m_maxNumResults = params.m_itemsCount;
  p.m_mode = search::Mode::Viewport;
  p.m_onResults = [params](Results const & results) {
    if (!results.IsEndMarker())
      return;

    switch (params.m_sortingType)
    {
    case DiscoverySearchParams::SortingType::None:
      params.m_onResults(results);
      break;
    case DiscoverySearchParams::SortingType::HotelRating:
    {
      Results r(results);
      r.SortBy(DiscoverySearchParams::HotelRatingComparator());
      params.m_onResults(r);
      break;
    }
    }
  };

  GetEngine().Search(p);
}

bool SearchAPI::SearchInDownloader(storage::DownloaderSearchParams const & params)
{
  SearchParams p;
  p.m_query = params.m_query;
  p.m_inputLocale = params.m_inputLocale;
  p.m_position = m_delegate.GetCurrentPosition();
  SetViewportIfPossible(p);  // Search request will be delayed if viewport is not available.
  p.m_maxNumResults = SearchParams::kDefaultNumResultsEverywhere;
  p.m_mode = Mode::Downloader;
  p.m_suggestsEnabled = false;
  p.m_needAddress = false;
  p.m_needHighlighting = false;

  p.m_onResults = DownloaderSearchCallback(static_cast<DownloaderSearchCallback::Delegate &>(*this),
                                           m_dataSource, m_infoGetter, m_storage, params);

  return Search(p, true /* forceSearch */);
}

bool SearchAPI::SearchInBookmarks(search::BookmarksSearchParams const & params)
{
  SearchParams p;
  p.m_query = params.m_query;
  p.m_position = m_delegate.GetCurrentPosition();
  SetViewportIfPossible(p);  // Search request will be delayed if viewport is not available.
  p.m_maxNumResults = SearchParams::kDefaultNumBookmarksResults;
  p.m_mode = Mode::Bookmarks;
  p.m_suggestsEnabled = false;
  p.m_needAddress = false;

  auto const onStarted = params.m_onStarted;
  p.m_onStarted = [this, onStarted]() {
    if (onStarted)
      RunUITask([onStarted]() { onStarted(); });
  };

  auto const onResults = params.m_onResults;
  p.m_onResults = BookmarksSearchCallback([this, onResults](
      BookmarksSearchParams::Results const & results, BookmarksSearchParams::Status status) {
    if (onResults)
      RunUITask([onResults, results, status]() { onResults(results, status); });
  });

  return Search(p, true /* forceSearch */);
}

void SearchAPI::PokeSearchInViewport(bool forceSearch)
{
  if (!m_isViewportInitialized || !IsViewportSearchActive())
    return;

  // Copy is intentional here, to skip possible duplicating requests.
  auto params = m_searchIntents[static_cast<size_t>(Mode::Viewport)].m_params;
  SetViewportIfPossible(params);
  params.m_position = m_delegate.GetCurrentPosition();
  Search(params, forceSearch);
}

void SearchAPI::CancelSearch(Mode mode)
{
  ASSERT_NOT_EQUAL(mode, Mode::Count, ());

  if (mode == Mode::Viewport)
  {
    m_delegate.ClearViewportSearchResults();
    m_delegate.SetSearchDisplacementModeEnabled(false /* enabled */);
  }

  auto & intent = m_searchIntents[static_cast<size_t>(mode)];
  intent.m_params.Clear();
  CancelQuery(intent.m_handle);
}

void SearchAPI::CancelAllSearches()
{
  for (size_t i = 0; i < static_cast<size_t>(Mode::Count); ++i)
    CancelSearch(static_cast<Mode>(i));
}

void SearchAPI::RunUITask(function<void()> fn) { return m_delegate.RunUITask(fn); }

void SearchAPI::SetHotelDisplacementMode()
{
  return m_delegate.SetSearchDisplacementModeEnabled(true);
}

bool SearchAPI::IsViewportSearchActive() const
{
  return !m_searchIntents[static_cast<size_t>(Mode::Viewport)].m_params.m_query.empty();
}

void SearchAPI::ShowViewportSearchResults(Results::ConstIter begin, Results::ConstIter end,
                                          bool clear)
{
  return m_delegate.ShowViewportSearchResults(begin, end, clear);
}

void SearchAPI::ShowViewportSearchResults(Results::ConstIter begin, Results::ConstIter end,
                                          bool clear, booking::filter::Types types)
{
  return m_delegate.ShowViewportSearchResults(begin, end, clear, types);
}

ProductInfo SearchAPI::GetProductInfo(Result const & result) const
{
  return m_delegate.GetProductInfo(result);
}

void SearchAPI::FilterResultsForHotelsQuery(booking::filter::Tasks const & filterTasks,
                                            search::Results const & results, bool inViewport)
{
  m_delegate.FilterResultsForHotelsQuery(filterTasks, results, inViewport);
}

void SearchAPI::OnBookmarksCreated(vector<pair<kml::MarkId, kml::BookmarkData>> const & marks)
{
  vector<BookmarkIdDoc> data;
  AppendBookmarkIdDocs(marks, data);
  m_engine.OnBookmarksCreated(data);
}

void SearchAPI::OnBookmarksUpdated(vector<pair<kml::MarkId, kml::BookmarkData>> const & marks)
{
  vector<BookmarkIdDoc> data;
  AppendBookmarkIdDocs(marks, data);
  m_engine.OnBookmarksUpdated(data);
}

void SearchAPI::OnBookmarksDeleted(vector<kml::MarkId> const & marks)
{
  vector<bookmarks::Id> data;
  AppendBookmarkIds(marks, data);
  m_engine.OnBookmarksDeleted(data);
}

bool SearchAPI::Search(SearchParams const & params, bool forceSearch)
{
  if (m_delegate.ParseSearchQueryCommand(params))
    return false;

  auto const mode = params.m_mode;
  auto & intent = m_searchIntents[static_cast<size_t>(mode)];

  if (!forceSearch && QueryMayBeSkipped(intent.m_params, params))
    return false;

  intent.m_params = params;

  // Cancels previous search request (if any) and initiates a new
  // search request.
  CancelQuery(intent.m_handle);

  intent.m_params.m_minDistanceOnMapBetweenResults = m_delegate.GetMinDistanceBetweenResults();

  Search(intent);

  return true;
}

void SearchAPI::Search(SearchIntent & intent)
{
  if (!m_isViewportInitialized)
  {
    intent.m_isDelayed = true;
    return;
  }

  intent.m_handle = m_engine.Search(intent.m_params);
  intent.m_isDelayed = false;
}

void SearchAPI::SetViewportIfPossible(SearchParams & params)
{
  if (m_isViewportInitialized)
    params.m_viewport = m_viewport;
}

bool SearchAPI::QueryMayBeSkipped(SearchParams const & prevParams,
                                  SearchParams const & currParams) const
{
  auto const & prevViewport = prevParams.m_viewport;
  auto const & currViewport = currParams.m_viewport;

  if (!prevParams.IsEqualCommon(currParams))
    return false;

  if (!prevViewport.IsValid() ||
      !IsEqualMercator(prevViewport, currViewport, kDistEqualQueryMeters))
  {
    return false;
  }

  if (prevParams.m_position && currParams.m_position &&
      MercatorBounds::DistanceOnEarth(*prevParams.m_position, *currParams.m_position) >
          kDistEqualQueryMeters)
  {
    return false;
  }

  if (static_cast<bool>(prevParams.m_position) != static_cast<bool>(currParams.m_position))
    return false;

  if (!hotels_filter::Rule::IsIdentical(prevParams.m_hotelsFilter, currParams.m_hotelsFilter))
    return false;

  return true;
}