[search] Refactored search API.

25 files changed, 253 insertions, 181 deletions

diff --git a/search/engine.cpp b/search/engine.cpp
index 97b63a2ea2..0f8c129a77 100644
--- a/search/engine.cpp
+++ b/search/engine.cpp
@@ -1,8 +1,8 @@
 #include "search/engine.hpp"
 
 #include "search/geometry_utils.hpp"
-#include "search/params.hpp"
 #include "search/processor.hpp"
+#include "search/search_params.hpp"
 
 #include "storage/country_info_getter.hpp"
 
diff --git a/search/engine.hpp b/search/engine.hpp
index 4760d9ba68..d46faa5a7e 100644
--- a/search/engine.hpp
+++ b/search/engine.hpp
@@ -1,9 +1,9 @@
 #pragma once
 
-#include "params.hpp"
-#include "processor_factory.hpp"
-#include "result.hpp"
-#include "suggest.hpp"
+#include "search/processor_factory.hpp"
+#include "search/result.hpp"
+#include "search/search_params.hpp"
+#include "search/suggest.hpp"
 
 #include "indexer/categories_holder.hpp"
 
diff --git a/search/everywhere_search_params.hpp b/search/everywhere_search_params.hpp
new file mode 100644
index 0000000000..f3df639644
--- /dev/null
+++ b/search/everywhere_search_params.hpp
@@ -0,0 +1,16 @@
+#pragma once
+
+#include "search/search_params.hpp"
+
+#include "std/string.hpp"
+
+namespace search
+{
+struct EverywhereSearchParams
+{
+  string m_query;
+  string m_inputLocale;
+
+  SearchParams::TOnResults m_onResults;
+};
+}  // namespace search
diff --git a/search/geocoder.cpp b/search/geocoder.cpp
index 8ff1add25c..cea3c3f4f9 100644
--- a/search/geocoder.cpp
+++ b/search/geocoder.cpp
@@ -411,6 +411,7 @@ void UniteCBVs(vector<CBV> & cbvs)
 
 // Geocoder::Params --------------------------------------------------------------------------------
 Geocoder::Params::Params() : m_mode(Mode::Everywhere) {}
+
 // Geocoder::Geocoder ------------------------------------------------------------------------------
 Geocoder::Geocoder(Index const & index, storage::CountryInfoGetter const & infoGetter,
                    PreRanker & preRanker, my::Cancellable const & cancellable)
@@ -850,7 +851,7 @@ void Geocoder::ForEachCountry(vector<shared_ptr<MwmInfo>> const & infos, TFn &&
     auto const & info = infos[i];
     if (info->GetType() != MwmInfo::COUNTRY && info->GetType() != MwmInfo::WORLD)
       continue;
-    if (info->GetType() == MwmInfo::COUNTRY && m_params.m_mode == Mode::World)
+    if (info->GetType() == MwmInfo::COUNTRY && m_params.m_mode == Mode::Downloader)
       continue;
 
     auto handle = m_index.GetMwmHandleById(MwmSet::MwmId(info));
diff --git a/search/interactive_search_callback.cpp b/search/interactive_search_callback.cpp
deleted file mode 100644
index d7981bab4d..0000000000
--- a/search/interactive_search_callback.cpp
+++ /dev/null
@@ -1,25 +0,0 @@
-#include "search/interactive_search_callback.hpp"
-
-#include "search/result.hpp"
-
-namespace search
-{
-InteractiveSearchCallback::InteractiveSearchCallback(TSetDisplacementMode && setMode,
-                                                     TOnResults && onResults)
-  : m_setMode(move(setMode)), m_onResults(move(onResults)), m_hotelsModeSet(false)
-{
-}
-
-void InteractiveSearchCallback::operator()(search::Results const & results)
-{
-  m_hotelsClassif.AddBatch(results);
-
-  if (!m_hotelsModeSet && m_hotelsClassif.IsHotelQuery())
-  {
-    m_setMode();
-    m_hotelsModeSet = true;
-  }
-
-  m_onResults(results);
-}
-}  // namespace search
diff --git a/search/interactive_search_callback.hpp b/search/interactive_search_callback.hpp
deleted file mode 100644
index 8d42f537a0..0000000000
--- a/search/interactive_search_callback.hpp
+++ /dev/null
@@ -1,32 +0,0 @@
-#pragma once
-
-#include "search/hotels_classifier.hpp"
-#include "search/params.hpp"
-
-#include "std/function.hpp"
-
-namespace search
-{
-class Results;
-
-// An on-results-callback that should be used for interactive search.
-//
-// *NOTE* the class is NOT thread safe.
-class InteractiveSearchCallback
-{
-public:
-  using TSetDisplacementMode = function<void()>;
-  using TOnResults = search::TOnResults;
-
-  InteractiveSearchCallback(TSetDisplacementMode && setMode, TOnResults && onResults);
-
-  void operator()(search::Results const & results);
-
-private:
-  TSetDisplacementMode m_setMode;
-  TOnResults m_onResults;
-
-  search::HotelsClassifier m_hotelsClassif;
-  bool m_hotelsModeSet;
-};
-}  // namespace search
diff --git a/search/mode.cpp b/search/mode.cpp
index 59c7eb751b..bd2bdc8c81 100644
--- a/search/mode.cpp
+++ b/search/mode.cpp
@@ -6,9 +6,10 @@ string DebugPrint(Mode mode)
 {
   switch (mode)
   {
-  case Mode::Viewport: return "Viewport";
   case Mode::Everywhere: return "Everywhere";
-  case Mode::World: return "World";
+  case Mode::Viewport: return "Viewport";
+  case Mode::Downloader: return "Downloader";
+  case Mode::Count: return "Count";
   }
   return "Unknown";
 }
diff --git a/search/mode.hpp b/search/mode.hpp
index 0b3b00cfbe..d5e6dabf10 100644
--- a/search/mode.hpp
+++ b/search/mode.hpp
@@ -6,9 +6,10 @@ namespace search
 {
 enum class Mode
 {
-  Viewport,
   Everywhere,
-  World
+  Viewport,
+  Downloader,
+  Count
 };
 
 string DebugPrint(Mode mode);
diff --git a/search/params.hpp b/search/params.hpp
deleted file mode 100644
index 0c688a1e3b..0000000000
--- a/search/params.hpp
+++ /dev/null
@@ -1,70 +0,0 @@
-#pragma once
-
-#include "search/mode.hpp"
-
-#include "geometry/point2d.hpp"
-#include "geometry/rect2d.hpp"
-
-#include "std/function.hpp"
-#include "std/string.hpp"
-
-
-namespace search
-{
-  class Results;
-
-  using TOnStarted = function<void()>;
-  using TOnResults = function<void (Results const &)>;
-
-  class SearchParams
-  {
-  public:
-    SearchParams();
-
-    /// @name Force run search without comparing with previous search params.
-    //@{
-    void SetForceSearch(bool b) { m_forceSearch = b; }
-    bool IsForceSearch() const { return m_forceSearch; }
-    //@}
-
-    inline void SetMode(Mode mode) { m_mode = mode; }
-    inline Mode GetMode() const { return m_mode; }
-
-    void SetPosition(double lat, double lon);
-    inline bool IsValidPosition() const { return m_validPos; }
-    inline bool IsSearchAroundPosition() const
-    {
-      return (m_searchRadiusM > 0 && IsValidPosition());
-    }
-
-    inline void SetSearchRadiusMeters(double radiusM) { m_searchRadiusM = radiusM; }
-    bool GetSearchRect(m2::RectD & rect) const;
-
-    /// @param[in] locale can be "fr", "en-US", "ru_RU" etc.
-    inline void SetInputLocale(string const & locale) { m_inputLocale = locale; }
-
-    inline void SetSuggestsEnabled(bool enabled) { m_suggestsEnabled = enabled; }
-    inline bool GetSuggestsEnabled() const { return m_suggestsEnabled; }
-
-    bool IsEqualCommon(SearchParams const & rhs) const;
-
-    inline void Clear() { m_query.clear(); }
-
-    TOnStarted m_onStarted;
-    TOnResults m_onResults;
-
-    string m_query;
-    string m_inputLocale;
-
-    double m_lat, m_lon;
-
-    friend string DebugPrint(SearchParams const & params);
-
-  private:
-    double m_searchRadiusM;
-    Mode m_mode;
-    bool m_forceSearch;
-    bool m_validPos;
-    bool m_suggestsEnabled;
-  };
-} // namespace search
diff --git a/search/processor.hpp b/search/processor.hpp
index ddc340556e..d28c43c4ab 100644
--- a/search/processor.hpp
+++ b/search/processor.hpp
@@ -1,10 +1,10 @@
 #pragma once
 #include "search/geocoder.hpp"
 #include "search/mode.hpp"
-#include "search/params.hpp"
 #include "search/pre_ranker.hpp"
-#include "search/ranker.hpp"
 #include "search/rank_table_cache.hpp"
+#include "search/ranker.hpp"
+#include "search/search_params.hpp"
 #include "search/search_trie.hpp"
 #include "search/suggest.hpp"
 #include "search/token_slice.hpp"
@@ -84,7 +84,7 @@ public:
   inline void SetMode(Mode mode) { m_mode = mode; }
   inline void SetSuggestsEnabled(bool enabled) { m_suggestsEnabled = enabled; }
   inline void SetPosition(m2::PointD const & position) { m_position = position; }
-  inline void SetOnResults(TOnResults const & onResults) { m_onResults = onResults; }
+  inline void SetOnResults(SearchParams::TOnResults const & onResults) { m_onResults = onResults; }
   inline string const & GetPivotRegion() const { return m_region; }
   inline m2::PointD const & GetPosition() const { return m_position; }
 
@@ -152,7 +152,7 @@ protected:
   m2::PointD m_position;
   Mode m_mode;
   bool m_suggestsEnabled;
-  TOnResults m_onResults;
+  SearchParams::TOnResults m_onResults;
 
   /// @name Get ranking params.
   //@{
diff --git a/search/processor_factory.hpp b/search/processor_factory.hpp
index 4eeb8cec74..b8946f6d23 100644
--- a/search/processor_factory.hpp
+++ b/search/processor_factory.hpp
@@ -1,7 +1,7 @@
 #pragma once
 
-#include "search/params.hpp"
 #include "search/processor.hpp"
+#include "search/search_params.hpp"
 #include "search/suggest.hpp"
 
 #include "std/unique_ptr.hpp"
diff --git a/search/ranker.hpp b/search/ranker.hpp
index fbea55b50c..9f81147177 100644
--- a/search/ranker.hpp
+++ b/search/ranker.hpp
@@ -6,9 +6,9 @@
 #include "search/keyword_lang_matcher.hpp"
 #include "search/locality_finder.hpp"
 #include "search/mode.hpp"
-#include "search/params.hpp"
 #include "search/result.hpp"
 #include "search/reverse_geocoder.hpp"
+#include "search/search_params.hpp"
 #include "search/suggest.hpp"
 
 #include "indexer/categories_holder.hpp"
@@ -62,7 +62,7 @@ public:
     TLocales m_categoryLocales;
 
     size_t m_limit = 0;
-    TOnResults m_onResults;
+    SearchParams::TOnResults m_onResults;
   };
 
   static size_t const kBatchSize;
diff --git a/search/result.cpp b/search/result.cpp
index 0fad1be9e5..6a9a00f3cc 100644
--- a/search/result.cpp
+++ b/search/result.cpp
@@ -319,10 +319,10 @@ string DebugPrint(AddressInfo const & info)
   return info.FormatNameAndAddress();
 }
 
-string DebugPrint(Result const & r)
+string DebugPrint(Result const & result)
 {
-  return "Result { Name: " + r.GetString() + "; Type: " + r.GetFeatureType() +
-         "; Info: " + DebugPrint(r.GetRankingInfo()) + " }";
+  return "Result { Name: " + result.GetString() + "; Type: " + result.GetFeatureType() +
+         "; Info: " + DebugPrint(result.GetRankingInfo()) + " }";
 }
 
 }  // namespace search
diff --git a/search/result.hpp b/search/result.hpp
index e541c9b1f4..916d28726d 100644
--- a/search/result.hpp
+++ b/search/result.hpp
@@ -15,7 +15,6 @@
 
 namespace search
 {
-
 // Search result. Search returns a list of them, ordered by score.
 class Result
 {
@@ -152,14 +151,14 @@ class Results
 public:
   Results() : m_status(NONE) {}
 
-  /// @name To implement end of search notification.
-  //@{
   static Results GetEndMarker(bool isCancelled) { return Results(isCancelled); }
+
   bool IsEndMarker() const { return (m_status != NONE); }
   bool IsEndedNormal() const { return (m_status == ENDED); }
-  //@}
+  bool IsEndedCancelled() const { return m_status == ENDED_CANCELLED; }
 
   bool AddResult(Result && res);
+
   /// Fast function that don't do any duplicates checks.
   /// Used in viewport search only.
   void AddResultNoChecks(Result && res)
@@ -172,8 +171,6 @@ public:
   inline void Clear() { m_vec.clear(); }
 
   typedef vector<Result>::const_iterator IterT;
-  inline IterT Begin() const { return m_vec.begin(); }
-  inline IterT End() const { return m_vec.end(); }
 
   inline IterT begin() const { return m_vec.begin(); }
   inline IterT end() const { return m_vec.end(); }
@@ -221,11 +218,10 @@ struct AddressInfo
   // Caroline, 7 vulica Frunze, Minsk, Belarus
   string FormatNameAndAddress(AddressType type = DEFAULT) const;
 
-  friend string DebugPrint(AddressInfo const & info);
-
   void Clear();
-};
 
-string DebugPrint(search::Result const &);
+  friend string DebugPrint(AddressInfo const & info);
+};
 
+string DebugPrint(search::Result const & result);
 }  // namespace search
diff --git a/search/search.pro b/search/search.pro
index 3f50c1dadf..6827455004 100644
--- a/search/search.pro
+++ b/search/search.pro
@@ -16,6 +16,7 @@ HEADERS += \
     common.hpp \
     dummy_rank_table.hpp \
     engine.hpp \
+    everywhere_search_params.hpp \
     feature_offset_match.hpp \
     features_filter.hpp \
     features_layer.hpp \
@@ -29,7 +30,6 @@ HEADERS += \
     house_detector.hpp \
     house_numbers_matcher.hpp \
     house_to_street_table.hpp \
-    interactive_search_callback.hpp \
     intermediate_result.hpp \
     intersection_result.hpp \
     interval_set.hpp \
@@ -44,7 +44,6 @@ HEADERS += \
     model.hpp \
     mwm_context.hpp \
     nested_rects_cache.hpp \
-    params.hpp \
     pre_ranker.hpp \
     pre_ranking_info.hpp \
     processor.hpp \
@@ -61,6 +60,7 @@ HEADERS += \
     retrieval.hpp \
     reverse_geocoder.hpp \
     search_index_values.hpp \
+    search_params.hpp \
     search_trie.hpp \
     stats_cache.hpp \
     street_vicinity_loader.hpp \
@@ -70,6 +70,8 @@ HEADERS += \
     token_slice.hpp \
     types_skipper.hpp \
     utils.hpp \
+    viewport_search_callback.hpp \
+    viewport_search_params.hpp
 
 SOURCES += \
     approximate_string_match.cpp \
@@ -88,7 +90,6 @@ SOURCES += \
     house_detector.cpp \
     house_numbers_matcher.cpp \
     house_to_street_table.cpp \
-    interactive_search_callback.cpp \
     intermediate_result.cpp \
     intersection_result.cpp \
     keyword_lang_matcher.cpp \
@@ -102,7 +103,6 @@ SOURCES += \
     model.cpp \
     mwm_context.cpp \
     nested_rects_cache.cpp \
-    params.cpp \
     pre_ranker.cpp \
     pre_ranking_info.cpp \
     processor.cpp \
@@ -117,7 +117,9 @@ SOURCES += \
     result.cpp \
     retrieval.cpp \
     reverse_geocoder.cpp \
+    search_params.cpp \
     street_vicinity_loader.cpp \
     streets_matcher.cpp \
     token_slice.cpp \
     types_skipper.cpp \
+    viewport_search_callback.cpp
diff --git a/search/search_integration_tests/interactive_search_test.cpp b/search/search_integration_tests/interactive_search_test.cpp
index d7b28ac138..f344973861 100644
--- a/search/search_integration_tests/interactive_search_test.cpp
+++ b/search/search_integration_tests/interactive_search_test.cpp
@@ -2,7 +2,7 @@
 
 #include "generator/generator_tests_support/test_feature.hpp"
 
-#include "search/interactive_search_callback.hpp"
+#include "search/viewport_search_callback.hpp"
 #include "search/mode.hpp"
 #include "search/search_integration_tests/helpers.hpp"
 #include "search/search_tests_support/test_results_matching.hpp"
@@ -37,16 +37,33 @@ public:
   }
 };
 
-class InteractiveSearchRequest : public TestSearchRequest
+class TestDelegate : public ViewportSearchCallback::Delegate
+{
+public:
+  TestDelegate(bool & mode) : m_mode(mode) {}
+
+  // ViewportSearchCallback::Delegate overrides:
+  void RunUITask(function<void()> /* fn */) override {}
+  void SetHotelDisplacementMode() override { m_mode = true; }
+  bool IsViewportSearchActive() const override { return true; }
+  void ShowViewportSearchResults(Results const & /* results */) override {}
+  void ClearViewportSearchResults() override {}
+
+ private:
+  bool & m_mode;
+};
+
+class InteractiveSearchRequest : public TestDelegate, public TestSearchRequest
 {
 public:
   InteractiveSearchRequest(TestSearchEngine & engine, string const & query,
                            m2::RectD const & viewport, bool & mode)
-    : TestSearchRequest(
+    : TestDelegate(mode)
+    , TestSearchRequest(
           engine, query, "en" /* locale */, Mode::Viewport, viewport,
           bind(&InteractiveSearchRequest::OnStarted, this),
-          InteractiveSearchCallback([&mode]() { mode = true; },
-                                    bind(&InteractiveSearchRequest::OnResults, this, _1)))
+          ViewportSearchCallback(static_cast<ViewportSearchCallback::Delegate &>(*this),
+                                 bind(&InteractiveSearchRequest::OnResults, this, _1)))
   {
   }
 };
diff --git a/search/search_integration_tests/processor_test.cpp b/search/search_integration_tests/processor_test.cpp
index 93d979cfa0..1797aa81bc 100644
--- a/search/search_integration_tests/processor_test.cpp
+++ b/search/search_integration_tests/processor_test.cpp
@@ -267,7 +267,7 @@ UNIT_CLASS_TEST(ProcessorTest, SearchByName)
   SetViewport(m2::RectD(m2::PointD(0.5, 0.5), m2::PointD(1.5, 1.5)));
   {
     TRules rules = {ExactMatch(worldId, london)};
-    TEST(ResultsMatch("london", Mode::World, rules), ());
+    TEST(ResultsMatch("london", Mode::Downloader, rules), ());
   }
   {
     TRules rules = {ExactMatch(worldId, london), ExactMatch(wonderlandId, cafe)};
@@ -291,7 +291,7 @@ UNIT_CLASS_TEST(ProcessorTest, DisableSuggests)
     SearchParams params;
     params.m_query = "londo";
     params.m_inputLocale = "en";
-    params.SetMode(Mode::World);
+    params.SetMode(Mode::Downloader);
     params.SetSuggestsEnabled(false);
 
     TestSearchRequest request(m_engine, params, m_viewport);
diff --git a/search/params.cpp b/search/search_params.cpp
index fa47eb86c7..aa8d490dd9 100644
--- a/search/params.cpp
+++ b/search/search_params.cpp
@@ -1,10 +1,9 @@
-#include "params.hpp"
+#include "search/search_params.hpp"
 
 #include "geometry/mercator.hpp"
 
 #include "coding/multilang_utf8_string.hpp"
 
-
 namespace search
 {
 SearchParams::SearchParams()
@@ -37,10 +36,8 @@ bool SearchParams::GetSearchRect(m2::RectD & rect) const
 
 bool SearchParams::IsEqualCommon(SearchParams const & rhs) const
 {
-  return (m_query == rhs.m_query &&
-          m_inputLocale == rhs.m_inputLocale &&
-          m_validPos == rhs.m_validPos &&
-          m_mode == rhs.m_mode &&
+  return (m_query == rhs.m_query && m_inputLocale == rhs.m_inputLocale &&
+          m_validPos == rhs.m_validPos && m_mode == rhs.m_mode &&
           m_searchRadiusM == rhs.m_searchRadiusM);
 }
 
@@ -51,4 +48,4 @@ string DebugPrint(SearchParams const & params)
      << ", Mode = " << DebugPrint(params.m_mode) << " }";
   return ss.str();
 }
-} // namespace search
+}  // namespace search
diff --git a/search/search_params.hpp b/search/search_params.hpp
new file mode 100644
index 0000000000..d3de882ee9
--- /dev/null
+++ b/search/search_params.hpp
@@ -0,0 +1,61 @@
+#pragma once
+
+#include "search/mode.hpp"
+
+#include "geometry/point2d.hpp"
+#include "geometry/rect2d.hpp"
+
+#include "std/function.hpp"
+#include "std/string.hpp"
+
+namespace search
+{
+class Results;
+
+class SearchParams
+{
+public:
+  using TOnStarted = function<void()>;
+  using TOnResults = function<void(Results const &)>;
+
+  SearchParams();
+
+  /// @name Force run search without comparing with previous search params.
+  //@{
+  void SetForceSearch(bool b) { m_forceSearch = b; }
+  bool IsForceSearch() const { return m_forceSearch; }
+  //@}
+
+  inline void SetMode(Mode mode) { m_mode = mode; }
+  inline Mode GetMode() const { return m_mode; }
+  void SetPosition(double lat, double lon);
+  inline bool IsValidPosition() const { return m_validPos; }
+  inline bool IsSearchAroundPosition() const { return (m_searchRadiusM > 0 && IsValidPosition()); }
+  inline void SetSearchRadiusMeters(double radiusM) { m_searchRadiusM = radiusM; }
+  bool GetSearchRect(m2::RectD & rect) const;
+
+  /// @param[in] locale can be "fr", "en-US", "ru_RU" etc.
+  inline void SetInputLocale(string const & locale) { m_inputLocale = locale; }
+  inline void SetSuggestsEnabled(bool enabled) { m_suggestsEnabled = enabled; }
+  inline bool GetSuggestsEnabled() const { return m_suggestsEnabled; }
+  bool IsEqualCommon(SearchParams const & rhs) const;
+
+  inline void Clear() { m_query.clear(); }
+  TOnStarted m_onStarted;
+  TOnResults m_onResults;
+
+  string m_query;
+  string m_inputLocale;
+
+  double m_lat, m_lon;
+
+  friend string DebugPrint(SearchParams const & params);
+
+private:
+  double m_searchRadiusM;
+  Mode m_mode;
+  bool m_forceSearch;
+  bool m_validPos;
+  bool m_suggestsEnabled;
+};
+}  // namespace search
diff --git a/search/search_quality/search_quality_tool/search_quality_tool.cpp b/search/search_quality/search_quality_tool/search_quality_tool.cpp
index 19b06c93e6..5be0d527ea 100644
--- a/search/search_quality/search_quality_tool/search_quality_tool.cpp
+++ b/search/search_quality/search_quality_tool/search_quality_tool.cpp
@@ -1,4 +1,4 @@
-#include "search/params.hpp"
+#include "search/search_params.hpp"
 
 #include "indexer/classificator_loader.hpp"
 #include "indexer/data_header.hpp"
diff --git a/search/search_tests_support/test_search_request.cpp b/search/search_tests_support/test_search_request.cpp
index 1c7f50d3ac..fc0b99c90c 100644
--- a/search/search_tests_support/test_search_request.cpp
+++ b/search/search_tests_support/test_search_request.cpp
@@ -31,7 +31,8 @@ TestSearchRequest::TestSearchRequest(TestSearchEngine & engine, SearchParams par
 
 TestSearchRequest::TestSearchRequest(TestSearchEngine & engine, string const & query,
                                      string const & locale, Mode mode, m2::RectD const & viewport,
-                                     TOnStarted onStarted, TOnResults onResults)
+                                     SearchParams::TOnStarted onStarted,
+                                     SearchParams::TOnResults onResults)
 {
   SearchParams params;
   params.m_query = query;
@@ -88,7 +89,7 @@ void TestSearchRequest::OnResults(search::Results const & results)
   }
   else
   {
-    m_results.assign(results.Begin(), results.End());
+    m_results.assign(results.begin(), results.end());
   }
 }
 }  // namespace tests_support
diff --git a/search/search_tests_support/test_search_request.hpp b/search/search_tests_support/test_search_request.hpp
index 4b86d5a3e2..5da71d2336 100644
--- a/search/search_tests_support/test_search_request.hpp
+++ b/search/search_tests_support/test_search_request.hpp
@@ -2,8 +2,8 @@
 
 #include "geometry/rect2d.hpp"
 
-#include "search/params.hpp"
 #include "search/result.hpp"
+#include "search/search_params.hpp"
 
 #include "std/condition_variable.hpp"
 #include "std/mutex.hpp"
@@ -36,8 +36,8 @@ public:
 
 protected:
   TestSearchRequest(TestSearchEngine & engine, string const & query, string const & locale,
-                    Mode mode, m2::RectD const & viewport, TOnStarted onStarted,
-                    TOnResults onResults);
+                    Mode mode, m2::RectD const & viewport, SearchParams::TOnStarted onStarted,
+                    SearchParams::TOnResults onResults);
 
   void SetUpCallbacks(SearchParams & params);
 
diff --git a/search/viewport_search_callback.cpp b/search/viewport_search_callback.cpp
new file mode 100644
index 0000000000..6fce48768b
--- /dev/null
+++ b/search/viewport_search_callback.cpp
@@ -0,0 +1,43 @@
+#include "search/viewport_search_callback.hpp"
+
+#include "search/result.hpp"
+
+namespace search
+{
+ViewportSearchCallback::ViewportSearchCallback(Delegate & delegate, TOnResults onResults)
+  : m_delegate(delegate), m_onResults(move(onResults)), m_hotelsModeSet(false), m_firstCall(true)
+{
+}
+
+void ViewportSearchCallback::operator()(Results const & results)
+{
+  m_hotelsClassif.AddBatch(results);
+
+  if (!m_hotelsModeSet && m_hotelsClassif.IsHotelQuery())
+  {
+    m_delegate.SetHotelDisplacementMode();
+    m_hotelsModeSet = true;
+  }
+
+  if (!results.IsEndMarker())
+  {
+    auto & delegate = m_delegate;
+    bool const firstCall = m_firstCall;
+
+    m_delegate.RunUITask([&delegate, firstCall, results]() {
+      if (!delegate.IsViewportSearchActive())
+        return;
+
+      if (firstCall)
+        delegate.ClearViewportSearchResults();
+
+      delegate.ShowViewportSearchResults(results);
+    });
+  }
+
+  if (m_onResults)
+    m_onResults(results);
+
+  m_firstCall = false;
+}
+}  // namespace search
diff --git a/search/viewport_search_callback.hpp b/search/viewport_search_callback.hpp
new file mode 100644
index 0000000000..ffc4c25c02
--- /dev/null
+++ b/search/viewport_search_callback.hpp
@@ -0,0 +1,44 @@
+#pragma once
+
+#include "search/hotels_classifier.hpp"
+#include "search/search_params.hpp"
+
+#include "std/function.hpp"
+
+namespace search
+{
+class Results;
+
+// An on-results-callback that should be used for interactive search.
+//
+// *NOTE* the class is NOT thread safe.
+class ViewportSearchCallback
+{
+public:
+  class Delegate
+  {
+  public:
+    virtual ~Delegate() = default;
+
+    virtual void RunUITask(function<void()> fn) = 0;
+    virtual void SetHotelDisplacementMode() = 0;
+    virtual bool IsViewportSearchActive() const = 0;
+    virtual void ShowViewportSearchResults(Results const & results) = 0;
+    virtual void ClearViewportSearchResults() = 0;
+  };
+
+  using TOnResults = SearchParams::TOnResults;
+
+  ViewportSearchCallback(Delegate & delegate, TOnResults onResults);
+
+  void operator()(Results const & results);
+
+private:
+  Delegate & m_delegate;
+  TOnResults m_onResults;
+
+  HotelsClassifier m_hotelsClassif;
+  bool m_hotelsModeSet;
+  bool m_firstCall;
+};
+}  // namespace search
diff --git a/search/viewport_search_params.hpp b/search/viewport_search_params.hpp
new file mode 100644
index 0000000000..5067ef5eb4
--- /dev/null
+++ b/search/viewport_search_params.hpp
@@ -0,0 +1,19 @@
+#pragma once
+
+#include "std/function.hpp"
+#include "std/string.hpp"
+
+namespace search
+{
+struct ViewportSearchParams
+{
+  using TOnStarted = function<void()>;
+  using TOnCompleted = function<void()>;
+
+  string m_query;
+  string m_inputLocale;
+
+  TOnStarted m_onStarted;
+  TOnCompleted m_onCompleted;
+};
+}  // namespace search