// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_VIZ_SERVICE_HIT_TEST_HIT_TEST_MANAGER_H_
#define COMPONENTS_VIZ_SERVICE_HIT_TEST_HIT_TEST_MANAGER_H_

#include <map>
#include <optional>
#include <vector>

#include "base/memory/raw_ptr.h"
#include "base/timer/elapsed_timer.h"
#include "components/viz/common/hit_test/aggregated_hit_test_region.h"
#include "components/viz/common/surfaces/surface_id.h"
#include "components/viz/service/surfaces/surface_manager.h"
#include "components/viz/service/surfaces/surface_observer.h"
#include "components/viz/service/viz_service_export.h"

namespace viz {

class LatestLocalSurfaceIdLookupDelegate;

// HitTestManager manages the collection of HitTestRegionList objects
// submitted in calls to SubmitCompositorFrame.  This collection is
// used by HitTestAggregator.
class VIZ_SERVICE_EXPORT HitTestManager : public SurfaceObserver {
 public:
  explicit HitTestManager(SurfaceManager* surface_manager);

  HitTestManager(const HitTestManager&) = delete;
  HitTestManager& operator=(const HitTestManager&) = delete;

  ~HitTestManager() override;

  // SurfaceObserver:
  void OnSurfaceActivated(const SurfaceId& surface_id) override;
  void OnSurfaceDestroyed(const SurfaceId& surface_id) override;

  // Called when HitTestRegionList is submitted along with every call
  // to SubmitCompositorFrame. Returns true if hit_test_region_list was
  // successfully submitted, and false if hit_test_region_list is invalid.
  bool SubmitHitTestRegionList(
      const SurfaceId& surface_id,
      const uint32_t frame_index,
      std::optional<HitTestRegionList> hit_test_region_list);

  // Returns the HitTestRegionList corresponding to the given
  // |frame_sink_id| and the active CompositorFrame matched by frame_index.
  // The returned pointer is not stable and should not be stored or used after
  // calling any non-const methods on this class. ActiveFrameIndex is stored
  // if |store_active_frame_index| is given, which is used to detect updates.
  const HitTestRegionList* GetActiveHitTestRegionList(
      LatestLocalSurfaceIdLookupDelegate* delegate,
      const FrameSinkId& frame_sink_id,
      uint32_t* store_active_frame_index = nullptr) const;

  int64_t GetTraceId(const SurfaceId& id) const;

  uint64_t submit_hit_test_region_list_index() const {
    return submit_hit_test_region_list_index_;
  }
  void SetNeedsSubmit() { submit_hit_test_region_list_index_++; }

 private:
  bool ValidateHitTestRegionList(const SurfaceId& surface_id,
                                 HitTestRegionList* hit_test_region_list);

  const raw_ptr<SurfaceManager> surface_manager_;

  std::map<SurfaceId, base::flat_map<uint32_t, HitTestRegionList>>
      hit_test_region_lists_;

  // Keeps track of the number of submitted HitTestRegionLists. This allows the
  // HitTestAggregators to stay in sync with the HitTestManager and only
  // aggregate when there is new hit-test data.
  uint64_t submit_hit_test_region_list_index_ = 0;
};

}  // namespace viz

#endif  // COMPONENTS_VIZ_SERVICE_HIT_TEST_HIT_TEST_MANAGER_H_