// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MOJO_UI_ASSOCIATES_RESOLVED_HIT_TEST_H_
#define MOJO_UI_ASSOCIATES_RESOLVED_HIT_TEST_H_

#include <iosfwd>
#include <memory>
#include <unordered_map>

#include "base/callback.h"
#include "base/macros.h"
#include "base/memory/scoped_ptr.h"
#include "mojo/services/ui/views/interfaces/view_associates.mojom.h"

namespace mojo {
namespace ui {

using SceneTokenValueToViewTokenMap =
    std::unordered_map<uint32_t, mojo::ui::ViewTokenPtr>;

// A hit test result combined with a map explaining how scenes are mapped
// to views.
class ResolvedHits {
 public:
  ResolvedHits(mojo::gfx::composition::HitTestResultPtr result);
  ~ResolvedHits();

  // The hit test result, not null unless |TakeResult| was called.
  const mojo::gfx::composition::HitTestResult* result() const {
    return result_.get();
  }
  mojo::gfx::composition::HitTestResultPtr TakeResult() {
    return result_.Pass();
  }

  // A map from scene token value to view token containing all scenes which
  // could be resolved.
  const SceneTokenValueToViewTokenMap& map() const { return map_; }

  // Adds a mapping for the specified scene token value to a view token.
  void AddMapping(uint32_t scene_token_value,
                  mojo::ui::ViewTokenPtr view_token);

 private:
  mojo::gfx::composition::HitTestResultPtr result_;
  SceneTokenValueToViewTokenMap map_;

  DISALLOW_COPY_AND_ASSIGN(ResolvedHits);
};

// Provides a resolved description of the hit test results, or null if the
// hit test could not be performed at all.
// TODO(jeffbrown): Would prefer to use |std::unique_ptr| here but it doesn't
// play nice with base::Callback right now.
using ResolvedHitsCallback = base::Callback<void(scoped_ptr<ResolvedHits>)>;

std::ostream& operator<<(std::ostream& os, const mojo::ui::ResolvedHits& value);
std::ostream& operator<<(std::ostream& os, const mojo::ui::ResolvedHits* value);

}  // namespace ui
}  // namespace mojo

#endif  // MOJO_UI_ASSOCIATES_RESOLVED_HIT_TEST_H_