/*
 * Copyright (c) 2020 Samsung Electronics Co., Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "text-overlap-example.h"
#include <dali-toolkit/dali-toolkit.h>
#include <dali/devel-api/actors/actor-devel.h>

#include <iostream>

using namespace Dali;
using namespace Dali::Toolkit;

static const int NUMBER_OF_LABELS(2);

namespace Demo
{
TextOverlapController::TextOverlapController(Application& app)
: mApplication(app),
  mTopmostLabel(1)
{
  app.InitSignal().Connect(this, &TextOverlapController::Create);
  app.TerminateSignal().Connect(this, &TextOverlapController::Destroy);
}

void TextOverlapController::Create(Application& app)
{
  Window window = app.GetWindow();
  window.KeyEventSignal().Connect(this, &TextOverlapController::OnKeyEvent);

  Vector2 windowSize = window.GetSize();

  mLabels[0] = TextLabel::New("Text Label 1");
  mLabels[1] = TextLabel::New("Text Label 2");

  mLabels[0].SetProperty(Dali::Actor::Property::NAME, "Label1");
  mLabels[1].SetProperty(Dali::Actor::Property::NAME, "Label2");

  mLabels[0].SetProperty(Dali::DevelActor::Property::SIBLING_ORDER, 1);
  mLabels[1].SetProperty(Dali::DevelActor::Property::SIBLING_ORDER, 2);

  mLabels[0].SetProperty(Control::Property::BACKGROUND, Color::RED);
  mLabels[1].SetProperty(Control::Property::BACKGROUND, Color::YELLOW);

  for(int i = 0; i < NUMBER_OF_LABELS; ++i)
  {
    mLabels[i].SetProperty(TextLabel::Property::HORIZONTAL_ALIGNMENT, "CENTER");
    mLabels[i].SetProperty(Actor::Property::ANCHOR_POINT, AnchorPoint::TOP_LEFT);
    mLabels[i].SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::TOP_LEFT);
    mLabels[i].SetProperty(Actor::Property::POSITION, Vector2(0, (i * 2 + 1) * windowSize.height * 0.25f));
  }

  window.Add(mLabels[0]);
  window.Add(mLabels[1]);

  mSwapButton = PushButton::New();
  mSwapButton.SetProperty(Button::Property::LABEL, "Swap depth order");
  mSwapButton.SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::BOTTOM_CENTER);
  mSwapButton.SetProperty(Actor::Property::ANCHOR_POINT, AnchorPoint::BOTTOM_CENTER);
  mSwapButton.ClickedSignal().Connect(this, &TextOverlapController::OnClicked);
  mSwapButton.SetResizePolicy(ResizePolicy::FILL_TO_PARENT, Dimension::WIDTH);
  mSwapButton.SetResizePolicy(ResizePolicy::USE_NATURAL_SIZE, Dimension::HEIGHT);
  window.Add(mSwapButton);

  Layer rootLayer = window.GetRootLayer();
  rootLayer.SetProperty(Dali::Actor::Property::NAME, "RootLayer");

  mPanDetector = PanGestureDetector::New();
  mPanDetector.Attach(rootLayer);
  mPanDetector.AddAngle(Radian(-0.5f * Math::PI));
  mPanDetector.AddAngle(Radian(0.5f * Math::PI));
  mPanDetector.DetectedSignal().Connect(this, &TextOverlapController::OnPan);
}

void TextOverlapController::OnPan(Actor actor, const PanGesture& gesture)
{
  const GestureState state = gesture.GetState();
  if(!mGrabbedActor || state == GestureState::STARTED)
  {
    const Vector2& gesturePosition = gesture.GetPosition();
    for(int i = 0; i < NUMBER_OF_LABELS; ++i)
    {
      Vector3 position = mLabels[i].GetCurrentProperty<Vector3>(Actor::Property::POSITION);
      Vector3 size     = mLabels[i].GetCurrentProperty<Vector3>(Actor::Property::SIZE);
      if(gesturePosition.y > position.y - size.y * 0.5f &&
         gesturePosition.y <= position.y + size.y * 0.5f)
      {
        mGrabbedActor = mLabels[i];
        break;
      }
    }
  }
  else if(mGrabbedActor && state == GestureState::CONTINUING)
  {
    Vector2        windowSize      = mApplication.GetWindow().GetSize();
    Vector3        size            = mGrabbedActor.GetCurrentProperty<Vector3>(Actor::Property::SIZE);
    const Vector2& gesturePosition = gesture.GetPosition();

    float y = Clamp(gesturePosition.y, size.y * 0.5f, windowSize.y - size.y * 0.5f);
    mGrabbedActor.SetProperty(Actor::Property::POSITION, Vector2(0, y));
  }
  else
  {
    mGrabbedActor.Reset();
  }
}

void TextOverlapController::Destroy(Application& app)
{
  mPanDetector.DetachAll();
  UnparentAndReset(mLabels[0]);
  UnparentAndReset(mLabels[1]);
  mGrabbedActor.Reset();
}

bool TextOverlapController::OnClicked(Button button)
{
  mTopmostLabel = 1 - mTopmostLabel; // toggles between 0 and 1
  mLabels[mTopmostLabel].RaiseToTop();
  return false;
}

void TextOverlapController::OnKeyEvent(const KeyEvent& keyEvent)
{
  if(keyEvent.GetState() == KeyEvent::DOWN &&
     (IsKey(keyEvent, DALI_KEY_BACK) ||
      IsKey(keyEvent, DALI_KEY_ESCAPE)))
  {
    mApplication.Quit();
  }
  else
  {
    Dali::Layer l  = mApplication.GetWindow().GetRootLayer();
    int         so = l.GetProperty<int>(Dali::DevelActor::Property::SIBLING_ORDER);
    l.SetProperty(Dali::DevelActor::Property::SIBLING_ORDER, so + 1);
  }
}

} // namespace Demo

int DALI_EXPORT_API main(int argc, char** argv)
{
  {
    Application                 app = Application::New(&argc, &argv);
    Demo::TextOverlapController controller(app);
    app.MainLoop();
  }
  exit(0);
}