#include "BsHandleSliderManager.h"
#include "BsDrawHelper.h"
#include "BsMaterial.h"
#include "BsBuiltinEditorResources.h"
#include "BsCoreThread.h"
#include "BsRendererManager.h"
#include "BsRenderer.h"
#include "BsTransientMesh.h"
#include "BsCamera.h"
#include "BsHandleSlider.h"

using namespace std::placeholders;

namespace BansheeEngine
{
	HandleSliderManager::HandleSliderManager()
		:mActiveSlider(nullptr), mHoverSlider(nullptr)
	{

	}

	HandleSliderManager::~HandleSliderManager()
	{

	}

	void HandleSliderManager::update(const HCamera& camera)
	{
		for (auto& slider : mSliders)
			slider->update(camera);
	}

	bool HandleSliderManager::hasHitSlider(const HCamera& camera, const Vector2I& inputPos) const
	{
		Ray inputRay = camera->screenPointToRay(inputPos);
		for (auto& slider : mSliders)
		{
			float t;
			if (slider->intersects(inputRay, t))
				return true;
		}

		return false;
	}

	void HandleSliderManager::handleInput(const HCamera& camera, const Vector2I& inputPos, bool pressed)
	{
		Ray inputRay = camera->screenPointToRay(inputPos);

		if (!pressed)
		{
			if (mActiveSlider != nullptr)
			{
				mActiveSlider->setInactive();
				mActiveSlider = nullptr;
			}

			float nearestT = std::numeric_limits<float>::max();
			HandleSlider* overSlider = nullptr;
			for (auto& slider : mSliders)
			{
				float t;
				if (slider->intersects(inputRay, t))
				{
					if (t < nearestT)
					{
						overSlider = slider;
						nearestT = t;
					}
				}
			}

			if (mHoverSlider != overSlider)
			{
				if (mHoverSlider != nullptr)
					mHoverSlider->setInactive();

				mHoverSlider = overSlider;

				if (mHoverSlider != nullptr)
					overSlider->setHover();
			}
		}
		else
		{
			if (mActiveSlider == nullptr)
			{
				float nearestT = std::numeric_limits<float>::max();
				HandleSlider* overSlider = nullptr;
				for (auto& slider : mSliders)
				{
					float t;
					if (slider->intersects(inputRay, t))
					{
						if (t < nearestT)
						{
							overSlider = slider;
							nearestT = t;
						}
					}
				}

				if (overSlider != nullptr)
				{
					mActiveSlider = overSlider;
					mActiveSlider->setActive(inputPos);
				}
			}

			if (mActiveSlider != nullptr)
			{
				mActiveSlider->handleInput(camera, inputPos, inputRay);
			}
		}
	}

	bool HandleSliderManager::isSliderActive() const
	{
		return mActiveSlider != nullptr;
	}

	void HandleSliderManager::_registerSlider(HandleSlider* slider)
	{
		mSliders.insert(slider);
	}

	void HandleSliderManager::_unregisterSlider(HandleSlider* slider)
	{
		mSliders.erase(slider);

		if (mActiveSlider == slider)
			mActiveSlider = nullptr;
	}
}