/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */

#include "Camera.hpp"
#include "Scene/Scene.hpp"
#include "Scene/SimpleDrawable.hpp"
#include "Scene/Geometry.hpp"
#include "Scene/Shader/Shader.hpp"
#include "Scene/TextDrawable.hpp"
#include "Scene/Prefabs/LabelDrawable.hpp"
#include "Scene/Ray.hpp"
#include "Scene/TextDrawable.hpp"

namespace OpenVulkano::Scene
{

	std::optional<DrawableRayHit> PerspectiveCamera::CastRay(const Math::Vector2i& xy) const
	{
		using namespace Math::Utils;

		auto scene = GetScene();

		// nds
		float ndsX = (2.f * xy.x) / m_width - 1.0f;
		float ndsY = (2.f * xy.y) / m_height - 1.0f;

		Math::Vector4f rayClip = { ndsX, ndsY, 0, 1.f };

		Math::Vector4f rayEye = inverse(m_projection) * rayClip;
		rayEye.z = -1;
		rayEye.a = 0;

		Math::Vector3f rayWorld = normalize(inverse(m_view) * rayEye);
		
		std::optional<DrawableRayHit> res;
		for (Drawable* d: scene->rayHittableDrawables)
		{
			const auto& m = d->GetNodes()[0]->GetWorldMatrix();
			const Math::Vector3f rayLocalDir = normalize(inverse(m) * Math::Vector4f(rayWorld, 0));
			const Math::Vector4f rayLocalPos = inverse(m) * m_camPosition;
			const Ray ray(rayLocalPos, rayLocalDir);
			if (auto hit = d->Intersect(ray))
			{
				// choose the closest one
				if (!res || (hit->distance < res->distance))
				{
					res = hit;
					res->drawable = d;
				}
			}
		}
		if (res)
		{
			if (SimpleDrawable* sd = dynamic_cast<SimpleDrawable*>(res->drawable))
			{
				Logger::APP->info("Ray intersects object {}", sd->GetMesh()->name);
			}
			else if (LabelDrawable* sd = dynamic_cast<LabelDrawable*>(res->drawable))
			{
				Logger::APP->info("Ray intersects label {}", sd->GetTexts().front().GetText());
			}
		}
		return res;
	}
}