/*
 * 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 "SimpleDrawable.hpp"
#include "Scene/Geometry.hpp"
#include "Scene/Shader/Shader.hpp"
#include "Base/Logger.hpp"
#include <stdexcept>

namespace OpenVulkano::Scene
{
	void SimpleDrawable::Init(Shader* shader, Geometry* mesh, Material* material, UniformBuffer* uniBuffer)
	{
		if (m_mesh || m_material || m_uniBuffer) throw std::runtime_error("Drawable is already initialized.");
		m_mesh = mesh;
		m_material = material;
		m_uniBuffer = uniBuffer;
		SetShader(shader);
	}

	void SimpleDrawable::Init(SimpleDrawable* drawable)
	{
		if (m_mesh || m_material || m_uniBuffer) throw std::runtime_error("Drawable is already initialized.");
		m_mesh = drawable->m_mesh;
		m_material = drawable->m_material;
		m_uniBuffer = drawable->m_uniBuffer;
		SetShader(drawable->GetShader());
	}

	std::optional<RayHit> SimpleDrawable::Intersect(const Ray& ray) const
	{
		if (!m_mesh || !GetShader())
		{
			return {};
		}
		if (m_mesh->aabb.IsEmpty())
		{
			m_mesh->CalculateAABB();
		}
		if (ray.IntersectAABB(m_mesh->aabb))
		{
			if (GetShader()->topology == Topology::TRIANGLE_LIST)
			{
				if (m_mesh->indexCount != 0)
				{
					for (int i = 0; i < m_mesh->indexCount / 3; i++)
					{
						if (m_mesh->indexType == VertexIndexType::UINT16)
						{
							uint16_t* indices = m_mesh->GetIndices16();
							if (auto hit = ray.IntersectTriangle(m_mesh->vertices[indices[i * 3]].position,
								m_mesh->vertices[indices[i * 3 + 1]].position,
								m_mesh->vertices[indices[i * 3 + 2]].position))
							{
								return hit;
							}
						}
						else
						{
							uint32_t* indices = m_mesh->GetIndices32();
							if (auto hit = ray.IntersectTriangle(m_mesh->vertices[indices[i * 3]].position,
							                                     m_mesh->vertices[indices[i * 3 + 1]].position,
							                                     m_mesh->vertices[indices[i * 3 + 2]].position))
							{
								return hit;
							}
						}
					}
				}
				else
				{
					for (int i = 0; i < m_mesh->vertexCount / 3; i++)
					{
						if (auto hit = ray.IntersectTriangle(m_mesh->vertices[i * 3].position,
						                                     m_mesh->vertices[i * 3 + 1].position,
						                                     m_mesh->vertices[i * 3 + 2].position))
						{
							return hit;
						}
					}
				}
			}
		}
		return {};
	}
}