// Copyright (C) 2022 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
// This file is part of the "Nazara Engine - OpenGL renderer"
// For conditions of distribution and use, see copyright notice in Config.hpp

#include <Nazara/OpenGLRenderer/OpenGLTexture.hpp>
#include <Nazara/Core/CallOnExit.hpp>
#include <Nazara/Utility/PixelFormat.hpp>
#include <stdexcept>
#include <Nazara/OpenGLRenderer/Debug.hpp>

namespace Nz
{
	OpenGLTexture::OpenGLTexture(OpenGLDevice& device, const TextureInfo& params) :
	m_params(params)
	{
		if (!m_texture.Create(device))
			throw std::runtime_error("failed to create texture object");

		auto format = DescribeTextureFormat(params.pixelFormat);
		if (!format)
			throw std::runtime_error("unsupported texture format");

		const GL::Context& context = m_texture.EnsureDeviceContext();
		context.ClearErrorStack();

		switch (params.type)
		{
			case ImageType::E1D:
				m_texture.TexStorage2D(GL::TextureTarget::Target2D, params.mipmapLevel, format->internalFormat, params.width, 1);
				break;

			case ImageType::E1D_Array:
				m_texture.TexStorage2D(GL::TextureTarget::Target2D, params.mipmapLevel, format->internalFormat, params.width, params.height);
				break;

			case ImageType::E2D:
				m_texture.TexStorage2D(GL::TextureTarget::Target2D, params.mipmapLevel, format->internalFormat, params.width, params.height);
				break;

			case ImageType::E2D_Array:
				m_texture.TexStorage3D(GL::TextureTarget::Target2D_Array, params.mipmapLevel, format->internalFormat, params.width, params.height, params.depth);
				break;

			case ImageType::E3D:
				m_texture.TexStorage3D(GL::TextureTarget::Target3D, params.mipmapLevel, format->internalFormat, params.width, params.height, params.depth);
				break;

			case ImageType::Cubemap:
				m_texture.TexStorage2D(GL::TextureTarget::Cubemap, params.mipmapLevel, format->internalFormat, params.width, params.height);
				break;
		}

		if (!context.DidLastCallSucceed())
			throw std::runtime_error("failed to create texture");

		m_texture.SetParameteri(GL_TEXTURE_MAX_LEVEL, m_params.mipmapLevel);
		m_texture.SetParameteri(GL_TEXTURE_SWIZZLE_R, format->swizzleR);
		m_texture.SetParameteri(GL_TEXTURE_SWIZZLE_G, format->swizzleG);
		m_texture.SetParameteri(GL_TEXTURE_SWIZZLE_B, format->swizzleB);
		m_texture.SetParameteri(GL_TEXTURE_SWIZZLE_A, format->swizzleA);
	}

	bool OpenGLTexture::Copy(const Texture& source, const Boxui& srcBox, const Vector3ui& dstPos)
	{
		const OpenGLTexture& glTexture = static_cast<const OpenGLTexture&>(source);

		const GL::Context& context = m_texture.EnsureDeviceContext();
		return context.CopyTexture(glTexture.GetTexture(), m_texture, srcBox, dstPos);
	}

	PixelFormat OpenGLTexture::GetFormat() const
	{
		return m_params.pixelFormat;
	}

	UInt8 OpenGLTexture::GetLevelCount() const
	{
		return m_params.mipmapLevel;
	}

	Vector3ui OpenGLTexture::GetSize(UInt8 level) const
	{
		return Vector3ui(GetLevelSize(m_params.width, level), GetLevelSize(m_params.height, level), GetLevelSize(m_params.depth, level));
	}

	ImageType OpenGLTexture::GetType() const
	{
		return m_params.type;
	}

	bool OpenGLTexture::Update(const void* ptr, const Boxui& box, unsigned int srcWidth, unsigned int srcHeight, UInt8 level)
	{
		auto format = DescribeTextureFormat(m_params.pixelFormat);
		assert(format);

		const GL::Context& context = m_texture.EnsureDeviceContext();

		UInt8 bpp = PixelFormatInfo::GetBytesPerPixel(m_params.pixelFormat);
		if (bpp % 8 == 0)
			context.glPixelStorei(GL_UNPACK_ALIGNMENT, 8);
		else if (bpp % 4 == 0)
			context.glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
		else if (bpp % 2 == 0)
			context.glPixelStorei(GL_UNPACK_ALIGNMENT, 2);
		else
			context.glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

		context.glPixelStorei(GL_UNPACK_ROW_LENGTH,   srcWidth);
		context.glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, srcHeight);

		switch (m_params.type)
		{
			case ImageType::E1D:
				break;

			case ImageType::E1D_Array:
				break;

			case ImageType::E2D:
				m_texture.TexSubImage2D(GL::TextureTarget::Target2D, level, box.x, box.y, box.width, box.height, format->format, format->type, ptr);
				break;

			case ImageType::E2D_Array:
				break;

			case ImageType::E3D:
				break;

			case ImageType::Cubemap:
			{
				std::size_t faceSize = PixelFormatInfo::ComputeSize(m_params.pixelFormat, m_params.width, m_params.height, 1);
				const UInt8* facePtr = static_cast<const UInt8*>(ptr);

				for (GL::TextureTarget face : { GL::TextureTarget::CubemapPositiveX, GL::TextureTarget::CubemapNegativeX, GL::TextureTarget::CubemapPositiveY, GL::TextureTarget::CubemapNegativeY, GL::TextureTarget::CubemapPositiveZ, GL::TextureTarget::CubemapNegativeZ })
				{
					m_texture.TexSubImage2D(face, level, box.x, box.y, box.width, box.height, format->format, format->type, facePtr);
					facePtr += faceSize;
				}
				break;
			}

			default:
				break;
		}

		return true;
	}
}