#include "Framebuffer.h"
#include <glad/glad.h>
#include <iostream>
#include <vector>
#include "DebugColors.h"
#include <stb_image_write.h>
#include <ctime>

int checkFramebufferStatus()
{
	int status = glCheckFramebufferStatus(GL_FRAMEBUFFER);

	switch (status)
	{
	case GL_FRAMEBUFFER_COMPLETE:
		return 0;
		break;
	default:
		fprintf(stderr, "Framebuffer.h: " DC_ERROR " code: %#04x\n", (int)status);
		return -1;
		break;
	}
}

Framebuffer::Framebuffer(const int& width, const int& height)
{
	glGenFramebuffers(1, &ID);
	glBindFramebuffer(GL_FRAMEBUFFER, ID);

	glGenTextures(1, &ColorBuffer);
	glBindTexture(GL_TEXTURE_2D, ColorBuffer);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glBindTexture(GL_TEXTURE_2D, 0);

	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, ColorBuffer, 0);

	glGenRenderbuffers(1, &DepthStencilBuffer);
	glBindRenderbuffer(GL_RENDERBUFFER, DepthStencilBuffer);
	glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, width, height);
	glBindRenderbuffer(GL_RENDERBUFFER, 0);

	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, DepthStencilBuffer);

	if (checkFramebufferStatus() != 0)
	{
		glDeleteRenderbuffers(1, &DepthStencilBuffer);
		glDeleteTextures(1, &ColorBuffer);
		glDeleteFramebuffers(1, &ID);
		std::cerr << "Framebuffer.h: " DC_ERROR " Could not create framebuffer object." << std::endl;
		ID = 0;
		return;
	}
	glBindFramebuffer(GL_FRAMEBUFFER, 0);

	this->width = width;
	this->height = height;
}
Framebuffer::~Framebuffer()
{
	destroy();
}
void Framebuffer::destroy()
{
	glDeleteRenderbuffers(1, &DepthStencilBuffer);
	glDeleteTextures(1, &ColorBuffer);
	glDeleteFramebuffers(1, &ID);
}
void Framebuffer::UpdateSize(const unsigned int& newWidth, const unsigned int& newHeight)
{
	if (!checkBind())
		glBindFramebuffer(GL_FRAMEBUFFER, ID);

	glBindTexture(GL_TEXTURE_2D, ColorBuffer);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, newWidth, newHeight, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
	glBindTexture(GL_TEXTURE_2D, 0);

	glDeleteRenderbuffers(1, &DepthStencilBuffer);
	glGenRenderbuffers(1, &DepthStencilBuffer);
	glBindRenderbuffer(GL_RENDERBUFFER, DepthStencilBuffer);
	glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, newWidth, newHeight);
	glBindRenderbuffer(GL_RENDERBUFFER, 0);

	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, DepthStencilBuffer);
}
void Framebuffer::Use()
{
	glBindFramebuffer(GL_FRAMEBUFFER, ID);	
}
void Framebuffer::UseDefault()
{
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
}
void Framebuffer::clearBuffers(float r, float g, float b, float a)
{
	if (!checkBind())
		glBindFramebuffer(GL_FRAMEBUFFER, ID);
	glClearColor(r, g, b, a);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);	
}
void Framebuffer::clearColorBuffer(float r, float g, float b, float a)
{
	if (!checkBind())
		glBindFramebuffer(GL_FRAMEBUFFER, ID);
	glClearColor(r, g, b, a);
	glClear(GL_COLOR_BUFFER_BIT);	
}
void Framebuffer::clearDepthBuffer()
{
	if (!checkBind())
		glBindFramebuffer(GL_FRAMEBUFFER, ID);
	glClear(GL_DEPTH_BUFFER_BIT);	
}
void Framebuffer::clearStencilBuffer()
{
	if (!checkBind())
		glBindFramebuffer(GL_FRAMEBUFFER, ID);
	glClear(GL_STENCIL_BUFFER_BIT);	
}
void Framebuffer::clearDepthStencilBuffer()
{
	if (!checkBind())
		glBindFramebuffer(GL_FRAMEBUFFER, ID);
	glClear(GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);	
}
unsigned int Framebuffer::getWidth()
{
	return width;
}
unsigned int Framebuffer::getHeight()
{
	return height;
}
bool Framebuffer::checkBind()
{
	int id = 0;
	glGetIntegerv(GL_FRAMEBUFFER_BINDING, &id);
	if ((unsigned int)id == ID)
		return true;
	return false;
}
unsigned int Framebuffer::getColorBuffer()
{
	return ColorBuffer;
}
unsigned int Framebuffer::getDepthSnectilBuffer()
{
	return DepthStencilBuffer;
}
std::string Framebuffer::screenshot(std::string path)
{	
	int id = 0;
	glGetIntegerv(GL_FRAMEBUFFER_BINDING, &id);	

	unsigned char *data = new unsigned char[(int)width * (int)height * 4];
	this->Use();
	glReadBuffer(GL_COLOR_ATTACHMENT0);
	glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, data);
	stbi_flip_vertically_on_write(1);
	std::string scr_name = path + "/" + getScreenshotName();
	stbi_write_png(scr_name.c_str(), width, height, 4, data, 4 * width);
	delete data;

	glBindFramebuffer(GL_FRAMEBUFFER, (unsigned int)id);

	return scr_name;
}

MSFramebuffer::MSFramebuffer(const int& width, const int& height, const unsigned int samples) 
	: Nsamples(samples), intermediateFBO(NULL)
{
	glGenFramebuffers(1, &ID);
	glBindFramebuffer(GL_FRAMEBUFFER, ID);

	glGenTextures(1, &ColorBuffer);
	glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, ColorBuffer);	
	glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, samples, GL_RGB, width, height, GL_TRUE);
	glTexParameteri(GL_TEXTURE_2D_MULTISAMPLE, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D_MULTISAMPLE, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, 0);

	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D_MULTISAMPLE, ColorBuffer, 0);	

	glGenRenderbuffers(1, &DepthStencilBuffer);
	glBindRenderbuffer(GL_RENDERBUFFER, DepthStencilBuffer);	
	glRenderbufferStorageMultisample(GL_RENDERBUFFER, samples, GL_DEPTH24_STENCIL8, width, height);
	glBindRenderbuffer(GL_RENDERBUFFER, 0);

	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, DepthStencilBuffer);

	if (checkFramebufferStatus() != 0)
	{
		glDeleteRenderbuffers(1, &DepthStencilBuffer);
		glDeleteTextures(1, &ColorBuffer);
		glDeleteFramebuffers(1, &ID);
		std::cerr << "Framebuffer.h: " DC_ERROR " Could not create multisampled framebuffer object." << std::endl;
		ID = 0;
		return;
	}
	glBindFramebuffer(GL_FRAMEBUFFER, 0);

	this->width = width;
	this->height = height;

	intermediateFBO = new Framebuffer(width, height);
}
MSFramebuffer::~MSFramebuffer()
{
	destroy();
	delete intermediateFBO;
}
std::string MSFramebuffer::screenshot(std::string path)
{
	int id = 0;
	glGetIntegerv(GL_FRAMEBUFFER_BINDING, &id);	

	unsigned char *data = new unsigned char[width * height * 4];
	getColorBuffer();
	intermediateFBO->Use();
	glReadBuffer(GL_COLOR_ATTACHMENT0);
	glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, data);
	stbi_flip_vertically_on_write(1);
	std::string scr_name = path + "/" + getScreenshotName();
	stbi_write_png(scr_name.c_str(), width, height, 4, data, 4 * width);
	delete data;

	glBindFramebuffer(GL_FRAMEBUFFER, (unsigned int)id);

	return scr_name;
}
void MSFramebuffer::UpdateSize(const unsigned int& newWidth, const unsigned int& newHeight)
{
	if (!checkBind())
		glBindFramebuffer(GL_FRAMEBUFFER, ID);

	glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, ColorBuffer);
	glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, Nsamples, GL_RGBA, newWidth, newHeight, GL_TRUE);
	glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, 0);

	glDeleteRenderbuffers(1, &DepthStencilBuffer);
	glGenRenderbuffers(1, &DepthStencilBuffer);
	glBindRenderbuffer(GL_RENDERBUFFER, DepthStencilBuffer);	
	glRenderbufferStorageMultisample(GL_RENDERBUFFER, Nsamples, GL_DEPTH24_STENCIL8, newWidth, newHeight);
	glBindRenderbuffer(GL_RENDERBUFFER, 0);

	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, DepthStencilBuffer);
}
unsigned int MSFramebuffer::getColorBuffer()
{
	glBindFramebuffer(GL_READ_FRAMEBUFFER, ID);
	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, intermediateFBO->ID);
	glBlitFramebuffer(0, 0, width, height, 0, 0, width, height, GL_COLOR_BUFFER_BIT, GL_NEAREST);
	glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);

	return intermediateFBO->getColorBuffer();
}
unsigned int MSFramebuffer::getDepthSnectilBuffer()
{
	glBindFramebuffer(GL_READ_FRAMEBUFFER, ID);
	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, intermediateFBO->ID);
	glBlitFramebuffer(0, 0, width, height, 0, 0, width, height, GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT, GL_NEAREST);
	glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);

	return intermediateFBO->getDepthSnectilBuffer();
}
unsigned int MSFramebuffer::getColorBufferMS()
{
	return ColorBuffer;
}

/* Static functions */
void Framebuffer::clearAllBuffers(float r, float g, float b, float a)
{
	glClearColor(r, g, b, a);
	glClear(GL_COLOR_BUFFER_BIT | GL_STENCIL_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
}
std::string Framebuffer::getScreenshotName()
{
	time_t tim = time(NULL);
	struct tm *ltm = localtime(&tim);
	
	char buf[50];
	snprintf(buf, sizeof(buf), "screenshot_%i%02i%02i_%02i%02i%02i.png",
	 ltm->tm_year + 1900, ltm->tm_mon + 1, ltm->tm_mday, ltm->tm_hour, ltm->tm_min, ltm->tm_sec);
	return std::string(buf);
}
std::string Framebuffer::screenshot_defaultFBO(unsigned int width, unsigned int height, std::string path)
{
	int id = 0;
	glGetIntegerv(GL_FRAMEBUFFER_BINDING, &id);

	uint8_t *data = new uint8_t[width * height * 4];
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, data);
	stbi_flip_vertically_on_write(1);
	std::string scr_name = path + "/" + getScreenshotName();
	stbi_write_png(scr_name.c_str(), width, height, 4, data, 4 * width);
	delete[] data;

	glBindFramebuffer(GL_FRAMEBUFFER, (unsigned int)id);
	return scr_name;
}

/* Depthmap Framebuffer */	
DepthmapFramebuffer::DepthmapFramebuffer(const Resolution& resolution) : resolution(resolution), depth_texture(0), ID(0)
{	
	glGenFramebuffers(1, &ID);	
	glGenTextures(1, &depth_texture);
	glBindTexture(GL_TEXTURE_2D, depth_texture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, resolution.Width, resolution.Height, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
	float borderColor[]{ 1.0f, 1.0f, 1.0f, 1.0f };
	glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, borderColor);
	glBindTexture(GL_TEXTURE_2D, 0);

	glBindFramebuffer(GL_FRAMEBUFFER, ID);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depth_texture, 0);
	glDrawBuffer(GL_NONE);
	glReadBuffer(GL_NONE);

	if (checkFramebufferStatus() != 0)
	{
		glDeleteFramebuffers(1, &ID);
		glDeleteTextures(1, &depth_texture);
		std::cerr << "Framebuffer.h " << DC_ERROR << " Could not create Depthmap Framebuffer object.\n";
		ID = 0;
		return;
	}
}
DepthmapFramebuffer::DepthmapFramebuffer(const unsigned int& width, const unsigned int& height) : 
	DepthmapFramebuffer(Resolution{width, height})
{}
DepthmapFramebuffer::~DepthmapFramebuffer()
{
	glDeleteFramebuffers(1, &ID);
	glDeleteTextures(1, &depth_texture);
}
void DepthmapFramebuffer::Use() const
{
	glBindFramebuffer(GL_FRAMEBUFFER, ID);
}
void DepthmapFramebuffer::Use(GLenum target) const
{
	glBindFramebuffer(target, ID);
}
unsigned int DepthmapFramebuffer::GetDepthTexture() const
{
	return depth_texture;
}
void DepthmapFramebuffer::ClearDepthBuffer() const
{
	Use();
	glClear(GL_DEPTH_BUFFER_BIT);
}

/* DepthCubemap Framebuffer */
DepthCubeFramebuffer::DepthCubeFramebuffer(int width, int height) : Width(width), Height(height)
{
	init();
}
DepthCubeFramebuffer::~DepthCubeFramebuffer()
{
	glDeleteFramebuffers(1, &ID);
	glDeleteTextures(1, &depthCubemap);	
}
void DepthCubeFramebuffer::init()
{
	glGenTextures(1, &depthCubemap);
	glBindTexture(GL_TEXTURE_CUBE_MAP, depthCubemap);
	for (unsigned int i = 0; i < 6; i++)
		glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_DEPTH_COMPONENT, Width, Height, 0,
			GL_DEPTH_COMPONENT, GL_FLOAT, 0);
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
	
	glGenFramebuffers(1, &ID);
	glBindFramebuffer(GL_FRAMEBUFFER, ID);
	glFramebufferTexture(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, depthCubemap, 0);
	glDrawBuffer(GL_NONE);
	glReadBuffer(GL_NONE);
	glBindFramebuffer(GL_FRAMEBUFFER, 0);

	if (checkFramebufferStatus() != 0)
	{
		ID = 0;
	}
}
unsigned int DepthCubeFramebuffer::getDepthCubemap() const
{
	return depthCubemap;
}
void DepthCubeFramebuffer::clearDepth() const
{
	glClear(GL_DEPTH_BUFFER_BIT);
}
void DepthCubeFramebuffer::Use() const
{
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
}