#include "Texture.h"
#include <GL\glew.h>
#include <iostream>

Texture::Texture(const std::string& path) {
	m_RendererId = 0;
	m_FilePath = path;
	m_LocalBuffer = nullptr;
	m_Width = 0;
	m_Height = 0;
	m_BPP = 0;

	stbi_set_flip_vertically_on_load(1);

	m_LocalBuffer = stbi_load(path.c_str(), &m_Width, &m_Height, &m_BPP, 4);

	glGenTextures(1, &m_RendererId);
	glBindTexture(GL_TEXTURE_2D, m_RendererId);
	glGenerateMipmap(GL_TEXTURE_2D);
	//glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	//glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_LOD_BIAS, -1.0f);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, m_Width, m_Height, 0, GL_RGBA, GL_UNSIGNED_BYTE, m_LocalBuffer);
	glGenerateMipmap(GL_TEXTURE_2D);
	if (m_LocalBuffer)
		stbi_image_free(m_LocalBuffer);
	else
		std::cout << "Error: failed to load texture: " << path << std::endl;
}

// Empty texture not from file.
Texture::Texture(glm::vec2 size, GLenum format)
{
	m_Format = format;

	m_Width = size.x;
	m_Height = size.y;

	glGenTextures(1, &m_RendererId);
	glBindTexture(GL_TEXTURE_2D, m_RendererId);
	glTexImage2D(GL_TEXTURE_2D, 0, format, size.x, size.y, 0, format, GL_UNSIGNED_BYTE, NULL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glGenerateMipmap(GL_TEXTURE_2D);
}


Texture::Texture(glm::vec2 size, msdfgen::BitmapConstRef<unsigned char, 4>& bitmap, bool t)
{
	m_Width = size.x;
	m_Height = size.y;

	glGenTextures(1, &m_RendererId);
	glBindTexture(GL_TEXTURE_2D, m_RendererId);

	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);


	auto pixel = bitmap(0, bitmap.height - 0 - 1);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, m_Width, m_Height, 0, GL_RGBA, GL_UNSIGNED_BYTE, (unsigned char*)bitmap.pixels);
}

void Texture::Resize(glm::vec2 size)
{
	glDeleteTextures(1, &m_RendererId);
	m_Width = size.x;
	m_Height = size.y;
	glGenTextures(1, &m_RendererId);
	glBindTexture(GL_TEXTURE_2D, m_RendererId);
	glTexImage2D(GL_TEXTURE_2D, 0, m_Format, size.x, size.y, 0, m_Format, GL_UNSIGNED_BYTE, NULL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
}

Texture::~Texture() {
	glDeleteTextures(1, &m_RendererId);
}

void Texture::AttachToFramebuffer(GLenum attachment)
{
	glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, attachment, GL_TEXTURE_2D, m_RendererId, 0);
}


void Texture::Bind(unsigned int slot) const {
	glActiveTexture(GL_TEXTURE0 + slot);
	glBindTexture(GL_TEXTURE_2D, m_RendererId);
}

void Texture::Unbind() const {
	glBindTexture(GL_TEXTURE_2D, 0);
}