#include "mesh.h"

#include "constants.h"

#include <GL/glew.h>

namespace kek {

Vertex::Vertex(glm::vec3 pos, glm::vec3 normal, glm::vec2 texCoords) {
	this->pos = pos;
	this->normal = normal;
	this->texCoords = texCoords;
}

Mesh::Mesh(std::vector<Vertex> vertices, std::vector<uint32_t> indices) {
	this->vertices = vertices;
	this->indices = indices;

	glGenVertexArrays(1, &vao);
	glGenBuffers(1, &vbo);
	glGenBuffers(1, &ebo);

	glBindVertexArray(vao);

	glBindBuffer(GL_ARRAY_BUFFER, vbo);
	glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(Vertex), &vertices[0], GL_STATIC_DRAW);
	//glBindBuffer(GL_ARRAY_BUFFER, 0);

	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
	glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(unsigned int), &indices[0], GL_STATIC_DRAW);
	//glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

	glVertexAttribPointer(KEK_VERTEX_SHADER_IN_POSITION, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), 0);
	glEnableVertexAttribArray(KEK_VERTEX_SHADER_IN_POSITION);

	glVertexAttribPointer(KEK_VERTEX_SHADER_IN_NORMAL, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void *) offsetof(Vertex, normal));
	glEnableVertexAttribArray(KEK_VERTEX_SHADER_IN_NORMAL);

	glVertexAttribPointer(KEK_VERTEX_SHADER_IN_TEXCOORD, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void *) offsetof(Vertex, texCoords));
	glEnableVertexAttribArray(KEK_VERTEX_SHADER_IN_TEXCOORD);

	glBindVertexArray(0);

	GLenum err = glGetError();
	if(err != GL_NO_ERROR) {
		std::cout << "OpenGL error while loading mesh: " << err << std::endl;
		exit(1);
	}
}

Mesh::~Mesh() {
	glDeleteBuffers(1, &ebo);
	glDeleteBuffers(1, &vbo);
	glDeleteVertexArrays(1, &vao);
}

void Mesh::draw(Shader *shader) {
	glBindVertexArray(vao);
	glBindBuffer(GL_ARRAY_BUFFER, vbo);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);

	/*if(!light) { // TODO: check if props exist
		material->diffuse->use(GL_TEXTURE0);
		glUniform1i(glGetUniformLocation(shader->id, "material.diffuse"), 0);

		material->specular->use(GL_TEXTURE1);
		glUniform1i(glGetUniformLocation(shader->id, "material.specular"), 1);
		glUniform1f(glGetUniformLocation(shader->id, "material.shininess"), material->shininess);
	}*/

	// Bind vertices + texture coordinates
	glDrawElements(GL_TRIANGLES, indices.size(), GL_UNSIGNED_INT, 0);
	glBindBuffer(GL_ARRAY_BUFFER, 0);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
	glBindVertexArray(0);
}

}