#include "material.h"

#include "../lib/glm/glm.hpp"

#include "shader.h"
#include "state.h"
#include "texture.h"

Material::Material(const std::shared_ptr<Texture>& tex,
		   const std::shared_ptr<Shader>&  shader)
    : shader_(shader), texture_(tex)
{
}

const std::shared_ptr<Shader>& Material::shader() const
{
	return shader_ ? shader_ : state::default_shader;
}

std::shared_ptr<Shader>& Material::shader()
{
	return shader_ ? shader_ : state::default_shader;
}

void Material::set_shader(const std::shared_ptr<Shader>& shader)
{
	shader_ = shader;
}

void Material::prepare()
{
	// Activate shader
	std::shared_ptr<Shader> active_shader = shader();
	if (!active_shader)
		return;

	active_shader->use();

	// Set uniform variables
	const glm::mat4 mvp =
	    state::projection_matrix * state::view_matrix * state::model_matrix;
	const int mvp_loc = active_shader->uniform_location("mvp");
	Shader::set_mat4(mvp_loc, mvp);

	// Set texture-related uniforms
	const int use_texture_loc =
	    active_shader->uniform_location("useTexture");
	if (texture_) {
		Shader::set_int(use_texture_loc, 1);
		const int sampler_loc =
		    active_shader->uniform_location("texSampler");
		Shader::set_int(sampler_loc, 0); // Texture unit 0
	} else {
		Shader::set_int(use_texture_loc, 0);
	}

	// Bind texture if available
	if (texture_) {
		texture_->bind();
	}
}