#include "opengl/data/shader_data.hpp"

#include "GL/glew.h"
#include "opengl/error.hpp"
#include "util/logger.hpp"

namespace zgl
{
std::error_code shader_data::build_from(
	const GLenum type,
	const std::string& source,
	shader_data& data
) {
	auto shader_id = GLuint{ 0 };

	if (not source.empty())
	{
		shader_id = glCreateShader(type);

		// Curious choice to take lists as parameters...
		const auto first_list_element = source.c_str();
		const auto first_list_element_len = static_cast<GLint>(source.length());
		glShaderSource(shader_id, 1, &first_list_element, &first_list_element_len);
		glCompileShader(shader_id);

		GLint success;
		glGetShaderiv(shader_id, GL_COMPILE_STATUS, &success);
		if (not success)
		{
			GLint log_length{};
			glGetShaderiv(shader_id, GL_INFO_LOG_LENGTH, &log_length);

			auto log = std::string(log_length, ' ');
			glGetShaderInfoLog(shader_id, log_length, nullptr, log.data());

			ztu::logger::warn("Error while compiling shader:\n%", log);

			return std::make_error_code(std::errc::invalid_argument);
		}
	}

	data = shader_data{ shader_id, type };

	return {};
}
}