#pragma once

#include <moggle/core/gl.hpp>
#include "renderbuffer.hpp"
#include "texture.hpp"

#include <vector>

/*
 * One can attach either an external renderbuffer/texture, or move one into fbo
 * In the latter case, the fbo will own the renderbuffer/texture
 *
 * Attachment can be one of: GL_COLOR_ATTACHMENT0, GL_DEPTH_ATTACHMENT, or GL_STENCIL_ATTACHMENT
 */

namespace moggle {

struct fbo {
	explicit fbo(bool create_now = false) {
		if(create_now) create();
	}

	~fbo() { destroy(); }

	fbo(fbo const &) = delete;
	fbo & operator=(fbo const&) = delete;

	fbo(fbo && r) : id(r.id) { r.id = 0; }
	fbo & operator=(fbo && r) { std::swap(id, r.id); return *this; }

	bool created() const { return id; }
	explicit operator bool() const { return created(); }

	void create(){ if(!id) gl::generate_framebuffers(1, &id); }
	void destroy(){ gl::delete_renderbuffers(1, &id); id = 0; }

	void bind() {
		create();
		gl::bind_framebuffer(GL_FRAMEBUFFER, id);
	}

	GLuint get_id() const {
		return id;
	}

	// Only well defined if the fbo owns the texture
	texture & get_texture() {
		return textures.front();
	}

	void attach(GLenum attachment, renderbuffer const & rb){
		bind();
		gl::framebuffer_renderbuffer(GL_FRAMEBUFFER, attachment, GL_RENDERBUFFER, rb.get_id());
	}

	void attach(GLenum attachment, renderbuffer && rb){
		renderbuffers.push_back(std::move(rb));
		attach(attachment, renderbuffers.back());
	}

	void attach(GLenum attachment, GLenum textarget, texture const & t){
		bind();
		gl::framebuffer_texture_2d(GL_FRAMEBUFFER, attachment, textarget, t.get_id(), 0);
	}

	void attach(GLenum attachment, GLenum textarget, texture && t){
		textures.push_back(std::move(t));
		attach(attachment, textarget, textures.back());
	}

	void clear(GLenum bufferbits){
		bind();
		gl::clear(bufferbits);
	}

	static fbo create_default(GLsizei width, GLsizei height){
		fbo f;
		f.attach(GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture::create(width, height, GL_RGBA32F));
		f.attach(GL_DEPTH_ATTACHMENT, renderbuffer::create(width, height, 1, GL_DEPTH_COMPONENT16));
		f.clear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
		return f;
	}

private:
	std::vector<renderbuffer> renderbuffers;
	std::vector<texture> textures;

	GLuint id = 0;
};

}