#pragma once

#include <vector>

#include "math/geom2d.h"
#include "gfx/texture_atlas.h"

// Everything you need to draw a UI collected into a single unit that can be passed around.
// Everything forward declared so this header is safe everywhere.

struct GLSLProgram;
class Texture;
class DrawBuffer;

// Kind of ugly connection to UI.
namespace UI {
	struct Drawable;
	struct Theme;
}

class DrawBuffer;

// Who should own this? Really not sure.
class UIContext {
public:
	UIContext() : uishader_(0), uitexture_(0), uidrawbuffer_(0), uidrawbufferTop_(0) {}

	void Init(const GLSLProgram *uishader, const GLSLProgram *uishadernotex, Texture *uitexture, DrawBuffer *uidrawbuffer, DrawBuffer *uidrawbufferTop) {
		uishader_ = uishader;
		uishadernotex_ = uishadernotex;
		uitexture_ = uitexture;
		uidrawbuffer_ = uidrawbuffer;
		uidrawbufferTop_ = uidrawbufferTop;
	}

	void Begin();
	void BeginNoTex();
	void Flush();
	void End();

	void RebindTexture() const;

	// TODO: Support transformed bounds using stencil
	void PushScissor(const Bounds &bounds);
	void PopScissor();
	Bounds GetScissorBounds();

	void ActivateTopScissor();

	DrawBuffer *Draw() const { return uidrawbuffer_; }

	const UI::Theme *theme;

	
	// Utility methods
	void FillRect(const UI::Drawable &drawable, const Bounds &bounds);



private:
	// TODO: Collect these into a UIContext
	const GLSLProgram *uishader_;
	const GLSLProgram *uishadernotex_;
	Texture *uitexture_;
	DrawBuffer *uidrawbuffer_;
	DrawBuffer *uidrawbufferTop_;

	std::vector<Bounds> scissorStack_;
};