#include "renderer.h"

#include <SDL2/SDL_opengl.h>

namespace Renderer
{
	State currentState		{RENDER_DEPTH};
	State stackedStates[10];
	char stackPos			{0};

	void DoLightOn();
	void DoLightOff();
	void DoFillOn();
	void DoFillOff();
	void DoDepthOn();
	void DoDepthOff();
	void DoBlendOn();
	void DoBlendOff();
	void DoTextureOn();
	void DoTextureOff();

	bool Light(const char state)
	{
		if (state == ON) {
			DoLightOn();
		} else if (state == OFF) {
			DoLightOff();
		}
		return (currentState & RENDER_LIGHT) == RENDER_LIGHT;
	}

	bool Fill(const char state)
	{
		if (state == ON) {
			DoFillOn();
		} else if (state == OFF) {
			DoFillOff();
		}
		return (currentState & RENDER_FILL) == RENDER_FILL;
	}

	bool Depth(const char state)
	{
		if (state == ON) {
			DoDepthOn();
		} else if (state == OFF) {
			DoDepthOff();
		}
		return (currentState & RENDER_DEPTH) == RENDER_DEPTH;
	}

	bool Blend(const char state)
	{
		if (state == ON) {
			DoBlendOn();
		} else if (state == OFF) {
			DoBlendOff();
		}
		return (currentState & RENDER_BLEND) == RENDER_BLEND;
	}

	bool Texture(const char state)
	{
		if (state == ON) {
			DoTextureOn();
		} else if (state == OFF) {
			DoTextureOff();
		}
		return (currentState & RENDER_TEXTURE) == RENDER_TEXTURE;
	}

	void Push()
	{
		if (stackPos == 10) return;
		stackedStates[stackPos++] = currentState;
	}

	void Pop()
	{
		if (stackPos == 0) return;
		SetState(stackedStates[--stackPos]);
	}

	void SetState(const State& state)
	{
		if ((state & RENDER_LIGHT)   == RENDER_LIGHT)   DoLightOn();   else DoLightOff();
		if ((state & RENDER_FILL)    == RENDER_FILL)    DoFillOn();    else DoFillOff();
		if ((state & RENDER_BLEND)   == RENDER_BLEND)   DoBlendOn();   else DoBlendOff();
		if ((state & RENDER_DEPTH)	 == RENDER_DEPTH)   DoDepthOn();   else DoDepthOff();
		if ((state & RENDER_TEXTURE) == RENDER_TEXTURE) DoTextureOn(); else DoTextureOff();
	}

	State GetState()
	{
		return currentState;
	}


	void DoLightOn()
	{
		if ((currentState & RENDER_LIGHT) == RENDER_LIGHT) return;
		glEnable(GL_LIGHTING);
		glEnable(GL_COLOR_MATERIAL);
		currentState |= RENDER_LIGHT;
	}

	void DoLightOff()
	{
		if ((currentState & RENDER_LIGHT) != RENDER_LIGHT) return;
		glDisable(GL_LIGHTING);
		glDisable(GL_COLOR_MATERIAL);
		currentState &= uint8_t(~RENDER_LIGHT);
	}

	void DoFillOn()
	{
		if ((currentState & RENDER_FILL) == RENDER_FILL) return;
		glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
		currentState |= RENDER_FILL;
	}

	void DoFillOff()
	{
		if ((currentState & RENDER_FILL) != RENDER_FILL) return;
		glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
		currentState &= uint8_t(~RENDER_FILL);
	}

	void DoDepthOn()
	{
		if ((currentState & RENDER_DEPTH) == RENDER_DEPTH) return;
		glEnable(GL_DEPTH_TEST);
		currentState |= RENDER_DEPTH;
	}

	void DoDepthOff()
	{
		if ((currentState & RENDER_DEPTH) != RENDER_DEPTH) return;
		glDisable(GL_DEPTH_TEST);
		currentState &= uint8_t(~RENDER_DEPTH);
	}

	void DoBlendOn()
	{
		if ((currentState & RENDER_BLEND) == RENDER_BLEND) return;
		glEnable(GL_BLEND);
		currentState |= RENDER_BLEND;
	}

	void DoBlendOff()
	{
		if ((currentState & RENDER_BLEND) != RENDER_BLEND) return;
		glDisable(GL_BLEND);
		currentState &= uint8_t(~RENDER_BLEND);
	}

	void DoTextureOn()
	{
		if ((currentState & RENDER_TEXTURE) == RENDER_TEXTURE) return;
		glEnable(GL_TEXTURE_2D);
		currentState |= RENDER_TEXTURE;
	}

	void DoTextureOff()
	{
		if ((currentState & RENDER_TEXTURE) != RENDER_TEXTURE) return;
		glDisable(GL_TEXTURE_2D);
		currentState &= uint8_t(~RENDER_TEXTURE);
	}

}