package skybox;

import org.atriaSoft.etk.math.Matrix4f;
import org.atriaSoft.etk.math.Vector3f;
import org.lwjgl.opengl.GL11;
import org.lwjgl.opengl.GL13;
import org.lwjgl.opengl.GL20;
import org.lwjgl.opengl.GL30;

import entities.Camera;
import models.RawModel;
import renderEngine.DisplayManager;
import renderEngine.Loader;

public class SkyboxRenderer {
	private static final float SIZE = 500f;
	private static final float[] VERTICES = {        
	    -SIZE,  SIZE, -SIZE,
	    -SIZE, -SIZE, -SIZE,
	     SIZE, -SIZE, -SIZE,
	     SIZE, -SIZE, -SIZE,
	     SIZE,  SIZE, -SIZE,
	    -SIZE,  SIZE, -SIZE,

	    -SIZE, -SIZE,  SIZE,
	    -SIZE, -SIZE, -SIZE,
	    -SIZE,  SIZE, -SIZE,
	    -SIZE,  SIZE, -SIZE,
	    -SIZE,  SIZE,  SIZE,
	    -SIZE, -SIZE,  SIZE,

	     SIZE, -SIZE, -SIZE,
	     SIZE, -SIZE,  SIZE,
	     SIZE,  SIZE,  SIZE,
	     SIZE,  SIZE,  SIZE,
	     SIZE,  SIZE, -SIZE,
	     SIZE, -SIZE, -SIZE,

	    -SIZE, -SIZE,  SIZE,
	    -SIZE,  SIZE,  SIZE,
	     SIZE,  SIZE,  SIZE,
	     SIZE,  SIZE,  SIZE,
	     SIZE, -SIZE,  SIZE,
	    -SIZE, -SIZE,  SIZE,

	    -SIZE,  SIZE, -SIZE,
	     SIZE,  SIZE, -SIZE,
	     SIZE,  SIZE,  SIZE,
	     SIZE,  SIZE,  SIZE,
	    -SIZE,  SIZE,  SIZE,
	    -SIZE,  SIZE, -SIZE,

	    -SIZE, -SIZE, -SIZE,
	    -SIZE, -SIZE,  SIZE,
	     SIZE, -SIZE, -SIZE,
	     SIZE, -SIZE, -SIZE,
	    -SIZE, -SIZE,  SIZE,
	     SIZE, -SIZE,  SIZE
	};
	
	private static String[] TEXTURE_FILES = { "skybox/right", "skybox/left", "skybox/top", "skybox/bottom", "skybox/back", "skybox/front"};
	private static String[] TEXTURE_FILES2 = { "skybox2/right", "skybox2/left", "skybox2/top", "skybox2/bottom", "skybox2/back", "skybox2/front"};
	
	private RawModel cube;
	private int texture;
	private int texture2;
	private SkyboxShader shader;
	private float time;
	
	public SkyboxRenderer(Loader loader, Matrix4f projectionMatrix) {
		cube = loader.loadToVAO(VERTICES, 3);
		texture = loader.loadCubeMap(TEXTURE_FILES);
		texture2 = loader.loadCubeMap(TEXTURE_FILES2);
		shader = new SkyboxShader();
		shader.start();
		shader.connectTextureUnits();
		shader.loadProjectionMatrix(projectionMatrix);
		shader.stop();
	}
	
	public void render(Camera camera, Vector3f colour) {
		shader.start();
		shader.loadViewMatrix(camera);
		shader.loadFogColour(colour);
		GL30.glBindVertexArray(cube.getVaoID());
		GL20.glEnableVertexAttribArray(0);
		bindTextures();
		GL11.glDrawArrays(GL11.GL_TRIANGLES, 0, cube.getVertexCount());
		GL20.glDisableVertexAttribArray(0);
		GL30.glBindVertexArray(0);
		shader.stop();
	}
	
	private void bindTextures(){
		time += DisplayManager.getFrameTimeSecconds() * 1000;
		time %= 24000;
		int texture1;
		int texture2;
		float blendFactor;		
		if(time >= 0 && time < 5000){
			texture1 = this.texture2;
			texture2 = this.texture2;
			blendFactor = (time - 0)/(5000 - 0);
		}else if(time >= 5000 && time < 8000){
			texture1 = this.texture2;
			texture2 = this.texture;
			blendFactor = (time - 5000)/(8000 - 5000);
		}else if(time >= 8000 && time < 21000){
			texture1 = this.texture;
			texture2 = this.texture;
			blendFactor = (time - 8000)/(21000 - 8000);
		}else{
			texture1 = this.texture;
			texture2 = this.texture2;
			blendFactor = (time - 21000)/(24000 - 21000);
		}
		GL13.glActiveTexture(GL13.GL_TEXTURE0);
		GL11.glBindTexture(GL13.GL_TEXTURE_CUBE_MAP, texture1);
		GL13.glActiveTexture(GL13.GL_TEXTURE1);
		GL11.glBindTexture(GL13.GL_TEXTURE_CUBE_MAP, texture2);
		shader.loadBlendFactor(blendFactor);
	}
	
}