package de.tudarmstadt.informatik.hostage.ui2.fragment.opengl;

import java.io.IOException;
import java.io.InputStream;
import java.util.Scanner;

import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;

import android.content.res.AssetManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;

import android.opengl.GLES20;
import android.opengl.GLSurfaceView.Renderer;
import android.opengl.GLUtils;
import android.opengl.Matrix;
import android.util.Log;

public class ThreatIndicatorGLRenderer implements Renderer {
	private static int threatLevel = 0;
	
	public static void setThreatLevel(int level) {
		threatLevel = level;
	}
	
	public static AssetManager assets;
	
	private int width;
	private int height;
	private float aspectRatio;
	
	private int program;
	private float [] modelview;
	private float [] projection;
	private float [] mvp;
	
	private AnimatedMesh androidMesh = null;
	private AnimatedMesh beeMesh = null;
	private int androidTexture;
	private int beeTexture;

	public ThreatIndicatorGLRenderer() {}
	
	public int loadTexture(String filePath) {
		Bitmap bitmap = null;
		try {
			bitmap = BitmapFactory.decodeStream(assets.open(filePath));
		} catch (IOException e) {
			e.printStackTrace();
			return 0;
		}
		
		int[] names = {0};
		GLES20.glGenTextures(1, names, 0);
		int tex = names[0];
		GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, tex);

		GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR);
		GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
		GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);
		bitmap.recycle(); // memory is now gpu -> free it
		
		GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, tex);
		
		return tex;
	}
	
	public void onSurfaceCreated(GL10 arg0, EGLConfig arg1) {
		GLES20.glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
		GLES20.glEnable(GLES20.GL_DEPTH_TEST);
		GLES20.glEnable(GLES20.GL_CULL_FACE);
		GLES20.glEnable(GLES20.GL_TEXTURE_2D);
		
		try {
			InputStream is = assets.open("meshes/android.amh");
			androidMesh = new AnimatedMesh(is);
		} catch (IOException e) {
			Log.e("gl", "Couldn't open android mesh");
		}
		androidTexture = loadTexture("textures/android-tex.png");
		try {
			InputStream is = assets.open("meshes/bee.amh");
			beeMesh = new AnimatedMesh(is);
		} catch (IOException e) {
			Log.e("gl", "Couldn't open bee mesh");
		}
		beeTexture = loadTexture("textures/bee-tex.png");
		
		modelview = new float[16];
		Matrix.setIdentityM(modelview, 0);
		projection = new float[16];
		mvp = new float[16];
		
		String vertexSource = "attribute vec3 position; void main() {gl_Position = vec4(position, 1.0);}";
		String fragmentSource = "void main() {gl_FragColor = vec4(1.0, 0.0, 1.0, 1.0);}";
		try {
			vertexSource = inputStreamToString(assets.open("shaders/skinned.vert"));
		} catch (IOException e) {
			e.printStackTrace();
		}
		try {fragmentSource = inputStreamToString(assets.open("shaders/skinned.frag"));
		} catch (IOException e) {
			e.printStackTrace();
		}
		program = loadProgram(vertexSource, fragmentSource);
	}

	static float beeAnimation = 0.0f;
	
	private float[] mixColor(float alpha, float[] color1, float[] color2) {
		float[] color3 = new float[4];
		color3[0] = (1.0f - alpha) * color1[0] + alpha * color2[0];
		color3[1] = (1.0f - alpha) * color1[1] + alpha * color2[1];
		color3[2] = (1.0f - alpha) * color1[2] + alpha * color2[2];
		color3[3] = (1.0f - alpha) * color1[3] + alpha * color2[3];
		return color3;
	}
	
	public void onDrawFrame(GL10 arg0) {
		GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
		
		GLES20.glUseProgram(program);
		int colorUniformLoc = GLES20.glGetUniformLocation(program, "color");
		int textureUniformLoc = GLES20.glGetUniformLocation(program, "texture");
		int mvpUniformLoc = GLES20.glGetUniformLocation(program, "mvp");
		
		//final float[] androidColor = {165.0f / 255.0f, 202.0f / 255.0f, 57.0f / 255.0f, 1.0f}; // ok
		final float[] whiteColor = {1.0f, 1.0f, 1.0f, 1.0f};
		final float[] redColor = {2.0f, 0.4f, 0.2f, 1.0f};
		final float[] yellowColor = {1.0f, 1.0f, 0.0f, 1.0f};
		
		float[] color = mixColor(0.5f + 0.5f * (float)Math.sin(0.2f * beeAnimation), whiteColor, redColor);
		GLES20.glUniform4fv(colorUniformLoc, 1, color, 0);
		Log.i("gl", color[0]+" "+color[1]+" "+color[2]+" "+color[3]);
		
		GLES20.glUniform1i(textureUniformLoc, 0);
		
		Matrix.setIdentityM(modelview, 0);
		Matrix.translateM(modelview, 0, 0.0f, -0.5f, -2.0f);
		Matrix.rotateM(modelview, 0, -80.0f, 1.0f, 0.0f, 0.0f);
		Matrix.multiplyMM(mvp, 0, projection, 0, modelview, 0);
		
		GLES20.glUniformMatrix4fv(mvpUniformLoc, 1, false, mvp, 0);
		
		GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, androidTexture);
		androidMesh.tick();
		androidMesh.draw(program);
		
		GLES20.glUniform4fv(colorUniformLoc, 1, whiteColor, 0);

		beeAnimation += 1.0f;
		float beeSize = 0.2f;
		Matrix.rotateM(modelview, 0, -4.0f * beeAnimation, 0.0f, 0.0f, 1.0f);
		Matrix.translateM(modelview, 0, 0.6f, 0.0f, 0.7f + 0.1f * (float)Math.sin(0.2f * beeAnimation));
		Matrix.rotateM(modelview, 0, 20.0f * (float)Math.cos(0.2f * beeAnimation), 1.0f, 0.0f, 0.0f);
		Matrix.scaleM(modelview, 0, beeSize, beeSize, beeSize);
		Matrix.multiplyMM(mvp, 0, projection, 0, modelview, 0);
		GLES20.glUniformMatrix4fv(mvpUniformLoc, 1, false, mvp, 0);

		GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, beeTexture);
		beeMesh.tick();
		beeMesh.draw(program);
	}

	public void onSurfaceChanged(GL10 arg0, int w, int h) {
		width = w;
		height = h;
		aspectRatio = (float)w / (float)h;
		Matrix.orthoM(projection, 0, -aspectRatio, aspectRatio, -1.0f, 1.0f, -1.0f, 1.0f);
		float near = 0.1f;
		float fov = 2.0f;
		Matrix.frustumM(projection, 0, near * -aspectRatio, near * aspectRatio, -near, near, fov * near, 100.0f);
		GLES20.glViewport(0, 0, width, height);
	}
	
	// see http://stackoverflow.com/questions/309424/read-convert-an-inputstream-to-a-string
	private static String inputStreamToString(InputStream is) {
	    Scanner scanner = new Scanner(is);
		Scanner s = scanner.useDelimiter("\\A");
	    String result = s.hasNext() ? s.next() : "";
	    scanner.close();
	    return result;
	}
	
	public static int loadShader(int type, String source) {
		int shader = GLES20.glCreateShader(type);
		GLES20.glShaderSource(shader, source);
		GLES20.glCompileShader(shader);
		Log.i("gl", GLES20.glGetShaderInfoLog(shader));
		return shader;
	}
	
	public static int loadProgram(String vertexSource, String fragmentSource) {
		int program = GLES20.glCreateProgram();
		GLES20.glAttachShader(program, loadShader(GLES20.GL_VERTEX_SHADER, vertexSource));
		GLES20.glAttachShader(program, loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentSource));
		GLES20.glLinkProgram(program);
		return program;
	}
}