package com.mygdx.game.Utils;

import com.badlogic.gdx.math.Vector2;

import com.mygdx.game.Utils.Bezier.*;

import java.util.ArrayList;
import java.util.Random;

/**
 * Created by Ryuu on 15.06.2017.
 */
public class PerlinNoise {

    public static PerlinNoise perlinNoise = new PerlinNoise();

    private final int SEED = 1245547;
    private final int OCTAVE = 10;

    public ArrayList<Vector2> generateMap(int width, int height) {

        float[][] whiteNoise = generateWhiteNoise(width, height);
        float[][] paralaNaiseX = generatePerlinNoise(whiteNoise, OCTAVE);

        Random random = new Random();

        return convertToVector2(paralaNaiseX, random.nextInt(height));
    }


    private float interpolate(float x0, float x1, float alpha) {
        return x0 * (1 - alpha) + alpha * x1;
    }

    private float[][] generateWhiteNoise(int width, int height) {
        Random random = new Random(SEED);
        float[][] noise = new float[width][height];

        for(int i = 0; i < width; i++) {
            for(int j = 0; j < height; j++) {
                noise[i][j] = (float)random.nextDouble() % 1;
            }
        }

        return noise;
    }

    private float[][] generateSmoothNoise(float[][] baseNoisem, int octave) {

        int width = baseNoisem.length;
        int height = baseNoisem[0].length;

        float[][] smoothNoise = new float[width][height];

        int samplePeriod = 1 ;
        float sampleFrequency = 1.0f;

        for (int i = 0 ; i < width; i++) {

            int sample_i0 = (i / samplePeriod) * samplePeriod;
            int sample_i1 = (sample_i0 + samplePeriod) % width;

            float horizontal_blend = (i - sample_i0) * sampleFrequency;

            for (int j = 0; j < height; j++) {
                int sample_j0 = (j / samplePeriod) * samplePeriod;
                int sample_j1 = (sample_j0 + samplePeriod) % height;
                float vertical_blend = (j - sample_j0) * sampleFrequency;

                float top = interpolate(baseNoisem[sample_i0][sample_j0], baseNoisem[sample_i1][sample_j0], horizontal_blend);
                float botton = interpolate(baseNoisem[sample_i0][sample_j1], baseNoisem[sample_i1][sample_j1], horizontal_blend);

                smoothNoise[i][j] = interpolate(top, botton, vertical_blend);
            }
        }

        return  smoothNoise;
    }

    float[][] generatePerlinNoise(float[][] baseNoise, int octaveCount) {

        int width = baseNoise.length;
        int height = baseNoise[0].length;

        float[][] smoothNoise = new float[octaveCount][]; //an array of 2D arrays containing

        float persistance = 0.5f;

        for (int i = 0; i < octaveCount; i++) {
            smoothNoise = generateSmoothNoise(baseNoise, i);
        }

        float[][] perlinNoise = new float[width][height];
        float aplitude = 1.0f;
        float totalAmplitude = 0.0f;

        for(int octave = octaveCount - 1; octave > 0; octave--) {
            aplitude *= persistance;
            totalAmplitude += aplitude;

            for (int i = 0; i < width ; i++) {
                for (int j = 0; j < height; j++) {
                    perlinNoise[i][j] += smoothNoise[i][j] * aplitude;
                }
            }
        }

        for (int i = 0; i < width; i++)
        {
            for (int j = 0; j < height; j++)
            {
                perlinNoise[i][j] /= totalAmplitude;
            }
        }

        return perlinNoise;
    }

    private ArrayList<Vector2> convertToVector2(float[][] perlinNoise, int y) {

        ArrayList<Vector2> vectorList = new ArrayList<>();

        int x = 0;

        for(int i = 0 ; i < perlinNoise.length; i++) {
            for(int j = 0; j < perlinNoise.length; j++) {

//                float y_ = (float) Math.cos(y * perlinNoise[i][j]) + (float)Math.sin(y * perlinNoise[i][j]);
                float y_ = y + perlinNoise[i][j];
                vectorList.add(new Vector2((x++ ) * Constanse.PPM , y_ * Constanse.PPM));

            }
        }

        System.out.println(vectorList.size());

        return vectorList;
    }
}