using System;
using System.Collections.Generic;
using System.IO;
using System.Numerics;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Text;
using MineCase.Algorithm.Noise;
using SixLabors.ImageSharp;
using Xunit;

namespace MineCase.UnitTest
{
    public class NoiseTest
    {
        public readonly string RootDir;

        public NoiseTest()
        {
            RootDir = SetRootDir();
        }

        private static string SetRootDir([CallerFilePath]string fileName = null) =>
            Path.Combine(Path.GetDirectoryName(fileName), "bin");

        [Fact]
        public void TestPerlinNoise3D()
        {
            const int xExtent = 100;
            const int yExtent = 100;

            using (var file = File.OpenWrite(Path.Combine(RootDir, "PerlinNoise3D.bmp")))
            using (var image = new Image<SixLabors.ImageSharp.PixelFormats.Rgb24>(xExtent, yExtent))
            {
                var noise = new PerlinNoise(100);
                var noiseValue = new float[xExtent, yExtent, 1];
                noise.Noise(noiseValue, Vector3.Zero, new Vector3(0.1f, 0.1f, 0));
                for (int x = 0; x < xExtent; x++)
                {
                    for (int y = 0; y < yExtent; y++)
                    {
                        var color = (byte)(noiseValue[x, y, 0] * 255);
                        image[x, y] = new SixLabors.ImageSharp.PixelFormats.Rgb24(color, color, color);
                    }
                }

                image.SaveAsBmp(file);
            }
        }

        [Fact]
        public void TestOctavedPerlinNoise3D()
        {
            const int xExtent = 100;
            const int yExtent = 100;

            using (var file = File.OpenWrite(Path.Combine(RootDir, "OctavedPerlinNoise3D.bmp")))
            using (var image = new Image<SixLabors.ImageSharp.PixelFormats.Rgb24>(xExtent, yExtent))
            {
                var noise = new OctavedNoise<PerlinNoise>(new PerlinNoise(100), 8, 0.25f);
                var noiseValue = new float[xExtent, yExtent, 1];
                noise.Noise(noiseValue, new Vector3(-10, 10, -10), new Vector3(0.1f, 0.1f, 0));
                for (int x = 0; x < xExtent; x++)
                {
                    for (int y = 0; y < yExtent; y++)
                    {
                        var color = (byte)(noiseValue[x, y, 0] * 255);
                        image[x, y] = new SixLabors.ImageSharp.PixelFormats.Rgb24(color, color, color);
                    }
                }

                image.SaveAsBmp(file);
            }
        }

        [Fact]
        public void TestPerlinNoise3DPerformance()
        {
            if (!Vector.IsHardwareAccelerated)
                throw new NotSupportedException();

            var noise = new PerlinNoise(100);
            for (int i = 0; i < 100_0000; i++)
            {
                noise.Noise(i, i, i);
            }
        }

        [Fact]
        public void TestPerlinNoise3DPerformanceArray()
        {
            if (!Vector.IsHardwareAccelerated)
                throw new NotSupportedException();

            var noiseValue = new float[100, 100, 10];
            var noise = new PerlinNoise(100);
            for (int i = 0; i < 100; i++)
            {
                noise.Noise(noiseValue, new Vector3(i, i, i), new Vector3(0.1f, 0.1f, 0.1f));
            }
        }
    }
}