using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Voxel
{
    public static class Worldgen
    {
        private static int baseHeight = 32;

        private static float res1 = 2;
        private static float res2 = 4;
        private static float amplitude1 = 4;
        private static float amplitude2 = 2;

        private static float mountainMapRes = (float)1/2;
        private static float mountainMapAmplitude = 8;

        private static float elevationMapRes = (float)1/8;
        private static float elevationMapAmplitude = 32;

        private static FastNoiseLite noise = new FastNoiseLite();
        private static Random random = new Random();
        
        public static int GetHeight(int x, int z)
        {
            float map1 = noise.GetNoise(
                x * res1,
                z * res1
                ) * amplitude1;

            float map2 = noise.GetNoise(x * res2,
                z * res2
                ) * amplitude2;

            float mountainMap = noise.GetNoise(
                x * mountainMapRes,
                z * mountainMapRes
                ) * mountainMapAmplitude;

            float elevationMap = (noise.GetNoise(
                x * elevationMapRes,
                z * elevationMapRes
                ) + 0.25f) * elevationMapAmplitude;
            return baseHeight + (int)(elevationMap + ((map1 + map2) * 1 + mountainMap));
        }

        public static Blocks GetBlock(int y, int maxY)
        {
            if (y > maxY)
            {
                return Blocks.Air;
            }

            if (y == maxY)
            {
                if (y < baseHeight)
                    return Blocks.Sand;
                else
                    return Blocks.Grass;
            }

            if (y < 4)
            {
                if (y == 0) return Blocks.Bedrock;

                float randomValue = random.NextSingle();

                if (randomValue < (1f / y))
                {
                    return Blocks.Bedrock;
                }

                return Blocks.Stone;
            }

            if (y > maxY - 6)
            {
                return Blocks.Dirt;
            }

            return Blocks.Stone;
        }
    }
}