#include "stdafx.h"
#include "net.minecraft.world.level.h"
#include "net.minecraft.world.level.tile.h"
#include "net.minecraft.world.level.biome.h"
#include "LargeCaveFeature.h"

void LargeCaveFeature::addRoom(__int64 seed, int xOffs, int zOffs, byteArray blocks, double xRoom, double yRoom, double zRoom)
{
	addTunnel(seed, xOffs, zOffs, blocks, xRoom, yRoom, zRoom, 1 + random->nextFloat() * 6, 0, 0, -1, -1, 0.5);
}

void LargeCaveFeature::addTunnel(__int64 seed, int xOffs, int zOffs, byteArray blocks, double xCave, double yCave, double zCave, float thickness, float yRot, float xRot, int step, int dist, double yScale)
{
    double xMid = xOffs * 16 + 8;
    double zMid = zOffs * 16 + 8;

    float yRota = 0;
    float xRota = 0;
    Random random = Random(seed);

    if (dist <= 0)
	{
        int max = radius * 16 - 16;
        dist = max - random.nextInt(max / 4);
    }
    bool singleStep = false;

    if (step == -1)
	{
        step = dist / 2;
        singleStep = true;
    }


    int splitPoint = random.nextInt(dist / 2) + dist / 4;
    bool steep = random.nextInt(6) == 0;

    for (; step < dist; step++)
	{
        double rad = 1.5 + (Mth::sin(step * PI / dist) * thickness) * 1;
        double yRad = rad * yScale;

        float xc = Mth::cos(xRot);
        float xs = Mth::sin(xRot);
        xCave += Mth::cos(yRot) * xc;
        yCave += xs;
        zCave += Mth::sin(yRot) * xc;

        if (steep)
		{
            xRot *= 0.92f;
        }
		else
		{
            xRot *= 0.7f;
        }
        xRot += xRota * 0.1f;
        yRot += yRota * 0.1f;

        xRota *= 0.90f;
        yRota *= 0.75f;
        xRota += (random.nextFloat() - random.nextFloat()) * random.nextFloat() * 2;
        yRota += (random.nextFloat() - random.nextFloat()) * random.nextFloat() * 4;


        if (!singleStep && step == splitPoint && thickness > 1 && dist > 0)
		{
            addTunnel(random.nextLong(), xOffs, zOffs, blocks, xCave, yCave, zCave, random.nextFloat() * 0.5f + 0.5f, yRot - PI / 2, xRot / 3, step, dist, 1.0);
            addTunnel(random.nextLong(), xOffs, zOffs, blocks, xCave, yCave, zCave, random.nextFloat() * 0.5f + 0.5f, yRot + PI / 2, xRot / 3, step, dist, 1.0);
            return;
        }
        if (!singleStep && random.nextInt(4) == 0) continue;
        {
            double xd = xCave - xMid;
            double zd = zCave - zMid;
            double remaining = dist - step;
            double rr = (thickness + 2) + 16;
            if (xd * xd + zd * zd - (remaining * remaining) > rr * rr)
			{
                return;
            }
        }

        if (xCave < xMid - 16 - rad * 2 || zCave < zMid - 16 - rad * 2 || xCave > xMid + 16 + rad * 2 || zCave > zMid + 16 + rad * 2) continue;

        int x0 = Mth::floor(xCave - rad) - xOffs * 16 - 1;
        int x1 = Mth::floor(xCave + rad) - xOffs * 16 + 1;

        int y0 = Mth::floor(yCave - yRad) - 1;
        int y1 = Mth::floor(yCave + yRad) + 1;

        int z0 = Mth::floor(zCave - rad) - zOffs * 16 - 1;
        int z1 = Mth::floor(zCave + rad) - zOffs * 16 + 1;

        if (x0 < 0) x0 = 0;
        if (x1 > 16) x1 = 16;

        if (y0 < 1) y0 = 1;
        if (y1 > Level::genDepth - 8) y1 = Level::genDepth - 8;

        if (z0 < 0) z0 = 0;
        if (z1 > 16) z1 = 16;

        bool detectedWater = false;
        for (int xx = x0; !detectedWater && xx < x1; xx++)
		{
            for (int zz = z0; !detectedWater && zz < z1; zz++)
			{
                for (int yy = y1 + 1; !detectedWater && yy >= y0 - 1; yy--)
				{
                    int p = (xx * 16 + zz) * Level::genDepth + yy;
                    if (yy < 0 || yy >= Level::genDepth) continue;
                    if (blocks[p] == Tile::water_Id || blocks[p] == Tile::calmWater_Id)
					{
                        detectedWater = true;
                    }
                    if (yy != y0 - 1 && xx != x0 && xx != x1 - 1 && zz != z0 && zz != z1 - 1)
					{
                        yy = y0;
                    }
                }
            }
        }
        if (detectedWater) continue;

        for (int xx = x0; xx < x1; xx++) 
		{
            double xd = ((xx + xOffs * 16 + 0.5) - xCave) / rad;
            for (int zz = z0; zz < z1; zz++)
			{
                double zd = ((zz + zOffs * 16 + 0.5) - zCave) / rad;
                int p = (xx * 16 + zz) * Level::genDepth + y1;
                bool hasGrass = false;
                if (xd * xd + zd * zd < 1)
				{
                    for (int yy = y1 - 1; yy >= y0; yy--)
					{
                        double yd = (yy + 0.5 - yCave) / yRad;
                        if (yd > -0.7 && xd * xd + yd * yd + zd * zd < 1)
						{
                            int block = blocks[p];
                            if (block == Tile::grass_Id) hasGrass = true;
                            if (block == Tile::rock_Id || block == Tile::dirt_Id || block == Tile::grass_Id)
							{
                                if (yy < 10) 
								{
                                    blocks[p] = (byte) Tile::lava_Id;
                                }
								else
								{
                                    blocks[p] = (byte) 0;
                                    if (hasGrass && blocks[p - 1] == Tile::dirt_Id) blocks[p - 1] = (byte) level->getBiome(xx + xOffs * 16, zz + zOffs * 16)->topMaterial;
                                }
                            }
                        }
                        p--;
                    }
                }
            }
        }
        if (singleStep) break;
    }

}

void LargeCaveFeature::addFeature(Level *level, int x, int z, int xOffs, int zOffs, byteArray blocks)
{
	int caves = random->nextInt(random->nextInt(random->nextInt(40) + 1) + 1);
    if (random->nextInt(15) != 0) caves = 0;

    for (int cave = 0; cave < caves; cave++)
	{
        double xCave = x * 16 + random->nextInt(16);
        double yCave = random->nextInt(random->nextInt(Level::genDepth - 8) + 8);
        double zCave = z * 16 + random->nextInt(16);

        int tunnels = 1;
        if (random->nextInt(4) == 0)
		{
            addRoom(random->nextLong(), xOffs, zOffs, blocks, xCave, yCave, zCave);
            tunnels += random->nextInt(4);
        }

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

            float yRot = random->nextFloat() * PI * 2;
            float xRot = ((random->nextFloat() - 0.5f) * 2) / 8;
            float thickness = random->nextFloat() * 2 + random->nextFloat();
			if (random->nextInt(10) == 0) thickness *= random->nextFloat() * random->nextFloat() * 3 + 1;

            addTunnel(random->nextLong(), xOffs, zOffs, blocks, xCave, yCave, zCave, thickness, yRot, xRot, 0, 0, 1.0);
        }
    }

}