package de.ellpeck.actuallyadditions.common.gen;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Random;

import de.ellpeck.actuallyadditions.common.blocks.InitBlocks;
import de.ellpeck.actuallyadditions.common.config.values.ConfigBoolValues;
import de.ellpeck.actuallyadditions.common.misc.DungeonLoot;
import de.ellpeck.actuallyadditions.common.tile.TileEntityGiantChest;
import net.minecraft.block.Block;
import net.minecraft.block.BlockDirectional;
import net.minecraft.block.state.IBlockState;
import net.minecraft.init.Blocks;
import net.minecraft.tileentity.TileEntity;
import net.minecraft.util.EnumFacing;
import net.minecraft.util.math.BlockPos;
import net.minecraft.util.math.MathHelper;
import net.minecraft.world.World;
import net.minecraft.world.gen.feature.WorldGenAbstractTree;
import net.minecraft.world.gen.feature.WorldGenBigTree;
import net.minecraft.world.gen.feature.WorldGenShrub;
import net.minecraft.world.gen.feature.WorldGenTrees;
import net.minecraft.world.gen.structure.StructureBoundingBox;
import net.minecraft.world.storage.loot.ILootContainer;

public class WorldGenLushCaves {

    public static final Block[] CRYSTAL_CLUSTERS = new Block[] { InitBlocks.blockCrystalClusterRedstone, InitBlocks.blockCrystalClusterLapis, InitBlocks.blockCrystalClusterDiamond, InitBlocks.blockCrystalClusterCoal, InitBlocks.blockCrystalClusterEmerald, InitBlocks.blockCrystalClusterIron };

    public boolean generate(World world, Random rand, BlockPos position, StructureBoundingBox blockRegion) {
        this.generateCave(world, position, rand, blockRegion);
        return true;
    }

    private void generateCave(World world, BlockPos center, Random rand, StructureBoundingBox chunkRegion) {
        int spheres = rand.nextInt(5) + 3;
        StructureBoundingBox spheresBox = new StructureBoundingBox(chunkRegion);
        //the region for spheres is larger so that trees can generate in the smaller one
        spheresBox.minX -= 7;
        spheresBox.minZ -= 7;
        spheresBox.maxX += 7;
        spheresBox.maxZ += 7;
        for (int i = 0; i <= spheres; i++) {
            //center already is random value within population area
            this.makeSphereWithGrassFloor(world, center.add(rand.nextInt(11) - 5, rand.nextInt(7) - 3, rand.nextInt(11) - 5), rand.nextInt(3) + 5, spheresBox, rand);
        }

        this.genTreesAndTallGrass(world, center, 11, spheres * 2, rand, chunkRegion);
    }

    private void genTreesAndTallGrass(World world, BlockPos center, int radius, int amount, Random rand, StructureBoundingBox box) {
        List<BlockPos> possiblePoses = new ArrayList<>();
        for (double x = -radius; x < radius; x++) {
            for (double y = -radius; y < radius; y++) {
                for (double z = -radius; z < radius; z++) {
                    BlockPos pos = center.add(x, y, z);
                    if (box.isVecInside(pos)) {
                        if (rand.nextDouble() >= 0.5D) {
                            if (world.getBlockState(pos).getBlock() == Blocks.GRASS) {
                                possiblePoses.add(pos);
                            }
                        } else {
                            if (ConfigBoolValues.DO_CRYSTAL_CLUSTERS.isEnabled() && rand.nextInt(20) == 0) {
                                EnumFacing[] values = EnumFacing.values();
                                EnumFacing side = values[rand.nextInt(values.length)];
                                BlockPos posSide = pos.offset(side);

                                if (!this.checkIndestructable(world, posSide)) {
                                    IBlockState state = world.getBlockState(pos);
                                    IBlockState stateSide = world.getBlockState(posSide);

                                    if (state.getBlock().isAir(state, world, pos) && stateSide.isSideSolid(world, posSide, side.getOpposite())) {
                                        Block block = CRYSTAL_CLUSTERS[rand.nextInt(CRYSTAL_CLUSTERS.length)];
                                        world.setBlockState(pos, block.getDefaultState().withProperty(BlockDirectional.FACING, side.getOpposite()), 2);
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }

        if (!possiblePoses.isEmpty()) {
            boolean crateGenDone = false;

            for (int i = 0; i <= amount; i++) {
                Collections.shuffle(possiblePoses);
                BlockPos pos = possiblePoses.get(0);
                if (rand.nextBoolean()) {
                    boolean genCrate = false;

                    WorldGenAbstractTree trees;
                    if (rand.nextBoolean()) {
                        if (rand.nextBoolean()) {
                            trees = new WorldGenBigTree(false);
                        } else {
                            trees = new WorldGenShrub(Blocks.LOG.getDefaultState(), Blocks.LEAVES.getDefaultState());
                            genCrate = true;
                        }
                    } else {
                        trees = new WorldGenTrees(false);
                    }
                    trees.generate(world, rand, pos.up());

                    if (ConfigBoolValues.DUNGEON_LOOT.isEnabled() && !crateGenDone && genCrate) {
                        BlockPos cratePos = pos.add(MathHelper.getInt(rand, -2, 2), MathHelper.getInt(rand, 3, 8), MathHelper.getInt(rand, -2, 2));

                        IBlockState state = world.getBlockState(cratePos);
                        if (state != null && state.getBlock().isLeaves(state, world, cratePos)) {
                            world.setBlockState(cratePos, InitBlocks.blockGiantChest.getDefaultState(), 2);

                            TileEntity tile = world.getTileEntity(cratePos);
                            if (tile instanceof TileEntityGiantChest) {
                                ((TileEntityGiantChest) tile).lootTable = DungeonLoot.LUSH_CAVES;
                            }
                        }

                        crateGenDone = true;
                    }
                } else {
                    Blocks.GRASS.grow(world, rand, pos, world.getBlockState(pos));
                }
            }
        }
    }

    private void makeSphereWithGrassFloor(World world, BlockPos center, int radius, StructureBoundingBox boundingBox, Random rand) {
        for (double x = -radius; x < radius; x++) {
            for (double y = -radius; y < radius; y++) {
                for (double z = -radius; z < radius; z++) {
                    if (Math.sqrt(x * x + y * y + z * z) < radius) {
                        BlockPos pos = center.add(x, y, z);
                        //Note: order matters, checkIndestructable will generate chunks if order is reversed
                        if (boundingBox.isVecInside(pos) && !this.checkIndestructable(world, pos)) {
                            world.setBlockToAir(pos);
                        }
                    }
                }
            }
        }

        for (double x = -radius; x < radius; x++) {
            for (double z = -radius; z < radius; z++) {
                for (double y = -radius; y <= -3; y++) {
                    BlockPos pos = center.add(x, y, z);
                    if (boundingBox.isVecInside(pos) && !this.checkIndestructable(world, pos)) {
                        IBlockState state = world.getBlockState(pos);
                        BlockPos posUp = pos.up();

                        if (!this.checkIndestructable(world, posUp)) {
                            IBlockState stateUp = world.getBlockState(posUp);
                            if (!state.getBlock().isAir(state, world, pos) && stateUp.getBlock().isAir(stateUp, world, posUp)) {
                                world.setBlockState(pos, Blocks.GRASS.getDefaultState(), 2);
                            }
                        }
                    }
                }
            }
        }
    }

    private boolean checkIndestructable(World world, BlockPos pos) {
        //If this isn't checked, the game crashes because it tries to destroy a chest that doesn't have any loot yet :v
        TileEntity tile = world.getTileEntity(pos);
        if (tile instanceof ILootContainer) { return true; }

        IBlockState state = world.getBlockState(pos);
        if (state != null) {
            Block block = state.getBlock();
            //check if it's tree or grass that is generated here
            if (block == Blocks.LOG || block == Blocks.LEAVES || block == Blocks.TALLGRASS) { return true; }
            if (block != null && (block.isAir(state, world, pos) || block.getHarvestLevel(state) >= 0F)) { return false; }
        }
        return true;
    }
}