NaturesAura/src/main/java/de/ellpeck/naturesaura/data/BlockLootProvider.java

package de.ellpeck.naturesaura.data;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import de.ellpeck.naturesaura.blocks.BlockGoldenLeaves;
import de.ellpeck.naturesaura.blocks.ModBlocks;
import de.ellpeck.naturesaura.blocks.Slab;
import de.ellpeck.naturesaura.items.ModItems;
import de.ellpeck.naturesaura.reg.IModItem;
import de.ellpeck.naturesaura.reg.ModRegistry;
import net.minecraft.advancements.criterion.StatePropertiesPredicate;
import net.minecraft.block.Block;
import net.minecraft.data.DataGenerator;
import net.minecraft.data.DirectoryCache;
import net.minecraft.data.IDataProvider;
import net.minecraft.data.loot.BlockLootTables;
import net.minecraft.item.Items;
import net.minecraft.util.ResourceLocation;
import net.minecraft.world.storage.loot.*;
import net.minecraft.world.storage.loot.conditions.BlockStateProperty;
import net.minecraft.world.storage.loot.conditions.RandomChance;
import net.minecraft.world.storage.loot.functions.SetCount;

import javax.annotation.Nonnull;
import java.io.IOException;
import java.nio.file.Path;
import java.util.HashMap;
import java.util.Map;
import java.util.function.Function;

public class BlockLootProvider implements IDataProvider {
    private static final Gson GSON = new GsonBuilder().setPrettyPrinting().create();
    private final DataGenerator generator;
    private final Map<Block, Function<Block, LootTable.Builder>> lootFunctions = new HashMap<>();

    public BlockLootProvider(DataGenerator generator) {
        this.generator = generator;

        for (IModItem item : ModRegistry.ALL_ITEMS) {
            if (!(item instanceof Block))
                continue;
            Block block = (Block) item;
            if (block instanceof Slab) {
                this.lootFunctions.put(block, LootTableHooks::genSlab);
            } else {
                this.lootFunctions.put(block, LootTableHooks::genRegular);
            }
        }

        this.lootFunctions.put(ModBlocks.ANCIENT_LEAVES, b -> LootTableHooks.genLeaves(b, ModBlocks.ANCIENT_SAPLING));
        this.lootFunctions.put(ModBlocks.DECAYED_LEAVES, LootTableHooks::genSilkOnly);
        this.lootFunctions.put(ModBlocks.GOLDEN_LEAVES, b -> LootTable.builder().addLootPool(LootPool.builder().rolls(ConstantRange.of(1)).addEntry(LootTableHooks.survivesExplosion(b, ItemLootEntry.builder(ModItems.GOLD_LEAF)).acceptCondition(BlockStateProperty.builder(b).fromProperties(StatePropertiesPredicate.Builder.newBuilder().withIntProp(BlockGoldenLeaves.STAGE, BlockGoldenLeaves.HIGHEST_STAGE)))).acceptCondition(RandomChance.builder(0.75F))));
        this.lootFunctions.put(ModBlocks.NETHER_WART_MUSHROOM, b -> LootTableHooks.genSilkOr(b, ItemLootEntry.builder(Items.NETHER_WART).acceptFunction(SetCount.builder(RandomValueRange.of(1, 2)))));
    }

    private static Path getPath(Path root, ResourceLocation res) {
        return root.resolve("data/" + res.getNamespace() + "/loot_tables/blocks/" + res.getPath() + ".json");
    }

    @Override
    public void act(DirectoryCache cache) throws IOException {
        for (Map.Entry<Block, Function<Block, LootTable.Builder>> function : this.lootFunctions.entrySet()) {
            Block block = function.getKey();
            Function<Block, LootTable.Builder> func = function.getValue();
            LootTable table = func.apply(block).setParameterSet(LootParameterSets.BLOCK).build();
            Path path = getPath(this.generator.getOutputFolder(), block.getRegistryName());
            IDataProvider.save(GSON, cache, LootTableManager.toJson(table), path);
        }
    }

    @Nonnull
    @Override
    public String getName() {
        return "Nature's Aura Loot";
    }

    // What a mess
    private static class LootTableHooks extends BlockLootTables {
        public static LootTable.Builder genLeaves(Block block, Block drop) {
            return droppingWithChancesAndSticks(block, drop, 0.05F, 0.0625F, 0.083333336F, 0.1F);
        }

        public static LootTable.Builder genSlab(Block block) {
            return droppingSlab(block);
        }

        public static LootTable.Builder genRegular(Block block) {
            return dropping(block);
        }

        public static LootTable.Builder genSilkOnly(Block block) {
            return onlyWithSilkTouch(block);
        }

        public static LootTable.Builder genSilkOr(Block block, LootEntry.Builder<?> builder) {
            return droppingWithSilkTouch(block, builder);
        }

        public static <T> T survivesExplosion(Block block, ILootConditionConsumer<T> then) {
            return withSurvivesExplosion(block, then);
        }
    }
}