Code/net/minecraft/world/level/storage/loot/LootPool.java

package net.minecraft.world.level.storage.loot;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;
import com.mojang.serialization.Codec;
import com.mojang.serialization.codecs.RecordCodecBuilder;
import com.mojang.serialization.codecs.RecordCodecBuilder.Instance;
import java.util.List;
import java.util.function.BiFunction;
import java.util.function.Consumer;
import java.util.function.Predicate;
import net.minecraft.Util;
import net.minecraft.util.Mth;
import net.minecraft.util.RandomSource;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.level.storage.loot.entries.LootPoolEntries;
import net.minecraft.world.level.storage.loot.entries.LootPoolEntry;
import net.minecraft.world.level.storage.loot.entries.LootPoolEntryContainer;
import net.minecraft.world.level.storage.loot.functions.FunctionUserBuilder;
import net.minecraft.world.level.storage.loot.functions.LootItemFunction;
import net.minecraft.world.level.storage.loot.functions.LootItemFunctions;
import net.minecraft.world.level.storage.loot.predicates.ConditionUserBuilder;
import net.minecraft.world.level.storage.loot.predicates.LootItemCondition;
import net.minecraft.world.level.storage.loot.providers.number.ConstantValue;
import net.minecraft.world.level.storage.loot.providers.number.NumberProvider;
import net.minecraft.world.level.storage.loot.providers.number.NumberProviders;
import org.apache.commons.lang3.mutable.MutableInt;

public class LootPool {
    public static final Codec<LootPool> CODEC = RecordCodecBuilder.create(
        p_341975_ -> p_341975_.group(
                LootPoolEntries.CODEC.listOf().fieldOf("entries").forGetter(p_297007_ -> p_297007_.entries),
                LootItemCondition.DIRECT_CODEC.listOf().optionalFieldOf("conditions", List.of()).forGetter(p_297008_ -> p_297008_.conditions),
                LootItemFunctions.ROOT_CODEC.listOf().optionalFieldOf("functions", List.of()).forGetter(p_297009_ -> p_297009_.functions),
                NumberProviders.CODEC.fieldOf("rolls").forGetter(p_297004_ -> p_297004_.rolls),
                NumberProviders.CODEC.fieldOf("bonus_rolls").orElse(ConstantValue.exactly(0.0F)).forGetter(p_297006_ -> p_297006_.bonusRolls)
            )
            .apply(p_341975_, LootPool::new)
    );
    private final List<LootPoolEntryContainer> entries;
    private final List<LootItemCondition> conditions;
    private final Predicate<LootContext> compositeCondition;
    private final List<LootItemFunction> functions;
    private final BiFunction<ItemStack, LootContext, ItemStack> compositeFunction;
    private final NumberProvider rolls;
    private final NumberProvider bonusRolls;

    LootPool(
        List<LootPoolEntryContainer> p_298341_,
        List<LootItemCondition> p_297697_,
        List<LootItemFunction> p_299722_,
        NumberProvider p_165131_,
        NumberProvider p_165132_
    ) {
        this.entries = p_298341_;
        this.conditions = p_297697_;
        this.compositeCondition = Util.allOf(p_297697_);
        this.functions = p_299722_;
        this.compositeFunction = LootItemFunctions.compose(p_299722_);
        this.rolls = p_165131_;
        this.bonusRolls = p_165132_;
    }

    private void addRandomItem(Consumer<ItemStack> p_79059_, LootContext p_79060_) {
        RandomSource randomsource = p_79060_.getRandom();
        List<LootPoolEntry> list = Lists.newArrayList();
        MutableInt mutableint = new MutableInt();

        for (LootPoolEntryContainer lootpoolentrycontainer : this.entries) {
            lootpoolentrycontainer.expand(p_79060_, p_79048_ -> {
                int k = p_79048_.getWeight(p_79060_.getLuck());
                if (k > 0) {
                    list.add(p_79048_);
                    mutableint.add(k);
                }
            });
        }

        int i = list.size();
        if (mutableint.intValue() != 0 && i != 0) {
            if (i == 1) {
                list.get(0).createItemStack(p_79059_, p_79060_);
            } else {
                int j = randomsource.nextInt(mutableint.intValue());

                for (LootPoolEntry lootpoolentry : list) {
                    j -= lootpoolentry.getWeight(p_79060_.getLuck());
                    if (j < 0) {
                        lootpoolentry.createItemStack(p_79059_, p_79060_);
                        return;
                    }
                }
            }
        }
    }

    public void addRandomItems(Consumer<ItemStack> p_79054_, LootContext p_79055_) {
        if (this.compositeCondition.test(p_79055_)) {
            Consumer<ItemStack> consumer = LootItemFunction.decorate(this.compositeFunction, p_79054_, p_79055_);
            int i = this.rolls.getInt(p_79055_) + Mth.floor(this.bonusRolls.getFloat(p_79055_) * p_79055_.getLuck());

            for (int j = 0; j < i; j++) {
                this.addRandomItem(consumer, p_79055_);
            }
        }
    }

    public void validate(ValidationContext p_79052_) {
        for (int i = 0; i < this.conditions.size(); i++) {
            this.conditions.get(i).validate(p_79052_.forChild(".condition[" + i + "]"));
        }

        for (int j = 0; j < this.functions.size(); j++) {
            this.functions.get(j).validate(p_79052_.forChild(".functions[" + j + "]"));
        }

        for (int k = 0; k < this.entries.size(); k++) {
            this.entries.get(k).validate(p_79052_.forChild(".entries[" + k + "]"));
        }

        this.rolls.validate(p_79052_.forChild(".rolls"));
        this.bonusRolls.validate(p_79052_.forChild(".bonusRolls"));
    }

    public static LootPool.Builder lootPool() {
        return new LootPool.Builder();
    }

    public static class Builder implements FunctionUserBuilder<LootPool.Builder>, ConditionUserBuilder<LootPool.Builder> {
        private final ImmutableList.Builder<LootPoolEntryContainer> entries = ImmutableList.builder();
        private final ImmutableList.Builder<LootItemCondition> conditions = ImmutableList.builder();
        private final ImmutableList.Builder<LootItemFunction> functions = ImmutableList.builder();
        private NumberProvider rolls = ConstantValue.exactly(1.0F);
        private NumberProvider bonusRolls = ConstantValue.exactly(0.0F);

        public LootPool.Builder setRolls(NumberProvider p_165134_) {
            this.rolls = p_165134_;
            return this;
        }

        public LootPool.Builder unwrap() {
            return this;
        }

        public LootPool.Builder setBonusRolls(NumberProvider p_165136_) {
            this.bonusRolls = p_165136_;
            return this;
        }

        public LootPool.Builder add(LootPoolEntryContainer.Builder<?> p_79077_) {
            this.entries.add(p_79077_.build());
            return this;
        }

        public LootPool.Builder when(LootItemCondition.Builder p_79081_) {
            this.conditions.add(p_79081_.build());
            return this;
        }

        public LootPool.Builder apply(LootItemFunction.Builder p_79079_) {
            this.functions.add(p_79079_.build());
            return this;
        }

        public LootPool build() {
            return new LootPool(this.entries.build(), this.conditions.build(), this.functions.build(), this.rolls, this.bonusRolls);
        }
    }
}