Code/net/minecraft/world/level/biome/MobSpawnSettings.java

package net.minecraft.world.level.biome;

import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Maps;
import com.mojang.logging.LogUtils;
import com.mojang.serialization.Codec;
import com.mojang.serialization.DataResult;
import com.mojang.serialization.MapCodec;
import com.mojang.serialization.codecs.RecordCodecBuilder;
import com.mojang.serialization.codecs.RecordCodecBuilder.Instance;
import java.util.Map;
import java.util.Map.Entry;
import javax.annotation.Nullable;
import net.minecraft.Util;
import net.minecraft.core.registries.BuiltInRegistries;
import net.minecraft.util.ExtraCodecs;
import net.minecraft.util.StringRepresentable;
import net.minecraft.util.random.WeightedList;
import net.minecraft.world.entity.EntityType;
import net.minecraft.world.entity.MobCategory;
import org.slf4j.Logger;

public class MobSpawnSettings {
    private static final Logger LOGGER = LogUtils.getLogger();
    private static final float DEFAULT_CREATURE_SPAWN_PROBABILITY = 0.1F;
    public static final WeightedList<MobSpawnSettings.SpawnerData> EMPTY_MOB_LIST = WeightedList.of();
    public static final MobSpawnSettings EMPTY = new MobSpawnSettings.Builder().build();
    public static final MapCodec<MobSpawnSettings> CODEC = RecordCodecBuilder.mapCodec(
        p_187051_ -> p_187051_.group(
                Codec.floatRange(0.0F, 0.9999999F).optionalFieldOf("creature_spawn_probability", 0.1F).forGetter(p_187055_ -> p_187055_.creatureGenerationProbability),
                Codec.simpleMap(
                        MobCategory.CODEC,
                        WeightedList.codec(MobSpawnSettings.SpawnerData.CODEC).promotePartial(Util.prefix("Spawn data: ", LOGGER::error)),
                        StringRepresentable.keys(MobCategory.values())
                    )
                    .fieldOf("spawners")
                    .forGetter(p_187053_ -> p_187053_.spawners),
                Codec.simpleMap(BuiltInRegistries.ENTITY_TYPE.byNameCodec(), MobSpawnSettings.MobSpawnCost.CODEC, BuiltInRegistries.ENTITY_TYPE)
                    .fieldOf("spawn_costs")
                    .forGetter(p_187049_ -> p_187049_.mobSpawnCosts)
            )
            .apply(p_187051_, MobSpawnSettings::new)
    );
    private final float creatureGenerationProbability;
    private final Map<MobCategory, WeightedList<MobSpawnSettings.SpawnerData>> spawners;
    private final Map<EntityType<?>, MobSpawnSettings.MobSpawnCost> mobSpawnCosts;

    MobSpawnSettings(
        float p_196689_, Map<MobCategory, WeightedList<MobSpawnSettings.SpawnerData>> p_196690_, Map<EntityType<?>, MobSpawnSettings.MobSpawnCost> p_196691_
    ) {
        this.creatureGenerationProbability = p_196689_;
        this.spawners = ImmutableMap.copyOf(p_196690_);
        this.mobSpawnCosts = ImmutableMap.copyOf(p_196691_);
    }

    public WeightedList<MobSpawnSettings.SpawnerData> getMobs(MobCategory p_151799_) {
        return this.spawners.getOrDefault(p_151799_, EMPTY_MOB_LIST);
    }

    @Nullable
    public MobSpawnSettings.MobSpawnCost getMobSpawnCost(EntityType<?> p_48346_) {
        return this.mobSpawnCosts.get(p_48346_);
    }

    public float getCreatureProbability() {
        return this.creatureGenerationProbability;
    }

    public static class Builder {
        private final Map<MobCategory, WeightedList.Builder<MobSpawnSettings.SpawnerData>> spawners = Util.makeEnumMap(
            MobCategory.class, p_390891_ -> WeightedList.builder()
        );
        private final Map<EntityType<?>, MobSpawnSettings.MobSpawnCost> mobSpawnCosts = Maps.newLinkedHashMap();
        private float creatureGenerationProbability = 0.1F;

        public MobSpawnSettings.Builder addSpawn(MobCategory p_48377_, int p_395205_, MobSpawnSettings.SpawnerData p_48378_) {
            this.spawners.get(p_48377_).add(p_48378_, p_395205_);
            return this;
        }

        public MobSpawnSettings.Builder addMobCharge(EntityType<?> p_48371_, double p_48372_, double p_48373_) {
            this.mobSpawnCosts.put(p_48371_, new MobSpawnSettings.MobSpawnCost(p_48373_, p_48372_));
            return this;
        }

        public MobSpawnSettings.Builder creatureGenerationProbability(float p_48369_) {
            this.creatureGenerationProbability = p_48369_;
            return this;
        }

        public MobSpawnSettings build() {
            return new MobSpawnSettings(
                this.creatureGenerationProbability,
                this.spawners.entrySet().stream().collect(ImmutableMap.toImmutableMap(Entry::getKey, p_390890_ -> p_390890_.getValue().build())),
                ImmutableMap.copyOf(this.mobSpawnCosts)
            );
        }
    }

    public record MobSpawnCost(double energyBudget, double charge) {
        public static final Codec<MobSpawnSettings.MobSpawnCost> CODEC = RecordCodecBuilder.create(
            p_48399_ -> p_48399_.group(
                    Codec.DOUBLE.fieldOf("energy_budget").forGetter(p_151813_ -> p_151813_.energyBudget),
                    Codec.DOUBLE.fieldOf("charge").forGetter(p_151811_ -> p_151811_.charge)
                )
                .apply(p_48399_, MobSpawnSettings.MobSpawnCost::new)
        );
    }

    public record SpawnerData(EntityType<?> type, int minCount, int maxCount) {
        public static final MapCodec<MobSpawnSettings.SpawnerData> CODEC = RecordCodecBuilder.<MobSpawnSettings.SpawnerData>mapCodec(
                p_390892_ -> p_390892_.group(
                        BuiltInRegistries.ENTITY_TYPE.byNameCodec().fieldOf("type").forGetter(p_151826_ -> p_151826_.type),
                        ExtraCodecs.POSITIVE_INT.fieldOf("minCount").forGetter(p_151824_ -> p_151824_.minCount),
                        ExtraCodecs.POSITIVE_INT.fieldOf("maxCount").forGetter(p_151820_ -> p_151820_.maxCount)
                    )
                    .apply(p_390892_, MobSpawnSettings.SpawnerData::new)
            )
            .validate(
                p_275168_ -> p_275168_.minCount > p_275168_.maxCount
                    ? DataResult.error(() -> "minCount needs to be smaller or equal to maxCount")
                    : DataResult.success(p_275168_)
            );

        public SpawnerData(EntityType<?> type, int minCount, int maxCount) {
            type = type.getCategory() == MobCategory.MISC ? EntityType.PIG : type;
            this.type = type;
            this.minCount = minCount;
            this.maxCount = maxCount;
        }

        @Override
        public String toString() {
            return EntityType.getKey(this.type) + "*(" + this.minCount + "-" + this.maxCount + ")";
        }
    }
}