safe-village.ts

import { world, type Entity } from '@minecraft/server'

/**
 * An array of entity ID prefixes for hostile mobs. Used to quickly identify hostile entities.
 */
const HOSTILE_MOB_PREFIXES = [
    "minecraft:blaze",
    "minecraft:creeper",
    "minecraft:drowned",
    "minecraft:enderman",
    "minecraft:evoker",
    "minecraft:ghast",
    "minecraft:guardian",
    "minecraft:hoglin",
    "minecraft:magma_cube",
    "minecraft:phantom",
    "minecraft:piglin",
    "minecraft:pillager",
    "minecraft:ravager",
    "minecraft:skeleton",
    "minecraft:slime",
    "minecraft:spider",
    "minecraft:stray",
    "minecraft:vex",
    "minecraft:vindicator",
    "minecraft:witch",
    "minecraft:zombie",
    "minecraft:zombified_piglin",
]

/**
 * The radius (in blocks) within which hostile mobs are prevented from spawning near villages.
 */
const VILLAGE_RADIUS_BLOCKS = 64

/**
 * Checks if an entity is a hostile mob based on its type ID.
 */
function isEntityHostileMob(entity: Entity): boolean {
    const entityId = entity.typeId
    for (const prefix of HOSTILE_MOB_PREFIXES) {
        if (entityId.startsWith(prefix)) {
            return true
        }
    }
    return false
}

/**
 * Checks if an entity is within VILLAGE_RADIUS_BLOCKS of a village.
 */
function isEntityNearVillage(entity: Entity): boolean {
    try {
        const villagers = world.getDimension("overworld").getEntities({
            type: "minecraft:iron_golem",
            location: entity.location,
            maxDistance: VILLAGE_RADIUS_BLOCKS
        })
        return villagers.length > 0
    } catch (err) {
        console.log('SafeVillage: failed to check if near village:', entity.typeId, err)
        // TODO: Figure out why entity.location is undefined sometimes
        return true
    }
}


/**
 * Checks if an entity is within VILLAGE_RADIUS_BLOCKS of a village.
 */
function killHostileMob(entity: Entity): void {
    try {
        console.log('SafeVillage: kiling hostile near village:', entity.typeId)
        entity.kill()
    } catch (err) {
        console.log('SafeVillage: failed to kill hostile mob:', entity.typeId, err)
        // TODO: Figure out why it sometimes throw errors when killing mobs
    }
}

/**
 * Subscribes to the entitySpawn event to kill hostile mobs near villages.
 */
world.afterEvents.entitySpawn.subscribe(e => {
    console.log('SafeVillage: checking spawned entity:', e.entity.typeId)

    if (isEntityHostileMob(e.entity) && isEntityNearVillage(e.entity)) {
        killHostileMob(e.entity)
    }
})