Paper/src/main/java/net/minecraft/server/VillageSiege.java

package net.minecraft.server;

import java.util.Iterator;
import java.util.List;

public class VillageSiege {

    private World world;
    private boolean b = false;
    private int c = -1;
    private int d;
    private int e;
    private Village f;
    private int g;
    private int h;
    private int i;

    public VillageSiege(World world) {
        this.world = world;
    }

    public void a() {
        boolean flag = false;

        if (flag) {
            if (this.c == 2) {
                this.d = 100;
                return;
            }
        } else {
            if (this.world.e()) {
                this.c = 0;
                return;
            }

            if (this.c == 2) {
                return;
            }

            if (this.c == 0) {
                float f = this.world.b(0.0F);

                if ((double) f < 0.5D || (double) f > 0.501D) {
                    return;
                }

                this.c = this.world.random.nextInt(10) == 0 ? 1 : 2;
                this.b = false;
                if (this.c == 2) {
                    return;
                }
            }
        }

        if (!this.b) {
            if (!this.b()) {
                return;
            }

            this.b = true;
        }

        if (this.e > 0) {
            --this.e;
        } else {
            this.e = 2;
            if (this.d > 0) {
                this.c();
                --this.d;
            } else {
                this.c = 2;
            }
        }
    }

    private boolean b() {
        List list = this.world.players;
        Iterator iterator = list.iterator();

        while (iterator.hasNext()) {
            EntityHuman entityhuman = (EntityHuman) iterator.next();

            this.f = this.world.villages.getClosestVillage((int) entityhuman.locX, (int) entityhuman.locY, (int) entityhuman.locZ, 1);
            if (this.f != null && this.f.getDoorCount() >= 10 && this.f.d() >= 20 && this.f.getPopulationCount() >= 20) {
                ChunkCoordinates chunkcoordinates = this.f.getCenter();
                float f = (float) this.f.getSize();
                boolean flag = false;
                int i = 0;

                while (true) {
                    if (i < 10) {
                        this.g = chunkcoordinates.x + (int) ((double) (MathHelper.cos(this.world.random.nextFloat() * 3.1415927F * 2.0F) * f) * 0.9D);
                        this.h = chunkcoordinates.y;
                        this.i = chunkcoordinates.z + (int) ((double) (MathHelper.sin(this.world.random.nextFloat() * 3.1415927F * 2.0F) * f) * 0.9D);
                        flag = false;
                        Iterator iterator1 = this.world.villages.getVillages().iterator();

                        while (iterator1.hasNext()) {
                            Village village = (Village) iterator1.next();

                            if (village != this.f && village.a(this.g, this.h, this.i)) {
                                flag = true;
                                break;
                            }
                        }

                        if (flag) {
                            ++i;
                            continue;
                        }
                    }

                    if (flag) {
                        return false;
                    }

                    Vec3D vec3d = this.a(this.g, this.h, this.i);

                    if (vec3d != null) {
                        this.e = 0;
                        this.d = 20;
                        return true;
                    }
                    break;
                }
            }
        }

        return false;
    }

    private boolean c() {
        Vec3D vec3d = this.a(this.g, this.h, this.i);

        if (vec3d == null) {
            return false;
        } else {
            EntityZombie entityzombie;

            try {
                entityzombie = new EntityZombie(this.world);
            } catch (Exception exception) {
                exception.printStackTrace();
                return false;
            }

            entityzombie.setPositionRotation(vec3d.a, vec3d.b, vec3d.c, this.world.random.nextFloat() * 360.0F, 0.0F);
            this.world.addEntity(entityzombie, org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.VILLAGE_INVASION); // CraftBukkit
            ChunkCoordinates chunkcoordinates = this.f.getCenter();

            entityzombie.b(chunkcoordinates.x, chunkcoordinates.y, chunkcoordinates.z, this.f.getSize());
            return true;
        }
    }

    private Vec3D a(int i, int j, int k) {
        for (int l = 0; l < 10; ++l) {
            int i1 = i + this.world.random.nextInt(16) - 8;
            int j1 = j + this.world.random.nextInt(6) - 3;
            int k1 = k + this.world.random.nextInt(16) - 8;

            if (this.f.a(i1, j1, k1) && SpawnerCreature.a(EnumCreatureType.MONSTER, this.world, i1, j1, k1)) {
                return Vec3D.create((double) i1, (double) j1, (double) k1);
            }
        }

        return null;
    }
}