package net.minecraft.world.entity.ai.goal;

import java.util.EnumSet;
import net.minecraft.core.BlockPos;
import net.minecraft.world.entity.PathfinderMob;
import net.minecraft.world.level.LevelReader;

public abstract class MoveToBlockGoal extends Goal {
	private static final int GIVE_UP_TICKS = 1200;
	private static final int STAY_TICKS = 1200;
	private static final int INTERVAL_TICKS = 200;
	protected final PathfinderMob mob;
	public final double speedModifier;
	/**
	 * Controls task execution delay
	 */
	protected int nextStartTick;
	protected int tryTicks;
	private int maxStayTicks;
	/**
	 * Block to move to
	 */
	protected BlockPos blockPos = BlockPos.ZERO;
	private boolean reachedTarget;
	private final int searchRange;
	private final int verticalSearchRange;
	protected int verticalSearchStart;

	public MoveToBlockGoal(PathfinderMob mob, double speedModifier, int searchRange) {
		this(mob, speedModifier, searchRange, 1);
	}

	public MoveToBlockGoal(PathfinderMob mob, double speedModifier, int searchRange, int verticalSearchRange) {
		this.mob = mob;
		this.speedModifier = speedModifier;
		this.searchRange = searchRange;
		this.verticalSearchStart = 0;
		this.verticalSearchRange = verticalSearchRange;
		this.setFlags(EnumSet.of(Goal.Flag.MOVE, Goal.Flag.JUMP));
	}

	@Override
	public boolean canUse() {
		if (this.nextStartTick > 0) {
			this.nextStartTick--;
			return false;
		} else {
			this.nextStartTick = this.nextStartTick(this.mob);
			return this.findNearestBlock();
		}
	}

	protected int nextStartTick(PathfinderMob creature) {
		return reducedTickDelay(200 + creature.getRandom().nextInt(200));
	}

	@Override
	public boolean canContinueToUse() {
		return this.tryTicks >= -this.maxStayTicks && this.tryTicks <= 1200 && this.isValidTarget(this.mob.level(), this.blockPos);
	}

	@Override
	public void start() {
		this.moveMobToBlock();
		this.tryTicks = 0;
		this.maxStayTicks = this.mob.getRandom().nextInt(this.mob.getRandom().nextInt(1200) + 1200) + 1200;
	}

	protected void moveMobToBlock() {
		this.mob.getNavigation().moveTo(this.blockPos.getX() + 0.5, this.blockPos.getY() + 1, this.blockPos.getZ() + 0.5, this.speedModifier);
	}

	public double acceptedDistance() {
		return 1.0;
	}

	protected BlockPos getMoveToTarget() {
		return this.blockPos.above();
	}

	@Override
	public boolean requiresUpdateEveryTick() {
		return true;
	}

	@Override
	public void tick() {
		BlockPos blockPos = this.getMoveToTarget();
		if (!blockPos.closerToCenterThan(this.mob.position(), this.acceptedDistance())) {
			this.reachedTarget = false;
			this.tryTicks++;
			if (this.shouldRecalculatePath()) {
				this.mob.getNavigation().moveTo(blockPos.getX() + 0.5, blockPos.getY(), blockPos.getZ() + 0.5, this.speedModifier);
			}
		} else {
			this.reachedTarget = true;
			this.tryTicks--;
		}
	}

	public boolean shouldRecalculatePath() {
		return this.tryTicks % 40 == 0;
	}

	protected boolean isReachedTarget() {
		return this.reachedTarget;
	}

	/**
	 * Searches and sets new destination block and returns true if a suitable block (specified in {@link #isValidTarget(net.minecraft.world.level.LevelReader, net.minecraft.core.BlockPos)}) can be found.
	 */
	protected boolean findNearestBlock() {
		int i = this.searchRange;
		int j = this.verticalSearchRange;
		BlockPos blockPos = this.mob.blockPosition();
		BlockPos.MutableBlockPos mutableBlockPos = new BlockPos.MutableBlockPos();

		for (int k = this.verticalSearchStart; k <= j; k = k > 0 ? -k : 1 - k) {
			for (int l = 0; l < i; l++) {
				for (int m = 0; m <= l; m = m > 0 ? -m : 1 - m) {
					for (int n = m < l && m > -l ? l : 0; n <= l; n = n > 0 ? -n : 1 - n) {
						mutableBlockPos.setWithOffset(blockPos, m, k - 1, n);
						if (this.mob.isWithinRestriction(mutableBlockPos) && this.isValidTarget(this.mob.level(), mutableBlockPos)) {
							this.blockPos = mutableBlockPos;
							return true;
						}
					}
				}
			}
		}

		return false;
	}

	/**
	 * Return {@code true} to set given position as destination
	 */
	protected abstract boolean isValidTarget(LevelReader level, BlockPos pos);
}