package net.minecraft.entity.ai;

import net.minecraft.entity.EntityCreature;
import net.minecraft.entity.EntityLivingBase;
import net.minecraft.util.math.Vec3d;

public class EntityAIMoveTowardsTarget extends EntityAIBase
{
    private final EntityCreature creature;
    private EntityLivingBase targetEntity;
    private double movePosX;
    private double movePosY;
    private double movePosZ;
    private final double speed;

    /**
     * If the distance to the target entity is further than this, this AI task will not run.
     */
    private final float maxTargetDistance;

    public EntityAIMoveTowardsTarget(EntityCreature creature, double speedIn, float targetMaxDistance)
    {
        this.creature = creature;
        this.speed = speedIn;
        this.maxTargetDistance = targetMaxDistance;
        this.setMutexBits(1);
    }

    /**
     * Returns whether the EntityAIBase should begin execution.
     */
    public boolean shouldExecute()
    {
        this.targetEntity = this.creature.getAttackTarget();

        if (this.targetEntity == null)
        {
            return false;
        }
        else if (this.targetEntity.getDistanceSq(this.creature) > (double)(this.maxTargetDistance * this.maxTargetDistance))
        {
            return false;
        }
        else
        {
            Vec3d vec3d = RandomPositionGenerator.findRandomTargetBlockTowards(this.creature, 16, 7, new Vec3d(this.targetEntity.posX, this.targetEntity.posY, this.targetEntity.posZ));

            if (vec3d == null)
            {
                return false;
            }
            else
            {
                this.movePosX = vec3d.x;
                this.movePosY = vec3d.y;
                this.movePosZ = vec3d.z;
                return true;
            }
        }
    }

    /**
     * Returns whether an in-progress EntityAIBase should continue executing
     */
    public boolean shouldContinueExecuting()
    {
        return !this.creature.getNavigator().noPath() && this.targetEntity.isEntityAlive() && this.targetEntity.getDistanceSq(this.creature) < (double)(this.maxTargetDistance * this.maxTargetDistance);
    }

    /**
     * Reset the task's internal state. Called when this task is interrupted by another one
     */
    public void resetTask()
    {
        this.targetEntity = null;
    }

    /**
     * Execute a one shot task or start executing a continuous task
     */
    public void startExecuting()
    {
        this.creature.getNavigator().tryMoveToXYZ(this.movePosX, this.movePosY, this.movePosZ, this.speed);
    }
}
