package net.minecraft.entity.ai;

import net.minecraft.entity.EntityCreature;
import net.minecraft.entity.EntityLivingBase;
import net.minecraft.util.Vec3;

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

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

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

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

        if (this.targetEntity == null)
        {
            return false;
        }
        else if (this.targetEntity.getDistanceSqToEntity(this.theEntity) > (double)(this.maxTargetDistance * this.maxTargetDistance))
        {
            return false;
        }
        else
        {
            Vec3 vec3 = RandomPositionGenerator.findRandomTargetBlockTowards(this.theEntity, 16, 7, new Vec3(this.targetEntity.posX, this.targetEntity.posY, this.targetEntity.posZ));

            if (vec3 == null)
            {
                return false;
            }
            else
            {
                this.movePosX = vec3.xCoord;
                this.movePosY = vec3.yCoord;
                this.movePosZ = vec3.zCoord;
                return true;
            }
        }
    }

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

    /**
     * Resets the task
     */
    public void resetTask()
    {
        this.targetEntity = null;
    }

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