LD39/game/Assets/Scripts/Enemy/ChaseBehavior.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

namespace EnemyAI
{
    internal class ChaseBehavior : Behavior
    {
        private const float playerDistanceThreshold = .5f;

        internal override Result Run(ref Blackboard blackboard)
        {
            blackboard.navMeshAgent.isStopped = false;

            if (!blackboard.Night)
            {
                blackboard.navMeshAgent.isStopped = true;
                return Result.Failure;
            }

            if (Vector3.Distance(blackboard.PlayerPosition, blackboard.EnemyPosition) < playerDistanceThreshold)
            {
                //Close enough to player
                return Result.Success;
            }

            //If the player moved so far that re-pathing is necessary
            if (Vector3.Distance(blackboard.PlayerPosition, blackboard.navMeshAgent.destination) > playerDistanceThreshold)
            {
                blackboard.navMeshAgent.destination = blackboard.PlayerPosition;
            }

            return Result.Running;
        }
    }
}