using Core.Health;
using UnityEngine;

namespace ActionGameFramework.Health
{
    /// <summary>
    /// A simple class for identifying enemies
    /// </summary>
    public class Targetable : DamageableBehaviour
    {
        /// <summary>
        /// The transform that will be targeted
        /// </summary>
        public Transform targetTransform;

        /// <summary>
        /// The position of the object
        /// </summary>
        protected Vector3 m_CurrentPosition, m_PreviousPosition;

        /// <summary>
        /// The velocity of the rigidbody
        /// </summary>
        public virtual Vector3 velocity { get; protected set; }

        /// <summary>
        /// 用于确认具体是哪一方的Agent.
        /// </summary>
        public bool opponentAgent { set; get; }

        /// <summary>
        /// The transform that objects target, which falls back to this object's transform if not set
        /// </summary>
        public Transform targetableTransform
        {
            get
            {
                return targetTransform == null ? transform : targetTransform;
            }
        }

        /// <summary>
        /// Returns our targetable's transform position
        /// </summary>
        public override Vector3 position
        {
            get { return targetableTransform.position; }
        }

        protected int mLiveID = 0;
        /// <summary>
        /// 用于判断延迟攻击的时候，是否是同一个Agent.
        /// </summary>
        public int liveID
        {
            protected set
            {
                mLiveID = value;
            }
            get { return this.mLiveID; }
        }

        /// <summary>
        /// Initialises any DamageableBehaviour logic
        /// </summary>
        protected override void Awake()
        {
            base.Awake();
            ResetPositionData();
        }

        /// <summary>
        /// Sets up the position data so velocity can be calculated
        /// </summary>
        protected void ResetPositionData()
        {
            m_CurrentPosition = position;
            m_PreviousPosition = position;
        }

        /// <summary>
        /// Calculates the velocity and updates the position
        /// </summary>
        void FixedUpdate()
        {
            m_CurrentPosition = position;
            velocity = (m_CurrentPosition - m_PreviousPosition) / Time.fixedDeltaTime;
            m_PreviousPosition = m_CurrentPosition;
        }
    }
}