using UnityEngine;

namespace BF
{
    public enum EAssetLoadStatus
    {
        Wait,       //等待加载
        Loading,    //加载中
        Complete,   //加载完成
        Error,      //加载完成，但出现错误
        Unloading,  //卸载过程中
        Unloaded,   //卸载完成
    }

    public abstract class AssetObjectBase
    {
        private static uint IdIndex = 0;

        public uint Id { get; protected set; }

        public string AssetPath { get; protected set; }

        public System.Type AssetType { get; protected set; }

        public uint RefCount { get; protected set; }

        public EAssetLoadStatus LoadStatus { get; set; }

        public Object Asset { get; protected set; }

        protected float unloadCountdownTime;

        public AssetObjectBase(string assetPath, System.Type type)
        {
            Id = ++IdIndex;
            AssetType = type;
            AssetPath = assetPath;
            LoadStatus = EAssetLoadStatus.Wait;
        }

        public virtual bool Tick() { return true; }

        public abstract bool Unload(bool immediately);

        public void UnloadCountdown(bool immediately)
        {
            if (immediately || unloadCountdownTime <= Time.time)
            {
                if (OnUnloadComplete())
                {
                    LoadStatus = EAssetLoadStatus.Unloaded;
                }
            }
        }

        protected abstract bool OnUnloadComplete();

    }
}