//**********************************************//
//作者:#杨全福#
//日期:#2020.02.12#
//简述:#帧动画脚本#
//*********************************************//

using Thousandto.Core.Asset;
using Thousandto.Plugins.Common;
using UnityEngine;

namespace Thousandto.GameUI.Form
{
    public class UIFrameAnimation : MonoCacheBase
    {
        #region//常量
        private const string AtlasName = "UIAnimationAtlas";
        #endregion

        #region//私有变量
        //动画ID，对应Atlas的索引
        private int _curAinmId = 0;
        //当前帧
        private int _curFrame = 0;
        //帧率计时器
        private float _frameTimer = 0f;
        //默认30帧
        private int _frameRate = 30;
        //单帧时间
        private float _oneFrameTime = 1f / 30;
        //使用的sprite
        private UISprite _targetSprite = null;
        //使用的atlas
        private UIAtlas _atlas = null;
        //帧数量
        private int _frameCount = 0;
        //是否循环
        private FrameAnimWrapMode _wrapMode = FrameAnimWrapMode.Once;
        #endregion

        #region//继承基类
        private void OnEnable()
        {
            LoadAtlas();
        }
        private void OnDisable()
        {
            UnLoadAtlas();
        }
        private void OnDestroy()
        {
            UnLoadAtlas();
        }
        private void Update()
        {
            if (_targetSprite == null || _curAinmId <= 0 || _atlas == null || _frameCount <= 0)
                return;
            _frameTimer -= Time.deltaTime;
            if(_frameTimer <= 0)
            {
                SetCurFrame(_curFrame + 1);
            }
        }
        #endregion

        #region//公有函数
        //播放动画
        public void PlayAnim(int animId, int frameRate, FrameAnimWrapMode wrapMode)
        {
            if (animId <= 0)
                return;
            if (frameRate <= 0)
                return;
            if(_targetSprite == null)
                _targetSprite = GetComponent<UISprite>();
            if(_targetSprite == null)
                return;
            if (_curAinmId == animId)
                return;

            //先释放老的
            UnLoadAtlas();

            _curAinmId = animId;
            _frameRate = frameRate;
            _oneFrameTime = 1f / _frameRate;
            _frameTimer = 0f;
            _wrapMode = wrapMode;
            //在加载新的
            LoadAtlas();
        }
        //停止动画
        public void StopAnim()
        {
            UnLoadAtlas();
        }
        #endregion

        #region//私有函数
        //设置当前帧
        private void SetCurFrame(int frame)
        {
            _curFrame = frame;
            var useFrame = 0;
            switch(_wrapMode)
            {
                case FrameAnimWrapMode.Loop:
                    useFrame = _curFrame % _frameCount;
                    break;
                case FrameAnimWrapMode.PingPong:
                    if((_curFrame / _frameCount) % 2 == 0)
                    {
                        useFrame = _curFrame % _frameCount;
                    }
                    else
                    {
                        useFrame = (_frameCount - 1) - (_curFrame % _frameCount);
                    }
                    break;
                default:
                    useFrame = Mathf.Min(_curFrame, _frameCount - 1);
                    break;
            }

            if (_frameTimer < 0)
            {
                _frameTimer = _oneFrameTime + _frameTimer;
            }
            else
            {
                _frameTimer = _oneFrameTime;
            }
            if (_targetSprite != null)
            {
                _targetSprite.spriteName = string.Format("{0}_{1}", _curAinmId, useFrame);
            }
        }
        //加载atlas
        private void LoadAtlas()
        {
            if(_targetSprite == null || _curAinmId <= 0)
                return;
            UIPoolAssetsLoader.LoadAtlasPrefabAsyn(AtlasName, _curAinmId, atlasTrans =>
            {
                if (atlasTrans != null)
                {
                    _atlas = atlasTrans.GetComponent<UIAtlas>();
                    if (null != _atlas)
                    {
                        _targetSprite.atlas = _atlas;
                        _frameCount = _atlas.spriteList.Count;
                        //从第0帧开始播放
                        SetCurFrame(0);
                    }
                }
            });
        }
        //释放atlas
        private void UnLoadAtlas()
        {
            if (_targetSprite == null || _curAinmId <= 0)
                return;
            _targetSprite.atlas = null;
            UIPoolAssetsLoader.UnloadAtlas(AtlasName, _curAinmId, _atlas.transform);
            _curAinmId = 0;
            _atlas = null;
        }
        #endregion
    }
}