using Base;
using UnityEngine;

namespace Prefab
{
    [RequireComponent(typeof(SpriteRenderer))]
    public class SpriteAnimator : MonoBehaviour, ITick
    {
        // 公开字段（可在编辑器中设置）
        [SerializeField] private Sprite[] _sprites; // 动画精灵序列
        [SerializeField] private float _fps = 2; // 每秒帧数
        [SerializeField] private Sprite _staticSprite; // 暂停时的静态精灵

        private SpriteRenderer _renderer; // 渲染器组件
        private bool _isPaused; // 暂停状态
        private float _frameTimer; // 帧计时器
        private int _currentFrameIndex; // 当前帧索引

        private void Awake()
        {
            _renderer = GetComponent<SpriteRenderer>();
            ValidateStartFrame();
        }

        // ITick接口实现
        public void Tick()
        {
            var deltaTime=Time.deltaTime;
            if (_isPaused)
            {
                HandlePausedState();
                return;
            }

            PlayAnimation(deltaTime);
        }

        private void ValidateStartFrame()
        {
            // 确保有精灵时可显示有效帧
            if (_sprites != null && _sprites.Length > 0)
            {
                _currentFrameIndex = Mathf.Clamp(_currentFrameIndex, 0, _sprites.Length - 1);
                _renderer.sprite = _sprites[_currentFrameIndex];
            }
            else
            {
                _renderer.sprite = null;
            }
        }

        private void HandlePausedState()
        {
            // 优先使用静态精灵，否则保持当前帧
            if (_staticSprite)
            {
                _renderer.sprite = _staticSprite;
            }
        }

        private void PlayAnimation(float deltaTime)
        {
            if (_sprites == null || _sprites.Length == 0) return;

            // 更新帧计时器
            _frameTimer += deltaTime;
            float frameDuration = 1f / _fps;

            // 检查帧切换条件
            while (_frameTimer >= frameDuration)
            {
                _frameTimer -= frameDuration;
                NextFrame();
            }
        }

        private void NextFrame()
        {
            // 循环播放动画
            _currentFrameIndex = (_currentFrameIndex + 1) % _sprites.Length;
            _renderer.sprite = _sprites[_currentFrameIndex];
        }

        // 外部控制方法
        public void SetPaused(bool paused) => _isPaused = paused;
        public void SetSprites(Sprite[] newSprites) => _sprites = newSprites;
        public void SetFPS(float newFPS) => _fps = Mathf.Max(0.1f, newFPS);
        public void SetStaticSprite(Sprite sprite) => _staticSprite = sprite;
    }
}