using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class FrameAnimation : MonoBehaviour
{
    [Header("动画设置")]
    [SerializeField] private Sprite[] frameSprites; // 序列帧数组（拖入125张图片）
    [SerializeField] private float totalTime = 5f;  // 总时长
    [SerializeField] private bool loop = true;      // 是否循环播放

    private Image img;
    private int totalFrames;
    private float frameInterval;
    private Coroutine animationCoroutine;

    void Start()
    {
        InitializeComponents();
        ValidateFrameData();
        CalculateFrameInterval();
        StartAnimation();
    }

    void InitializeComponents()
    {
        img = GetComponent<Image>();
        if (img == null)
        {
            img = gameObject.AddComponent<Image>();
        }
    }

    void ValidateFrameData()
    {
        if (frameSprites == null || frameSprites.Length == 0)
        {
            Debug.LogError("请分配序列帧图片！");
            enabled = false;
            return;
        }

        totalFrames = frameSprites.Length;
        if (totalFrames != 125)
        {
            Debug.LogWarning("建议使用125帧获得精确时长，当前帧数：" + totalFrames);
        }
    }

    void CalculateFrameInterval()
    {
        // 计算每帧持续时间（总时长 / 总帧数）
        frameInterval = totalTime / totalFrames;
    }

    public void StartAnimation()
    {
        if (animationCoroutine != null)
        {
            StopCoroutine(animationCoroutine);
        }
        animationCoroutine = StartCoroutine(PlayAnimation());
    }

    IEnumerator PlayAnimation()
    {
        int currentFrame = 0;

        do
        {
            // 更新当前帧
            img.sprite = frameSprites[currentFrame];
            // 等待帧间隔时间
            yield return new WaitForSeconds(frameInterval);

            // 递增帧索引
            currentFrame = (currentFrame + 1) % totalFrames;

        } while (loop || currentFrame != 0); // 循环控制

        animationCoroutine = null;
    }

    void OnDisable()
    {
        if (animationCoroutine != null)
        {
            StopCoroutine(animationCoroutine);
            animationCoroutine = null;
        }
    }

    // 在Inspector修改参数时实时更新
    void OnValidate()
    {
        if (Application.isPlaying && animationCoroutine != null)
        {
            CalculateFrameInterval();
            StartAnimation();
        }
    }
}