using System;
using System.Collections;
using UnityEngine;
using UnityEngine.AddressableAssets;
using UnityEngine.ResourceManagement.AsyncOperations;
using UnityEngine.UI;

public class DownAddress : MonoBehaviour
{
    public string preloadLabel = "XJMH";
    public Image image;

    public void Awake()
    {
        image = GetComponent<Image>();
    }

    public void XZ()
    {
        StartCoroutine(StartDownload());
    }

    IEnumerator StartDownload()
    {
        // 1. 获取大小
        long size = 0;
        yield return DownloadManager.Instance.GetSize(preloadLabel, s => size = s);

        if (size <= 0)
        {
            Debug.Log("无需下载");
            yield break;
        }

        Debug.Log($"需要下载 {size / 1024f / 1024f:F2} MB");

        // 2. 下载
        yield return DownloadManager.Instance.DownloadLabel(
            preloadLabel,
            progress =>
            {
                image.fillAmount = progress;
            },
            success =>
            {
                Debug.Log(success ? "下载完成" : "下载失败");
            }
        );
    }
}


public class DownloadManager : Singleton<DownloadManager>
{
    /// <summary>
    /// 获取某个 Label 的下载大小（字节）
    /// </summary>
    public IEnumerator GetSize(string label, Action<long> callback)
    {
        var handle = Addressables.GetDownloadSizeAsync(label);
        yield return handle;

        long size = 0;

        if (handle.Status == AsyncOperationStatus.Succeeded)
            size = handle.Result;
        else
            Debug.LogError($"GetSize 失败：{label}");

        callback?.Invoke(size);

        Addressables.Release(handle);
    }

    /// <summary>
    /// 下载某个 Label 的所有资源
    /// </summary>
    public IEnumerator DownloadLabel(string label, Action<float> onProgress, Action<bool> onFinished)
    {
        // 不要自动释放
        var handle = Addressables.DownloadDependenciesAsync(label, false);

        while (!handle.IsDone)
        {
            onProgress?.Invoke(handle.PercentComplete);
            yield return null;
        }

        bool success = handle.Status == AsyncOperationStatus.Succeeded;

        if (!success)
            Debug.LogError($"下载失败：{label}");

        onFinished?.Invoke(success);

        Addressables.Release(handle);
    }
}