using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.Networking;
using UnityEngine.SceneManagement;
using UnityEngine.UI;

public class BundleLoader : MonoBehaviour
{
    public static BundleLoader Instance;

    private void Awake()
    {
        Instance = this;
    }

    #region 预加载碰撞点及展示点
    /// <summary>
    /// 是否从Bundle中动态加载展示点数据
    /// </summary>
    public bool loadSpotsFromBundle;

    /// <summary>
    /// 是否从Bundle中动态加载展示触发点数据
    /// </summary>
    public bool loadTipPointsFromBundle;

    /// <summary>
    /// 展示点数据父对象
    /// </summary>
    public Transform tranMainScene;

    void Start()
    {
        if (loadSpotsFromBundle)
        {
            Invoke("LoadSpots", 0.5f);
        }
        if (loadTipPointsFromBundle)
        {
            Invoke("LoadTipPoints", 0.5f);
        }
    }

    /// <summary>
    /// 加载展示点数据
    /// </summary>
    void LoadSpots()
    {
        LoadBundle("Spots", "Spots" + (Application.isEditor ? "_win" : ""), OnBundleLoaded);
    }
    
    /// <summary>
     /// 加载展示点数据
     /// </summary>
    void LoadTipPoints()
    {
        LoadBundle("TipPoints", "TipPoints" + (Application.isEditor ? "_win" : ""), OnBundleLoaded);
    }

    /// <summary>
    /// 加载结束设置父对象
    /// </summary>
    void OnBundleLoaded()
    {
        CurrentBundleObject.transform.parent = tranMainScene;
    }
    #endregion

    /// <summary>
    /// 动态加载AssetBundle资源
    /// </summary>
    /// <param name="prefabName">预设体名称</param>
    /// <param name="bundleName">AssetBundle资源名称</param>
    /// <param name="BundleLoaded">加载结束事件处理程序</param>
    public void LoadBundle(string prefabName, string bundleName = null, UnityAction BundleLoaded = null)
    {
        if (bundleName == null)
        {
            bundleName = prefabName;
        }

        string path = CommonData.DataServer + "/Bundles/" + bundleName + ".assetbundle";

        StartCoroutine(LoadAssetBundle_Prefab(path, prefabName, BundleLoaded));
    }

    /// <summary>
    /// 当前加载的AssetBundle资源
    /// </summary>
    static GameObject CurrentBundle;

    /// <summary>
    /// 当前加载AssetBundle资源所创建的对象
    /// </summary>
    public static GameObject CurrentBundleObject;

    /// <summary>
    /// 加载进度条
    /// </summary>
    public Slider sliderProgress;

    /// <summary>
    /// 显示进度条
    /// </summary>
    void ShowSlider()
    {
        if (sliderProgress.value != 1)
        {
            sliderProgress.gameObject.SetActive(true);
        }
    }

    /// <summary>
    /// 加载AssetBundle(预设体)
    /// </summary>
    /// <param name="abPath">AssetBundle资源路径</param>
    /// <param name="prefabName">预设体名称</param>
    /// <param name="BundleLoaded">加载结束事件处理程序</param>
    /// <returns></returns>
    IEnumerator LoadAssetBundle_Prefab(string abPath, string prefabName, UnityAction BundleLoaded)
    {
        // Debug.Log(path);
        sliderProgress.value = 0;

        Invoke("ShowSlider", 0.5f);

        // 从网络读取 AssetBundle 文件
        UnityWebRequest www = UnityWebRequestAssetBundle.GetAssetBundle(abPath);
        www.SendWebRequest();

        while (!www.isDone)
        {
            // print("当前的下载进度为：" + www.downloadProgress);
            sliderProgress.value = www.downloadProgress;
            yield return 0;
        }

        sliderProgress.value = 1;
        sliderProgress.gameObject.SetActive(false);

        if (www.result != UnityWebRequest.Result.Success)
        {
            Debug.Log(www.error);
        }
        else
        {
            AssetBundle bundle = DownloadHandlerAssetBundle.GetContent(www);
            // 加载预制体资源
            CurrentBundle = bundle.LoadAsset<GameObject>(prefabName);
            // 实例化预制体
            CurrentBundleObject = Instantiate(CurrentBundle);
            // Destroy(prefab, 5f);

            // 释放 AssetBundle 资源
            bundle.Unload(false);

            if (BundleLoaded != null)
            {
                BundleLoaded();
            }
        }
    }

    /// <summary>
    /// 动态加载AssetBundle资源
    /// </summary>
    /// <param name="prefabName">预设体名称</param>
    /// <param name="bundleName">AssetBundle资源名称</param>
    /// <param name="BundleLoaded">加载结束事件处理程序</param>
    public void LoadScene(string abName, string sceneName, UnityAction BundleLoaded = null)
    {
        string abPath = CommonData.DataServer + "/Bundles/" + abName + ".unity3d";

        StartCoroutine(LoadAssetBundle_Scene(abPath, sceneName, BundleLoaded));
    }

    AssetBundle oldSceneBundle;
    AssetBundle currentSceneBundle;
    string oldSceneName;
    string currentSceneName;
    /// <summary>
    /// 加载AssetBundle(场景)
    /// </summary>
    /// <param name="index">场景索引</param>
    /// <returns></returns>
    public IEnumerator LoadAssetBundle_Scene(string abPath, string sceneName,
        UnityAction BundleLoaded = null, LoadSceneMode mode = LoadSceneMode.Additive)
    {
        sliderProgress.value = 0;
        ShowSlider();
       
        //  Caching.ClearCache();

        UnityWebRequest download = UnityWebRequestAssetBundle.GetAssetBundle(abPath);
        download.SendWebRequest();
        while (!download.isDone)
        {
            sliderProgress.value = download.downloadProgress;
            yield return null;
        }
        yield return download;

        oldSceneBundle = currentSceneBundle;
        currentSceneBundle = DownloadHandlerAssetBundle.GetContent(download);

        // 异步加载场景
        var sceneAsync = SceneManager.LoadSceneAsync(sceneName, LoadSceneMode.Additive);
        currentSceneName = sceneName;
        while (!sceneAsync.isDone)
        {
            yield return null;
        }

        sliderProgress.value = 1;
        sliderProgress.gameObject.SetActive(false);

        if (BundleLoaded != null)
        {
            BundleLoaded();
        }

        oldSceneName = sceneName;
    }

    public void UnLoadOldScene()
    {
        if (oldSceneBundle != null && oldSceneName != null)
        {
            oldSceneBundle.Unload(true);
            SceneManager.UnloadSceneAsync(oldSceneName);
        }
    }

    public void UnLoadCurrentScene()
    {
        if (currentSceneName != null)
        {
            currentSceneBundle.Unload(true);
            SceneManager.UnloadSceneAsync(currentSceneName);
        }
    }

}