import canvasContext from "./canvas-context";
const downloadedTextures = {};
const downloadingTextures = {};
const downloadFailedTextures = {};

let hasCheckSupportedExtensions = false;
//不让外部使用
if(typeof window !='undefined' && window.indexedDB){
  Object.defineProperty(window, 'indexedDB', {
    get() { return; },
    set() {},
    enumerable : true,
    configurable : true
  });
}
const err = function(msg){GameGlobal.manager.printErr(msg)};
const PotList = [1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096];

const UseDXT5 = "$UseDXT5$";

let isStopDownloadTexture = false;
let cachedDownloadTask = [];
wx.stopDownloadTexture = function(){
  isStopDownloadTexture = true;
}

wx.starDownloadTexture = function(){
  isStopDownloadTexture = false;
  while (cachedDownloadTask.length>0){
    var task = cachedDownloadTask.shift();
    mod.WXDownloadTexture(task.path,task.width,task.height,task.callback);
  }
}

const mod = {
  getSupportedExtensions(){
    if(hasCheckSupportedExtensions){
      return GameGlobal.TextureCompressedFormat;
    }
    const list = canvas.getContext(GameGlobal.managerConfig.contextConfig.contextType == 2 ? 'webgl2': 'webgl').getSupportedExtensions();
    if(list.indexOf('WEBGL_compressed_texture_astc')!==-1){
      GameGlobal.TextureCompressedFormat = 'astc';
    }else if(list.indexOf('WEBGL_compressed_texture_etc')!==-1){
      GameGlobal.TextureCompressedFormat = 'etc2';
    }else if(list.indexOf('WEBGL_compressed_texture_pvrtc')!==-1){
      GameGlobal.TextureCompressedFormat = 'pvr';
    }else if(list.indexOf('WEBGL_compressed_texture_s3tc') !==-1 && UseDXT5){
      GameGlobal.TextureCompressedFormat = 'dds';
    }/*else if(list.indexOf('WEBGL_compressed_texture_etc1')!==-1){ //ect1不支持透明通道，先屏蔽
            GameGlobal.TextureCompressedFormat = 'etc1';
        }*/else{
      GameGlobal.TextureCompressedFormat = '';
    }
    if(list.indexOf('WEBGL_compressed_texture_etc')!==-1){
      GameGlobal.TextureEtc2Supported = true;
    }
    if(list.indexOf('WEBGL_compressed_texture_pvrtc')!==-1){
      GameGlobal.TexturePVRTCSupported = true;
    }
    hasCheckSupportedExtensions = true;
    return GameGlobal.TextureCompressedFormat;
  },
  getRemoteImageFile(path,width,height){
    if(!GameGlobal.TextureCompressedFormat || (GameGlobal.TextureCompressedFormat == 'pvr' && (width != height || PotList.indexOf(width)===-1)) || (GameGlobal.TextureCompressedFormat == 'dds' && (width%4!==0 || height%4!==0))){
      mod.downloadFile(path,width,height)
    }else{
      mod.requestFile(path,width,height);
    }
  },
  reTryRemoteImageFile(path,width,height){
    var cid = path;
    if(!downloadFailedTextures[cid]){
      downloadFailedTextures[cid] = {
        count:0,
        path,width,height
      };
    }
    if(downloadFailedTextures[cid].count > 4){
      return;
    }

    setTimeout(()=>{
      mod.getRemoteImageFile(path,width,height)
    }, Math.pow(2,downloadFailedTextures[cid].count) * 250);

    downloadFailedTextures[cid].count++;
  },
  requestFile(path,width,height){
    var cid = path;
    var format = GameGlobal.TextureCompressedFormat;
    var url = GameGlobal.manager.assetPath.replace(/\/$/,'')+'/Textures/'+format+'/'+width+"/"+path+'.txt';
    var xmlhttp = new GameGlobal.unityNamespace.UnityLoader.UnityCache.XMLHttpRequest();
    xmlhttp.responseType = 'arraybuffer';
    xmlhttp.open("GET",url,true);
    xmlhttp.onload = function(){
      let res = xmlhttp;
      if(res.status === 200){
        downloadedTextures[cid] = {
          data:res.response,
          tmpFile:''
        };
        if(downloadingTextures[cid] instanceof Array){
          downloadingTextures[cid].forEach(v=>v());
        }else{
          downloadingTextures[cid] && downloadingTextures[cid]();
        }

        delete downloadingTextures[cid];
        delete downloadFailedTextures[cid];
        delete downloadedTextures[cid].data;
        /*
        const fileManager = wx.getFileSystemManager();
        const tmpFilePath = wx.env.USER_DATA_PATH+"/"+cid+'.txt';
        fileManager.writeFile({
            filePath:tmpFilePath,
            data:res.response,
            success(){
                downloadedTextures[cid].tmpFile = tmpFilePath;
            },
            fail(err){
                console.error(err,"压缩纹理保存失败！id:"+textureId);
                delete GameGlobal.DownloadedTextures[cid]
            }
        }); */
      }else{
        //   err("压缩纹理下载失败！url:"+url);
        mod.reTryRemoteImageFile(path,width,height);
      }
    };
    xmlhttp.onerror = function(){
      //   err("压缩纹理下载失败！url:"+url);
      mod.reTryRemoteImageFile(path,width,height);
    }
    xmlhttp.send(null);
  },
  downloadFile(path,width,height){

    var url = GameGlobal.manager.assetPath.replace(/\/$/,'')+'/Textures/png/'+width+"/"+path+'.png';
    var cid = path;

    var image = wx.createImage();
    image.crossOrigin = '';
    image.src = url;
    image.onload = function () {
      downloadedTextures[cid] = {
        data:image,
        tmpFile:''
      };
      if(downloadingTextures[cid] instanceof Array){
        downloadingTextures[cid].forEach(v=>v());
      }else{
        downloadingTextures[cid] && downloadingTextures[cid]();
      }
      delete downloadingTextures[cid];
      delete downloadFailedTextures[cid];
      delete downloadedTextures[cid];
    };

    image.onerror = function(){
      mod.reTryRemoteImageFile(path,width,height);
    };
  },
  readFile(textureId,callback,width,height){
    var cid = textureId;
    const fileManager = wx.getFileSystemManager();
    const filePath = wx.env.USER_DATA_PATH+"/"+cid+'.txt';
    fileManager.readFile({
      filePath,
      success(res){
        if(!GameGlobal.TextureCompressedFormat){
          var image = wx.createImage();
          image.src = filePath;
          image.onload = function () {
            handleLoaded(image);
            delete downloadedTextures[cid];
          }
        }else{
          handleLoaded();
          delete downloadedTextures[cid].data;
        }
        function handleLoaded(image){
          downloadedTextures[cid] = {
            data:image || res.data,
            tmpFile:filePath
          };
          callback();
        }
      },
      fail(err){
        err(err,"读取压缩纹理失败！id:"+cid);
        handleError();
      }
    });


    function handleError(){
      var path;
      if(type === "Texture"){
        path = GameGlobal.TextureConfig[textureId].p;
      }else{
        path = GameGlobal.SpriteAtlasConfig[textureId].p;
      }
      if(downloadingTextures[cid]){
        downloadingTextures[cid].push(callback);
      }else{
        downloadingTextures[cid] = [callback];
      }
      mod.getRemoteImageFile(textureId,type,path.replace(/\\/g,'/'),width,height);
    }
  },
  WXDownloadTexture(path,width,height,callback){
    if(!hasCheckSupportedExtensions){
      mod.getSupportedExtensions();
    }
    var cid = path;
    /*
    if(downloadedTextures[cid]){
        if(downloadedTextures[cid].data){
            callback();
        }else{
            mod.readFile(id,type,callback,width,height);
        }
    }else */
    if(isStopDownloadTexture){
      cachedDownloadTask.push({
        path,width,height,callback
      });
      return;
    }
    if(downloadingTextures[cid]){
      downloadingTextures[cid].push(callback);
    }else{
      downloadingTextures[cid] = [callback];
      mod.getRemoteImageFile(path,width,height);
    }
  }
};

GameGlobal.DownloadedTextures = downloadedTextures;
GameGlobal.TextureCompressedFormat = ''; //支持的压缩格式

GameGlobal.ParalleLDownloadTexture = function(filename){
  filename = filename.replace(GameGlobal.managerConfig.DATA_CDN,'').replace(/^\//,'');
  filename = "/"+filename;
  if (GameGlobal.TEXTURE_BUNDLES[filename]) {
    GameGlobal.TEXTURE_BUNDLES[filename].forEach(function (v) {
      var f = GameGlobal.TextureCompressedFormat;
      if (!f) {
        var p = GameGlobal.manager.assetPath + '/Textures/png/' + v.w + '/' + v.p + '.png';
        var image = wx.createImage();
        image.crossOrigin = '';
        image.src = p
      } else if (f != 'pvr') {
        var http = new GameGlobal.unityNamespace.UnityLoader.UnityCache.XMLHttpRequest();
        var p = GameGlobal.manager.assetPath + '/Textures/' + f + '/' + v.w + '/' + v.p + '.txt';
        http.open('GET', p, true);
        http.responseType = 'arraybuffer';
        http.send()
      }
    })
  }
}


export default {
  WXDownloadTexture:mod.WXDownloadTexture
}


canvasContext.addCreatedListener(()=>{
  if(GameGlobal.USED_TEXTURE_COMPRESSION){
    mod.getSupportedExtensions();
    if(GameGlobal.TextureCompressedFormat == '' || GameGlobal.TextureCompressedFormat == "pvr"){
      wx.getSystemInfo({
        success(res){
          if(res.platform == 'ios'){
            wx.showModal({
              title: '提示',
              content: "当前操作系统版本过低，建议您升级至最新版本。",
            });
          }
        }
      });
    }
  }
  wx.onNetworkStatusChange(function(res){
    if(res.isConnected){
      for(var key in downloadFailedTextures){
        var v = downloadFailedTextures[key];
        if(v.count >4){
          mod.getRemoteImageFile(v.path,v.width,v.height)
        }
      }
    }
  });
});