(function () {
  let iatWS;
  let resultText = "";
  let resultTextTemp = "";

  /**
   * 获取websocket url
   * 该接口需要后端提供，这里为了方便前端处理
   */
  function getWebSocketUrl() {
    // 请求地址根据语种不同变化
    var url = "wss://iat-api.xfyun.cn/v2/iat";
    var host = "iat-api.xfyun.cn";
    var apiKey = API_KEY;
    var apiSecret = API_SECRET;
    var date = new Date().toGMTString();
    var algorithm = "hmac-sha256";
    var headers = "host date request-line";
    var signatureOrigin = `host: ${host}\ndate: ${date}\nGET /v2/iat HTTP/1.1`;
    var signatureSha = CryptoJS.HmacSHA256(signatureOrigin, apiSecret);
    var signature = CryptoJS.enc.Base64.stringify(signatureSha);
    var authorizationOrigin = `api_key="${apiKey}", algorithm="${algorithm}", headers="${headers}", signature="${signature}"`;
    var authorization = btoa(authorizationOrigin);
    url = `${url}?authorization=${authorization}&date=${date}&host=${host}`;
    return url;
  }

  function toString(buffer) {
    var binary = "";
    var bytes = new Uint8Array(buffer);
    var len = bytes.byteLength;
    for (var i = 0; i < len; i++) {
      binary += String.fromCharCode(bytes[i]);
    }
    return binary;
  }

  function renderResult(resultData) {
    // 识别结束
    let jsonData = JSON.parse(resultData);
    if (jsonData.data && jsonData.data.result) {
      let data = jsonData.data.result;
      let str = "";
      let ws = data.ws;
      for (let i = 0; i < ws.length; i++) {
        str = str + ws[i].cw[0].w;
      }
      // 开启wpgs会有此字段(前提：在控制台开通动态修正功能)
      // 取值为 "apd"时表示该片结果是追加到前面的最终结果；取值为"rpl" 时表示替换前面的部分结果，替换范围为rg字段
      if (data.pgs) {
        if (data.pgs === "apd") {
          // 将resultTextTemp同步给resultText
          resultText = resultTextTemp;
        }
        // 将结果存储在resultTextTemp中
        resultTextTemp = resultText + str;
      } else {
        resultText = resultText + str;
      }
      document.getElementById("result").innerText =
        resultTextTemp || resultText || "";
    }
    if (jsonData.code === 0 && jsonData.data.status === 2) {
      iatWS.close();
    }
    if (jsonData.code !== 0) {
      iatWS.close();
      console.error(jsonData);
    }
  }

  function connectWebSocket(callback) {
    const websocketUrl = getWebSocketUrl();
    if ("WebSocket" in window) {
      iatWS = new WebSocket(websocketUrl);
    } else if ("MozWebSocket" in window) {
      iatWS = new MozWebSocket(websocketUrl);
    } else {
      alert("浏览器不支持WebSocket");
      return;
    }
    iatWS.onopen = (e) => {
      var params = {
        common: {
          app_id: APPID,
        },
        business: {
          language: "zh_cn",
          domain: "iat",
          accent: "mandarin",
          vad_eos: 5000,
          dwa: "wpgs",
        },
        data: {
          status: 0,
          format: "audio/L16;rate=16000",
          encoding: "raw",
        },
      };
      iatWS.send(JSON.stringify(params));
      callback();
    };
    iatWS.onmessage = (e) => {
      renderResult(e.data);
    };
    iatWS.onerror = (e) => {
      console.error(e);
    };
  }

  document.getElementById("input_file").onchange = (e) => {
    if (e.target.files[0]) {
      connectWebSocket(() => {
        const reader = new FileReader();
        reader.readAsArrayBuffer(e.target.files[0]);
        
        reader.onload = (evt) => {
          console.log(evt.target.result);
          const audioString = toString(evt.target.result)
          // console.log(audioString.length, evt.target.result.byteLength)
          let offset = 0;

          while(offset < audioString.length) {
            const subString = audioString.substring(offset, offset + 1280)
            offset += 1280
            // console.log(subString.length, subString)
            const isEnd = offset >= audioString.length
            iatWS.send(
              JSON.stringify({
                data: {
                  status: isEnd ? 2 : 1,
                  format: "audio/L16;rate=16000",
                  encoding: "raw",
                  audio: window.btoa(subString)
                },
              })
            );
          }
          // const interval = setInterval(() => {
          //   const subString = audioString.substring(offset, offset + 1280)
          //   offset += 1280
          //   // console.log(subString.length, subString)
          //   const isEnd = offset >= audioString.length
          //   iatWS.send(
          //     JSON.stringify({
          //       data: {
          //         status: isEnd ? 2 : 1,
          //         format: "audio/L16;rate=16000",
          //         encoding: "raw",
          //         audio: window.btoa(subString)
          //       },
          //     })
          //   );
          //   if (isEnd) {
          //     clearInterval(interval)
          //   }
          // }, 20)
          
        };
        reader.onerror = () => {
          iatWS.close();
        };
      });
    }
  };
})();