import request from '@/utils/request';
// 新增：存储全局串口和读取器实例
    let port = null;
    let reader = null;
    let accumulatedData = ""; // 移到全局，便于关闭时重置
    let weightList = []; // 用于存储重量值的列表

    async function sendWeightsToBackend(weights) {
      try {
        // 使用 await 等待 request 函数返回结果
        const response = await request({
          url: "/weight/handleWeights",
          method: "POST",
          data: weights, // 通常 request 函数使用 data 字段传递数据
        });
        // 根据 request 函数的实现判断响应是否成功
        if (response.code !== 200) { // 假设 response 有 code 字段，200 表示成功
          throw new Error(`Backend response error: ${response.message}`);
        }
        return response.data; // 假设响应数据在 data 字段中
      } catch (error) {
        console.error('发送重量数据到后端失败:', error);
        throw error;
      }
    }

    async function connect() {
        try {
          port = await navigator.serial.requestPort(); // 修改为全局变量
          await port.open({ baudRate: 9600 });

          reader = port.readable.getReader(); // 修改为全局变量
          const decoder = new TextDecoder();
          accumulatedData = ""; // 重置累积数据

          console.log("串口连接成功，开始接收数据...");

          while (true) {
            const { value, done } = await reader.read();
            if (done) break;

            const decodedChunk = decoder.decode(value, { stream: true });
            accumulatedData += decodedChunk;
            console.log("接收到数据块:", decodedChunk);

            processAccumulatedData(accumulatedData);
          }
        } catch (error) {
          console.error("串口错误:", error);
        }
    }
      function processAccumulatedData(data) {

        if (data.includes("\n")) {
          const messages = data.split("\n");

          for (let i = 0; i < messages.length - 1; i++) {
            const completeMessage = messages[i];
            console.log("完整消息:", completeMessage);
            // 提取数值
            const weightValue = extractWeightValue(completeMessage);
            if (!isNaN(weightValue)) {
              console.log("提取的重量值:", weightValue); 
              // 将有效重量值添加到列表
              weightList.push(weightValue);

              // 当列表长度达到 6 时，发送数据到后端并清空列表
              if (weightList.length === 6) { 
                sendWeightsToBackend({
                  weights: weightList
                })
                .then(() => {
                  console.log('数据发送成功');
                  weightList = [];
                })
                .catch(() => {
                  console.log('发送失败，保留数据待重试');
                });
              }
            }
          }

          accumulatedData = messages[messages.length - 1];
        }

        // 其他消息拆分示例保持不变
        /*
        while (accumulatedData.length >= 32) {
          const message = accumulatedData.substring(0, 32);
          accumulatedData = accumulatedData.substring(32);
          handleMessage(message);
        }
        */

        /*
        let startIndex = 0;
        while (true) {
          const start = accumulatedData.indexOf(0xAA, startIndex);
          if (start === -1) break;
          
          const end = accumulatedData.indexOf(0x55, start + 1);
          if (end === -1) break;
          
          const message = accumulatedData.substring(start, end + 1);
          accumulatedData = accumulatedData.substring(end + 1);
          handleMessage(message);
          startIndex = start;
        }
        */
      }
    }
    // 新增提取重量数值的方法
    function extractWeightValue(message) {
      // 匹配数值部分，可处理正负号
      const match = message.match(/-?\d+\.?\d*/); 
      if (match) {
        return parseFloat(match[0]);
      }
      return NaN;
    }

    // 新增：关闭连接函数
    async function disconnect() {
      if (!port || !reader) {
        console.log("未建立连接，无需关闭");
        return;
      }

      try {
        // 先取消读取器
        await reader.cancel();
        // 再关闭串口
        await port.close();
        console.log("串口连接已关闭");

        // 重置全局变量
        port = null;
        reader = null;
        accumulatedData = "";
      } catch (error) {
        console.error("关闭连接失败:", error);
      }
    }

    export { connect, disconnect,weightList };