var cmd1 = "FE FE FE 7C 00 09 01 ff ff 00 00 00 00 ** ** 16";
var cmd2 = "FE FE FE 7C 00 09 02 00 FF 00 01 00 00 ** ** 16";
var cmd3 = "FE FE FE 7C 00 18 03 00 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 00 00 00 00 ** ** 16";
var cmd4 = "FE FE FE 7C 00 09 04 00 FF 00 01 00 00 ** ** 16";
var startWith = "FE FE FE 7C";



function getCmd(msg){
   var mingling = msg.type;
   var sendMsg = '';
   switch(mingling) {
    case '01':
       console.log("开始请求第一条通信协议");
       sendMsg = getSendMsg(mingling,"ff ff"," 00 00 00 00");
       break;
    case '02':
        console.log("开始请求第二条通信协议");
        sendMsg = getSendMsg(mingling,"00 ff 00 01"," 00 00 00 00");
       break;
    case '03':
        console.log("开始请求第三条通信协议");
        sendMsg = getSendMsg(mingling,msg.sbid);
        break;
    case '04':
        console.log("开始请求第四条通信协议");
        sendMsg = getSendMsg(mingling,msg.sbid);
        break;
    default:
    } 
    console.log(sendMsg);
}

/**
 * 数字转16进制码
 * @param {*} num 
 */
function toHex16(num){
    console.log("dayin"+num)
    var hex  = num.toString(16).toUpperCase();
    var length = hex.length;
    switch(length){
        case 1:
            hex = "00 "+"0"+hex;
        break;
        case 2:
            hex = "00 "+hex;
        break;
        case 3:
            hex = "0 "+hex;
            hex = hex.substring(0, 2) + hex.substring(2, 4);
        break;
        case 4:
            hex = hex.substring(0, 2) +" "+ hex.substring(2, 4);
        break;
        default:
        break;
    }
    console.log(hex);
    return hex;
}

/**
 * 检查是否是Hex
 * @param {*} dataStr 
 */
function checkHexStr(dataStr) {
    dataStr = dataStr.replace(/\s/g, "");
    if (dataStr.length % 2 != 0) {
        return "";
    }
    if (/[0-9A-Fa-f]/g.test(dataStr)) {
        return dataStr;
    }
    return "";
}

/**
 * 组装发送数据
 * @param {*} mingling 
 * @param {*} sbid 
 */
function getSendMsg(mingling,sbid,mess){
    var cmd = mingling+" "+sbid+mess;
    var length = toHex16(cmd.split(" ").length);
    cmd = length +" "+cmd;
    var crc = CRC.ToModbusCRC16(cmd,false);
    cmd = startWith+" "+cmd+" "+crc.substring(0, 2) +" "+ crc.substring(2, 4)+" 16";
    return cmd;
}

function bin_to_hex(str) {
    let hex_array = [{key:0,val:"0000"},{key:1,val:"0001"},{key:2,val:"0010"},{key:3,val:"0011"},{key:4,val:"0100"},{key:5,val:"0101"},{key:6,val:"0110"},{key:7,val:"0111"},
        {key:8,val:"1000"},{key:9,val:"1001"},{key:'a',val:"1010"},{key:'b',val:"1011"},{key:'c',val:"1100"},{key:'d',val:"1101"},{key:'e',val:"1110"},{key:'f',val:"1111"}]
    let value = '';
    let list=[];
    if(str.length%4!==0){
        let a = "0000"
        let b=a.substring(0,4-str.length%4)
        str = b.concat(str)
    }
    while (str.length > 4) {
        list.push(str.substring(0, 4))
        str = str.substring(4);
    }
    list.push(str);
    for(let i=0;i<list.length;i++){
        for(let j=0;j<hex_array.length;j++){
            if(list[i]==hex_array[j].val){
                value = value.concat(hex_array[j].key)
                break
            }
        }
    }
    return value;
}

//ASCII码转16进制
function strToHexCharCode(str) {
    if (str === "") {
        return "";
    } else {
        var hexCharCode = [];
        hexCharCode.push("0x");
        for (var i = 0; i < str.length; i++) {
            hexCharCode.push((str.charCodeAt(i)).toString(16));
        }
        return hexCharCode.join("");
    }
}
//十六进制转ASCII码
function hexCharCodeToStr(hexCharCodeStr) {
    var trimedStr = hexCharCodeStr.trim();
    var rawStr = trimedStr.substr(0, 2).toLowerCase() === "0x" ? trimedStr.substr(2) : trimedStr;
    var len = rawStr.length;
    if (len % 2 !== 0) {
        alert("存在非法字符!");
        return "";
    }
    var curCharCode;
    var resultStr = [];
    for (var i = 0; i < len; i = i + 2) {
        curCharCode = parseInt(rawStr.substr(i, 2), 16);
        resultStr.push(String.fromCharCode(curCharCode));
    }
    return resultStr.join("");
}

var CRC = {};

CRC.CRC16 = function (data) {
    var len = data.length;
    if (len > 0) {
        var crc = 0xFFFF;

        for (var i = 0; i < len; i++) {
            crc = (crc ^ (data[i]));
            for (var j = 0; j < 8; j++) {
                crc = (crc & 1) != 0 ? ((crc >> 1) ^ 0xA001) : (crc >> 1);
            }
        }
        var hi = ((crc & 0xFF00) >> 8);  //高位置
        var lo = (crc & 0x00FF);         //低位置

        return [hi, lo];
    }
    return [0, 0];
};

CRC.isArray = function (arr) {
    return Object.prototype.toString.call(arr) === '[object Array]';
};

CRC.ToCRC16 = function (str, isReverse) {
    return CRC.toString(CRC.CRC16(CRC.isArray(str) ? str : CRC.strToByte(str)), isReverse);
};

CRC.ToModbusCRC16 = function (str, isReverse) {
    return CRC.toString(CRC.CRC16(CRC.isArray(str) ? str : CRC.strToHex(str)), isReverse);
};

CRC.strToByte = function (str) {
    var tmp = str.split(''), arr = [];
    for (var i = 0, c = tmp.length; i < c; i++) {
        var j = encodeURI(tmp[i]);
        if (j.length == 1) {
            arr.push(j.charCodeAt());
        } else {
            var b = j.split('%');
            for (var m = 1; m < b.length; m++) {
                arr.push(parseInt('0x' + b[m]));
            }
        }
    }
    return arr;
};

CRC.convertChinese = function (str) {
    var tmp = str.split(''), arr = [];
    for (var i = 0, c = tmp.length; i < c; i++) {
        var s = tmp[i].charCodeAt();
        if (s <= 0 || s >= 127) {
            arr.push(s.toString(16));
        }
        else {
            arr.push(tmp[i]);
        }
    }
    return arr;
};

CRC.filterChinese = function (str) {
    var tmp = str.split(''), arr = [];
    for (var i = 0, c = tmp.length; i < c; i++) {
        var s = tmp[i].charCodeAt();
        if (s > 0 && s < 127) {
            arr.push(tmp[i]);
        }
    }
    return arr;
};

CRC.strToHex = function (hex, isFilterChinese) {
    hex = isFilterChinese ? CRC.filterChinese(hex).join('') : CRC.convertChinese(hex).join('');

    //清除所有空格
    hex = hex.replace(/\s/g, "");
    //若字符个数为奇数，补一个0
    hex += hex.length % 2 != 0 ? "0" : "";

    var c = hex.length / 2, arr = [];
    for (var i = 0; i < c; i++) {
        arr.push(parseInt(hex.substr(i * 2, 2), 16));
    }
    return arr;
};

CRC.padLeft = function (s, w, pc) {
    if (pc == undefined) {
        pc = '0';
    }
    for (var i = 0, c = w - s.length; i < c; i++) {
        s = pc + s;
    }
    return s;
};

CRC.toString = function (arr, isReverse) {
    if (typeof isReverse == 'undefined') {
        isReverse = true;
    }
    var hi = arr[0], lo = arr[1];
    return CRC.padLeft((isReverse ? hi + lo * 0x100 : hi * 0x100 + lo).toString(16).toUpperCase(), 4, '0');
};