--[[
--provide CRC16, base64 encode/decode--
local dyutils=require("dyutils")
--provide bitwise--
local bit=require("bit")
--provide bpack/bunpack--
local lpack=require("lua_pack")
--provide json encode/decode--
local cjson=require("cjson")
require("base64")
]]--
syslog.openlog("DLT645", syslog.LOG_PERROR + syslog.LOG_ODELAY, "LOG_USER")
function protocol_encode(json_str, len)
    local err_code=0
    --取出入参--
    local obj=cjson.decode(json_str)
    local id=obj.identifier
    local term_addr_str=''
    for i=#obj.term_addr-1,1,-2 do
       term_addr_str=term_addr_str .. string.char(tonumber(string.sub(obj.term_addr, i, i+1),16))
    end
    --编码--
    local data_id=''
    local format="C1AC3<I1"
    local data_str=''
    if (id == 'GetTotalElectricEnergy') then
        data_id=0x00000000+0x33333333
        format="C1AC3<I1"
        data_str=bpack(format, 0x68, term_addr_str, 0x68, 0x11, 0x04, data_id)
    elseif (id == 'GetTotalForwardElectricEnergy') then
        data_id=0x00010000+0x33333333
        format="C1AC3<I1"
        data_str=bpack(format, 0x68, term_addr_str, 0x68, 0x11, 0x04, data_id)
    elseif (id == 'GetTotalReverseElectricEnergy') then
        data_id=0x00020000+0x33333333
        format="C1AC3<I1"
        data_str=bpack(format, 0x68, term_addr_str, 0x68, 0x11, 0x04, data_id)
    elseif (id == 'GetVoltageA') then
        data_id=0x02010100+0x33333333
        format="C1AC3<I1"
        data_str=bpack(format, 0x68, term_addr_str, 0x68, 0x11, 0x04, data_id)
    elseif (id == 'GetVoltageB') then
        data_id=0x02010200+0x33333333
        format="C1AC3<I1"
        data_str=bpack(format, 0x68, term_addr_str, 0x68, 0x11, 0x04, data_id)
    elseif (id == 'GetVoltageC') then
        data_id=0x02010300+0x33333333
        format="C1AC3<I1"
        data_str=bpack(format, 0x68, term_addr_str, 0x68, 0x11, 0x04, data_id)
    elseif (id == 'GetCurrentA') then
        data_id=0x02020100+0x33333333
        format="C1AC3<I1"
        data_str=bpack(format, 0x68, term_addr_str, 0x68, 0x11, 0x04, data_id)
    elseif (id == 'GetCurrentB') then
        data_id=0x02020200+0x33333333
        format="C1AC3<I1"
        data_str=bpack(format, 0x68, term_addr_str, 0x68, 0x11, 0x04, data_id)
    elseif (id == 'GetCurrentC') then
        data_id=0x02020300+0x33333333
        format="C1AC3<I1"
        data_str=bpack(format, 0x68, term_addr_str, 0x68, 0x11, 0x04, data_id)
    elseif (id == 'GetActivePowerA') then
        data_id=0x02030100+0x33333333
        format="C1AC3<I1"
        data_str=bpack(format, 0x68, term_addr_str, 0x68, 0x11, 0x04, data_id)
    elseif (id == 'GetActivePowerB') then
        data_id=0x02030200+0x33333333
        format="C1AC3<I1"
        data_str=bpack(format, 0x68, term_addr_str, 0x68, 0x11, 0x04, data_id)
    elseif (id == 'GetActivePowerC') then
        data_id=0x02030300+0x33333333
        format="C1AC3<I1"
        data_str=bpack(format, 0x68, term_addr_str, 0x68, 0x11, 0x04, data_id)
    elseif (id == 'GetAddr') then
        format="C1AC3"
        local term_addr="\170\170\170\170\170\170"
        data_str=bpack(format, 0x68, term_addr, 0x68, 0x13, 0x00)
    else
        return -1,nil,0
    end
    local crc=0
    for i=1, #data_str do
        crc = bit.band(crc + string.byte(string.sub(data_str,i,i)), 0xFF)
    end
    format="AC2"
    local bin_str=bpack(format, data_str, crc, 0x16)
    --出参格式化--
    local t_str=''
    for i=1, #bin_str do
        t_str= t_str .. (string.format("%02X", string.byte(string.sub(bin_str, i, i))))
    end
    bin_str=t_str
    --print("encode", err_code, bin_str, #bin_str)
    return err_code, bin_str, #bin_str
  end
  function protocol_decode(input_str, len)
    local err_code=0
    syslog.syslog("LOG_WARNING","==============" .. input_str)
    --取出入参--
    local obj={}
    local input_obj=cjson.decode(input_str)
    local bin_str=input_obj.raw_data
    local id=input_obj.identifier
    --入参中的raw_data的二进制转换--
    local t_str=''
    for i=1,#bin_str,2 do
       t_str=t_str .. string.char(tonumber(string.sub(bin_str, i, i+1),16))
    end
    bin_str=t_str
    --分割位域--
    if string.sub(bin_str,1,4) == string.char(0xFE,0xFE,0xFE,0xFE) then
        bin_str = string.sub(bin_str,5,#bin_str)
    end
    local format="C1A6C3<I2C2"
    if (id == 'GetTotalElectricEnergy' or
        id == 'GetTotalForwardElectricEnergy' or
        id == 'GetTotalReverseElectricEnergy') then
        format="C1A6C3<I1C6"
        _,_,addr,_,control,length,data_id,data1,data2,data3,data4,crc,_=bunpack(bin_str,format)
    elseif (id == 'GetVoltageA' or
        id == 'GetVoltageB' or
        id == 'GetVoltageC') then
        format="C1A6C3<I1C4"
        _,_,addr,_,control,length,data_id,data1,data2,crc,_=bunpack(bin_str,format)
        data3=0
        data4=0
    elseif (id == 'GetActivePowerA' or
            id == 'GetActivePowerB' or
            id == 'GetActivePowerC' or
            id == 'GetCurrentA' or
            id == 'GetCurrentB' or
            id == 'GetCurrentC') then
        format="C1A6C3<I1C5"
        _,_,addr,_,control,length,data_id,data1,data2,data3,crc,_=bunpack(bin_str,format)
        data4=0
    elseif (id == 'GetAddr') then
        format="C1A6C3A6C2"
        _,_,addr,_,control,length,data1,crc,_=bunpack(bin_str,format)
        data1=0
        data2=0
        data3=0
        data4=0
    else
        return -1,nil,0
    end
    if ((id ~= "GetAddr" and control ~= 0x91) or (id == "GetAddr" and control ~= 0x93)) then
        return -2,nil,0
    end
    local calc_crc=0
    for i=1,#bin_str-2 do
        calc_crc = bit.band(calc_crc + string.byte(string.sub(bin_str,i,i)),0xFF)
    end
    if (calc_crc ~= crc) then
        return -3,nil,0
    end
    --计算--
    data1=data1-0x33
    data2=data2-0x33
    data3=data3-0x33
    data4=data4-0x33
    data1=((bit.rshift(data1,4))*10 + (bit.band(data1,0x0f)))
    data2=((bit.rshift(data2,4))*10 + (bit.band(data2,0x0f)))
    data3=((bit.rshift(data3,4))*10 + (bit.band(data3,0x0f)))
    data4=((bit.rshift(data4,4))*10 + (bit.band(data4,0x0f)))
    if (id == 'GetTotalElectricEnergy') then
        obj.totalElectricEnergy=(data4*1000000+data3*10000+data2*100+data1)/100
    elseif (id == 'GetTotalForwardElectricEnergy') then
        obj.totalForwardElectricEnergy=(data4*1000000+data3*10000+data2*100+data1)/100
    elseif (id == 'GetTotalReverseElectricEnergy') then
        obj.totalReverseElectricEnergy=(data4*1000000+data3*10000+data2*100+data1)/100
    elseif (id == 'GetVoltageA') then
        obj.voltageA=(data2*100+data1)/10
    elseif (id == 'GetVoltageB') then
        obj.voltageB=(data2*100+data1)/10
    elseif (id == 'GetVoltageC') then
        obj.voltageC=(data2*100+data1)/10
    elseif (id == 'GetCurrentA') then
        obj.currentA=(data3*10000+data2*100+data1)/1000
    elseif (id == 'GetCurrentB') then
        obj.currentB=(data3*10000+data2*100+data1)/1000
    elseif (id == 'GetCurrentC') then
        obj.currentC=(data3*10000+data2*100+data1)/1000
    elseif (id == 'GetActivePowerA') then
        obj.activePowerA=(data3*10000+data2*100+data1)/1000
    elseif (id == 'GetActivePowerB') then
        obj.activePowerB=(data3*10000+data2*100+data1)/1000
    elseif (id == 'GetActivePowerC') then
        obj.activePowerC=(data3*10000+data2*100+data1)/1000
    end
    --出参格式化--
    obj.term_addr=''
    for i=#addr,1,-1 do
        obj.term_addr = obj.term_addr .. (string.format("%02X", string.byte(string.sub(addr, i, i))))
    end
    obj.identifier='post'
    obj.ammeterAddr=obj.term_addr
    local json_str=cjson.encode(obj)
    --print("decode:", err_code, json_str, #json_str)
    return err_code,json_str,#json_str
  end
  --protocol_encode('{"term_addr":"053602000000","identifier":"GetTotalElectricEnergy"}',36)
  --protocol_encode('{"raw_data":"68493405082401689108333333335CBB33336116","identifier":"GetActivePowerC"}',36)