require "log"
require "sys"
require "utils"
require "patch"
lpack=require("lua_pack")
MQTT=require("mqtt_library")
base64=require("base64")
dyutils=require("dyutils")

----------------------[MODBUS write data]--------------------------
local function write_once_register(obj,start,data,cmd)
    return 0x05,start,nil,nil,data
end

local function read_coil(obj,start,len,cmd)
    return cmd or 0x02,start,len
end

----------------------[控制服务]--------------------------
local function control_general(obj)
    local field={"","TAG_520","TAG_51E"}
    for i,key in ipairs(field) do
        if key and #key > 0 and obj[key] then
            local data = bpack(">S",obj[key])
            return write_once_register(obj,i-1,data)
        end
    end
end

local function response_general(raw_data, len)
    local obj={}
    return obj
end

local list={}
local last={}

local function response_DIRead(raw_data, len)
    local DEEP = 2
    local obj={}
    local field={"","TAG_579","TAG_4B2","TAG_519","TAG_6A5","TAG_6A6","TAG_6A7"}
    local _, DIRead= bunpack(raw_data,"<S")
    for i,key in ipairs(field) do
        if key and #key > 0 then
            -- log.info(nil,DIRead,key)
            obj[key] = bit.band(bit.rshift(DIRead,i-1),1)
        end
    end

    local out={}
    table.insert(list,obj)
    if #list > DEEP then table.remove(list,1) end
        -- log.info(nil,"==============",#list)

    if #list < DEEP then
        out = obj
    else
        for i,key in ipairs(field) do --每个key都经行比对
            if key and #key > 0 then
                local diff
                for _,hist in ipairs(list) do
                    if hist[key] ~= obj[key] then
                        diff = true
                        break
                    end
                end
                if diff then
                    out[key] = last[key]
                else
                    out[key] = obj[key]
                end
            end
        end
    end

    last = out
    return out
end


global_identifier_func_tab = {
    {
        identifier="DIRead",
        create_bin_func=read_coil,
        create_bin_args={0,0x10,0x02},
        parser_bin_func=response_DIRead
    },
    {
        identifier="DOfireall",
        create_bin_func=control_general,
        create_bin_args={nil,nil},
        parser_bin_func=response_general
    },
    {
        identifier="DOfire1",
        create_bin_func=control_general,
        create_bin_args={nil,nil},
        parser_bin_func=response_general
    },
}


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 server_period=obj.server_period
    local dev_sn=obj.sn
    local addr=1

    local raw_data=nil
    for i,v in pairs(global_identifier_func_tab) do
        if v.identifier == id then
            local call_func = v.create_bin_func
            local func,start,len,data_len,data = call_func(obj,v.create_bin_args[1],v.create_bin_args[2],v.create_bin_args[3])
            if not func then
                log.error(nil, "invalid function code")
                return
            end
            local bin=nil
            if not len then
                raw_data = bpack("CC>S",addr,func,start)
                for i = 1, #data do raw_data = raw_data .. bpack("c",data:byte(i)) end
            elseif not data then
                raw_data = bpack("CC>S>S",addr,func,start,len)
            else
                raw_data = bpack("CC>S>SC",addr,func,start,len,data_len)
                for i = 1, #data do raw_data = raw_data .. bpack("c",data:byte(i)) end
            end
            raw_data = raw_data .. bpack(">S",dyutils.CRC16(raw_data,#raw_data))

            local t_str=''
            for i=1, #raw_data do
                t_str=t_str .. (string.format("%02X", string.byte(string.sub(raw_data, i, i))))
            end

            print(t_str,#t_str)
            return err_code, t_str, #t_str
        end
    end
    return -1, nil, 0
end

function protocol_decode(input_str, len)
    -- log.info(nil,input_str);
    local err_code=0
    --取出入参--
    local obj={}
    local input_obj=cjson.decode(input_str)
    local id=input_obj.identifier
    local bin_str=input_obj.raw_data
    --入参中的raw_data的二进制转换--
    --入参中的raw_data的二进制转换--
    if not bin_str or #bin_str < 6 then
        print(string.format( "Input args failed,args:%s",input_str))
        return nil
    end
    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

    local raw_data=t_str
    _,addr,func = bunpack(raw_data,"CC")
    local addr = 1


    local crc = dyutils.CRC16(raw_data,#raw_data - 2)
    _,crc_pack = bunpack(string.sub(raw_data,#raw_data - 1),">S")

    if (crc ~= crc_pack) then
        log.info(nil,string.format( "Data crc check failed cal:%04X packet:%04X",crc,crc_pack))
        return nil
    end
    for i,v in pairs(global_identifier_func_tab) do
        log.info(nil,v.identifier ,id)
        if v.identifier == id then
            local call_func = v.parser_bin_func
            local data,data_len = nil,0
            if func == 0x05 then data_len = #raw_data - 5 - 1 data = string.sub(raw_data,5,-3)
            elseif  func == 0x01 or func == 0x02 or func == 0x03 or func == 0x04 then data_len = #raw_data - 4 - 1 data = string.sub(raw_data,4,-3)
            elseif func == 0x10  then data_len = 0 data = nil
            else
                log.info(string.format( "unknow function code %02X",func))
                return -1
            end
            log.info(nil,"protocol_decode","protocol_decode raw_data ",string.toHex(data) )
            local json_obj = call_func(data,data_len)-- 调用不同的函数执行解析数据
            if not json_obj then
                -- log.info("decode failed,raw_data",string.toHex(data),data_len)
                log.warn("protocol_decode","decode failed,raw_data:",string.toHex(data))
                return
            end
            json_obj.identifier=id                             -- 返回调用标识
            json_obj.term_addr=string.format( "%02X",addr)
            local json_str=cjson.encode(json_obj)
            print(err_code, json_str, #json_str)
            return err_code,json_str,#json_str
        end
    end
    return nil
end

-- protocol_encode('{"sn":"21880A0002FE_DI","identifier":"DIRead","server_period":2000,"term_addr":"01"}');
-- protocol_decode('{"raw_data":"0102020000B9B8","identifier":"DIRead","sn":"21880A0002FE_DI"}')
-- protocol_encode('{"identifier":"DOfireall","sn":"21880A0002FE_DI","mi":84724073,"TAG_520":6,"timestamp":1658220984,"term_addr":"01"}')