require "internal_api"
require "log"
require "sys"
require "utils"
require "patch"
require "fs"
siganl = require 'posix.signal'
syswait = require 'posix.sys.wait'
unistd = require 'posix.unistd'
mqtt = require "mosquitto"
lpack = require("lua_pack")
base64 = require("base64")
dyutils = require("dyutils")
math = require("math")
cjson = require("cjson")
require "lsqlite3"
bit=require("bit")
bnot = bit.bnot 
band, bor, bxor = bit.band, bit.bor, bit.bxor 
lshift, rshift, rol = bit.lshift, bit.rshift, bit.rol 



--- 数据解析后处理函数 - 转成数字
-- @string input, 数据内容，例如 01020304
-- @number size, 数据长度
-- @return number,转换后的数据
-- @usage PostFunc_ToNumber(string.sub(one_data['Data'], offset + 1, offset + size), size)
function PostFunc_ToNumber(input, size)
    local result = 0
    for i=1,size do
        result = lshift(result, 8) + string.byte(input, i, i)
    end
    return result
end

--- 数据解析后处理函数 - 转成base64的字符串
-- @string input, 数据内容，例如 05060708
-- @number size, 数据长度
-- @return string, base64之后的数据
function PostFunc_Base64_Encode(input, size)
    print(dyutils.bin_str_to_hex(input))
    local result = base64.encode(input)
    return result
end

--- 数据解析后处理函数 - 转成数字，并进行计算
-- @string input, 数据内容，例如 01020304
-- @number size, 数据长度
-- @return number,转换后的数据
function PostFunc_Calc_Temp(input, size)
    local r = PostFunc_ToNumber(input, size)
    r = r * 0.1 - 40
    return r
end

-- Memory Areas
-- 0x03 - System info of S200 family
-- 0x05 - System flags of S200 family
-- 0x06 - Analog inputs of S200 family
-- 0x07 - Analog outputs of S200 family
-- 0x1C - S7 counters (C)
-- 0x1D - S7 timers (T)
-- 0x1E - IEC counters (200 family)
-- 0x1F - IEC timers (200 family)
-- 0x80 - Direct peripheral access (P)
-- 0x81 - Inputs (I)
-- 0x82 - Outputs (Q)
-- 0x83 - Flags (M) (Merker)
-- 0x84 - Data blocks (DB)
-- 0x85 - Instance data blocks (DI)
-- 0x86 - Local data (L)
-- 0x87 - Unknown yet (V)

-- WordLen
-- S7WLBit 0x01 Bit (inside a word)
-- S7WLByte 0x02 Byte (8 bit)
-- S7WLWord 0x04 Word (16 bit)
-- S7WLDWord 0x06 Double Word (32 bit)
-- S7WLReal 0x08 Real (32 bit float)
-- S7WLCounter 0x1C Counter (16 bit)
-- S7WLTimer 0x1D Timer (16 bit)

-- 这里的serive必须和协议模板里面的标识符和协议里面的topic一致
-- Area和WordLen字段感觉上面注释的内容填写
-- PostFunc为接收到数据后的后处理函数，当不设置时，默认采用PostFunc_ToNumber作为处理函数
service_table = {
    {
        service = "read_DB",
        data_table = {
            operation = "read",
            areas = {
                {
                    id = "CurA",
                    Area = 0x84,
                    DBNumber = 1,
                    Start = 0,
                    Amount = 4,
                    WordLen = 0x02,
                    PostFunc = PostFunc_ToNumber 
                },
                {
                    id = "CurB",
                    Area = 0x84,
                    DBNumber = 1,
                    Start = 4,
                    Amount = 4,
                    WordLen = 0x02,
                    PostFunc = PostFunc_ToNumber
                },
                {
                    id = "CurC",
                    Area = 0x84,
                    DBNumber = 1,
                    Start = 8,
                    Amount = 4,
                    WordLen = 0x02
                },
                {
                    id = "VolA",
                    Area = 0x84,
                    DBNumber = 1,
                    Start = 0x40,
                    Amount = 4,
                    WordLen = 0x02
                },
                {
                    id = "VolB",
                    Area = 0x84,
                    DBNumber = 1,
                    Start = 0x44,
                    Amount = 4,
                    WordLen = 0x02
                },
                {
                    id = "VolC",
                    Area = 0x84,
                    DBNumber = 1,
                    Start = 0x48,
                    Amount = 4,
                    WordLen = 0x02
                },
                {
                    id = "Temp",
                    Area = 0x84,
                    DBNumber = 1,
                    Start = 0x50,
                    Amount = 4,
                    WordLen = 0x02,
                    PostFunc = PostFunc_Calc_Temp
                },
                {
                    id = "Temp2",
                    Area = 0x84,
                    DBNumber = 1,
                    Start = 0x60,
                    Amount = 4,
                    WordLen = 0x02,
                    PostFunc = PostFunc_Calc_Temp
                },
                {
                    id = "Temp3",
                    Area = 0x84,
                    DBNumber = 2,
                    Start = 0x64,
                    Amount = 0x60,
                    WordLen = 0x02,
                    PostFunc = PostFunc_Base64_Encode
                }
            }
        }
    },
    {
        service = "read_temp",
        data_table = {
            operation = "read",
            areas = {
                {
                    id = "CurA",
                    Area = 0x82,
                    DBNumber = -1,
                    Start = 0,
                    Amount = 4,
                    WordLen = 0x02
                },
                {
                    id = "CurB",
                    Area = 0x82,
                    DBNumber = -1,
                    Start = 4,
                    Amount = 4,
                    WordLen = 0x02
                },
                {
                    id = "CurC",
                    Area = 0x82,
                    DBNumber = -1,
                    Start = 8,
                    Amount = 4,
                    WordLen = 0x02
                }
            }
        }
    },
    {
        service = "write_db1",
        data_table = {
            operation = "write",
            areas = {
                {
                    id = "AA",
                    Area = 0x84,
                    DBNumber = 1,
                    Start = 0,
                    Amount = 4,
                    WordLen = 0x02
                },
                {
                    id = "BB",
                    Area = 0x84,
                    DBNumber = 1,
                    Start = 4,
                    Amount = 4,
                    WordLen = 0x02
                }
            }
        }
    }
}


MAX_HOLE_SIZE = 8
down_table = nil

function get_size_from_wordlen(WordLen)
    if WordLen == 0x1 then
        return 1
    elseif WordLen == 0x02 then
        return 1
    elseif WordLen == 0x04 then
        return 2
    elseif WordLen == 0x06 then
        return 4
    elseif WordLen == 0x08 then
        return 4
    elseif WordLen == 0x1c then
        return 2
    elseif WordLen == 0x1D then
        return 2
    else
        return -1;
    end
end

function print_r ( t )  
    local print_r_cache={}
    local function sub_print_r(t,indent)
        if (print_r_cache[tostring(t)]) then
            print(indent.."*"..tostring(t))
        else
            print_r_cache[tostring(t)]=true
            if (type(t)=="table") then
                for pos,val in pairs(t) do
                    if (type(val)=="table") then
                        print(indent.."["..pos.."] => "..tostring(t).." {")
                        sub_print_r(val,indent..string.rep(" ",string.len(pos)+8))
                        print(indent..string.rep(" ",string.len(pos)+6).."}")
                    elseif (type(val)=="string") then
                        print(indent.."["..pos..'] => "'..val..'"')
                    else
                        print(indent.."["..pos.."] => "..tostring(val))
                    end
                end
            else
                print(indent..tostring(t))
            end
        end
    end
    if (type(t)=="table") then
        print(tostring(t).." {")
        sub_print_r(t,"  ")
        print("}")
    else
        sub_print_r(t,"  ")
    end
    print()
end

--- 解析服务表，合并相邻数据
function analysis_down_area(service_table)
    if down_table ~= nil then
        print("already analysised")
        syslog.syslog("LOG_DEBUG", "already analysised")
        return 0
    end
    down_table = {}
    for i, v in pairs(service_table) do
        if v['data_table']['operation'] == 'read' then
            local service_data = {}
            service_data['service'] = v['service']
            service_data['data_table'] = {}
            service_data['data_table']['operation'] = v['data_table']['operation']
            local down_data = {}
            for _i, Area in pairs(v['data_table']['areas']) do
                local find_match = 0
                --print("analysing Area:"..Area['Area'].." DBNumber:"..Area['DBNumber'].." Start:"..Area['Start'].." Amount:"..Area['Amount'])
                for __i, down in pairs(down_data) do
                    if down['Area'] == Area['Area'] and down['DBNumber'] == Area['DBNumber'] and down['WordLen'] == Area['WordLen'] then
                        --print("\tmatching Area:"..down['Area'].." DBNumber:"..down['DBNumber'].." Start:"..down['Start'].." Amount:"..down['Amount'])
                        if ((down['Start'] + down['Amount']) <= Area['Start']) and ((down['Start'] + down['Amount'] + MAX_HOLE_SIZE) >= Area['Start']) then
                            down['Amount'] = down['Amount'] + (Area['Start'] - (down['Start'] + down['Amount'])) + Area['Amount']
                            find_match = 1
                            break
                        end
                    end
                end
                if find_match == 0 then
                    local once = {}
                    once['Area'] = Area['Area']
                    once['DBNumber'] = Area['DBNumber']
                    once['Start'] = Area['Start']
                    once['Amount'] = Area['Amount']
                    once['WordLen'] = Area['WordLen']
                    table.insert(down_data, once)
                end
            end
            service_data['data_table']['areas'] = down_data
            table.insert(down_table, service_data)
        elseif v['data_table']['operation'] == 'write' then
            local service_data = {}
            service_data['service'] = v['service']
            service_data['data_table'] = {}
            service_data['data_table']['operation'] = v['data_table']['operation']
            local down_data = {}
            for _i, Area in pairs(v['data_table']['areas']) do
                local once = {}
                once['Area'] = Area['Area']
                once['DBNumber'] = Area['DBNumber']
                once['Start'] = Area['Start']
                once['Amount'] = Area['Amount']
                once['WordLen'] = Area['WordLen']
                once['id'] = Area['id']
                table.insert(down_data, once)
            end
            service_data['data_table']['areas'] = down_data
            table.insert(down_table, service_data)
        end
    end
    print_r(down_table)
end

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 bin_str = nil

    analysis_down_area(service_table)

    syslog.syslog("LOG_DEBUG", "S7 PLC encode:" .. json_str)
    print(bin_str)

    for i, v in pairs(down_table) do
        if (v["service"] == id) then
            if (v['data_table']['operation'] == 'read') then
                bin_str = cjson.encode(v['data_table'])
            elseif (v['data_table']['operation'] == 'write') then
                for _i, area in pairs(v['data_table']['areas']) do
                    if obj[area['id']] ~= nil then
                        local size = get_size_from_wordlen(area['WordLen']) * area['Amount']
                        if (size == 4) then
                            tmp = bpack(">I", obj[area['id']])
                        elseif (size == 2) then
                            tmp = bpack(">S", obj[area['id']])
                        elseif (size == 1) then
                            tmp = bpack("C", obj[area['id']])
                        end
                        area['Data'] = base64.encode(tmp)
                    end
                end
                bin_str = cjson.encode(v['data_table'])
            end
            break
        end
    end

    -- 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(err_code, bin_str, #bin_str)
    return err_code, bin_str, #bin_str
end

function protocol_decode(input_str, len)
    local err_code = 0
    -- 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
    obj.identifier = id

    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
    print(bin_str)
    local data = cjson.decode(bin_str)

    for i, v in pairs(data) do
        if v['Data_B64'] ~= nil then
            v["Data"] = base64.decode(v['Data_B64'])
        end
    end

    for i, v in pairs(service_table) do
        if id == v['service'] then
            for _i, Area in pairs(v['data_table']['areas']) do
                for __i, one_data in pairs(data) do
                    if Area['Area'] == one_data['Area'] and Area['DBNumber'] == one_data['DBNumber'] and Area['Start'] >= one_data['Start'] and Area['Start'] + Area['Amount'] <= one_data['Start'] + one_data['Amount'] then
                        if v['data_table']['operation'] == 'write' then
                            obj[Area['id']..'_Result'] = one_data['Result']
                        elseif one_data['Result'] == 0 then
                            local size = get_size_from_wordlen(Area['WordLen']) * Area['Amount']
                            local offset = (Area['Start'] - one_data['Start']) * get_size_from_wordlen(Area['WordLen'])
                            if Area['PostFunc'] == nil then
                                obj[Area['id']] = PostFunc_ToNumber(string.sub(one_data['Data'], offset + 1, offset + size), size)
                            else
                                obj[Area['id']] = Area['PostFunc'](string.sub(one_data['Data'], offset + 1, offset + size), size)
                            end
                        end
                        break
                    end
                end
            end
            break
        end
    end

    -- 出参格式化--
    local json_str = cjson.encode(obj)
    --print(err_code, json_str, #json_str)
    return err_code, json_str, #json_str
end