#!/usr/bin/lua

require("json")
require("socket")

function startswith(String,Start)
   if String then
     return string.sub(String,1,string.len(Start))==Start
   else
     return False
   end    
end

function url_encode(str)
  if (str) then
    str = string.gsub (str, "\n", "\r\n")
    str = string.gsub (str, "([^%w %-%_%.%~])",
        function (c) return string.format ("%%%02X", string.byte(c)) end)
    str = string.gsub (str, " ", "+")
  end
  return str	
end

function capture(cmd, raw)
  local f = assert(io.popen(cmd, 'r'))
  local s = assert(f:read('*a'))
  f:close()
  if raw then return s end
  s = string.gsub(s, '^%s+', '')
  s = string.gsub(s, '%s+$', '')
  s = string.gsub(s, '[\n\r]+', ' ')
  return s
end

function mqtt_encode(str)
  if (str) then
    str = string.gsub (str, "\n", "")
    str = string.gsub (str, "/", "-")
  end
  return str	
end

function getConfig(configname)

  local uci=require("uci")
  local cur=uci.cursor()
  local config
  if configname then
    config=configname
  else
    config="weathermon"
  end

  web_url  = cur.get(config,"web","url")
  web_user = cur.get(config,"web","user")
  web_pass = cur.get(config,"web","password")
  web_devid = cur.get(config,"web","devid")

  web_iface = cur.get(config,"web","iface")

  if web_iface then
  
    command = '/sbin/ifconfig '..web_iface..' | grep \'\\<inet\\>\' | sed -n \'1p\' | tr -s \' \' | cut -d \' \' -f3 | cut -d \':\' -f2'
    f=io.popen(command,'r')
    ip_addr=f:read()
  
  end

  if not web_devid then
  
    if web_iface then
      io.input("/sys/class/net/"..web_iface.."/address")
    else
      io.input("/sys/class/net/eth0/address")
    end

    mac = io.read("*line")
    mac = mac:gsub(":","")
    mac = mac:upper()

    web_devid = mac

  end

  logging = cur.get(config,"logging","enabled") 
  touch_file = cur.get(config,"logging","touch_file") 

  serial_port = cur.get(config,"serial","port")
  serial_baud = cur.get(config,"serial","baud")

  input_file = cur.get(config,"input","file")
  input_exec = cur.get(config,"input","exec")
  alarm_exec = cur.get(config,"alarm","exec")

  if serial_port then

    command = "stty -F  "..serial_port.." "..serial_baud
    capture(command)

  end

  mqtt_host = cur.get(config,"mqtt","host")
  mqtt_port = cur.get(config,"mqtt","port")
  mqtt_id = cur.get(config,"mqtt","id")
  mqtt_topic = cur.get(config,"mqtt","topic")
  mqtt_alarm_topic = cur.get(config,"mqtt","alarm_topic")

  mqtt_user = cur.get(config,"mqtt","user")
  mqtt_passwd = cur.get(config,"mqtt","password")

  if mqtt_host and not mqtt_id then
    mqtt_id="weather-"..web_devid
  end

  if mqtt_host and not mqtt_port then
    mqtt_port = 1883
  end

  if mqtt_host and not mqtt_topic then
    mqtt_topic = 'weathermon/{dev}/{type}/{id}/{param}'
  end

  if mqtt_host and not mqtt_alarm_topic then
    mqtt_alarm_topic = 'alarm/{dev}/{type}/{id}'
  end

end

function touch()
  if touch_file then
    local file = io.open(touch_file, 'w')
    file:close()
  end  
end

function sleep(sec)
  socket.select(nil, nil, sec)
end

function splitStr(str,char)

  local res = {}
  local idx = 1

  while str:len()>0 do
    pos = str:find(char); 
    if pos == nil then
      res[idx]=str
      str=""
    else
      res[idx]=str:sub(1,pos-1)
      idx=idx+1
      str=str:sub(pos+1)
    end
  end

  return res

end

function printLog(str)
  if logging=="on" then
    capture("logger -t weathermon "..str)
    print(str)  
  elseif logging=="syslog" then
    capture("logger -t weathermon "..str)
  elseif logging=="stdout" then 
    print(str)  
  end 
end

function submitValue(type,id,param,val)

  url = web_url.."?stype="..url_encode(type).."&sid="..url_encode(id).."&param="..url_encode(param).."&value="..url_encode(val)

  command = "curl"

  if web_iface then
    command = command.." --interface "..ip_addr
  end

  if web_user then
    command = command.." -u "..web_user..":"..web_pass
  end

  command = command.." \""..url.."\" 2>&1"

  result = capture(command)

  touch()

end

function processJson(str)

  msg=json.decode(str)

  sensor={}

  for key,value in pairs(msg) do
    if value then
      if key=="model" or key=="device" then
        sensor_type=value
      elseif key=="id" then
        sensor_id=value
      elseif key=='time' then
        sensor_time=value
      else
        sensor[key]=value
      end
    end
  end

  if not (sensor_type==nil or sensor_id==nil or sensor_type=='' or sensor_id=='') then
    if next(sensor)==nil then
      sensor["command"]="alarm"
    end
    for k,v in pairs(sensor) do
      printLog("Type = "..sensor_type..", ID = "..sensor_id..", Param = "..k..", Value = \""..v.."\"")
      submitValue(sensor_type,sensor_id,k,v)
      if mqtt_client then
        mqtt_path=string.gsub(mqtt_topic,"{(.-)}", 
          function (name) 
            if name=="dev" then
              return mqtt_encode(web_devid)
            elseif name=="type" then
              return mqtt_encode(sensor_type)
            elseif name=="id" then
              return mqtt_encode(sensor_id)
            elseif name=="param" then
              return k
            else
              return '{'..name..'}'
            end      
          end)
        mqtt_client:publish(mqtt_path,v)
      end  
    end
  else
    printLog("Cannot parse sensor input: "..msg_body)
  end

end

function processLine(str)

  msg=splitStr(line,':')
  msg_type=msg[1] or ''
  msg_body=msg[2] or ''
  if msg_type=="STATUS" then
    printLog("Status: "..msg_body)
  elseif msg_type=="ERROR" then
    printLog("Error: "..msg_body)  
  elseif msg_type=="SENSOR" then
    printLog("SENSOR: "..msg_body)  
    sens = splitStr(msg_body,",")
    sensor = {}
    idx = 1
    sensor_type = nil
    sensor_id = web_devid
    for i,rec in ipairs(sens) do
      recrd=splitStr(rec,'=')
      key=recrd[1] or ''
      value=recrd[2] or ''
      if value then
        if key=="TYPE" then
          sensor_type=value
        elseif key=="ID" then
          sensor_id=value
        else
          sensor[key]=value
        end
      end
    end
    if not (sensor_type==nil or sensor_id==nil or sensor_type=='' or sensor_id=='') then
      for k,v in pairs(sensor) do
        printLog("Type = "..sensor_type..", ID = "..sensor_id..", Param = "..k..", Value = "..v)
        submitValue(sensor_type,sensor_id,k,v)
        if mqtt_client then
          mqtt_path=string.gsub(mqtt_topic,"{(.-)}", 
            function (name) 
              if name=="dev" then
                return web_devid
              elseif name=="type" then
                return sensor_type
              elseif name=="id" then
                return sensor_id
              elseif name=="param" then
                return k
              else
                return '{'..name..'}'
              end      
            end)
          mqtt_client:publish(mqtt_path,v)
        end  
      end
    else
      printLog("Cannot parse sensor input: "..msg_body)
    end
  elseif msg_type=="ALARM" then
    printLog("ALARM: "..msg_body)  
    sens = splitStr(msg_body,",")
    sensor = {}
    idx = 1
    sensor_type = nil
    sensor_id = web_devid
    mqtt_param = {}
    for i,rec in ipairs(sens) do
      recrd=splitStr(rec,'=')
      key=recrd[1] or ''
      value=recrd[2] or ''
      if value then
        if key=="TYPE" then
          alarm_type=value
        elseif key=="ID" then
          alarm_id=value
        end
      end
    end
    if not (alarm_type==nil or alarm_id==nil or alarm_type=='' or alarm_id=='') then
      if mqtt_client then
        mqtt_path=string.gsub(mqtt_alarm_topic,"{(.-)}", 
          function (name) 
            if name=="dev" then
              return web_devid
            elseif name=="type" then
              return sensor_type
            elseif name=="id" then
              return sensor_id
            else
              return '{'..name..'}'
            end      
          end)
        mqtt_client:publish(mqtt_path,msg_body)
      end
      if alarm_exec then
        command=alarm_exec..
          " \""..string.gsub(alarm_type,"\"","\\\"")..
          "\" \""..string.gsub(alarm_id,"\"","\\\"")..
          "\" \""..string.gsub(msg_body,"\"","\\\"").."\""
        capture(command)
      end
    else
      printLog("Cannot parse alarm input: "..msg_body)
    end
  end

end

getConfig(arg[1])

if mqtt_host then
  MQTT = require "mosquitto"
  mqtt_client = MQTT.new(mqtt_id)
  if mqtt_user then
    mqtt_client:login_set(mqtt_user, mqtt_passwd)
  end
  mqtt_client:connect(mqtt_host,mqtt_port)
end

if serial_port then
  serialin=io.open(serial_port,"r")
elseif input_file == "-" then
  serialin=io.stdin;
elseif input_file then
  serialin=io.open(input_file,"r")
elseif input_exec then
  serialin=io.popen(input_exec,"r")
else
  printLog("No input selected")
  return
end  
while 1 do
  line=serialin:read()
  if line == nil then
    break
  end
  printLog("Received: "..line);
  if startswith(line,'{') then
    processJson(line)
  else
    processLine(line)
  end
end