#!/usr/bin/lua

socket = require "socket"
json = require "json"
require "uci"
cur = uci.cursor()
require "wm_util"

config_name = arg[1]
if not config_name then
  config_name = "weathermon"
end  

weather_file = uci.get(config_name,"process","dump_file")

function round(num, numDecimalPlaces)
  local mult = 10^(numDecimalPlaces or 0)
  return math.floor(num * mult + 0.5) / mult
end

function trim(s)
  return (s:gsub("^%s*(.-)%s*$", "%1"))
end

function lpad(s, l, c)
  local res = string.rep(c or ' ', l - #s) .. s
  return res, res ~= s
end

function process_file()
  txt = get_file_content(weather_file)
  data = json.decode(txt)
  for k,v in pairs(data) do
    return v
  end
end

function get_display_config()
  width  = tonumber(uci.get(config_name,"display","width"))
  height = tonumber(uci.get(config_name,"display","height"))
  cols   = tonumber(uci.get(config_name,"display","columns"))
  title  = uci.get(config_name,"display","title")
  col_width = math.floor(width/cols)
  
  pages = {}
  pagetitles = {}
  
  local page, def, line, col, pos
  
  cur.foreach(config_name,"display", function(s) 
      page = {}
      local pagetitle = s["title"]
      if not pagetitle then
        pagetitle = title
      end
      if not (pagetitle=="") then
        line = 2
      else
        line = 1
      end
      col = 1
      pos = 0
      for k,v in pairs(s["parameter"]) do
        def = {}
        if not(v == "") then
          v = split(v,":")
          def["sensor"] = v[1]
          def["param"] = v[2]
          def["label"] = v[3]
          def["unit"] = v[4]
          def["scale"] = tonumber(v[5])
          def["round"] = tonumber(v[6])
          def["pos"] = tonumber(v[7])
          def["line"] = line
          def["col"] = col
          page[#page+1] = def
        end
        col = col + 1
        if col > cols then
          col = 1
          line = line + 1
        end
      end
      pages[#pages+1] = page
      pagetitles[#pages] = pagetitle
    end)

end

function connect_server()
  local ip = uci.get(config_name,"display","server")
  local port = uci.get(config_name,"display","port")
  conn = socket.connect(ip,port)
  return conn
end

function write_command(conn,command)
  conn:send(command.."\n")
  return(conn:receive())
end

function setup_pages(conn)
  write_command(conn,"hello")
  write_command(conn,"client_set -name weathermon")
  for i,page in pairs(pages) do
    local pageid = "page"..trim(tostring(i))
    write_command(conn,"screen_add "..pageid)
    local pagetitle = pagetitles[i]
    if not(pagetitle == "") then
      write_command(conn,"screen_set -name "..pagetitle)
      write_command(conn,"widget_add "..pageid.." "..pageid..".title title")
      write_command(conn,"widget_set "..pageid.." "..pageid..".title \"".. pagetitle.."\"")
    end
    for j,def in pairs(page) do
      defid = def["sensor"].."."..def["param"]
      write_command(conn,"widget_add "..pageid.." "..defid.." string")
    end
  end
end

function process_vals(vals)
  for i,page in pairs(pages) do
    local pageid = "page"..trim(tostring(i))
    for j,def in pairs(page) do
      val = vals[def["sensor"]][def["param"]]
      if val then
        val = round(val * def["scale"], def["round"])
      end
      defid = def["sensor"].."."..def["param"]
      val = lpad(tostring(val),def["pos"]).." "..def["unit"]
      if not(def["label"] == "") then
        val = def["label"]..": "..val
      end
      write_command(conn,"widget_set "..pageid.." "..defid.." "..trim(tostring((def["col"]-1)*col_width+1)).." "..def["line"].." \""..val.."\"")
    end
  end
end  

get_display_config()

conn = connect_server()

setup_pages(conn)

while true do

  pcall(function ()

      vals = process_file()
      process_vals(vals)

      os.execute("inotifywait -e MODIFY \""..weather_file.."\"")
      socket.sleep(3)
  
    end)
  
end