OC print server

local component = require("component")
local event = require("event")
local ser = require("serialization")
local network = require ("network")
local fs = require("filesystem")
local op = component.openprinter
local extra = require("extralib")

local VERSION = "1.0"

local CONFIGFILE = "/etc/printserver.cfg"
local SERVERNAME = "pserver1"
local LOGFOLDER = "/var/log/"
local LOGFILE = "printserver.log"
local PORT = 9100
local WARNPAPER = 10
local WARNCOLOR = 5
local WARNBLACK = 5
local TIMERCOUNT = 0.1

local activeJob = 1
local queuedJobs = 0
local queueTable = {}

local timerEvent = nil

function ensureLogFolderExists()
    if not fs.exists(LOGFOLDER) then
        fs.makeDirectory(LOGFOLDER)
    end
end

function logwrite(str)
  local file = io.open(LOGFOLDER .. "/" .. LOGFILE,"a")
  file:write(str)
  file:close()
end

function checkPrinter()
    if op.getPaperLevel() then
      if op.getPaperLevel() < WARNPAPER then
    logwrite(os.date() .. " Running out of paper\n")
    return false
      end
    else
    logwrite(os.date() .. " No paper.\n")
    return false
    end
    if op.getColorInkLevel() then
      if op.getColorInkLevel() < WARNCOLOR then
    logwrite(os.date() .. " Less then 5% color ink left\n")
    return false
      end
    else
      logwrite(os.date() .. " Out off color Ink.\n")
      return false
    end
    if op.getBlackInkLevel() then
      if op.getBlackInkLevel() < WARNBLACK then
    logwrite(os.date() .. " Less then 5% black ink left\n")
    return false
      end
    else
      logwrite(os.date() .. " Out off black Ink.\n")
      return false
    end
    return true
end

function timerCallback()
  if checkPrinter() == true then
    if activeJob <= queuedJobs then     -- only if there are files waiting
    --print("Job ID : " .. queueTable[activeJob].id)
    --print("From   : " .. queueTable[activeJob].client)
    --print("Status : " .. queueTable[activeJob].status)
    --print("Line   : " .. queueTable[activeJob].pageLine .. " of " .. queueTable[activeJob].lines)
    --print("........................................................")
      if queueTable[activeJob].status == "queued" then
    queueTable[activeJob].status = "printing"           -- set the status of the job to printing
    logwrite(os.date() .. " Starting print of job " .. activeJob .. "\n")
      end
      if queueTable[activeJob].pageLine ==19 then           -- Page is full
    op.setTitle(queueTable[activeJob].client)
    op.writeln("<" .. queueTable[activeJob].page .. ">")
    queueTable[activeJob].page = queueTable[activeJob].page + 1 -- page counter for job one up
    queueTable[activeJob].pageLine = 1
    op.print()
      else
    op.writeln(queueTable[activeJob].data[queueTable[activeJob].activeLine])
    queueTable[activeJob].activeLine = queueTable[activeJob].activeLine + 1
    queueTable[activeJob].pageLine = queueTable[activeJob].pageLine + 1
      end
      if queueTable[activeJob].activeLine > queueTable[activeJob].lines then
    queueTable[activeJob].status = "finished"
    local i = queueTable[activeJob].pageLine
    for j=i, 19 do
      op.writeln("")
    end
    op.setTitle(queueTable[activeJob].client)
    op.writeln("<" .. queueTable[activeJob].page .. ">")
    op.print()
    logwrite(os.date() .. " Finshed print of job " .. activeJob .. "\n")
    activeJob = activeJob + 1
      end
    end
  end
  timerEvent = event.timer(TIMERCOUNT, timerCallback)
end

local function response(_, type, _a, _b, _c, _d)
  local channel = 0
  local remoteAddr = ""
  local port = 0
  if type == "connection" then
    channel = _a
    remoteAddr = _b
    port =_c
    logwrite(os.date() .. " Connection from " .. remoteAddr .. " ch " .. channel .. " port " .. port .. "\n")
  elseif type == "message" then
    channel = _a
    message = _b
    remoteAddr = _c
    port =_d
    local tmpTable = {}
    local msgTable = ser.unserialize(message)
    logwrite(os.date() .. " " .. remoteAddr .. " send message '" .. msgTable.command .. "' ch " .. channel .." port " .. port .. "\n")
    if msgTable.command == "info" then
      local msgTable ={}
      msgTable["command"] = "info"
      msgTable["version"] = VERSION
      msgTable["jobs"] = queuedJobs
      --print(ser.serialize(msgTable))
      network.tcp.send(channel, ser.serialize(msgTable))

    elseif msgTable.command == "print" then
      queuedJobs = queuedJobs + 1
      logwrite(os.date() .. " " .. remoteAddr .. " queueing job " ..queuedJobs .. " filename : " .. msgTable.filename .. "\n")
      for key,value in pairs(ser.unserialize(msgTable.data)) do
    done = false
    while done == false do
      if value:len() > 30 then
        table.insert(tmpTable,value:sub(1,30))
        value=">"..value:sub(31)
      else
        table.insert(tmpTable,value)
        done = true
      end
    end
      end
      local qTable = {}

      qTable["filename"] = msgTable.filename
      qTable["lines"] = #tmpTable
      qTable["activeLine"] = 1
      qTable["data"] = tmpTable
      qTable["pageLine"] = 1
      qTable["status"] = "queued"       -- will be queued, printing or finished
      qTable["client"] = remoteAddr
      qTable["id"] = queuedJobs
      qTable["page"] = 1

      queueTable[queuedJobs] = qTable
    end

  elseif type == "close" then
    channel = _a
    logwrite(os.date() .. " Connection on channel " .. channel .. " closed\n")
  end
end

function loadConfig()
  local option = {}
  local configFile = io.open(CONFIGFILE, "r")
  while true do
    line = configFile:read()
    if line == nil then
      break
    else
      if line[1] ~= "#" then
    option = extra.splitString(line,"=")    -- extralib sring split
    if option[1] == "LOGFILE" then
      LOGFILE = option[2]
    elseif option[1] == "LOGFOLDER" then
      LOGFOLDER = option[2]
    elseif option[1] == "SERVERNAME" then
      SERVERNAME = option[2]
    elseif option[1] == "PORT" then
      PORT = tonumber(option[2])
    elseif option[1] == "WARNPAPER" then
      WARNPAPER = tonumber(option[2])
    elseif option[1] == "WARNCOLOR" then
      WARNCOLOR = tonumber(option[2])
    elseif option[1] == "WARNBLACK" then
      WARNBLACK = tonumber(option[2])
    elseif option[1] == "TIMERCOUNT" then
      TIMERCOUNT = tonumber(option[2])
    end
      end
    end
end

  configFile:close()
end


function start()
  loadConfig()
  ensureLogFolderExists()
  logwrite(os.date() .. " Starting print server (v" .. VERSION .. ") " .. SERVERNAME .. " at port " .. PORT .. "\n")
  if op == nil then
    logwrite(os.date() .. " No openprinter found!\n")
    logwrite(os.date() .. " Aborting!")
    return false
  end
  network.ip.bind(SERVERNAME)
  network.tcp.listen(PORT)
  event.listen("tcp", response)
  checkPrinter()
  op.clear()
  timerEvent = event.timer(TIMERCOUNT, timerCallback)
end

function stop()
  logwrite(os.date() .. " Stopping print server\n")
  network.tcp.unlisten(PORT)
end