leosat - no fuel check

local sVersion = "1.4"
local tPingmap = {}
local sPass = "pass"
local tAuthed = {}
local sHelp
local sHelpFallback = "LeoSat v"..sVersion
local bGps = true
local x,y,z

local tArgs = {...}

term.clear()
term.setCursorPos(1,1)

function table.find(s, tAble)
  for i=1, #tAble do
    if tAble[i] == s then
      return true
    end
  end
  return false
end

function table.removeKey(s, tAble)
  for k, v in ipairs(tAble) do
    if v == s then
      table.remove(k, tAble)
      return true
    end
  end
  return false
end

print("Initalizing LeoSat "..sVersion)

-- Checks if help file exists, reads help information from it
if fs.exists("./help") then
  file = fs.open("./help", "r")
  sHelp = file.readAll()
  file:close()
else
  print("No help file found, using fallback.")
end

rednet.open("right")

-- Checks if user disabled GPS host
if tArgs[1] == "false" then
  bGps = false
  print("GPS host disabled.")
-- Checks if the user provided valid coordinates
elseif tArgs[1] ~= nil and tArgs[2] ~= nil and tonumber(tArgs[2]) <= 254 and tArgs[3] ~= nil then
  x = tonumber(tArgs[1])
  y = tonumber(tArgs[2])
  z = tonumber(tArgs[3])
  print("Valid location provided.")
else
  -- Tries to get position autmatically
  print("None or invalid location provided, attempting to get location via GPS...")
  x, y, z = gps.locate(2)
  if x ~= nil then
    print("Position appears to be "..x..","..y..","..z)
  else
    print("Could not determine position, disabling GPS host.")
    bGps = false
  end
end

while true do
  id, msg, dist = rednet.receive()

  -- Ping command
  if msg:lower() == "ping" then
    if not bGps then
      rednet.send(id, "PONG")
    else
      rednet.send(id, textutils.serialize({x,y,z}))
    end
    print(id, " executed ping.")

  -- Help command
  elseif msg:lower() == "help" then
    if sHelp ~= nil then
      rednet.send(id, sHelp)
    else
      rednet.send(id, sHelpFallback)
    end
    print(id, " executed help.")

  -- Pingmap command
  elseif msg:lower() == "pingmap" then
    print(id, " executed pingmap.")
    rednet.broadcast("PING")
    os.startTimer(2)
    local i = 0
    while true do
      local event, p1, p2, p3 = os.pullEvent()
      if event == "timer" then
        break
      elseif event == "rednet_message" then
        i = i + 1
        tPingmap[p1] = {p2, p3}
      end
    end
    rednet.send(id, textutils.serialize(tPingmap))

  -- Login command
  elseif msg:lower():sub(1, 5) == "login" then
    if msg:sub(7) == sPass then
      table.insert(tAuthed, id)
      rednet.send(id, "Successfully logged in!")
      print(id, " logged in.")
    else
      rednet.send(id, "Login failed!")
      print(id, " failed to login.")
    end

  -- Logout command
  elseif msg:lower():sub(1, 6) == "logout" then
    if table.removeKey(id, tAuthed) then
      rednet.send(id, "Successfully logged out!")
      print(id, " logged out.")
    else
      rednet.send(id, "Not logged in!")
      print(id, " failed to logout.")
    end

  -- Down command
  elseif msg:lower() == "down" then
    if table.find(id, tAuthed) then
      rednet.send(id, "Moving down...")
      print(id, " executed down.")
      while turtle.down() do
        if turtle.getFuelLevel() == 0 then
          rednet.send(id, "Out of fuel!")
          print("Out of fuel!")
        end
      end
      rednet.send(id, "Arrived at ground level!")
      print("Arrived at ground level!")
    else
      rednet.send(id, "You are not permitted to execute this command!")
      print(id, " failed to execute down.")
    end

  -- Up command
  elseif msg:lower() == "up" then
    if table.find(id, tAuthed) then
      rednet.send(id, "Moving up...")
      print(id, " executed up.")
      while turtle.up() do
      end
      if y < 254 then
        for i=1, 254-y do
          turtle.down()
        end
        if not fs.exists("startup") then
          f = fs.open("startup", "w")
          f.write("shell.run(\"leosat\", ".."\""..x.."\""..", ".."\""..y.."\""..",".."\""..z.."\")")
          f.close()
          print("Created startup file.")
        end
      end
      rednet.send(id, "Arrived at level "..y.."!")
      print("Arrived at level "..y.."!")
    else
      rednet.send(id, "You are not permitted to execute this command!")
      print(id, " failed to execute up.")
    end

  -- Reboot command
  elseif msg:lower() == "reboot" then
    if table.find(id, tAuthed) then
      rednet.send(id, "Rebooting...")
      shell.run("reboot")
    else
      rednet.send(id, "You are not permitted to execute this command!")
      print(id, " failed to execute up.")
    end
  end
end