local sVersion = "1.2"
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 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.")
      if turtle.getFuelLevel() > 370 then
        while turtle.up() do
       end
           if tArgs[4] == "east" or tArgs[4] == "west" then
                        turtle.down()
                        turtle.down()
                        turtle.down()
                 f =    fs.open("startup", "w")
                                f.write([[shell.run("leosat", ]] ..[["]].. tArgs[1]..[[", ]] .. [["]].. "251"..[[", ]] .. [["]].. tArgs[3] ..[[", ]].. [["]]..  tArgs[4].. [[")]])
    f.close()
	   else

                 f =    fs.open("startup", "w")
                                f.write([[shell.run("leosat", ]] ..[["]].. tArgs[1]..[[", ]] .. [["]].. "254"..[[", ]] .. [["]].. tArgs[3] ..[[", ]].. [["]]..  tArgs[4].. [[")]])
    f.close()
        end
                rednet.send(id, "Arrived at top level!")
        print("Arrived at top level!")
      else
        rednet.send(id, "Not enough fuel left, please refuel!")
        print("Low fuel level!")
      end
    else
      rednet.send(id, "You are not permitted to execute this command!")
      print(id, " failed to execute up.")
    end
  end
end