[CC] quadPipe - with bug

--default values for command line arguments
--users can change these values if they wish, just keep in mind that command line arguments override these at run time
local defaults = {
  quadProgram = {"east","suck","north","west 3","up 54","east","drop","west","down 54", "east 2", "south"},
  numOfQuads = 3,
  delayMult = 1, --without a delay, all of the quads leave at the same time
  ignoreRedstone = false, --quadracopters will run all the time
  anyKeyTerminate = false, --if false then use ctrl-t
  bSide = "left", --side of quadracopter base
  rSide = "back", --side of redstone input
}
--user editables end here

local usage = {
  "multiple different args are accepted",
  "if multiple of the same arg are given then the last one will be used - this is redundent don't do it",
  "we will tell you that arg number which causes any errors",
  "  -h | print this usage information",
  "  -f <filePath> | where filePath points to a file which contains the quadProgram",
  "  -n <interger/number> | numOfQuads",
  "  -d <float/number> | delayMult",
  "  -r <side/\"ignore\"> | redstoneSide or ignoreRedstone = true",
  "  -b <side> | baseSide",
  "  -t <bool> | anyKeyTerminate",
}

local function printUsage()
  print(table.concat(usage, "\n"))
end

local function myError(msg, lvl)
  printUsage()
  error(msg, lvl+1)
end

local arg = {...}
--set vaiables to default, we will overide these with the arg later
local quadProgram = defaults.quadProgram
local numOfQuads = defaults.numOfQuads
local delayMult = defaults.delayMult
local ignoreRedstone = defaults.ignoreRedstone
local anyKeyTerminate = defaults.anyKeyTerminate
local bSide = defaults.bSide
local rSide = defaults.rSide

--lower case everything
for i = 1, #arg do
  if tostring(arg[i]) then
    arg[i] = string.lower(arg[i])
  end
end
--process arg
for i = 1, #arg do
  if arg[i] == "-h" then
    printUsage()
  elseif arg[i] == "-f" then --quadProgram
    do --make my editor look clearer
    myError("arg "..i.." Can't load file", 2)
    i = i + 1 --this is definatly really bad practise
    end --make my editor look clearer
  elseif arg[i] == "-n" then --numOfQuads
    do --make my editor look clearer
    local n = tonumber(arg[i+1])
    if n == nil or n < 1 then
      myError("arg "..i.." -n arg must be followed by a whole number greater than 0 (1 or greater are valid)", 2)
    else
      local a,b = math.modf(n)
      if b ~= 0 then
        myError("arg "..i.." -n arg must be followed by a whole number greater than 0 (1 or greater are valid)", 2)
      end
    end
    if n > 64 then
      print("arg "..i.." Warning: numOfQuads is larger than one stack(64). Did the max per base change or are you piping them in?")
    end
    numOfQuads = n
    i = i + 1 --this is definatly really bad practise
    end --make my editor look clearer
  elseif arg[i] == "-d" then --delayMult
    do --make my editor look clearer
    local d = tonumber(arg[i+1])
    if d == nil then
      myError("arg "..i.." -d arg must be followed by a number", 2)
    end
    delayMult = d
    i = i + 1 --this is definatly really bad practise
    end --make my editor look clearer
  elseif arg[i] == "-r" then --redstoneSide
    do --make my editor look clearer
    local r = tostring(arg[i+1])
    if r == nil then
     myError("arg "..i.." -r arg must be followed by a string representing a side or equal to 'ignore'", 2)
    end
    if r == "ignore" then
      ignoreRedstone = true
    elseif r == "left" or r == "right" or r == "front" or r == "back" then
      rSide = r
      ignoreRedstone  = false
    else
      myError("arg "..i.." -r arg must be followed by a string representing a side or equal to 'ignore'", 2)
    end
    i = i + 1 --this is definatly really bad practise
    end --make my editor look clearer
  elseif arg[i] == "-b" then --baseSide
    do --make my editor look clearer
    local b = tostring(arg[i+1])
    if b == nil then
      myError("arg "..i.." -b arg must be followed by a string representing a side", 2)
    end
    if b == "left" or b == "right" or b == "front" or b == "back" then
      bSide = r
    else
      myError("arg "..i.." -b arg must be followed by a string representing a side", 2)
    end
    i = i + 1 --this is definatly really bad practise
    end --make my editor look clearer
  elseif arg[i] == "-t" then --anyKeyTerminate
    do --make my editor look clearer
    local t = tostring(arg[i+1])
    if t == nil then
      nyError("arg "..i.." -t arg must be followed by a string equal to 'true' or 'false'", 2)
    end
    if t == "true" then
      anyKeyTerminate = true
    elseif t == "false" then
      anyKeyTerminate = false
    else
      myError("arg "..i.." -t arg must be followed by a string equal to 'true' or 'false'", 2)
    end
    i = i + 1 --this is definatly really bad practise
    end --make my editor look clearer
  else
    myError("arg "..i.." unprocessed arg",2)
  end
end


--main program
local base = peripheral.wrap(bSide)


print("Lupus590's Quadracopter Program\nLicenced under MIT") --http://opensource.org/licenses/mit-license.php
if anyKeyTerminate then
  print("Press any key to terminate.")
else
  print("Press ctrl-t to terminate.")
end

local event
if ignoreRedstone then
  --launch all drones
  local i = 1
  for i = 1, numOfQuads do
    base.flyQuad(quadProgram)
    sleep(delayMult*#quadProgram/numOfQuads)--don't want them all to go at the same time, we want roughly even spacing
  end
  while true do
    event = os.pullEvent()
    --no rest till we are done
    if event == "quad_landed" then
      base.flyQuad(quadProgram)
    elseif anyKeyTerminate and event == "key" then
      return
    end
  end--while true
else
  if redstone.getInput(rSide) then os.queueEvent("redstone") end --if redstone is already on then we need to simulate an update to do our stuff
  while true do
    event = os.pullEvent()
    if event == "redstone" then
      --launch all drones
      local i = 1
      for i = 1, numOfQuads do
        base.flyQuad(quadProgram)
        sleep(delayMult*#quadProgram/numOfQuads)--don't want them all to go at the same time, we want roughly even spacing
      end
      while redstone.getInput(rSide) do
        event = os.pullEvent()
        --no rest till we are done
        if event == "quad_landed" and redstone.getInput(rSide) then
          base.flyQuad(quadProgram)
        elseif anyKeyTerminate and event == "key" then
          return
        end
      end --while redstone

    elseif anyKeyTerminate and event == "key" then
      return
    end --if event == redstone
  end --while true
end--if ignoreRedstone