ComputerCraft Platform Builder

--[[
Credit to Zach Dyer for the original program that I based this on
'Easy Platform Builder'.

Current version: 2.0
Pastebin: M0i8fDU5

Customized by MMaster

Changelog:
5/20/2014 - added torch placing, block detection
5/31/2014 - added mob attacking, better block detection,
inventory requests when empty, resume on keypress.
--]]

local tArgs = {...}

local length = tonumber(tArgs[1])
local width = tonumber(tArgs[2])
local torch_interval = tonumber(tArgs[3])
local go_down = tonumber(tArgs[4])

if torch_interval == nil then
    torch_interval = 0
end
if go_down == nil then
    go_down = 0
end

local turnRight = true
local slot = 1
local interval = 0

function pauseAnyKey()
   -- if event == "key" and p1 == keys.q then
   while true do
        local event, p1,p2,p3 = os.pullEvent()
        if event == "key" then
            return p1
        end
        sleep(0.5)
   end
end

-- Kudos to BlockSmith on ComputerCraft.info forums for the suggestion!
function refuel(dim1,dim2)
        dim1 = dim1 or 1
        dim2 = dim2 or 1
        fuelReq = dim1 * dim2
        turtle.select(15)
        while (turtle.getFuelLevel() < fuelReq) do
                --inform the user that the turtle is out of fuel
                print("Waiting for fuel in slot 15...")
                print("Press any key to continue.")
                pauseAnyKey()
                -- use all of the fuel in slot 15
                turtle.refuel()
                -- then go back and check the level again
        end

        -- select the active slot
        turtle.select(slot)
end

function flip()
    turtle.turnRight()
    turtle.turnRight()
end

function digDetect()
    while turtle.detect() do
        turtle.dig()
    end
end

function psycho()
    turtle.attack()
    turtle.attackUp()
    turtle.attackDown()
    turtle.turnLeft()
    turtle.attack()
    turtle.turnRight()
    turtle.turnRight()
    turtle.attack()
    turtle.turnLeft()
end

function digDetectUp()
    while turtle.detectUp() do
        turtle.digUp()
    end
end

function tryForward()
    while not turtle.forward() do
        psycho() --turtle.attack()
        turtle.dig()
    end
end

function tryPlaceDown(mode)
    mode = mode or "ignore me"
    while not turtle.placeDown() do
        if mode == "dig" then
            turtle.digDown()
        end
        --turtle.attackDown()
        psycho()
        turtle.attack()
    end
end

function findInventory()
    for i=slot,14 do
        if turtle.getItemCount(i) > 0 then
            return i
        end
    end
    for i=1,slot-1 do
        if turtle.getItemCount(i) > 0 then
            return i
        end
    end
    return -1
end

function torchPlacer()
    turtle.select(16)
    if turtle.getItemCount(16) == 0 then
        print("I need more torches!")
        print("Put more torches in slot 16 and press any key to make me resume!")
        pauseAnyKey()
    end
    turtle.placeBack()
end

if width == nil then
    print("1. Place turtle facing direction of said platform on left side.")
    print("2. Load turtle with materials for the platform. If placing torches, add light source blocks to slot 16.")
    print("3. Type 'platform <length> <width> [torch_interval]'")
    return
end

turtle.select(slot)


-- set the initial fuel load
refuel(length,width)
tryForward()
if turtle.getItemCount(slot) == 0 then
x = findInventory()
while x == -1 do
  if x == -1 then
      print("I ran out of materials!")
      print("Put mats in slots 1 to 14 then")
      print("press any key to continue.")
      pauseAnyKey()
      x = findInventory()
  end
end
slot = x
end
for i = 1, go_down, 1 do
  turtle.down()
end
for j = 1, width, 1 do
  for i = 1, length, 1 do
    if turtle.getItemCount(slot) == 0 then
        x = findInventory()
      while x == -1 do
          if x == -1 then
              print("I ran out of materials!")
              print("Put mats in slots 1 to 14 then")
              print("press any key to continue.")
              pauseAnyKey()
              x = findInventory()
          end
     end
     slot = x
    end

    turtle.select(slot)
    tryPlaceDown("dig")

    if i < length then
      digDetect()
      tryForward()
    end

    if (torch_interval > 0) and (j % torch_interval == 0) then
        interval = interval + 1
        if interval == torch_interval then
          interval = 0
          torchPlacer()
        end
    end

  end

  if j < width then

    if turnRight == true then
      turtle.turnRight()
      digDetect()
      tryForward()
      turtle.turnRight()
      turnRight = false
    else
      turtle.turnLeft()
      digDetect()
      tryForward()
      turtle.turnLeft()
      turnRight = true
    end

  end

  refuel(5) -- cursory check for fuel
end