Computercraft Turtle Sugar Farm

--[[

    TMDart's Modification of
        Lazy Nub's Sugar Cane Harvester v0.01a
    Original code http://www.pastebin.com/wG6EartB

        This program will teach your turtle how to
        harvest a micro farm of sugar cane crops.

        Things you will need are:

        1 Turtle (Felling,digging,mining does not matter)
        1 chest (wood,iron,gold,diamond you pick)
        1 bucket of water
        4 pieces of sugar cane to plant
        and a fuel source like coal. (fueling slot is slot 1)

        Link to you tube video: http://youtu.be/34B3dsVHU4s
        Link to post of program: http://www.computercraft.info/forums2/index.php?/topic/13176-lazy-nub-sugar-cane-farmer-v001/
        Pastebin link: http://pastebin.com/BXwFpnnc

        Type the following into your turtle to load program: (Must have http enabled)
        pastebin get BXwFpnnc sugarfarm

    To optionally enable automatic restarting:
    pastebin get BXwFpnnc startup

        There are two modes you can run the harvester in:
        Regular and Economy
        In Regular mode you will need to supply fuel to use it.
        In Economy mode you need no fuel in the turtle to use it.

        The following options modified by TMDart to reverse the modes on startup:
        Just start the program as normal to use economy.
        To enter normal mode start the program with /n after the program name.

        ie:  sugarfarm /n


]]--



--[[ Robust Turtle
 Modified version of
 Robust Turtle API by SpeedR
 integrated
]]--
--Digging with gravel/sand detection

        local maxTries = 5

function dig()
  local tries = 0
  while turtle.detect() do
    turtle.dig()
    sleep(0.5)
    tries = tries + 1
    if tries>maxTries then
      print("Error: dug for too long.")
      return false
    end
  end
  return true
end

function digUp()
  local tries = 0
  while turtle.detectUp() do
    turtle.digUp()
    sleep(0.5)
    tries = tries + 1
    if tries>maxTries then
      print("Error: dug up for too long.")
      return false
    end
  end
  return true
end

function digDown()
  local tries = 0
  while turtle.detectDown() do
    turtle.digDown()
    sleep(0.5)
    tries = tries + 1
    if tries>maxTries then
      print("Error: dug down for too long.")
      return false
    end
  end
  return true
end


--Traveling: Goes in the direction no matter what (almost)
--Will not be stopped by blocks or mobs
function forward(l)
  l=l or 1
  for i=1,l do
    local tries = 0
    while turtle.forward() ~= true do
      turtle.dig()
      turtle.attack()
      sleep(0.2)
      tries = tries + 1
      if tries>maxTries then
        print("Error: can't move forward.")
        return false
      end
    end
  end
  return true
end

function up(l)
  l=l or 1
  for i=1,l do
    local tries = 0
    while turtle.up() ~= true do
      turtle.digUp()
      turtle.attackUp()
      sleep(0.2)
      tries = tries + 1
      if tries>maxTries then
        print("Error: can't move up.")
        return false
      end
    end
  end
  return true
end

function down(l)
  l=l or 1
  for i=1,l do
    local tries = 0
    while turtle.down() ~= true do
      turtle.digDown()
      turtle.attackDown()
      sleep(0.2)
      tries = tries + 1
      if tries>maxTries then
        print("Error: can't move down.")
        return false
      end
    end
  end
  return true
end

function back(l)
  l=l or 1
  for i=1,l do
    if turtle.back() ~= true then
      turnAround()
      forward()
      turnAround()
    end
  end
end


--Place blocks
--Does not place when there's already the right block.
function place(block)
  turtle.select(block)
  if turtle.compare()==false then
    if turtle.getItemCount(block)==0 then
      outOfResource(block)
    end
    dig()
    turtle.place()
  end
end

function placeUp(block)
  turtle.select(block)
  if turtle.compareUp()==false then
    if turtle.getItemCount(block)==0 then
      outOfResource(block)
    end
    digUp()
    turtle.placeUp()
  end
end

function placeDown(block)
  turtle.select(block)
  if turtle.compareDown()==false then
    if turtle.getItemCount(block)==0 then
      outOfResource(block)
    end
    digDown()
    turtle.placeDown()
  end
end

local function outOfResource()
  print("Ran out of a resource. Block: ",block , ".")
  print("Refill, then say something to proceed.")
  read()
end

function placeRight(block)
  turtle.turnRight()
  place(block)
  turtle.turnLeft()
end

function placeLeft(block)
  turtle.turnLeft()
  place(block)
  turtle.turnRight()
end

function placeBack(block)
  turnAround()
  place(block)
  turnAround()
end

--place row     e.g. placeRow(up, marble, forward, 15)
function placeRow(placeDir, block, travelDir, l)
  l=l or 1
  for i=1,l do
    if placeDir == "forward" then
      place(block)
    elseif placeDir == "up" then
      placeUp(block)
    elseif placeDir == "down" then
      placeDown(block)
    elseif placeDir == "right" then
      placeRight(block)
    elseif placeDir == "left" then
      placeLeft(block)
    elseif placeDir == "back" then
      placeBack(block)
    else
      print('"', placeDir, '" is not a valid direction!')
      return false
    end
    if travelDir == "forward" then
      forward()
    elseif travelDir == "up" then
      up()
    elseif travelDir == "down" then
      down()
    elseif travelDir == "right" then
      strafeRight()
    elseif travelDir == "left" then
      strafeLeft()
    elseif travelDir == "back" then
      back()
    else
      print('"', travelDir, '" is not a valid direction!')
      return false
    end
  end
  return true
end


--Turning
function turnAround()
  turtle.turnRight()
  turtle.turnRight()
end

function right()
  turtle.turnRight()
end

function left()
  turtle.turnLeft()
end

function goRight(l)
  l=l or 1
  turtle.turnRight()
  forward(l)
end

function goLeft(l)
  l=l or 1
  turtle.turnLeft()
  forward(l)
end

function strafeRight(l)
  l=l or 1
  goRight(l)
  turtle.turnLeft()
end

function strafeLeft(l)
  l=l or 1
  goLeft(l)
  turtle.turnRight()
end
--[[ End of Robust Turtle
]]--

--[[
    MAIN LOOP START HERE
]]--

    local args = { ... }
    local running = true
    local isEconoMode = false
    local currFuelLevel = 0

if (#args == 0) then                -- start in Economy Mode or Regular
    isEconoMode = true
    print("Economy Mode Active")
elseif (args[1] == "/n") then
    isEconoMode = false
    print("Entering Regular Mode")
end

while running do                    -- start of main loop
    while not turtle.dig() do       -- start loop looking for harvest-able crop
        term.clear()
        if isEconoMode then
            print("Economy Mode Working...")
        else
            print("Regular Mode Working...")
        end
        left()
        turtle.select(1)            -- make sure on fuel slot
        if not isEconoMode then
            currFuelLevel = turtle.getFuelLevel()
            while (currFuelLevel ~= "unlimited")
            and (currFuelLevel < 4) do  -- if out of fuel stop to refuel
                print("Need fuel, refuelling from slot 1")
                turtle.refuel()
                currFuelLevel = turtle.getFuelLevel()
            end
        end
    end
                                    -- got growth so time to harvest
    dig()
    if not isEconoMode then
        down()
        dig()
    end
    turtle.dropDown()
    if not isEconoMode then
        up()
    end
end -- end of program