Farm Tools - Fir

local args = { ... }
local height = 0
local sapling = 0
local meal = 0

function suppliesLast()
  sapling = 0
  meal = 0
  if turtle.getItemCount(1) > 3 then
    sapling = 1
  end
  if turtle.getItemCount(2) > 0 then
    meal = 2
  end
  return sapling >= 0 and meal >= 0
end

function step()
  while not turtle.forward() do
    turtle.dig()
  end
end

function stepBack()
  if not turtle.back() then
    turtle.turnRight()
    turtle.turnRight()
    step()
    turtle.turnRight()
    turtle.turnRight()
  end
end

function stepUp()
  while not turtle.up() do
    turtle.digUp()
  end
end

function stepDown()
  while not turtle.down() do
    turtle.digDown()
  end
end

while suppliesLast() do
  height = 0
  turtle.select(sapling)
  step()
  step()
  turtle.turnRight()
  turtle.place()
  turtle.turnLeft()
  stepBack()
  turtle.place()
  turtle.turnRight()
  turtle.place()
  turtle.turnLeft()
  turtle.stepBack()
  turtle.place()
  turtle.select(meal)
  turtle.place()
  while turtle.detect() do
    turtle.dig()
    step()
    turtle.dig()
    step()
    turtle.turnRight()
    turtle.dig()
    turtle.turnLeft()
    stepBack()
    turtle.turnRight()
    turtle.dig()
    turtle.turnLeft()
    stepBack()
    stepUp()
    height = height + 1
  end
  for i = 1, height, 1 do
    stepDown()
  end
  turtle.turnRight()
  turtle.turnRight()
  for i = 3, 16, 1 do
    turtle.select(i)
    turtle.drop()
  end
  turtle.turnRight()
  turtle.turnRight()
end