ComputerCraft/Tree_Farm/farmtree.lua

--[[Tree Farming App by Al Sweigart
Plants tree and cuts it down.]]

os.loadAPI('modules.lua') -- Load the modules module

local NUM_OF_TREES = 4
local TREE_SAPLING = 'oak'

-- Check if choptree program exists
if not fs.exists('choptree.lua') then
  error('You must install choptree app first')
end

while true do
  -- First of all, wait a few minutes
  os.sleep(300)

  -- Sort all Items together
  modules.sort_items()


  -- Empty everything except for the saplings
  for i = 1, 16 do
    local item = turtle.getItemDetail(i)

    if item ~= nil and item['name'] ~= 'minecraft:' .. TREE_SAPLING .. '_sapling' then
      turtle.select(i)
      turtle.drop()
    end
  end


  -- Check if we have saplings in our inventory
  if not modules.select_item('minecraft:' .. TREE_SAPLING .. '_sapling') then
    error('Out of ' .. TREE_SAPLING .. ' saplings')
  end

  -- Build a Loop, where we plant and cut trees
  turtle.turnLeft()
  turtle.turnLeft()
  for i = 1, NUM_OF_TREES do
    for j = 1, 3 do
      check_fuel()
      if i ~= 3 * NUM_OF_TREES then
        turtle.dig()
      end
      turtle.forward()
    end
    turtle.turnLeft()
    blockExists, item = turtle.inspect()
    if blockExists and item['name'] == 'minecraft:' .. TREE_SAPLING .. '_log' then
      modules.selectEmptySlot()
      shell.run('choptree.lua') -- Run Choptree
    elseif blockExists and item['name'] ~= 'minecraft:' .. TREE_SAPLING .. '_sapling' then
      print('Error! Wrong block')
    elseif not blockExists then
      turtle.forward()
      local success, underneath = turtle.inspectDown()
      if underneath['name'] ~= 'minecraft:dirt' and underneath['name'] ~= 'minecraft:grass_block' then
        print('Error. No Dirt or Grass underneath to plant a tree. Found: ' .. underneath['name'])
        turtle.back()
      else
        turtle.back()
        modules.selectItem('minecraft:' .. TREE_SAPLING .. '_sapling')
        turtle.place()
      end
    end
    turtle.turnRight()
  end

  -- Move forward to the chest again
  turtle.turnLeft()
  turtle.turnLeft()
  for i = 1, (3 * NUM_OF_TREES) do
    check_fuel()
    if i ~= 3 * NUM_OF_TREES then
      turtle.dig()
    end
    turtle.foward()
  end

end