semistationaryTreeFarm.lua

local sapling = "minecraft:sapling"
local wood = "minecraft:log"
local sleepTime = 35
local beneath = {"minecraft:stone", 1} -- blockname, damage


local function isHome()
  local isBlock, block = turtle.inspectDown()
  if isBlock then
    if block.name == beneath[1] and block.metadata == beneath[2] then
      return true
    end
  end

  return false
end

local function moveSaplings()
  local slot1 = turtle.getItemDetail(1)
  if slot1 and slot1.name ~= sapling then
    turtle.select(1)
    for i = 2, 16 do
      if turtle.transferTo(i) then
        break
      end
    end
  end

  for i = 2, 16 do
    local sloti = turtle.getItemDetail(i)
    if sloti and sloti.name == sapling then
      turtle.transferTo(1)
    end
  end
end

local function emptyInv()
  turtle.turnRight()
  for i = 2, 16 do
    turtle.select(i)
    turtle.drop()
  end
  turtle.turnLeft()
end

local function digTree()
  local up = 0
  while turtle.detectUp() do
    for i = 1, 4 do
      turtle.dig()
      turtle.turnRight()
    end
    turtle.digUp()
    turtle.up()
    up = up + 1
  end

  for i = 1, up do
    turtle.down()
  end
  turtle.back()
end

local function refuel()
  local function dropInGoodOrder()
    for i = 1, 16 do
      local item = turtle.getItemDetail(i)
      if item and item.name == wood then
        turtle.select(i)
        turtle.drop()
      end
    end
    for i = 1, 16 do
      turtle.select(i)
      turtle.drop()
    end
  end


  local function pullWood()
    print("Pulling wood")
    for i = 1, 16 do
      turtle.select(i)
      turtle.suck()
      local item = turtle.getItemDetail(i)
      if item and item.name ~= wood then
        turtle.drop()
        break
      elseif not item then
        break
      end
    end
  end

  local function grab()
    turtle.select(1)
    for i = 1, 16 do
      turtle.suck()
    end
  end

  local function plankRefuel()
    pullWood()

    local h = 0
    print("Checking # stacks of logs")
    for i = 1, 16 do
      if turtle.getItemCount(i) > 0 then
        h = h + 1
      end
    end
    if h == 0 then
      print("No items to refuel with.")
      grab()
      return
    end

    print("dropping extra wood")
    for i = 2, 16 do
      turtle.select(i)
      turtle.drop()
    end

    print("Crafting.")
    turtle.craft()

    print("refuelling using planks recieved.")
    for i = 1, 16 do
      turtle.select(i)
      turtle.refuel()
    end

    if h > 1 then return plankRefuel() end
    grab()
  end

  local max = turtle.getFuelLimit()
  local cur = turtle.getFuelLevel()
  print("fuel:", cur, '/', max)

  if cur < max * 0.05 then
    print("Doing a refuelly boi")
    turtle.turnLeft()
    dropInGoodOrder()
    -- drop all items in inventory into chest, wood first.
    plankRefuel()
    turtle.turnRight()
  end

end

local function checkLog()
  local isBlock, block = turtle.inspect()
  if isBlock then
    if block.name == wood then
      return true, true -- there is a log, place sapling after op.
    end

    if block.name ~= sapling then
      return true, true -- there isn't a log, but dig and replace what is there.
    end
    return false, false -- there is no log, but likely sapling, do not place sapling.
  end

  return false, true -- there is no block at all, place sapling.
end

----------------------------------------------------------
local function main()
  while true do
    print("==================================")
    assert(isHome(), "Please return me to homebase.")
    print("At home. Run.")

    local doDig, doSapling = checkLog()
    if doDig then
      print("Digging.")
      turtle.dig()
      turtle.forward()
      digTree()
    end
    moveSaplings()
    if doSapling then
      print("Placing a sapling.")
      turtle.select(1)
      assert(turtle.place())
    end

    print("Do Refuel.")
    refuel()
    moveSaplings()

    print("Empty inventory")
    emptyInv()

    print("Waiting " .. tostring(sleepTime) .. " seconds.")
    os.sleep(sleepTime)
  end
end

main()