Felling Program

local clr, cp = term.clear, term.setCursorPos

local function ensure(func, ...) -- Thanks Fatboychummy
  local args = table.pack(...)
  while not func() do
    for i = 1, args.n do
      args[i]()
    end
  end
end

local function find(item)
  local slot = 1
  while slot ~= 17 do
    local data = turtle.getItemDetail(slot)
    if data then
      if data.name == item then return slot end
    end
    slot = slot + 1
  end
  return false
end

local function refuel()
  if turtle.getFuelLevel() == 0 then
    print("Refueling...")
    turtle.select(find("minecraft:coal_block") or find("minecraft:coal") or 1)
    turtle.refuel(1)
    if turtle.getFuelLevel() == 0 then
      print("Refuel Needed.")
      while turtle.getFuelLevel() == 0 do
        sleep(.5) turtle.select(find("minecraft:coal") or 1) turtle.refuel(1)
      end
    end
  end
end

local function forward() refuel() write("F") ensure(turtle.forward) end
local function reverse() refuel() write("B") ensure(turtle.back) end
local function up() refuel() write("U") ensure(turtle.up) end
local function down() refuel() write("D") ensure(turtle.down) end
local function turn(d) write("2") if d == 1 then ensure(turtle.turnRight) else ensure(turtle.turnLeft) end end

--[[

Only when idle: <<= create the config only when it is time to move
  - config file does not exist
Only while moving forward: <<= only edit config when starting to turn
  - config file exists with:
    - turned = false
Only while turning: <<== edit on every stage of turn
  - config file exists with:
    - turned = true
    - stage = x

--]]

local wait = 5
local tbl = {}
local function reset()
  local d = tbl.data or {farmed = 0}
  tbl = {waittimes = {wait, 0}, running = false, staging = false, stage = 0, ended = 0, data=d}
end reset()

local function save()
  write("*")
  local f = fs.open("/ft_config.lua", "w") f.write(textutils.serialize(tbl)) f.close()
end

if fs.exists("/ft_config.lua") then
  local f = fs.open("/ft_config.lua", "r")
  if not f then return printError("Failed to open ft_config.lua") end
  tbl = textutils.unserialize(f.readAll()) f.close()
  if type(tbl) ~= "table" then return printError("Failed to read ft_config.lua") end
end

clr()
print("Rebooted:")
print(textutils.serialize(tbl)) sleep(3) clr()


local stages = {
  turtle.dig,
  forward,
  turtle.digUp,
  up,
  turtle.digUp,
  up,
  turtle.digUp,
  up,
  turtle.digUp,
  up,
  turtle.digUp,
  down,
  down,
  down,
  down,
  reverse,
}

--[[
if turtle.detect() then
    if tbl.stage == 2 or tbl.stage == 5 then tbl.staging, tbl.ended = false, 1 return end
  end
  if tbl.stage == 6 then tbl.staging = false end
  if tbl.stage > 6 then tbl.stage = 1 end
  local tmp = tbl.stage
  if tbl.stage == 3 then tbl.staging = false end save()
  if tbl.ended ~= 1 then write("4["..tbl.stage.."]") stages[tmp]() end
--]]


local function doStage()
  tbl.stage = tbl.stage + 1
  if tbl.stage > #stages then tbl.stage, tbl.running = 0, false end save()
  if tbl.running then stages[tbl.stage]() else
    clr() local b,c = false, false
    for i=1, 16 do
      local a = turtle.getItemDetail(i)
      if a then
        if a.name == "minecraft:sapling" and not b then
          b=true
          turtle.select(i)
          turtle.transferTo(2,64)
        elseif a.name == "minecraft:coal_block" and not c then
          c=true
          turtle.select(i)
          turtle.transferTo(1,64)
        else
          turtle.select(i)
          turtle.dropDown(64)
        end
      end
    end
  end
end


while true do
  if tbl.running then
      doStage()
  else
    cp(1,1) print("Farmed: "..tbl.data.farmed)
    sleep(1) local a,b = turtle.inspect() if a then if b.name == "minecraft:log" then tbl.running = true end else local a = find("minecraft:sapling") if a ~= false then turtle.select(a) turtle.place() end end
    turtle.suckUp()
    turtle.suck()
  end
end