ChopTree

local success = false
local data = nil

local facing = 1;

local height = 0;

---------------------------------------
-- BASIC FUNCTIONS FOR TURTLE CONTROL -
---------------------------------------

local function gf(n)
  if n==nil then
    n=1
  end
  for i=1,n,1 do
    turtle.forward()
  end
end
local function gb(n)
  if n==nil then
    n=1
  end
  for i=1,n,1 do
    turtle.back()
  end
end
local function gu(n)
  if n==nil then
    n=1
  end
  for i=1,n,1 do
    turtle.up()
  end
end
local function gd(n)
  if n==nil then
    n=1
  end
  for i=1,n,1 do
    turtle.down()
  end
end
local function tl()
  turtle.turnLeft()
  if facing == 1 then
    facing = 4
  else
    facing = facing - 1
  end
end
local function tr()
  turtle.turnRight()
  if facing == 4 then
    facing = 1
  else
    facing = facing + 1
  end
end
local function pf()  turtle.place()       end
local function pu()  turtle.placeUp()     end
local function pd()  turtle.placeDown()   end
local function df()  return turtle.dig()  end
local function du()  turtle.digUp()       end
local function dd()  turtle.digDown()     end
local function sf()  turtle.suck()        end
local function su(n)
  if n==nil then
    while turtle.suckUp() do end
  else
    for i=1,n do
      turtle.suckUp()
    end
  end
end
local function sd(n)
  if n==nil then
    while turtle.suckDown() do end
  else
    for i=1,n do
      turtle.suckDown()
    end
  end
end
local function Df()  turtle.drop()       end
local function Du()  turtle.dropUp()     end
local function Dd(n)
  if n==nil then n=64 end
  turtle.dropDown(n)
end
local function ss(s) turtle.select(s)    end
local function cf() turtle.compare()     end
local function cu() turtle.compareUp()   end

---------------------------------------
--          Building Blocks          --
---------------------------------------

local function lightUp()
    redstone.setOutput("back", true)
    redstone.setOutput("right", true)
    redstone.setOutput("left", true)
    redstone.setOutput("top", true)
    redstone.setOutput("bottom", true)
end

local function findLog()
    repeat
        tl()
        success, data = turtle.inspect()
    until data.name == "minecraft:log"
end

local function chop2x2()
    data = nil
    repeat
        height = height - 1
        dd()
        gd()
        findLog()
        df()
        findLog()
        df()
    until height == 0
    gu()
end

local function chopTree()
    success, data = turtle.inspect()
    if data.name == "minecraft:log" then
        df()
        gf()
        while success do
            success, data = turtle.inspectUp()
            if data.name == "minecraft:log" then
                du()
                gu()
                height = height + 1
            else
                break
            end
        end
        success, data = turtle.inspect()
        if data.name == "minecraft:log" then
            df()
            gf()
            du()
            findLog()
            df()
            gf()
            du()
            findLog()
            df()
            gf()
            du()
            gb()
        else
            gd()
            height = height - 1
            success, data = turtle.inspect()
            if data.name == "minecraft:log" then
                df()
                gf()
                findLog()
                df()
                gf()
                findLog()
                df()
            end
        end
        if data.name == "minecraft:log" then
            chop2x2()
        else
            repeat
                gd()
                height = height - 1
            until height == 0
        end
    else
        print("No tree found")
    end
end

---------------------------------------
---------         MAIN        ---------
---------------------------------------

chopTree()

lightUp()