2*2 Tree Feller

--2*2 tree farm
--made by warfar
--http://pastebin.com/u/warfar
local y = 0
local function askForFuel()
    while turtle.getFuelLevel() < 500 do
        print("Low fuel, please place fuel in slot 10.")
        turtle.select(10)
        turtle.refuel()
        sleep(.01)
    end
end
local function printSlots()
    print("Please place sapling in slot 13 and 1,bonemeal in slot 14 and 2, and logs in slot 15 and 3.")
    while true do
        if turtle.getItemCount(13) ~= 0 and turtle.getItemCount(14) ~= 0 and turtle.getItemCount(15) ~= 0 then
            return
        end
        sleep(1)
    end
end
if turtle.getFuelLevel() < 500 then
    askForFuel()
end
if turtle.getItemCount(13) == 0 or turtle.getItemCount(14) == 0 or turtle.getItemCount(15)  == 0 then
    printSlots()
end
local function plant()
    turtle.select(1)
    turtle.up()
    turtle.forward()
    if turtle.detectDown() then turtle.digDown() end
    turtle.placeDown()
    turtle.forward()
    if turtle.detectDown() then turtle.digDown() end
    turtle.placeDown()
    turtle.turnLeft()
    turtle.forward()
    if turtle.detectDown() then turtle.digDown() end
    turtle.placeDown()
    turtle.turnLeft()
    turtle.forward()
    if turtle.detectDown() then turtle.digDown() end
    turtle.placeDown()
    turtle.forward()
    turtle.turnLeft()
    turtle.forward()
    turtle.turnLeft()
    turtle.down()
    turtle.select(2)
    sleep(.1)
    turtle.place()
    turtle.select(1)
end
local function checkSlots()
    if turtle.getItemCount(1) < 4 or turtle.getItemCount(2) == 0 then
        turtle.select(1)
        turtle.suckDown()
        turtle.turnLeft()
        turtle.select(2)
        turtle.suck()
        turtle.turnRight()
    end
    if turtle.getItemCount(1) < 4 or turtle.getItemCount(2) == 0 then
        error("No items in chest!")
    end
    if turtle.getItemCount(1) > 4 then
        turtle.select(1)
        turtle.transferTo(11,turtle.getItemCount(1) - 4)
        turtle.select(11)
        turtle.dropDown()
    end
end
local function fellTree()
    local y = 0
    turtle.select(3)
    turtle.dig()
    turtle.forward()
    while turtle.detectUp() do
        turtle.digUp()
        turtle.up()
        y = y + 1
    end
    turtle.dig()
    turtle.forward()
    for i=1,y do
        turtle.digDown()
        turtle.down()
    end
    turtle.turnLeft()
    turtle.dig()
    turtle.forward()
    for i=1,y do
        turtle.digUp()
        turtle.up()
    end
    turtle.turnLeft()
    turtle.dig()
    turtle.forward()
    for i=1,y do
        turtle.digDown()
        turtle.down()
    end
    turtle.up()
    turtle.forward()
    turtle.turnLeft()
    turtle.forward()
    turtle.turnLeft()
    turtle.down()
end
local function dropOff()
    turtle.turnLeft()
    turtle.turnLeft()
    for i = 1,12 do
        turtle.select(i)
        if turtle.compareTo(15) then
            turtle.drop()
        end
    end
    for i = 2,12 do
        turtle.select(i)
        if turtle.compareTo(13) then
            turtle.dropDown()
        end
    end
    turtle.turnLeft()
    turtle.turnLeft()
    while redstone.getInput("right") do sleep(1) end
end
while true do
    checkSlots()
    plant()
    fellTree()
    dropOff()
end