Ineentho's Cutter

trees = 3

local main

function clearInventory()
    slot = 1
    while slot < 16 do
        slot = slot + 1
        turtle.select(slot)
        turtle.drop()
    end
end

function plantSaplings()
    turtle.select(1)
    turtle.forward()
    turtle.place()
    turtle.turnRight()
    turtle.forward()
    turtle.turnLeft()
    turtle.place()
    turtle.turnLeft()
    turtle.forward()
    turtle.turnLeft()
    turtle.turnLeft()
    turtle.place()
    turtle.turnRight()
    turtle.forward()
    turtle.turnRight()
    turtle.turnRight()
    turtle.place()
end

function dropAndLoot()
    --Saplings should be in the first slot
    --and logs in the rest (but always in the last)

    --Drop all logs and take back one stack
    turtle.turnLeft()
    clearInventory()
    turtle.select(16)
    turtle.suck()

    --rotate to the other chest
    turtle.turnLeft()
    turtle.turnLeft()

    --Loot one stack saplings..
    turtle.select(1)
    turtle.suck()

    --and drop the rest..
    turtle.select(2)
    turtle.drop()

    --Rotate to its orginal position
    turtle.turnLeft()
end

function checkFuel()
    while turtle.getFuelLevel() < 500 do
        turtle.select(16)
        if turtle.refuel(1) then
            if turtle.getFuelLevel() < 500 then
                print("Fuel level (waiting for 500): " .. turtle.getFuelLevel())
            end
        else
            --Fuel level too low and no logs left.
            dropAndLoot()
        end
    end
end

function cutTree()

    --Get inside of the tree
    turtle.dig()
    turtle.forward()

    treeHeight = 0

    --Climb the tree up
    while turtle.dig() do
        turtle.digUp()
        turtle.up()
        treeHeight = treeHeight + 1
    end

    --At the top, get to the second half of the tree
    turtle.turnRight()
    turtle.dig()
    turtle.forward()
    turtle.turnLeft()
    turtle.digDown()
    turtle.down()
    turtle.dig()
    --Get down again

    level = treeHeight - 1

    while level > 0 do
        level = level - 1
        turtle.digDown()
        turtle.down()
        turtle.dig()
    end

    --Get back to the starting position
    turtle.turnLeft()
    turtle.forward()
    turtle.turnLeft()
    turtle.forward()
    turtle.turnLeft()
    turtle.turnLeft()

    print("Tree cut.")
    print("Replanting saplings")
    plantSaplings()
    print("Planted saplings.")

end

function goForward(steps)
    for step = 1, steps, 1 do
        turtle.forward()
    end
end

function waitForNext()
    for i = 3, 1, -1 do
        print("Waiting " .. i .. " minutes..")
        sleep(60)
    end
end

function nextTree()
    tree = tree + 1
    if tree > trees then
        print("Returning to base..")
        turtle.turnRight()
        goForward(4 * (trees - 1) + 3)
        turtle.turnLeft()
        turtle.forward()
        turtle.turnRight()
        turtle.forward()
        turtle.turnLeft()
        turtle.turnLeft()
        turtle.down()
        waitForNext()
    else
        --Go to next tree
        turtle.turnLeft()
        goForward(4)
        turtle.turnRight()
        checkTree()
    end
end

function checkTree()
    turtle.select(1)
    if turtle.compare() then
        --It's still a sapling, go to next tree.
        print("Still saplings")
        nextTree()
    else
        print("Tree is fully grown. Cutting.")
        cutTree()
        nextTree()
    end
end

function goToFirstTree()
    --Move from the starting position to the cutting position of the first tree.
    turtle.up()
    turtle.forward()
    turtle.forward()
    turtle.turnLeft()
    turtle.forward()
    turtle.turnRight()
    turtle.forward()
    turtle.forward()
    turtle.turnRight()

    tree = 1

    checkTree()
end

function main()
    dropAndLoot()
    checkFuel()
    goToFirstTree()
end

while true do
    --Main is run once for each "round"
    main()
    print("Done")
end