Logging v1.2

local args = {...}
local saplingSlot = 1
local logSlot = 2
local length = 20
local rows = 2
local treeSpacing = 4
local rowsSpacing = 4
local endOfLineOffset = 3
local maxCuttingHeight = 10

local repeats = 1


local function forward()
    while (not turtle.forward()) do
        if (turtle.detect()) then
            turtle.dig()
        else
            turtle.attack()
        end
    end
end

local function turn(curRow)
    if (curRow%2 == 1) then
        turtle.turnRight()
    else
        turtle.turnLeft()
    end
end

local function detectTree()
    if (turtle.detectUp()) then
        turtle.select(logSlot)
        if (turtle.compareUp()) then
            return true
        end
    end
    return false
end

local function cutTree()
    local height = 0
    turtle.digDown()
    while (detectTree()) do
        turtle.digUp()
        if (height < maxCuttingHeight) then
            while (not turtle.up()) do
                if (turtle.detectUp()) then
                    turtle.digUp()
                else
                    turtle.attackUp()
                end
            end
        end
        height = height +1
    end
    for i=1, height do
        while (not turtle.down()) do
            if (turtle.detectDown()) then
                turtle.digDown()
            else
                turtle.attackDown()
            end
        end
    end
end

local function plantSapling()
    turtle.select(saplingSlot)
    turtle.placeDown()
    turtle.suckDown()
end

local function moveLoop()

    for r=1, rows do
        for i=1, endOfLineOffset do
            forward()
        end

        for i=1, length do
            if (i%treeSpacing == 0 and turtle.getItemCount(saplingSlot)>1 ) then
                plantSapling()
            end

            forward()
            if (detectTree()) then
                cutTree()
            end
        end

        for i=1, endOfLineOffset do
            forward()
        end

        if (r ~= rows) then
            turn(r)
            for i=1, rowsSpacing do
                forward()
            end
            turn(r)
        end
    end
end

local function returnBase()
    local distanceToBase = (rows-1) * rowsSpacing -1
    local distanceToRowStart = 0

    if (rows%2 == 1) then
        distanceToRowStart = length+2*endOfLineOffset-1
        turn(1)
        forward()
        turn(1)
        for i=0, distanceToRowStart do
            forward()
        end
        turn(1)
        forward()
    else
        turn(1)
    end

    for i=0, distanceToBase do
        forward()
    end
    turn(1)
end

local function messageNeedSapplings()
    term.clear()
    print("Please put the correct sort of saplings in the first slot\nor in the chest the turtle is currently facing.")
    os.sleep(30)
end

local function manageInventory()
    local logDropCount = turtle.getItemCount(2)-1
    local fuelNeeded = ((length + (2*endOfLineOffset) + rowsSpacing) * rows + ((length/treeSpacing) * rows * maxCuttingHeight) ) - turtle.getFuelLevel()
    local saplingsNeeded = (length/treeSpacing*rows) - turtle.getItemCount(1)

    turtle.turnLeft()
    if (saplingsNeeded >0) then
        turtle.select(1)
        while (saplingsNeeded >0) do
            if (turtle.suck(saplingsNeeded)) then
                saplingsNeeded = (length/treeSpacing*rows) - turtle.getItemCount(1)
                if (saplingsNeeded > 0) then
                    messageNeedSapplings()
                end
            else
                messageNeedSapplings()
            end
        end

    end

    turtle.select(2)
    turtle.dropDown(logDropCount)


    for i=3, 16 do
        turtle.select(i)
        if (turtle.compareTo(1)) then
            turtle.drop()
        else
            turtle.dropDown()
        end
    end

    while (fuelNeeded > 0) do
        if (turtle.suckUp()) then
            print("Refuelling...")
        else
            term.clear()
            print("Waiting for fuel in the last inventory slot\nor in an inventory on top.")
            os.sleep(30)
        end
        turtle.refuel()
        fuelNeeded = ((length + (2*endOfLineOffset) + rowsSpacing) * rows + ((length/treeSpacing) * rows * maxCuttingHeight) ) - turtle.getFuelLevel()
    end

    turtle.turnRight()
end

local function mainLoop()
    local i=0
    if (args[1] > 1) then
        repeats = args[1]
    end
    while (i<repeats) do
        term.clear()
        print("Managing inventory")
        manageInventory()
        print("Starting move loop")
        moveLoop()
        print("Returning base")
        returnBase()

--~         Real line:
        os.sleep(300)

        i = i+1

    end
end

mainLoop()