Tree cutter Turtle

gps = require("turtle_gps")


Drop_in_world = false

function check_inventory()

    -- check logs slot
    current_slot = 1
    over = turtle.getItemCount(current_slot)
    if over > 1 then
        turtle.select(current_slot)
        -- refuel
        while turtle.getFuelLevel() < 200 and over > 1 do
            turtle.refuel(1)
            over = over - 1
        end

        if over > 1 then
            if Drop_in_world then
                -- keeps 1 log to compare
                turtle.drop(over - 1)
            else
                while turtle.dropDown(over - 1) == false do
                    print("Inventory full. Press ENTER to continue")
                    read()
                end
            end
        end
    end

    -- check saplings slot
    current_slot = 2
    over = turtle.getItemCount(current_slot)
    if over < 5 then
        turtle.select(current_slot)
        turtle.suckDown(5 - over)
    end

    -- drop other slots' content
    for current_slot = 3, 16, 1 do
        over  = turtle.getItemCount(current_slot)
        if over > 0 then
            turtle.select(current_slot)

            -- refuel
            while turtle.getFuelLevel() < 200 and over > 0 do
                turtle.refuel(1)
                over = over - 1
            end

            if Drop_in_world then
                turtle.drop()
            else
                while turtle.dropDown() == false do
                    print("Inventory full. Press ENTER to continue")
                    read()
                end
            end
        end
    end

end


function check_layer()
    did_cut = false
    turtle.select(1)

    turnToDirection(Directions.Forward)
    if turtle.compare() then
        turtle.dig()
        did_cut = true
    end

    turnToDirection(Directions.Right)
    if turtle.compare() then
        turtle.dig()
        did_cut = true
    end

    turnToDirection(Directions.Backwards)
    if turtle.compare() then
        turtle.dig()
        did_cut = true
    end

    turnToDirection(Directions.Left)
    if turtle.compare() then
        turtle.dig()
        did_cut = true
    end


    turnToDirection(Directions.Forward)
    return did_cut
end

function plant()
    -- select the sapling slot
    turtle.select(2)
    planted = 0

    if turtle.getItemCount(2) >= 5 then
        turnToDirection(Directions.Forward)
        if turtle.detect() == false then
            turtle.place()
            planted = planted + 1
        end
        turnToDirection(Directions.Right)
        if turtle.detect() == false then
            turtle.place()
            planted = planted + 1
        end
        turnToDirection(Directions.Backwards)
        if turtle.detect() == false then
            turtle.place()
            planted = planted + 1
        end
        turnToDirection(Directions.Left)
        if turtle.detect() == false then
            turtle.place()
            planted = planted + 1
        end
    else
        print("Out of saplings")
    end

    return planted
end


-------------------------------
function main()
    Auto_refuel = false

    print("Please place 1 log in slot 1 and 5 saplings in slot 2 (less saplings can work)")
    print("_________________________________")
    print("Place a chest underneath the turtle to replenish saplings")
    print("_________________________________")
    print("Drop items in world [Y/n]?  (when using [vacuum] hoppers)")
    if string.lower(read()) == 'y' then
        Drop_in_world = true
        term.clear()
        term.setCursorPos(1, 1)
        print("Turtle will drop items infront of it")
    else
        term.clear()
        term.setCursorPos(1, 1)
        print("Turtle will drop items in the inventory below it")
    end

    -- refuel
    turtle.select(16)
    while turtle.getFuelLevel() < 200 do
        print("Not enough fuel: "..turtle.getFuelLevel().." / 200")
        print("place fuel in slot 16 and Press ENTER to continue...")
        read()
        turtle.refuel()
    end

    print("_________________________________")
    print("The turtle  will use logs to refuel during operation")
    print("Press ENTER to start logging")
    read()

    term.clear()
    term.setCursorPos(1, 1)


    read_position()

    print("Turtle is now logging trees...")
    if plant() > 0 then
        sleep(10)
    end


    while true do
        if check_layer() then
            if turtle.detectUp() then
                turtle.digUp()
            end
            moveTo(0,0,Local_z + 1, 'xyz')
        else
            if Local_z > 0 then
                moveTo(0,0,0, 'xyz')
                check_inventory()
                if plant() > 0 then
                    sleep(10)
                end
            else
                sleep(10)
            end
        end
    end

end


main()