Better Mine (Computercraft)

function onEnd()
    if turtle.getFuelLevel() < 5000 then
        shell.run("refuel all")
    end
    turtle.select(1)
    while turtle.detect() do
        turtle.dig()
        os.sleep(0.3)
    end

    turtle.place()

    for i=2,16,1 do

        turtle.select(i)
        turtle.drop()

    end
    turtle.select(1)
    turtle.dig()
end

-- Presetup
if not fs.exists("appdata") then
    fs.makeDir("appdata")
end

if not fs.exists("appdata/bettermine") then
    fs.makeDir("appdata/bettermine")
end

local xfile = fs.open("appdata/bettermine/x", "w")
local yfile = fs.open("appdata/bettermine/y", "w")

local x = tonumber(xfile.readAll());
local y = tonumber(yfile.readAll());

-- Programm
turtle.select(1)
shell.run("clear")
if turtle.getFuelLevel() < 5000 then
    print("Not enough fuel, please put in fuel, it will be filled in automatically")
end
while turtle.getFuelLevel() < 5000 do
    turtle.refuel(64)
end
turtle.select(1)
if turtle.getItemSpace(1) > 63 then
    print("Please insert a enderchest into the first slot!")
end
while turtle.getItemSpace(1) > 63 do
    os.sleep(0.2)
end
shell.run("clear")
while true do

    while turtle.detect() do
        turtle.dig()
        os.sleep(0.3)
    end

    turtle.forward()

    for i=0,4,1 do
        while turtle.detectDown() do
            turtle.digDown()
            os.sleep(0.3)
        end
        turtle.down()
    end

    turtle.turnLeft()

    for i=0,4,1 do
        while turtle.detect() do
            turtle.dig()
            os.sleep(0.3)
        end
        turtle.forward()
    end

    turtle.turnLeft()
    turtle.turnLeft()

    for i=0,9,1 do
        while turtle.detect() do
            turtle.dig()
            os.sleep(0.3)
        end
        turtle.forward()
    end

    turtle.turnLeft()
    turtle.turnLeft()

    for i=0,8,1 do

        while turtle.detectUp() do
            turtle.digUp()
            os.sleep(0.3)
        end
        turtle.up()

        for i=0,9,1 do
            while turtle.detect() do
                turtle.dig()
                os.sleep(0.3)
            end
            turtle.forward()
        end

        turtle.turnLeft()
        turtle.turnLeft()
    end

    for i=0,4,1 do
        while turtle.detect() do
            turtle.dig()
            os.sleep(0.3)
        end
        turtle.forward()
    end

    for i=0,3,1 do
        while turtle.detectDown() do
            turtle.digDown()
            os.sleep(0.3)
        end
        turtle.down()
    end
    turtle.turnLeft()

    onEnd()
end