Mine

------------
--slot 1 is crapslot

direction = "north"
tdirection = "north"
x = 0
y = 0
z = 0

lx = 0
ly = 0
lz = 0

tx = 0
ty = 0
tz = 0
gotnumber = false
dropCobble = true
finished = false
movedown = false
full = false
fuelComeBack = true
function mine()
    turtle.dig()
end

function compareItems()

    if not turtle.detect() then return true end
    for i=1 , 16 do
        turtle.select(i)
        amount = turtle.getItemCount(i)
        if amount == 0 then return true end
        if turtle.compare() and amount<64 then return true end

    end
    return false
end
function dumpItems()
    if not dropCobble then
        turtle.select(1)
        if not turtle.drop() and turtle.getItemCount(i) > 0 then
            return false
        end
    end
    for i=2 , 16 do
        turtle.select(i)
        if not turtle.drop() and turtle.getItemCount(i) > 0 then
            return false
        end
    end
    return true
end
function goFurther()
    turtle.turnRight()
    turtle.turnRight()
    while ly < ty do
        turtle.down()
        ly = ly + 1
    end
    if tdirection == "west" then tz = tz - 1 end
    while lz < tz do

        turtle.forward()
        lz = lz + 1
    end
    turtle.turnRight()
    while lx < tx do

        turtle.forward()
        lx = lx + 1
    end
    direction = "east"
    if tdirection == "north" then

        turtle.turnLeft()
        direction = "north"
    end
    if tdirection == "west" then

        turtle.turnLeft()

        turtle.forward()
        lz = lz + 1
        turtle.turnLeft()
        direction = "west"
    end

end
function goBack()

    tx = lx
    ty = ly
    tz = lz
    tdirection = direction
    if direction == "west" then
        turtle.turnLeft()
        turtle.forward()
        turtle.turnRight()
    end

    --- first go back to x = 0
    if direction == "north" then
        direction = "west"
        turtle.turnLeft()
    end
    if direction == "east" then
        direction = "west"
        turtle.turnLeft()
        turtle.turnLeft()
    end

    while lx > 0 do
        turtle.forward()
        lx = lx - 1
    end
    turtle.turnLeft()

    --- then go back to chest
    while lz > 0 do
        turtle.forward()
        lz = lz - 1
    end
    if ly == y  and not full then
        finished = true
        print("I'm at the correct level")
    end

    tlevel = ly
    while ly > 0 do
        turtle.up()
        ly = ly - 1
    end
    if not dumpItems() then
        finished = true
        print("I couldn't drop my items")
    end
    turtle.select(1)
    if full then
        goFurther()
    elseif not finished and movedown then
        tlevel = tlevel + 1
        while ly < tlevel do
            turtle.digDown()
            turtle.down()
            ly = ly + 1
        end
        turtle.turnRight()
        turtle.turnRight()
        direction = "north"
    end
    movedown = false
    full = false
end

function move()
    while not turtle.forward() do
        mine()
    end
    if direction == "north" then lz = lz + 1
    elseif direction == "west" then lx = lx - 1
    elseif direction == "east" then lx = lx + 1
    else lz = lz - 1
    end

    if lx == 0 and direction == "north" then
        turtle.turnRight()
        direction = "east"
    end

    if lx == x and direction == "north" then
        turtle.turnLeft()
        direction = "west"
    end

    if lx == 0 and direction == "west" then

        turtle.turnRight()
        direction = "north"
        if lz == z then
            movedown = true
            goBack()
        end
    end

    if lx == x  and direction == "east" then

        turtle.turnLeft()
        direction = "north"
        if lz == z then
            movedown = true
            goBack()
        end

    end


end
function checkItems()
    for i=1 , 16 do
        n = turtle.getItemCount(i)
        if n == 64 then
            if i == 1 and dropCobble == true then
                turtle.select(1)
                turtle.drop(63)
            else
                full = true
                goBack()
            end
        end
    end
end

function checkFuel()

    fuelNeeded = lx+lz+ly+5
    fuelLevel = turtle.getFuelLevel()
    if fuelComeBack and fuelLevel<fuelNeeded then
        finished = true
        goBack()
        print("Fuel is up")
    elseif fuelLevel<1 then
        finished = true
        print("Fuel is up")
    end


end


----start
turtle.select(1)
term.clear()
term.setCursorPos(1,1)
print("What dimensions do you want?")
print("")


while not gotnumber do
    term.write("X: ")
    x = io.read()
    gotnumber = true
    if not tonumber(x) or x == "0" then
        print("Please enter a number higher than 0")
        gotnumber = false
        end
    end
gotnumber = false
while not gotnumber do
    term.write("Y: ")
    y = io.read()
    gotnumber = true
    if not tonumber(y) or y == "0" then
        print("Please enter a number higher than 0")
        gotnumber = false
        end
    end

gotnumber = false
while not gotnumber do
    term.write("Z: ")
    z = io.read()
    gotnumber = true
    if not tonumber(z) or z == "0" then
        print("Please enter a number higher than 0")
        gotnumber = false
        end
    end
answer = "no"
gotnumber = false
while not gotnumber do
    term.write("Drop cobblstone? ")
    answer = io.read()
    gotnumber = true
    if answer == "no" or answer == "yes" or answer == "y" or answer == "n" or answer == "true" or answer == "false" or answer == "1" or answer == "0" then break end
    print("Please say yes or no")
    gotnumber = false
end
if answer == "yes" or answer == "y" or answer == "true" or answer == "1" then dropCobble = true else dropCobble = false end

answer = "no"
gotnumber = false
while not gotnumber do
    print("Come back when fuel is up? ")
    answer = io.read()
    gotnumber = true
    if answer == "no" or answer == "yes" or answer == "y" or answer == "n" or answer == "true" or answer == "false" or answer == "1" or answer == "0" then break end
    print("Please say yes or no")
    gotnumber = false
end
if answer == "yes" or answer == "y" or answer == "true" or answer == "1" then fuelComeBack = true else fuelComeBack = false end


x = math.abs(tonumber(x))-1
y = math.abs(tonumber(y))-1
z = math.abs(tonumber(z))


while not finished do
    --if not compareItems() then full = true goBack() end
    mine()
    checkItems()
    move()
    checkFuel()

end
turtle.turnRight()
turtle.turnRight()