t = turtle

function distanceInput()
    print("Input Distance")
    num = io.read()
    num = tonumber(num)
    return num
end
function fuel(distance)
    t.refuel()
end
function hole(distance)
    while distance > 0 do
        if t.detectDown() then
            t.digDown()
            t.down()
        else
            t.down()
        end
    distance = distance - 1
    end
end
function modulo(tile)
    while tile > 8 do
        tile = tile - 8
    end
    print("Currently at tile: ", tile)
    return tile
end
function turn(num)
    while num > 0 do
        t.turnRight()
        num = num - 1
    end
end
function turnAround()
    t.turnLeft()
    t.turnLeft()
end
function dleft()
    t.turnLeft()
    print("Left")
    if t.detect() then
        t.dig()
        t.forward()
    else
        t.forward()
    end
    t.turnRight()
end
function dright()
    t.turnRight()
    print("Right")
    if t.detect() then
        t.dig()
        t.forward()
    else
        t.forward()
    end
    t.turnLeft()
end
function dback()
    turnAround()
    print("Backward")
    if t.detect() then
        t.dig()
        t.forward()
    else
        t.forward()
    end
    turnAround()
end
function dforward()
    print("Forward")
    if t.detect() then
        t.dig()
        t.forward()
    else
        t.forward()
    end
end
function mineLayer(module)
    if module == 2 or module == 4 or module == 6 or module == 8 then
        turn(module/2)
        dleft()
        dforward()
        dback()
        dback()
        dright()
        dright()
        dforward()
        dforward()
        dback()
        dleft()
    else
        turn((module+1)/2)
        dforward()
        dright()
        dback()
        dback()
        dleft()
        dleft()
        dforward()
        dright()
    end
end
function mine(distance)
    module = 0
    while distance > 0 do
        module = modulo(distance)
        mineLayer(module)
        t.up()
        distance = distance - 1
    end
end
function spiral()
    distance = distanceInput()
    fuel(distance)
    print("3x3 Spiral Initiated; No further input required")
    hole(distance)
    mine(distance)
end

spiral()