ComputerCraft Program: buildTunnel

--pastebin get H6kpjMY6

function isCobbleFront()
    if turtle.inspect() ~= "minecraft:cobblestone" then
        turtle.dig()
    end
end

function isCobbleUp()
    if turtle.inspectUp() ~= "minecraft:cobblestone" then
    turtle.digUp()
    end
end

function isCobbleDown()
    if turtle.inspectDown() ~= "minecraft:cobblestone" then
        turtle.digDown()
    end
end

function moveForward()
  if not turtle.detect() then
    turtle.forward()
    else turtle.dig()
  end
end

function checkUp()
  if not turtle.detectUp() then
    turtle.select(1)
    turtle.placeUp()
  end
end

function bottomSpot()
    isCobbleDown()
        if not turtle.detectDown() then
            turtle.select(1)
            turtle.placeDown()
        end
end

function firstLeftWall()
    turtle.turnLeft()
    --isCobbleFront()
    if not turtle.detect() then
        turtle.select(1)
        turtle.place()
    end
end

function secondLeftWall()
    turtle.up()
    --isCobbleUp()
    if not turtle.detect() then
        turtle.select(1)
        turtle.place()
    end
end

function aboutFace()
    for i = 1, 2 do
        turtle.turnLeft()
    end
end

function secondRightWall()
    --isCobbleFront()
    if not turtle.detect() then
        turtle.select(1)
        turtle.place()
    end
end

function roof()
    --isCobbleUp()
    if not turtle.detectUp() then
        turtle.select(1)
        turtle.placeUp()
    end
end

function firstRightWall()
    turtle.down()
    --isCobbleFront()
    if not turtle.detect() then
        turtle.select(1)
        turtle.place()
    end
end

print("How far would you like to go?")
distance = io.read()

for i = 1, distance do
        bottomSpot()
        firstLeftWall()
        secondLeftWall()
        aboutFace()
        secondRightWall()
        roof()
        firstRightWall()
        secondRightWall()
        turtle.turnLeft()
        moveForward()
end