FirstTestTunnel

--[[
    Author
        Rasmus Sommer mod by me

    How to use:
        Slot 1 - Fuel
        Slot 2 - Bridge material
        Slot 3 - Torches

        torchedtunnel <length>
--]]

local tArgs = { ... }
if #tArgs ~= 1 then
    print( "Usage: torchedtunnel <length>" )
    return
end

local length = tonumber( tArgs[1] )
if length < 1 then
    print( "Tunnel length must be positive" )
    return
end

local function tryRefuel()
    if turtle.getFuelLevel() == 0 then
        turtle.select(1)
        turtle.refuel(1)
    end
end

local function tryDig()
    while turtle.detect() == true do
        turtle.dig()
        sleep(0.5)
    end
end

local function tryDigUp()
    while turtle.detectUp() == true do
        turtle.digUp()
        sleep(0.5)
    end
end

local function tryUp()
    tryDigUp()
    tryRefuel()
    turtle.up()
end

local function tryDown()
    while turtle.detectDown() == true do
        turtle.digDown()
        sleep(0.5)
    end
    tryRefuel()
    turtle.down()
end

local function tryForward()
    tryDig()
    tryRefuel()
    turtle.forward()
end

local function tryBackward()
    tryRefuel()
    turtle.back()
end

local function makeBridge()
    if turtle.detectDown() == false then
        turtle.select(2)
        turtle.placeDown()
    turtle.turnLeft()
    if turtle.detect() == false then
        turtle.place()
    end
    turtle.turnRight()
    turtle.turnRight()
    if turtle.detect() == false then
        turtle.place()
    end
    turtle.turnLeft()
    end
end

local count = 1
while true do
    tryForward()
    makeBridge()
    tryDigUp()
    if count % 8 == 0 then
        turtle.select(3)
        turtle.placeUp()
    end
    count = count + 1
end

for i = 1, length do
    tryBackward()
end
for i = 4, 16 do
    turtle.select(i)
    turtle.dropDown()
end