Turtle Tunnel no torch

--[[
    Original Author
        Rasmus Sommer aka. TheSommer
        youtube.com/thesommersmc
        twitch.tv/thesommer
    Edited by Mjmac85

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

Edit:Place chest directly behind the turtle at the start point.

        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 makeBridge()
    if turtle.detectDown() == false then
        turtle.select(2)
        turtle.placeDown()
    end
end

local count = 1

--Emptys inventory into a chest
local function dropItems()
    local invCount = 4
    for invCount = 4, 16 do
        turtle.select(invCount)
        turtle.drop()
    end
    turtle.select(4)
end


--Turns the turtle around calls dropItems and goes back to mining
local function returnTrip(count)
    turtle.turnRight()
    turtle.turnRight()
    for moveCount = 1, count - 1 do
        tryForward()
    end
    turtle.turnLeft()
    dropItems()
    turtle.turnLeft()

    for moveCount = 1, count - 1 do
        tryForward()
    end
end


for i = 1, length do
--Checks item count and drops if full
    if turtle.getItemCount(16) > 0 then
        returnTrip(count)
    end
    tryForward()
    count = count + 1
    makeBridge()
    tryDigUp()
    turtle.turnLeft()
    tryDig()
    tryUp()
    tryDig()
--Torches taken out
    --if count % 8 == 0 then
        --turtle.select(3)
        --turtle.place()
    --end
    turtle.turnRight()
    turtle.turnRight()
    tryDig()
    tryDown()
    tryDig()
    turtle.turnLeft()
end

--Takes the turtle back to start point, drops items, and faces forward to start again
turtle.turnRight()
turtle.turnRight()
for i = 1, count - 1 do
    tryForward()
end
turtle.turnLeft()
dropItems()
turtle.turnLeft()
print("Finished boss!")