Mining Turtle Tunnel 3x3 with Torches

-- 3 x 3 Tunnel with torches
local tArgs = {...}
print("Checking inventory...")

if (#tArgs ~= 1) then
    print("Program call: <mprogramName> <tunnelLength>")
    return
end

local tunnelLength = tonumber(tArgs[1])
local distanceTravelled = 0
local torchSlot = 1
local hasTorches = false;

-- define functions
local function EmptyInventory()
    print("Emptying inventory...")
    for i = 1, 16, 1 do
        turtle.select(i)
        turtle.drop()
    end
    print("Fuel left: "..turtle.getFuelLevel())
end

local function ReturnHome()
    print("Returning...")
    turtle.turnLeft()
    turtle.turnLeft()
    for i = 0, distanceTravelled, 1 do
        turtle.forward()
    end
    EmptyInventory()
end

local function CheckForFuel()
    local foundFuel = false
    for i = 1, 16, 1 do
        turtle.select(i);
        if (turtle.refuel(0)) then
            print("Found Fuel.")
            foundFuel = true
            print("Trying to refuel...");
            if (turtle.getFuelLevel() <= turtle.getFuelLimit()) then
                turtle.refuel()
                print("Refueled succesfully.")
            else
                print("Refueling failed. Fuel already full.")
            end
        end
    end
    turtle.select(1)
    if (foundFuel == false) then
        print("No fuel found!")
    end
    return foundFuel
end

local function CheckForTorches()
    hasTorches = false;
    for i = 1, 16, 1 do
        turtle.select(i)
        if (turtle.getItemDetail()) then
            if (turtle.getItemDetail().name == "minecraft:torch") then
                print("Found torches.")
                torchSlot = i
                hasTorches = true
            end
        end
    end
    if (hasTorches == false) then
        print("No torches found!.")
    end
    turtle.select(1)
    return hasTorches
end

local function CheckTorchSlot(index)
    turtle.select(index)
    if (turtle.getItemDetail()) then
        if (turtle.getItemDetail().name == "minecraft:torch") then
            return
        else
            print("torchSlot out of torches. Searching for torches...")
            CheckForTorches()
        end
    else
        print("torchSlot out of torches. Searching for torches...")
        CheckForTorches()
    end
end

local function CheckDistance()
    local isReturning = false
    if (turtle.getFuelLevel() <= distanceTravelled + 5) then
        print("Fuel is low.")
        if (CheckForFuel() == false) then
            isReturning = true
            print("Returning...")
            ReturnHome()
        end
    end
    return isReturning
end

local function ClearRow(setTorch)
    turtle.turnLeft()
    turtle.dig()
    turtle.turnLeft()
    turtle.turnLeft()
    turtle.dig()
    if (setTorch == true) then
        turtle.select(torchSlot)
        if (turtle.getItemDetail()) then
            if (turtle.getItemDetail().name == "minecraft:torch") then
                turtle.place()
            end
        end
        turtle.select(1)
    end
    turtle.turnLeft()
end

local function ClearBlock()
    ClearRow(false)
    turtle.digUp()
    turtle.up()
    if distanceTravelled % 6 == 0 then
        ClearRow(true)
    else
        ClearRow(false)
    end
    turtle.digUp()
    turtle.up()
    ClearRow(false)
end

local function ResetPosition()
    turtle.down()
    turtle.down()
    CheckDistance()
end

local function GoBackABlock()
    turtle.turnLeft()
    turtle.turnLeft()
    turtle.forward()
    turtle.turnLeft()
    turtle.turnLeft()
end

-- tunnel

if(CheckForFuel() == false and turtle.getFuelLevel() < 5) then
    print("Fuel is needed!")
    return
end

if (CheckForTorches() == false) then
    print("Torches are needed!")
    return
end

for i = 1, tunnelLength, 1 do
    ClearBlock()
    ResetPosition()
    turtle.dig()
    turtle.forward()
    distanceTravelled = distanceTravelled + 1
end
GoBackABlock()
ReturnHome()