Tunnel V2

-- Function to place a torch behind the turtle
local function placeTorch()
    turtle.select(2) -- Select torch slot
    turtle.place()  -- Place torch
end

-- Function to drop items behind the turtle when inventory is full
local function dropItems()
    for slot = 3, 16 do
        turtle.select(slot)
        turtle.drop()
    end
end

-- Main function to dig the tunnel
local function digTunnel(length, resumeIfNoTorches)
    local torchInterval = 10
    local torchesAvailable = true
    local fuelLevel = turtle.getFuelLevel()

    for i = 1, length do
        -- Check fuel level and refuel if needed
        if fuelLevel == nil or fuelLevel <= 0 then
            print("Out of fuel!")
            -- Attempt to refuel
            if not turtle.refuel() then
                print("Unable to refuel!")
                return
            end
            fuelLevel = turtle.getFuelLevel() -- Update fuel level
        end

        -- Dig forward
        if not turtle.dig() then
            -- If unable to dig, try to move forward and dig again
            turtle.forward()
            turtle.dig()
        end

        -- Drop items behind the turtle if inventory is full
        if turtle.getItemCount(16) > 0 then
            dropItems()
        end

        -- Place torch every torchInterval blocks behind the turtle
        if torchesAvailable and i % torchInterval == 0 then
            if turtle.getItemCount(2) > 0 then
                placeTorch()
            else
                print("Out of torches!")
                if not resumeIfNoTorches then
                    return
                end
                torchesAvailable = false
            end
        end

        -- Move up and clear any obstacles
        if not turtle.digUp() then
            turtle.up()
        end
    end
end

-- Main program
local args = {...}
local tunnelLength = tonumber(args[1])
local resumeIfNoTorches = args[2] == "true"

if tunnelLength == nil or tunnelLength <= 0 then
    print("Invalid tunnel length. Please provide a positive number as argument.")
    return
end

if tunnelLength == math.huge then
    tunnelLength = 999999999 -- Set a large finite number for infinite tunneling
end

print("Digging tunnel...")
digTunnel(tunnelLength, resumeIfNoTorches)
print("Tunneling complete.")