Mineshaft

--[[
    Author
        Rasmus Sommer aka. TheSommer
        youtube.com/thesommersmc
        twitch.tv/thesommer

    How to use:
        Slot 1 - Fuel
        Slot 2 - (OPTIONAL) Torches

        mineshaft <param: right | left>
    OPTIONAL parameters: right OR left

    This program uses optional parameters.
    You don't HAVE to write something after the program name,
    but if you write "right" or "left" the turtle will place torches to the specified side.
--]]

local tArgs = { ... }
local side = "NA"
if #tArgs == 0 then
elseif #tArgs == 1 then
    if tArgs[1] == "right" then
        side = "right"
    elseif tArgs[1] == "left" then
        side = "left"
    else
        print ("Usage: mineshaft <param>")
        print ("OPTIONAL parameters: right OR left")
        print ("--- Using parameters will make the turtle place torches! ---")
    end
else
    print ("Usage: mineshaft <param>")
    print ("OPTIONAL parameters: right OR left")
    print ("--- Using parameters will make the turtle place torches! ---")
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
        if turtle.dig() == false then
            return false
        end
        sleep(0.5)
    end
end

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

local function tryDigDown()
    while turtle.detectDown() == true do
        if turtle.digDown() == false then
            return false
        end
        sleep(0.5)
    end
end

local function tryForward()
    if tryDig() == false then
        return false
    end
    tryRefuel()
    turtle.forward()
end

local function tryDown()
    if tryDigDown() == false then
        return false
    end
    tryRefuel()
    turtle.down()
end

local count = 0
local torchSpacing = 3

while true do
    count = count + 1
    if tryForward() == false then
        print("Can't dig that, aborting.")
        return
    end
    if tryDigUp() == false then
        print("Can't dig that, aborting.")
        return
    end

    if count % torchSpacing == 0 then
        if side == "right" then
            turtle.turnRight()
            tryDig()
            turtle.select(2)
            turtle.place()
            turtle.turnLeft()
        elseif side == "left" then
            turtle.turnLeft()
            tryDig()
            turtle.select(2)
            turtle.place()
            turtle.turnRight()
        end
    end

    if tryDown() == false then
        print("Can't dig that, aborting.")
        return
    end
    if tryDigDown() == false then
        print("Can't dig that, aborting.")
        return
    end
end