Branch 1.2.1

local tArgs = {...}
local length = tArgs[1]
local numTunnels = tArgs[2]
local inv = true
local checkTorch = 0
local height = 0

-- The basic function to move forward and dig
function tunnel()
  -- These used throughout to erase screen
  term.clear()
  term.setCursorPos(1,1)
  print("Mining...")
  for i=1,length do
    fuel()
    turtle.dig()
    -- This loop prevents gravel from screwing it all up
    while turtle.forward() == false do
      turtle.dig()
    end
    turtle.digUp()
    torch()
  end
end

-- The function to turn around and go the other direction down the tunnel, also clears side tunnels
function turnAround()
  term.clear()
  term.setCursorPos(1,1)
  print("Turning around...")
  for k = 1,6 do
    fuel()
    turtle.dig()
    while turtle.forward() == false do
      turtle.dig()
    end
    turtle.digUp()
    torch()
  end

  checkInv()

  while turtle.back() == false do
    turtle.turnRight()
    turtle.turnRight()
    turtle.dig()
    for i = 1,3 do
      turtle.forward()
      turtle.dig()
    end
    turtle.turnRight()
    turtle.turnRight()
    for i = 1,3 do
      turtle.back()
    end
  end
  turtle.back()
  turtle.back()
end

-- Clears the specified item from the inventory, most likely cobble
function checkInv()
  term.clear()
  term.setCursorPos(1,1)
  print("Trashing...")
  for y = 2,16 do
    turtle.select(y)
    if turtle.compareTo(1) then
      turtle.drop()
    end
  end
end

-- Checks how long since the last torch, then decides to place one above or not
function torch()
  -- Checks if low on torches
  if turtle.getItemCount(16) < 5 then
    term.clear()
    term.setCursorPos(1,1)
    print("Waiting for torches...place in bottom right.")
    while turtle.getItemCount(16) < 5 do
      sleep(2)
    end
  end
  term.clear()
  term.setCursorPos(1,1)
  print("Mining...")
  if checkTorch == 8 then
    fuel()
    turtle.select(16)
    turtle.up()
    turtle.digUp()
    -- This if and loop will bring the turtle back down from the placed torch
    if turtle.placeUp() or turtle.getItemCount(16) == 0 then
        for i = 0,height do
          fuel()
          turtle.down()
        end
        turtle.select(1)
        checkTorch = 0
        height = 0
    else
        height = height + 1
        torch()
    end
  -- If it's too soon, dont place a torch
  else
    checkTorch = checkTorch + 1
  end
end

-- Checks the fuel level, asks for more if necessary
function fuel()
  if turtle.getFuelLevel() < 50 then
    print ("Wating for fuel...place in bottom left.")
    while turtle.getFuelLevel() < 50 do
      turtle.select(13)
      turtle.refuel()
      sleep(2)
    end
  end
  term.clear()
  term.setCursorPos(1,1)
  print("Mining...")
  turtle.select(1)
end

-- This function is a one time startup function, makes sure the turtle has the necessary materials
function begin()
  turtle.select(1)
  -- Checks for trash item
  if turtle.getItemCount(1) == 0 then
    print("Please place an item to trash in the top left.")
    while turtle.getItemCount(1) == 0 do
      sleep(1)
    end
    term.clear()
    term.setCursorPos(1,1)
    begin()
  -- Confirms trashed item
  else
    print("The item in the top left will be trashed...confirm?")
    os.pullEvent("key")
  end
  term.clear()
  term.setCursorPos(1,1)
end

-- From here is the main code
begin()
-- Loops for the specified # of tunnels, one tunnel being up and back
for j = 1,numTunnels do
  tunnel()
  turtle.turnLeft()
  turnAround()
  turtle.turnLeft()
  tunnel()
  turtle.turnRight()
  turnAround()
  turtle.turnRight()
end
-- Resets the screen and displays a confirmation of finishing
term.clear()
term.setCursorPos(1,1)
print("Done!")