Tunnel

--Tunnel Simple Script v1
--Turtle Program Computer Craft
--by SemlerPDX(July2021)

--pastebin get CJ5iY7G0 Tunnel

--COMMENT SYNTAX EXPLAINATION
--torches must be in slot 1 (one for every 8th block, 2nd row high)

--Tunnel 20 (length in increments of 10)
--example:  Tunnel 20 (makes tunnel 20 deep with torches)


-- Variables --
local args = {...}
local d = args[1] or 0
local r = 0 + d
local t = turtle

-- F-ACK --
if #args ~= 1 then
  print("<error420: syntax>")
  print("<ex: Tunnel 20 (starts digging tunnel 20 blocks deep)>")
  return
end

if d == 0 then
  print("<error421: missing length>")
  print("<ex: Tunnel 20 (starts digging tunnel 20 blocks deep)>")
  return
end

-- Functions --
--force forward function by CCCode
local function forceForward()
  while not t.forward() do
    t.dig()
  end
end

--dig down, decrement lit variable
local function fDown()
  t.digDown()
  t.down()
end

--dig up, turn around
local function fUp()
  t.digUp()
  t.up()
end

local function fRow()
  fUp()
  fUp()
  for v=1,3 do
    for s=1,10 do
      if v == 3 and s == 5 then
        t.placeUp()
      end
      forceForward()
    end
    if v ~= 3 then
      t.turnLeft()
      t.turnLeft()
      fDown()
    end
  end
end

--return home
local function fHome()
  t.turnLeft()
  t.turnLeft()
  while r ~=0 do
    forceForward()
    r = r -1
  end
end

--clear display screen
local function fset()
  term.clear()
  term.setCursorPos(1,1)
end

-- Pre-fire scripts --
fset()
print("Beginning Tunnel "..tostring(d).." blocks long...")
--t.up()
--t.down()
sleep(2)

---- Main Loop ----
while d ~= 0 do

  local function fcancel()
    local event, key = os.pullEvent("key")
  end

  local function fmain()
    fRow()
    d = d - 10
  end

  FunctionEnabled = parallel.waitForAny(fcancel,fmain)

  if FunctionEnabled == 1 then
    textutils.slowPrint("Cancelling Tunnel...", 15)
    sleep(1.65)
    break
  end

end

-- Evaluate Ending --
if FunctionEnabled == 1 then    --(1 = functions cancelled, 2 = standard function looped)
  fset()
  print("Tunnel Cancelled by user")
else
  fset()
  print("Tunnel Completed")
  print("Returning home...")
  fHome()
  t.select(1)
  fset()
  print("...program complete")
end