dig tunnel

function hasTorches()
  if ( turtle.getItemCount(16) > 0 ) then
    return true
  else
    return false
  end
end

function invFull()
  full=true
  for i=1,16 do
    full = ( turtle.getItemCount(i) > 0 and full )
  end
  return full
end

function checkInv()
  if ( invFull() ) then
    print("Inventory Full, Please Empty")
    while ( invFull() ) do
      sleep(1)
    end
  end
end

function moveUp()
  while ( not turtle.up() ) do
    turtle.digUp()
    checkInv()
  end
end

function moveDown()
  while ( not turtle.down() ) do
    turtle.digDown()
    checkInv()
  end
end

function moveForward()
  while ( not turtle.forward() ) do
    turtle.dig()
    checkInv()
  end
end

function digForward()
  while ( turtle.detect() ) do
    turtle.dig()
    checkInv()
  end
end

function rotate()
  for i=1,2 do
    turtle.turnLeft()
  end
end

function digTunnel(height, putTorch)
  for i=1,height-1 do
    checkFuel()
    digForward()
    moveUp()
    if ( height-1 == i and putTorch ) then
      placeTorch()
    end
  end
  moveForward()
  for i=1,height-1 do
    checkFuel()
    digForward()
    moveDown()
  end
  moveForward()
end

function placeTorch()
  if ( not hasTorches() ) then
    print("No More Torches, Please replenish")
    while ( not hasTorches() ) do
      sleep(1)
    end
  end
  turtle.select(16)
  turtle.placeDown()
  turtle.select(1)
end

function checkFuel()
  if ( turtle.getFuelLevel() < 10 ) then
    print("Fuel Level is less than 10, please place fuel in slot 1")
    turtle.select(1)
    while ( turtle.getFuelLevel() < 10 ) do
      if ( turtle.getItemCount(1) > 0 ) then
        turtle.refuel()
      end
      sleep(1)
    end
    print("Turtle Refuled, Fuel Level = " .. turtle.getFuelLevel())
  end
end

args = { ... }
tunnelHeight=tonumber(args[1])
tunnelLength=tonumber(args[2])
for i=1,tunnelLength/2 do
  if ( i % 3 == 1 ) then
    digTunnel(tunnelHeight, true)
  else
    digTunnel(tunnelHeight, false)
  end
  if ( i % 10 == 0 ) then
    output=string.format("%.2f%% of the Tunnel Completed.", i/(tunnelLength/2)*100)
    print(output)
  end
end