-- Strip mining turtle program.
-- mashen *********, mashen ********. 13/12/12

--[[fuel must be placed in slot 15,
torches must be placed in slot 16.]]

-- Create the function for refueling
function checkFuel()
  if turtle.getFuelLevel() <= 10 then
    turtle.select(15)
    turtle.refuel(1)
    turtle.select(1)
  end --if
end --checkFuel()

-- Create the turnAround function
function turnAround()
  turtle.turnRight()
  turtle.turnRight()
end --turnAround()

-- Digs the tunnel for the given length
function tunnel(givenLength)
  local distance = 0
  for index = 1,givenLength do
    turtle.dig()
    if turtle.forward() then
      distance = distance + 1
    end --if
    turtle.digUp()
    turtle.select(1)
    turtle.placeDown()

-- Places a torch every 10 blocks
    if distance == 10 then
      turtle.select(16)
      print("Placing torch...")
      turnAround()
      turtle.place()
      turnAround()
      distance = 0
      checkFuel()
    end --if
  end --for

-- Sends the turtle back to the start
    turtle.up()
    for index = 1,givenLength do
      turtle.back()
    end --for
    turtle.down()
end --tunnel()

-- Main script
print("Input tunnel length:")
local length = read()
print("starting excavation...")
checkFuel()
tunnel(length)
print("The tunnel has been excavated!")