tunnelCenter

startup = true

function saveDirection()
  file = fs.open("direction","w")
  file.write(direction)
  file:close()
end

if fs.exists("direction") == true then
  file = fs.open("direction","r")
  direction = file.readAll()
  file:close()
else
  file = fs.open("direction","w")
  file.write(0)
  file:close()
  direction = 0
end

while tonumber(direction) ~= 0 do
  if tonumber(direction) > 0 then
    turtle.turnLeft()
    direction = direction - 1
  elseif tonumber(direction) < 0 then
    turtle.turnRight()
    direction = direction + 1
  end
  file = fs.open("direction","w")
  file.write(direction)
  file:close()
end

while true do
  if startup == false then
    partners = false
    topPartner = false
    bottomPartner = false
    while partners == false do
      a,b = turtle.inspectUp()
      if b == "No block to inspect" then
        b = {"no","block"}
      end
      c,d = turtle.inspectDown()
      if d == "No block to inspect" then
        d = {"no","block"}
      end
      for k,v in pairs(b) do
        if v == "computercraft:CC-Turtle" then
          topPartner = true
        end
      end
      for k,v in pairs(d) do
        if v == "computercraft:CC-Turtle" then
          bottomPartner = true
        end
      end
      if topPartner == true and bottomPartner == true then
        partners = true
      end
      sleep(.05)
    end
    while partners == true do -- new 20170428 check for cableLayer to move on
      a,b = turtle.inspectUp()
      if b == "No block to inspect" then
        b = {"no","block"}
      end
      for k,v in pairs(b) do
        if v ~= "computercraft:CC-Turtle" then
          partners = false
        end
      end
    end
    startup = false
  elseif startup == true then
   startup = false
   sleep(1.5)
  end
  sleep(.5)
  turtle.dig()
  turtle.forward()
  turtle.turnRight()
  direction = direction +1
  saveDirection()
  while turtle.getItemCount( turtle.getSelectedSlot() ) == 0 do
    if turtle.getSelectedSlot() == 9 then
      turtle.select(1)
    else
      turtle.select(turtle.getSelectedSlot() +1)
    end
  end
  turtle.place()
  turtle.turnLeft()
  direction = direction -1
  saveDirection()
  turtle.turnLeft()
  direction = direction -1
  saveDirection()
  while turtle.getItemCount( turtle.getSelectedSlot() ) == 0 do
    if turtle.getSelectedSlot() == 9 then
      turtle.select(1)
    else
      turtle.select(turtle.getSelectedSlot() +1)
    end
  end
  turtle.place()
  turtle.turnRight()
  direction = direction +1
  saveDirection()
end