startup

rednet.open("right")
local prevLiquid = -1

function place()
  turtle.select(1)
  turtle.place()
  turtle.back()
  turtle.select(2)
  turtle.place()
  turtle.up()
  turtle.select(3)
  turtle.place()
  prevLiquid = -1
end

function brk()
  turtle.select(3)
  turtle.dig()
  turtle.down()
  turtle.select(2)
  turtle.dig()
  turtle.select(1)
  turtle.forward()
  turtle.dig()
end

function move()
  turtle.turnRight()

  for i = 1, 10 do
    turtle.forward()
    sleep(2)
  end
end

function hasLessLiquid()
  local tank = peripheral.wrap("front")
  local amount = tank.getTankInfo("front")[1]["amount"]

  if amount < prevLiquid then
    return true
  end

  prevLiquid = amount
  return false
end


function waitForTankOrMsg()
  while true do
    local id,msg = rednet.receive(5)
    if id ~= nil and msg ~= nil then
      if id == 1 and msg == "break" then
        brk()
      end
    else
      if hasLessLiquid() then
        sendStop()
        break
      end
    end
  end
end

function sendStop()
  rednet.send(1,"break")
end

while true do
  id,msg = rednet.receive()

  if id == 1 then
    if msg == "place" then
      place()
      waitForTankOrMsg()
    elseif msg == "move" then
      move()
    elseif msg == "break" then
      brk()
    end
  end
end