local args = {...}

local stripLength = 32
local posx = 0
local posz = 0
local oposx = 0
local oposz = 0
local left = false

if not #args == 1 then
  print("Usage: smine <mines>")
  return
end

function strip()
  for i=1,stripLength do
    checkFuel()
    checkInv()
    while not turtle.forward() do turtle.dig() end
    posz = posz + 1
    while turtle.detectUp() do
      turtle.digUp()
      sleep(0.2)
    end
    while turtle.detectDown() do
      turtle.digDown()
      sleep(0.2)
    end

    if i%8 == 0 then
      turtle.select(16)
      while not turtle.forward() do turtle.dig() end
      posz = posz + 1
      while turtle.detectUp() do
        turtle.digUp()
        sleep(0.2)
      end
      if not turtle.back() then
        turtle.turnLeft()
        turtle.turnLeft()
        while not turtle.forward do turtle.dig() end
        turtle.turnLeft()
        turtle.turnLeft()
      end
      turtle.placeUp()
      turtle.select(1)
    end
  end

  turtle.turnLeft()
  turtle.turnLeft()

  for i=1,stripLength do
    while not turtle.forward() do turtle.dig() end
    posz = posz - 1
  end
end

function checkFuel()
  if turtle.getFuelLevel() <= 64 then
    print("Error: Low fuel")
    for i=1,14 do
      turtle.select(i)
      turtle.refuel()
    end
  end
end

function goHome()
    oposx = posx
    oposz = posz
    turtle.turnLeft()
    turtle.turnLeft()
    for x=1,posx do
        while not turtle.forward() do turtle.dig() end
    end

    if left == false then
        turtle.turnLeft()
    else
        turtle.turnRight()
    end

    for z=1,posz do
        while not turtle.forward() do turtle.dig() end
    end

    if not turtle.detectDown() then
        turtle.select(15)
        turtle.placeDown()
    end

    for i=1,14 do
        turtle.select(i)
        turtle.dropDown()
    end

    turtle.turnLeft()
    turtle.turnLeft()
    for x=1,posz do
        while not turtle.forward() do turtle.dig() end
    end

    if left == false then
        turtle.turnRight()
    else
        turtle.turnLeft()
    end

    for z=1,posx do
        while not turtle.forward() do turtle.dig() end
    end
end

function checkInv()
  isFull = true

  for i=1,14 do
    if turtle.getItemCount(i) == 0 then
      isFull = false
    end
  end

  if isFull == true then
    --turtle.select(15)
    --while not turtle.placeDown() do turtle.digDown() end
    --for i=1,14 do
      --turtle.select(i)
      --turtle.dropDown()
    --end
    goHome()
  end
end

function goForward()
    for i=0,3 do
        while not turtle.forward() do turtle.dig() end
        posx = posx + 1
        while turtle.detectUp() do
            turtle.digUp()
            sleep(0.2)
        end

        while turtle.detectDown() do
            turtle.digDown()
            sleep(0.2)
        end
    end

    turtle.select(16)
    while not turtle.placeDown() do turtle.digDown() end
end

for x=1,args[1] do
  turtle.turnLeft()
  left = true
  strip()
  left = false
  strip()
  turtle.turnRight()
  goForward()
  --for y=1,3 do turtle.forward() end
end