ex

args = {...}

widthx=0
widthy=0
depth=0

x=0
y=0
d=0

xdir=1
ydir=0

xdirSurface = 1
ydirSurface = 0

onWayUp=0

ignoreCount=0

onWayHome=0

lastSpotx=0
lastSpoty=0
lastSpotd=0

function getCountFreeSlots()
  freeslots = 0
  for i=ignoreCount+1,15 do
    if turtle.getItemCount(i)==0 then
      freeslots=freeslots+1
    end
  end
  return freeslots
end

function checkInventory()
  if getCountFreeSlots() == 0 then
    goHome()
  end
  if onWayHome==1 then
    goHome()
  end
  if onWayHome==-1 then
    goBack()
  end
end

function right()
  if turtle.turnRight() then
    help=xdir
    xdir=-ydir
    ydir=help
  end
  save()
end

function left()
  if turtle.turnLeft() then
    help=xdir
    xdir=ydir
    ydir=-help
  end
  save()
end

function forward()
  refuel()
  while not turtle.forward() do
    os.sleep(1)
    turtle.dig()
    checkInventory()
  end
  x=x+xdir
  y=y+ydir
  save()
end

function forwardAndDig()
  refuel()
  if isRabbitHoleSpot() then
    rabbitHole()
  end
  while not turtle.forward() do
    os.sleep(1)
    turtle.dig()
    checkInventory()
  end
  x=x+xdir
  y=y+ydir
  save()
end

function up()
  refuel()
  while turtle.up() == false do
    os.sleep(1)
    turtle.digUp()
    checkInventory()
  end
  d=d-1
  save()
end

function down()
  refuel()
  while turtle.down() == false do
    os.sleep(1)
    if not turtle.digDown() then
      return false
    end
    checkInventory()
  end
  d=d+1
  save()
  return true
end

function isRabbitHoleSpot()
  if ((x + ((y*2) % 5)) % 5) == 0 then
    return true
  else
    return false
  end
end

function rabbitHole()
  if onWayUp == 0 then
    xdirSurface=xdir
    ydirSurface=ydir
    while d~=depth and down() do
      rotaDigger()
    end
    onWayUp=1
  end
  if onWayUp==1 then
    while d ~= 0 do
      up()
    end
    while not (xdir == xdirSurface and ydir == ydirSurface) do
      left()
    end

    for i=1,ignoreCount do
      if turtle.getItemCount(i) > 1 then
        turtle.select(i)
        turtle.placeDown()
        i=ignoreCount
      end
    end
    turtle.select(1)
    onWayUp=0
  end

end

function isIgnoreBlock()
  for i = 1,ignoreCount do
    turtle.select(i)
    if turtle.compare() then
      return true
    end
  end
  return false
end

function rotaDigger()
  for i=1,3 do
    if isIgnoreBlock() == false then
      turtle.dig()
      checkInventory()
    end
    left()
  end
  if isIgnoreBlock() == false then
    turtle.dig()
    checkInventory()
  end
end

function goHome()
  if not onWayHome == 1 then
    lastSpotx=x
    lastSpoty=y
    lastSpotd=d
        onWayHome=1
    end

  if d ~= 0 then
    onWayUp=1
    RabbitHole()
  end
  while not (xdir==-1) do
    left()
  end
  while not (x==0) do
    forward()
  end
  while not (ydir==-1) do
    left()
  end
  while not (y==0) do
    forward()
  end
  while not (xdir==-1) do
    left()
  end
  clearInventory()
  onWayHome=-1
end

function goBack()
  if d ~= 0 then
    onWayUp=1
    RabbitHole()
  end
  while not (xdir==1) do
    left()
  end
  while not (x==lastSpotx) do
    foward()
  end
  while not (ydir==1) do
    left()
  end
  while not (y==lastSpoty) do
    forward()
  end
  while not (d==lastSpotd) do
    down()
  end
  onWayHome=0
end

function refuel()
  while turtle.getFuelLevel() < 80 do
    for i=ignoreCount+1,15 do
      turtle.select(i)
      if turtle.compareTo(16) then
        turtle.transferTo(16)
      end
    end
    turtle.select(16)
    turtle.refuel(turtle.getItemCount(16)-1)
  end
  turtle.select(1)
end

function clearInventory()
  for i=ignoreCount+1,15 do
    turtle.select(i)
    if turtle.compareTo(16) then
      turtle.transferTo(16)
    end
  end
  for i=ignoreCount+1,15 do
    turtle.select(i)
    turtle.drop()
  end
end

function uTurn()
  if y == widthy-1 then
    return
  end
  if xdir == 1 and x == widthx-1 then
    right()
    forwardAndDig()
    right()
    return
  end
  if xdir == -1 and x == 0 then
    left()
    forwardAndDig()
    left()
    return
  end
  if (xdir==0 and (x==0 or x==widthx-1)) then
    if x==0 then
      if y%2==1 then
        forwardAndDig()
      end
    left()
    return
    end
    if x==widthx-1 then
      if y%2==0 then
        forwardAndDig()
      end
      right()
      return
    end
  end
end

function readFromSave()
  if fs.exists("ex.save") then
    h=fs.open("ex.save","r")
    if h ~= nil then
      widthx=tonumber(h.readLine())
      widthy=tonumber(h.readLine())
      depth=tonumber(h.readLine())
      x=tonumber(h.readLine())
      y=tonumber(h.readLine())
      d=tonumber(h.readLine())
      xdir=tonumber(h.readLine())
      ydir=tonumber(h.readLine())
      xdirSurface=tonumber(h.readLine())
      ydirSurface=tonumber(h.readLine())
      onWayUp=tonumber(h.readLine())
      ignoreCount=tonumber(h.readLine())
      onWayHome=tonumber(h.readLine())
      lastSpotx=tonumber(h.readLine())
      lastSpoty=tonumber(h.readLine())
      lastSpotd=tonumber(h.readLine())
      h.close()
      return true
    else
      return false
    end
  else
    return false
  end
end

function save()
  h=fs.open("ex.save","w")
  if h~= nil then
    h.writeLine(widthx)
    h.writeLine(widthy)
    h.writeLine(depth)
    h.writeLine(x)
    h.writeLine(y)
    h.writeLine(d)
    h.writeLine(xdir)
    h.writeLine(ydir)
    h.writeLine(xdirSurface)
    h.writeLine(ydirSurface)
    h.writeLine(onWayUp)
    h.writeLine(IgnoreCount)
    h.writeLine(onWayHome)
    h.writeLine(lastSpotx)
    h.writeLine(lastSpoty)
    h.writeLine(lastSpotd)
    h.flush()
    h.close()
    os.sleep(0.2)
  end
end

function main()
  if args[1] == nil or args[1] == "" then
    print("Arguments: widht-X, width-Y, depth,")
    print("           ignore-block-count")
    print("        OR 'continue' to continue")
    print("           previous excavation")
    print("Put ignore-blocks")
    print("  in slot 1 to #ignoreblockcount")
    print("  and fuel in slot 16")
    return
  end
  if args[1] == "continue" then
   if readFromSave() == false then
     return 1
   end
  else
    widthx=tonumber(args[1])
    widthy=tonumber(args[2])
    depth=tonumber(args[3])
    ignoreCount=tonumber(args[4])
  end
  repeat
    forwardAndDig()
    uTurn()
    term.clear()
  until y == widthy-1 and ((xdir==-1 and x==0) or (xdir==1 and x==widthx-1))

  goHome()
  onWayHome=0
  clearInventory()
end

main()