sifting(for chunkDig series)

-- slot1 : chest x3
-- slot2 : cobblestone x1
-- slot3 : dirt x1
-- slot4 : gravel x1
-- ----------------------------
-- config
-- ----------------------------
local CHEST_SLOT = 1
local EXCLUSION_SLOTS = {2,3,4}
local OTHER_SLOTS = {5,6,7,8,9,10,11,12,13,14,15,16}

-- ----------------------------
-- application
-- ----------------------------
local function extractItems(itemChestPlaced)
  local garbageList = {}
  local itemList = {}
  for _, i in ipairs(OTHER_SLOTS) do
    if 0 < turtle.getItemCount(i) then
      turtle.select(i)
      local isItem = true
      for _, j in ipairs(EXCLUSION_SLOTS) do
        if turtle.compareTo(j) then
          isItem = false
          table.insert(garbageList, i)
          break
        end
      end
      if isItem then
        if not itemChestPlaced then
          turtle.select(CHEST_SLOT)
          while not turtle.placeUp() do
            turtle.digUp()
          end
          itemChestPlaced = true
          turtle.select(i)
        end
        turtle.dropUp()
        table.insert(itemList, i)
      end
    end
  end
  return garbageList, itemList, itemChestPlaced
end

local function dump(garbageList, garbageChestPlaced)
  turtle.turnLeft()
  turtle.turnLeft()
  if not garbageChestPlaced then
    turtle.select(CHEST_SLOT)
    turtle.place()
  end
  for _, i in ipairs(garbageList) do
    turtle.select(i)
    turtle.drop()
  end
  for _, i in ipairs(EXCLUSION_SLOTS) do
    turtle.select(i)
    turtle.drop(turtle.getItemCount(i) - 1)
  end
  turtle.turnRight()
  turtle.turnRight()
  return true
end

local function sifting()
  local gcPlaced = false
  local icPlaced = false
  local garbageList
  local itemList
  while true do
    local empty = true
    while turtle.suck() do empty = false end
    garbageList, itemList, icPlaced = extractItems(icPlaced)
    if 0 == #itemList then
      gcPlaced = dump(garbageList, gcPlaced)
    end
    if empty then
      if turtle.getItemCount(CHEST_SLOT) < 64 then
        turtle.select(CHEST_SLOT)
        turtle.dig()
      end
      break
    end
  end
end

local function dumpItems()
  turtle.turnLeft()
  turtle.turnLeft()
  for _, i in ipairs(OTHER_SLOTS) do
    if 0 < turtle.getItemCount(i) then
      turtle.select(i)
      while not turtle.drop() do
        print("Cannot drop items. sleep(5)")
        os.sleep(5)
      end
    end
  end
  local chestCnt = turtle.getItemCount(CHEST_SLOT)
  if 3 < chestCnt then
    turtle.select(CHEST_SLOT)
    while not turtle.drop(chestCnt - 3) do
      print("Cannot drop chests. sleep(5)")
      os.sleep(5)
    end
  end
  turtle.turnRight()
  turtle.turnRight()
end

local function transportItems()
  while turtle.suckUp() do empty = false end
end

local function hasEmptySlot()
  for i = 1, 16 do
    if 0 == turtle.getItemCount(i) then
      return true
    end
  end
  return false
end
-- ----------------------------
-- main
-- ----------------------------
while true do
  local noResult = true
  for i = 1, 100 do
    turtle.up()
    if turtle.detect() then
      if turtle.suck() then
        sifting()
        noResult = false
      else
        turtle.select(CHEST_SLOT)
        if turtle.compare() then
          if turtle.getItemCount(CHEST_SLOT) < 64 then
            turtle.dig()
          else
            noResult = false
          end
        end
      end
    end
    if turtle.detectUp() then
      if turtle.suckUp() then
        transportItems()
        noResult = false
      else
        turtle.select(CHEST_SLOT)
        if turtle.compareUp() then
          if hasEmptySlot() and not turtle.suckUp() then
            turtle.digUp()
          end
          noResult = false
        else
          break
        end
      end
    end
  end
  while turtle.down() do end
  dumpItems()
  if noResult then
    break
  end
end
print("sifting was completed!")