recycle

--=================================================
-- Recycle Bin by Kadoba
---------------------------------------------------
-- Turns an attached chest into a recycle bin.
-- Recycle bins only delete stacks that have been
-- inside of them for more than a specific length
-- of time. By default this is one minute.
--=================================================

---------------------------------------------------
-- Config
---------------------------------------------------

-- Delay in seconds between deleting items
local delay = 5

-- The side of the computer that the recycle
-- bin is on. Takes the first program argument
-- or defaults to "right" if one isn't passed.

local side = ({...})[1] or "right"

-- If true then recycled items are logged
local dolog = true

-- The log filename
local logname = "recycle_log"

---------------------------------------------------
-- Setup -
---------------------------------------------------

local timeleft = delay    -- Delay time left
local blink = false       -- Cursor blinking
local deleted = 0         -- Total deleted stacks
local list = {}           -- Buffered deleted list
list.size = 8             -- Buffer size
list.i = 0                -- List increment

-- Returns the buffer index for the list given
-- the incremental index
function list.increment_index(n)
  return n % list.size
end

-- Returns the buffer index for the list given
-- the terminal display offset.
function list.display_index(n)
  return (n + list.i) % list.size
end

-- Terminal display lines
local lines = {}
lines[1]  = "Recycle program has started."
lines[2]  = "Attaching to %s on %s side."
lines[3]  = ""
lines[4]  = "Waiting 0..."
lines[5]  = ""
lines[6]  = "Most recent deleted items:"
lines[7]  = "-------------------------------------"
-- Buffered list is lines 8 through 15
lines[16] = "-------------------------------------"
lines[17] = "Deleted a total of 0 item stacks."

local log

if dolog then
  local exists = fs.exists(logname)
  log = fs.open(logname, exists and "a" or "w")
end

---------------------------------------------------
-- Peripheral Attachment
---------------------------------------------------

local chest = peripheral.wrap(side)

if not chest then
  error("Could not find chest on side: "..side)
else
  lines[2] = string.format(lines[2],
    chest.getInventoryName(),
    side
  )
end

local prev_stacks = chest.getAllStacks()

---------------------------------------------------
-- Loop Functions
---------------------------------------------------

-- Recycle stacks
local function recycle()

  local stacks = chest.getAllStacks()
  local prev_info, info, text
  local prev_deleted = deleted

  if not stacks then
    error("Chest appears to have been destroyed.")
  end

  for slot, stack in pairs(prev_stacks) do
    if stacks[slot] then
      prev_info = stack.basic()
      info = stacks[slot].basic()
      if prev_info.id == info.id then
        deleted = deleted + 1
        text = string.format("%s x %d",
                            info.display_name,
                            info.qty)
        list[ list.increment_index(list.i) ] = text
        list.i = list.i + 1
        if dolog then
          log.writeLine(text)
        end
        chest.destroyStack(slot)
        stacks[slot] = nil
      end
    end
  end

  if deleted > prev_deleted and dolog then
    log.flush()
  end
  prev_stacks = stacks

end

-- Draw to terminal
local function draw()

  local text = "Deleted a total of %d item stacks."
  lines[17] = string.format(text, deleted)
  text = "Waiting %d..."
  lines[4] = string.format(text, timeleft)

  for i=0,list.size-1 do
    lines[8+i] = list[ list.display_index(i) ] or ""
  end

  term.clear()
  for k,v in pairs(lines) do
    term.setCursorPos(1,k)
    term.write(lines[k])
  end

end

---------------------------------------------------
-- Main Program
---------------------------------------------------

while true do

  timeleft = timeleft - 1
  if timeleft <= 0 then
    recycle()
    timeleft = delay
  end

  draw()
  sleep(1)

end