AUID_gmnotes.ttslua

-- an AUID (Actually Unique ID) is a dumb integer that is always unique for each object
-- AUID is set and incremented every time we see an object without one, or each time a new object spawns from scratch.

-- AUIDs are unique keys that are stored in a table. AUIDs are keys that can point at 1 of 3 types of values-
-- (userdata) associated object reference for existing objects
-- (integer) container's AUID for objects that have entered containers (since they're not truly deleted)
-- (string) "destroyed" for objects that have been directly deleted

local newbimap = require "bimap/bimap"
local AUIDs, AUIDs_rev = newbimap()

local function getAUID(obj) -- this one has no side effect
  local GMNote = obj.getGMNotes()
  return GMNote and GMNote:match("\nAUID: (%d+)$")
  -- stupid workaround because TTS object string properties aren't always strings, they can also be nil
end

-- naively appends AUID to GMNote, as a side effect adds the object to AUIDs. Rarely used.
local function addAUID(obj)
  local newAUID = #AUIDs + 1
  obj.setGMNotes((obj.getGMNotes() or "") .. "\nAUID: " .. newAUID)
  AUIDs[newAUID] = obj
  return newAUID
end

-- sets and returns a GUID, overwrites existing AUID if any. used with onObjectSpawn if the object is not spawning from a container.
local function forceAddAUID(obj)
  local newAUID = #AUIDs + 1
  local newAUID_string = "\nAUID: " .. newAUID

  local newGMNote, num_matches = obj.getGMNotes():gsub("\nAUID: %d+$",  newAUIDString)
  if num_matches == 1 then
    obj.setGMNotes(newGMNote)
  elseif num_matches == 0 then
    obj.setGMNotes(newGMNote .. newAUID_string)
  else
    error("duplicate AUIDs on object with guid " .. obj.guid ", dumping its GMNote:\n" .. obj.getGMNotes())
  end
  AUIDs[newAUID] = obj
  return newAUID
end

-- gets and returns AUID, or adds and returns one if it didn't exist yet. in either case, indexes the object in the AUIDs map.
local function startTracking(obj)
  local objAUID = getAUID(obj)
  if objAUID then
    if not AUIDs[objAUID] then -- simply start tracking the object
      AUIDs[objAUID] = obj
      return objAUID
    else -- if auid is taken, assign a new one
      local newAUID = forceAddAUID(obj)
      log(string.format("duplicate AUID found, reassigning new obj! old auid/guid: %s/%s, new auid: %s",
      objAUID, AUIDs[objAUID].guid, newAUID))
      return newAUID
    end
  else
    return addAUID(obj) -- if no auid yet, add one.
  end
end

-- Event Functions:

local function AUID_onLoad() -- called during onLoad()
  for i,obj in ipairs(getAllObjects()) do
    local objAUID = getAUID(obj)
    if objAUID then
      if not AUIDs[objAUID] then
        AUIDs[objAUID] = obj
      else
        log(string.format("duplicate object with AUID %s found! guids (old and new): %s and %s",
        objAUID, obj.guid, AUIDs[objAUID].guid))
      end
    else
      addAUID(obj)
    end
  end
end

-- when an pre-existing object leaves a container, add it to the AUID map (unless that AUID is already taken).
function AUID_onObjectLeaveContainer(container, obj)
  local objAUID = getAUID(obj)
  if objAUID then
    if not AUIDs[objAUID] then
      AUIDs[objAUID] = obj
    else
      local newAUID = forceAddAUID(obj)
      log(string.format("duplicate AUID found, reassigning new obj! old auid/guid: %s/%s, new auid: %s",
      objAUID, AUIDs[objAUID].guid, newAUID))
      return
    end
  else
    addAUID(obj)
  end
end

-- if the spawning object was not from a container, had no AUID, or its AUID was taken, then give it a new AUID
local function AUID_onObjectSpawn(obj)
  if not AUIDs_rev[obj] then -- check that the object isn't tracked, but we shouldn't need to
    forceAddAUID(obj)
  end
end

-- when an object goes into a container, set its AUID to point at the container's AUID.
local function AUID_onObjectEnterContainer(container, obj)
  local objAUID = AUIDs_rev[obj] and next(AUIDs_rev[obj]) -- first check if table exists, then get first (should be only) element
  local containerAUID = AUIDs_rev[container] and next(AUIDs_rev[container])
  if not AUIDs_rev[obj] or not AUIDs_rev[container] then
    log(string.format("untracked object entering container, container guid: %s obj guid: %s",
    container.guid, obj.guid))
    return
  end
  if objAUID and containerAUID then
    AUIDs[objAUID] = containerAUID
  end
end

local function markDestroyed(destroyed_auid)
  local contents = AUIDs_rev[destroyed_auid] -- the set of things that list destroyed obj as their container
  if contents then
    for key in pairs(contents) do
      markDestroyed(key) -- could cause issues with more than 65535 objects? followup on performance
    end
  end
  AUIDs[destroyed_auid] = "destroyed"
end

local function AUID_onObjectDestroy(dying_object)
  local objAUID = getAUID(dying_object)
  if not objAUID then
    log("destroyed object had no AUID! guid: " .. obj.guid)
    return
  end
  local AUID_entry = AUIDs[objAUID]
  if not AUID_entry then
    log("destroyed object had an AUID but was not tracked! guid: " .. obj.guid)
    return
  end
  if AUID_entry == AUIDs_rev[dying_object] then -- if it's a number, then obj is in a tracked container and already accounted for.
    markDestroyed(objAUID)
  else
    log(string.format("AUID entry of destroyed object %s was not an obj reference to itself! instead it was: %s",
    objAUID, logString(AUID_entry)))
  end
end

local EventManager = require('ge_tts/EventManager')
EventManager.addHandler('onObjectLeaveContainer', AUID_onObjectLeaveContainer)
EventManager.addHandler('onObjectSpawn', AUID_onObjectSpawn)
EventManager.addHandler('onObjectDestroy', AUID_onObjectDestroy)
EventManager.addHandler('onLoad', AUID_onLoad)

return {AUIDs = AUIDs, AUIDs_rev = AUIDs_rev, getAUID = getAUID, startTracking = startTracking}