local _situations = {}

--- Registers a new situation with the Situation manager.
-- Overwrites existing situation if an ID conflict occurs.
-- @param situation table A table containing the situation definition.
--        Must include an `id` field (string).
--        Optional fields:
--        - `handle` (function): Function to execute when the situation is applied. Defaults to an empty function.
--        - `update` (function): Function to execute each frame while the situation is active. Defaults to an empty function.
function Situation.register(situation)
  if not situation or not situation.id then
    PopupWindow.show({"Error: Invalid situation object registered (missing id)!"})
    return
  end
  if not situation.handle then
    situation.handle = function() end
  end
  if not situation.update then
    situation.update = function() end
  end
  if _situations[situation.id] then
    trace("Warning: Overwriting situation with id: " .. situation.id)
  end
  _situations[situation.id] = situation
end

--- Retrieves a registered situation by its ID.
-- @param id string The ID of the situation to retrieve.
-- @return table The situation table, or `nil` if not found.
function Situation.get(id)
  return _situations[id]
end

--- Applies a situation, making it the current active situation.
-- The situation's `handle` function is executed.
-- This function first checks if the situation is valid and if it's allowed
-- on the current screen (as defined in `Context.screens[Context.current_screen].situations`).
-- If successful, `Context.current_situation` is updated with the ID of the applied situation.
-- @param id string The ID of the situation to apply.
function Situation.apply(id)
  local situation = Situation.get(id)
  if not situation then
    trace("Error: No situation found with id: " .. id)
    return
  end

  local current_screen_obj = Screen.get_by_id(Context.current_screen)
  if current_screen_obj and not current_screen_obj.situations[id] then
    trace("Info: Situation " .. id .. " cannot be applied to current screen (id: " .. Context.current_screen .. ").")
    return
  end

  Context.current_situation = id
  situation.handle()
end