local SAVE_GAME_BANK = 6
local SAVE_GAME_MAGIC_VALUE_ADDRESS = 0
local SAVE_GAME_MAGIC_VALUE = 0xCA

local SAVE_GAME_CURRENT_SCREEN_ADDRESS = 6

-- Define a consistent order for screens for save/load operations
local SCREEN_ID_ORDER = {"home", "toilet", "walking_to_office", "office", "walking_to_home"}

--- Gets initial data for Context.
-- @return table Initial context data.
local function get_initial_data()
  return {
    active_window = WINDOW_SPLASH,
    intro = {
      y = Config.screen.height,
      speed = 0.5,
      text = [[Norman Reds’ everyday life
seems ordinary: work,
meetings, coffee, and
endless notifications.
But beneath him, or around
him — something is
constantly building, and
it soon becomes clear
that there is more going
on than meets the eye.]]
    },
    splash_timer = Config.timing.splash_duration,
    popup = {
      show = false,
      content = {}
    },
    player = {
      sprite_id = Config.player.sprite_id
    },
    ground = {
      x = 0,
      y = Config.screen.height,
      w = Config.screen.width,
      h = 8
    },
    menu_items = {},
    selected_menu_item = 1,
    game_in_progress = false,
    minigame_ddr = Minigame.get_default_ddr(),
    minigame_button_mash = Minigame.get_default_button_mash(),
    minigame_rhythm = Minigame.get_default_rhythm(),
    meters = Meter.get_initial(),
    game = {
      current_screen = "home",
      current_situation = nil,
    }
  }
end

--- Global game context.
Context = {}

--- Resets game context to initial state.
local function reset_context_to_initial_state()
  local initial_data = get_initial_data()

  for k in pairs(Context) do
    if type(Context[k]) ~= "function" then       Context[k] = nil
    end
  end

  for k, v in pairs(initial_data) do
    Context[k] = v
  end
end


--- Starts a new game.
function Context.new_game()
  reset_context_to_initial_state()
  Context.game_in_progress = true
  MenuWindow.refresh_menu_items()
  Screen.get_by_id(Context.game.current_screen).init()
end

--- Saves the current game state.
function Context.save_game()
  if not Context.game_in_progress then return end

  mset(SAVE_GAME_MAGIC_VALUE, SAVE_GAME_MAGIC_VALUE_ADDRESS, SAVE_GAME_BANK)

  local screen_index_to_save
  for i, screen_id in ipairs(SCREEN_ID_ORDER) do
    if screen_id == Context.game.current_screen then
      screen_index_to_save = i
      break
    end
  end

  if screen_index_to_save then
    mset(screen_index_to_save, SAVE_GAME_CURRENT_SCREEN_ADDRESS, SAVE_GAME_BANK)
  else
    trace("Error: Current screen ID '" .. Context.game.current_screen .. "' not found in SCREEN_ID_ORDER for saving.")
  end
end

--- Loads a saved game state.
function Context.load_game()
  if mget(SAVE_GAME_MAGIC_VALUE_ADDRESS, SAVE_GAME_BANK) ~= SAVE_GAME_MAGIC_VALUE then
        Context.new_game()
    return
  end

  reset_context_to_initial_state()

  local loaded_screen_index = mget(SAVE_GAME_CURRENT_SCREEN_ADDRESS, SAVE_GAME_BANK)
  if loaded_screen_index and SCREEN_ID_ORDER[loaded_screen_index] then
    Context.game.current_screen = SCREEN_ID_ORDER[loaded_screen_index]
  else
    trace("Error: Invalid screen index loaded: " .. tostring(loaded_screen_index) .. ". Defaulting to new game state.")
    Context.new_game()
    return
  end

  Context.game_in_progress = true
  MenuWindow.refresh_menu_items()
  Screen.get_by_id(Context.game.current_screen).init()
end