local constants = require("constants")

local util = {}

--- Get the current blueprint from the item stack, if it exists and is set up.
--- @param item_stack LuaItemStack
--- @return LuaItemStack?
function util.get_blueprint(item_stack)
  if not item_stack or not item_stack.valid_for_read then
    return
  end
  local blueprint
  if item_stack.is_blueprint then
    blueprint = item_stack
  elseif item_stack.is_blueprint_book and item_stack.active_index then
    local inventory = item_stack.get_inventory(defines.inventory.item_main) --[[@as LuaInventory]]
    if inventory.is_empty() or item_stack.active_index > #inventory then
      return
    end
    blueprint = util.get_blueprint(inventory[item_stack.active_index])
  end

  if blueprint and blueprint.is_blueprint_setup() then
    return blueprint
  end
end

--- @param entity BlueprintEntity
function util.get_rail_tiles(entity)
  local category = constants.rail_tiles[prototypes.entity[entity.name].type]
  if not category then
    return
  end

  return category[entity.direction or 0]
end

--- Displays notification for player at cursor position.
--- @param player LuaPlayer Player to notify.
--- @param message LocalisedString Message to show to player.
--- @param sound SoundPath|nil Optional sound to play for the player.
function util.cursor_notification(player, message, sound)
  player.create_local_flying_text({
    text = message,
    create_at_cursor = true,
  })

  if sound then
    player.play_sound({ path = sound })
  end
end

--- Calculates largest build grid size for all entities in the passed-in list of blueprints.
--- Useful when dealing with things like rails and train stops that can only be repositioned in increments of two.
--- @param blueprints LuaItemStack[] List of blueprints for which to calculate the value. Must be valid for read.
function util.get_blueprint_largest_build_grid_size(blueprints)
  local build_grid_size = 1

  for _, blueprint in pairs(blueprints) do
    for _, entity in pairs(blueprint.get_blueprint_entities() or {}) do
      if prototypes.entity[entity.name].building_grid_bit_shift > build_grid_size then
        build_grid_size = prototypes.entity[entity.name].building_grid_bit_shift
      end
    end
  end

  return build_grid_size
end

--- Returns list of all blueprints in a blueprint book.
--- @param book LuaItemStack
--- @return LuaItemStack[]
function util.get_book_blueprints(book)
  --- Helper function that recursively collects blueprints from the passed-in blueprint book and stores them in the passed-in result table.
  --- @param book LuaItemStack
  --- @param result_table LuaItemStack[]
  local function collect_blueprints(book, result_table)
    local items = book.get_inventory(defines.inventory.item_main) --[[@as LuaInventory]]
    for i = 1, #items do
      local item = items[i]
      if not item then
        return
      elseif item.is_blueprint_book then
        collect_blueprints(item, result_table)
      elseif item.is_blueprint then
        table.insert(result_table, item)
      end
    end
  end

  local blueprints = {}
  collect_blueprints(book, blueprints)
  return blueprints
end

--- @param box BoundingBox
--- @param callback fun(pos: MapPosition)
function util.for_each_position(box, callback)
  for y = box.left_top.y, box.right_bottom.y - 1 do
    for x = box.left_top.x, box.right_bottom.x - 1 do
      callback({ x = x, y = y })
    end
  end
end

return util