text: import os
  from copy import deepcopy
  from pystac.errors import STACTypeError
  from typing import (
      Any,
      Callable,
      Dict,
      Iterable,
      List,
      Optional,
      TYPE_CHECKING,
      Tuple,
      Union,
      cast,
  )
  
  import pystac
  from pystac.stac_object import STACObject, STACObjectType
  from pystac.layout import (
      BestPracticesLayoutStrategy,
      HrefLayoutStrategy,
      LayoutTemplate,
  )
  from pystac.link import Link
  from pystac.cache import ResolvedObjectCache
  from pystac.serialization import (
      identify_stac_object_type,
      identify_stac_object,
      migrate_to_latest,
  )
  from pystac.utils import (
      StringEnum,
      is_absolute_href,
      make_absolute_href,
      make_relative_href,
  )
  
  if TYPE_CHECKING:
      from pystac.asset import Asset as Asset_Type
      from pystac.item import Item as Item_Type
      from pystac.collection import Collection as Collection_Type
  
  
  class CatalogType(StringEnum):
      SELF_CONTAINED = "SELF_CONTAINED"
      """A 'self-contained catalog' is one that is designed for portability.
      Users may want to download an online catalog from and be able to use it on their
      local computer, so all links need to be relative.
  
      See:
          :stac-spec:`The best practices documentation on self-contained catalogs
          <best-practices.md#self-contained-catalogs>`
      """
  
      ABSOLUTE_PUBLISHED = "ABSOLUTE_PUBLISHED"
      """
      Absolute Published Catalog is a catalog that uses absolute links for everything,
      both in the links objects and in the asset hrefs.
  
      See:
          :stac-spec:`The best practices documentation on published catalogs
          <best-practices.md#published-catalogs>`
      """
  
      RELATIVE_PUBLISHED = "RELATIVE_PUBLISHED"
      """
      Relative Published Catalog is a catalog that uses relative links for everything, but
      includes an absolute self link at the root catalog, to identify its online location.
  
      See:
          :stac-spec:`The best practices documentation on published catalogs
          <best-practices.md#published-catalogs>`
      """
  
      @classmethod
      def determine_type(cls, stac_json: Dict[str, Any]) -> Optional["CatalogType"]:
          """Determines the catalog type based on a STAC JSON dict.
  
          Only applies to Catalogs or Collections
  
          Args:
              stac_json : The STAC JSON dict to determine the catalog type
  
          Returns:
              Optional[CatalogType]: The catalog type of the catalog or collection.
                  Will return None if it cannot be determined.
          """
          self_link = None
          relative = False
          for link in stac_json["links"]:
              if link["rel"] == pystac.RelType.SELF:
                  self_link = link
              else:
                  relative |= not is_absolute_href(link["href"])
  
          if self_link:
              if relative:
                  return cls.RELATIVE_PUBLISHED
              else:
                  return cls.ABSOLUTE_PUBLISHED
          else:
              if relative:
                  return cls.SELF_CONTAINED
              else:
                  return None
  
  
  class Catalog(STACObject):
      """A PySTAC Catalog represents a STAC catalog in memory.
  
      A Catalog is a :class:`~pystac.STACObject` that may contain children,
      which are instances of :class:`~pystac.Catalog` or :class:`~pystac.Collection`,
      as well as :class:`~pystac.Item` s.
  
      Args:
          id : Identifier for the catalog. Must be unique within the STAC.
          description : Detailed multi-line description to fully explain the catalog.
              `CommonMark 0.28 syntax <https://commonmark.org/>`_ MAY be used for rich
              text representation.
          title : Optional short descriptive one-line title for the catalog.
          stac_extensions : Optional list of extensions the Catalog implements.
          href : Optional HREF for this catalog, which be set as the
              catalog's self link's HREF.
          catalog_type : Optional catalog type for this catalog. Must
              be one of the values in :class:`~pystac.CatalogType`.
      """
  
      catalog_type: CatalogType
      """The catalog type. Defaults to :attr:`CatalogType.ABSOLUTE_PUBLISHED`."""
  
      description: str
      """Detailed multi-line description to fully explain the catalog."""
  
      extra_fields: Dict[str, Any]
      """Extra fields that are part of the top-level JSON properties of the Catalog."""
  
      id: str
      """Identifier for the catalog."""
  
      links: List[Link]
      """A list of :class:`~pystac.Link` objects representing all links associated with
      this Catalog."""
  
      title: Optional[str]
      """Optional short descriptive one-line title for the catalog."""
  
      stac_extensions: List[str]
      """List of extensions the Catalog implements."""
  
      _resolved_objects: ResolvedObjectCache
  
      STAC_OBJECT_TYPE = pystac.STACObjectType.CATALOG
  
      _stac_io: Optional[pystac.StacIO] = None
      """Optional instance of StacIO that will be used by default
      for any IO operations on objects contained by this catalog.
      Set while reading in a catalog. This is set when a catalog
      is read by a StacIO instance."""
  
      DEFAULT_FILE_NAME = "catalog.json"
      """Default file name that will be given to this STAC object in
      a canonical format.
      """
  
      def __init__(
          self,
          id: str,
          description: str,
          title: Optional[str] = None,
          stac_extensions: Optional[List[str]] = None,
          extra_fields: Optional[Dict[str, Any]] = None,
          href: Optional[str] = None,
          catalog_type: CatalogType = CatalogType.ABSOLUTE_PUBLISHED,
      ):
          super().__init__(stac_extensions or [])
  
          self.id = id
          self.description = description
          self.title = title
          if extra_fields is None:
              self.extra_fields = {}
          else:
              self.extra_fields = extra_fields
  
          self._resolved_objects = ResolvedObjectCache()
  
          self.add_link(Link.root(self))
  
          if href is not None:
              self.set_self_href(href)
  
          self.catalog_type: CatalogType = catalog_type
  
          self._resolved_objects.cache(self)
  
      def __repr__(self) -> str:
          return "<Catalog id={}>".format(self.id)
  
      def set_root(self, root: Optional["Catalog"]) -> None:
          STACObject.set_root(self, root)
          if root is not None:
              root._resolved_objects = ResolvedObjectCache.merge(
                  root._resolved_objects, self._resolved_objects
              )
  
              # Walk through resolved object links and update the root
              for link in self.links:
                  if link.rel == pystac.RelType.CHILD or link.rel == pystac.RelType.ITEM:
                      target = link.target
                      if isinstance(target, STACObject):
                          target.set_root(root)
  
      def is_relative(self) -> bool:
          return self.catalog_type in [
              CatalogType.RELATIVE_PUBLISHED,
              CatalogType.SELF_CONTAINED,
          ]
  
      def add_child(
          self,
          child: Union["Catalog", "Collection_Type"],
          title: Optional[str] = None,
          strategy: Optional[HrefLayoutStrategy] = None,
      ) -> None:
          """Adds a link to a child :class:`~pystac.Catalog` or :class:`~pystac.Collection`.
          This method will set the child's parent to this object, and its root to
          this Catalog's root.
  
          Args:
              child : The child to add.
              title : Optional title to give to the :class:`~pystac.Link`
              strategy : The layout strategy to use for setting the
                  self href of the child.
          """
  
          # Prevent typo confusion
          if isinstance(child, pystac.Item):
              raise pystac.STACError("Cannot add item as child. Use add_item instead.")
  
          if strategy is None:
              strategy = BestPracticesLayoutStrategy()
  
          child.set_root(self.get_root())
          child.set_parent(self)
  
          # set self link
          self_href = self.get_self_href()
          if self_href:
              child_href = strategy.get_href(child, os.path.dirname(self_href))
              child.set_self_href(child_href)
  
          self.add_link(Link.child(child, title=title))
  
      def add_children(
          self, children: Iterable[Union["Catalog", "Collection_Type"]]
      ) -> None:
          """Adds links to multiple :class:`~pystac.Catalog` or `~pystac.Collection` objects.
          This method will set each child's parent to this object, and their root to
          this Catalog's root.
  
          Args:
              children : The children to add.
          """
          for child in children:
              self.add_child(child)
  
      def add_item(
          self,
          item: "Item_Type",
          title: Optional[str] = None,
          strategy: Optional[HrefLayoutStrategy] = None,
      ) -> None:
          """Adds a link to an :class:`~pystac.Item`.
          This method will set the item's parent to this object, and its root to
          this Catalog's root.
  
          Args:
              item : The item to add.
              title : Optional title to give to the :class:`~pystac.Link`
          """
  
          # Prevent typo confusion
          if isinstance(item, pystac.Catalog):
              raise pystac.STACError("Cannot add catalog as item. Use add_child instead.")
  
          if strategy is None:
              strategy = BestPracticesLayoutStrategy()
  
          item.set_root(self.get_root())
          item.set_parent(self)
  
          # set self link
          self_href = self.get_self_href()
          if self_href:
              item_href = strategy.get_href(item, os.path.dirname(self_href))
              item.set_self_href(item_href)
  
          self.add_link(Link.item(item, title=title))
  
      def add_items(self, items: Iterable["Item_Type"]) -> None:
          """Adds links to multiple :class:`~pystac.Item` s.
          This method will set each item's parent to this object, and their root to
          this Catalog's root.
  
          Args:
              items : The items to add.
          """
          for item in items:
              self.add_item(item)
  
      def get_child(
          self, id: str, recursive: bool = False
      ) -> Optional[Union["Catalog", "Collection_Type"]]:
          """Gets the child of this catalog with the given ID, if it exists.
  
          Args:
              id : The ID of the child to find.
              recursive : If True, search this catalog and all children for the
                  item; otherwise, only search the children of this catalog. Defaults
                  to False.
  
          Return:
              Optional Catalog or Collection: The child with the given ID,
              or None if not found.
          """
          if not recursive:
              return next((c for c in self.get_children() if c.id == id), None)
          else:
              for root, _, _ in self.walk():
                  child = root.get_child(id, recursive=False)
                  if child is not None:
                      return child
              return None
  
      def get_children(self) -> Iterable[Union["Catalog", "Collection_Type"]]:
          """Return all children of this catalog.
  
          Return:
              Iterable[Catalog or Collection]: Iterable of children who's parent
              is this catalog.
          """
          return map(
              lambda x: cast(Union[pystac.Catalog, pystac.Collection], x),
              self.get_stac_objects(pystac.RelType.CHILD),
          )
  
      def get_collections(self) -> Iterable["Collection_Type"]:
          """Return all children of this catalog that are :class:`~pystac.Collection`
          instances."""
          return map(
              lambda x: cast(pystac.Collection, x),
              self.get_stac_objects(pystac.RelType.CHILD, pystac.Collection),
          )
  
      def get_all_collections(self) -> Iterable["Collection_Type"]:
          """Get all collections from this catalog and all subcatalogs. Will traverse
          any subcatalogs recursively."""
          yield from self.get_collections()
          for child in self.get_children():
              yield from child.get_collections()
  
      def get_child_links(self) -> List[Link]:
          """Return all child links of this catalog.
  
          Return:
              List[Link]: List of links of this catalog with ``rel == 'child'``
          """
          return self.get_links(pystac.RelType.CHILD)
  
      def clear_children(self) -> None:
          """Removes all children from this catalog.
  
          Return:
              Catalog: Returns ``self``
          """
          child_ids = [child.id for child in self.get_children()]
          for child_id in child_ids:
              self.remove_child(child_id)
  
      def remove_child(self, child_id: str) -> None:
          """Removes an child from this catalog.
  
          Args:
              child_id : The ID of the child to remove.
          """
          new_links: List[pystac.Link] = []
          root = self.get_root()
          for link in self.links:
              if link.rel != pystac.RelType.CHILD:
                  new_links.append(link)
              else:
                  link.resolve_stac_object(root=root)
                  child = cast("Catalog", link.target)
                  if child.id != child_id:
                      new_links.append(link)
                  else:
                      child.set_parent(None)
                      child.set_root(None)
          self.links = new_links
  
      def get_item(self, id: str, recursive: bool = False) -> Optional["Item_Type"]:
          """Returns an item with a given ID.
  
          Args:
              id : The ID of the item to find.
              recursive : If True, search this catalog and all children for the
                  item; otherwise, only search the items of this catalog. Defaults
                  to False.
  
          Return:
              Item or None: The item with the given ID, or None if not found.
          """
          if not recursive:
              return next((i for i in self.get_items() if i.id == id), None)
          else:
              for root, _, _ in self.walk():
                  item = root.get_item(id, recursive=False)
                  if item is not None:
                      return item
              return None
  
      def get_items(self) -> Iterable["Item_Type"]:
          """Return all items of this catalog.
  
          Return:
              Iterable[Item]: Generator of items whose parent is this catalog.
          """
          return map(
              lambda x: cast(pystac.Item, x), self.get_stac_objects(pystac.RelType.ITEM)
          )
  
      def clear_items(self) -> None:
          """Removes all items from this catalog.
  
          Return:
              Catalog: Returns ``self``
          """
          for link in self.get_item_links():
              if link.is_resolved():
                  item = cast(pystac.Item, link.target)
                  item.set_parent(None)
                  item.set_root(None)
  
          self.links = [link for link in self.links if link.rel != pystac.RelType.ITEM]
  
      def remove_item(self, item_id: str) -> None:
          """Removes an item from this catalog.
  
          Args:
              item_id : The ID of the item to remove.
          """
          new_links: List[pystac.Link] = []
          root = self.get_root()
          for link in self.links:
              if link.rel != pystac.RelType.ITEM:
                  new_links.append(link)
              else:
                  link.resolve_stac_object(root=root)
                  item = cast(pystac.Item, link.target)
                  if item.id != item_id:
                      new_links.append(link)
                  else:
                      item.set_parent(None)
                      item.set_root(None)
          self.links = new_links
  
      def get_all_items(self) -> Iterable["Item_Type"]:
          """Get all items from this catalog and all subcatalogs. Will traverse
          any subcatalogs recursively.
  
          Returns:
              Generator[Item]: All items that belong to this catalog, and all
                  catalogs or collections connected to this catalog through
                  child links.
          """
          yield from self.get_items()
          for child in self.get_children():
              yield from child.get_all_items()
  
      def get_item_links(self) -> List[Link]:
          """Return all item links of this catalog.
  
          Return:
              List[Link]: List of links of this catalog with ``rel == 'item'``
          """
          return self.get_links(pystac.RelType.ITEM)
  
      def to_dict(
          self, include_self_link: bool = True, transform_hrefs: bool = True
      ) -> Dict[str, Any]:
          links = self.links
          if not include_self_link:
              links = [x for x in links if x.rel != pystac.RelType.SELF]
  
          d: Dict[str, Any] = {
              "type": self.STAC_OBJECT_TYPE.value.title(),
              "id": self.id,
              "stac_version": pystac.get_stac_version(),
              "description": self.description,
              "links": [link.to_dict(transform_href=transform_hrefs) for link in links],
          }
  
          if self.stac_extensions is not None:
              d["stac_extensions"] = self.stac_extensions
  
          for key in self.extra_fields:
              d[key] = self.extra_fields[key]
  
          if self.title is not None:
              d["title"] = self.title
  
          return d
  
      def clone(self) -> "Catalog":
          cls = self.__class__
          clone = cls(
              id=self.id,
              description=self.description,
              title=self.title,
              stac_extensions=self.stac_extensions,
              extra_fields=deepcopy(self.extra_fields),
              catalog_type=self.catalog_type,
          )
          clone._resolved_objects.cache(clone)
  
          for link in self.links:
              if link.rel == pystac.RelType.ROOT:
                  # Catalog __init__ sets correct root to clone; don't reset
                  # if the root link points to self
                  root_is_self = link.is_resolved() and link.target is self
                  if not root_is_self:
                      clone.set_root(None)
                      clone.add_link(link.clone())
              else:
                  clone.add_link(link.clone())
  
          return clone
  
      def make_all_asset_hrefs_relative(self) -> None:
          """Makes all the HREFs of assets belonging to items in this catalog
          and all children to be relative, recursively.
          """
          for _, _, items in self.walk():
              for item in items:
                  item.make_asset_hrefs_relative()
  
      def make_all_asset_hrefs_absolute(self) -> None:
          """Makes all the HREFs of assets belonging to items in this catalog
          and all children to be absolute, recursively.
          """
          for _, _, items in self.walk():
              for item in items:
                  item.make_asset_hrefs_absolute()
  
      def normalize_and_save(
          self,
          root_href: str,
          catalog_type: Optional[CatalogType] = None,
          strategy: Optional[HrefLayoutStrategy] = None,
          stac_io: Optional[pystac.StacIO] = None,
      ) -> None:
          """Normalizes link HREFs to the given root_href, and saves the catalog.
  
          This is a convenience method that simply calls :func:`Catalog.normalize_hrefs
          <pystac.Catalog.normalize_hrefs>` and :func:`Catalog.save <pystac.Catalog.save>`
          in sequence.
  
          Args:
              root_href : The absolute HREF that all links will be normalized
                  against.
              catalog_type : The catalog type that dictates the structure of
                  the catalog to save. Use a member of :class:`~pystac.CatalogType`.
                  Defaults to the root catalog.catalog_type or the current catalog
                  catalog_type if there is no root catalog.
              strategy : The layout strategy to use in setting the
                  HREFS for this catalog. Defaults to
                  :class:`~pystac.layout.BestPracticesLayoutStrategy`
              stac_io : Optional instance of :class:`~pystac.StacIO` to use. If not
                  provided, will use the instance set while reading in the catalog,
                  or the default instance if this is not available.
          """
          self.normalize_hrefs(root_href, strategy=strategy)
          self.save(catalog_type, stac_io=stac_io)
  
      def normalize_hrefs(
          self, root_href: str, strategy: Optional[HrefLayoutStrategy] = None
      ) -> None:
          """Normalize HREFs will regenerate all link HREFs based on
          an absolute root_href and the canonical catalog layout as specified
          in the STAC specification's best practices.
  
          This method mutates the entire catalog tree.
  
          Args:
              root_href : The absolute HREF that all links will be normalized against.
              strategy : The layout strategy to use in setting the HREFS
                  for this catalog. Defaults to
                  :class:`~pystac.layout.BestPracticesLayoutStrategy`
  
          See:
              :stac-spec:`STAC best practices document <best-practices.md#catalog-layout>`
              for the canonical layout of a STAC.
          """
          if strategy is None:
              _strategy: HrefLayoutStrategy = BestPracticesLayoutStrategy()
          else:
              _strategy = strategy
  
          # Normalizing requires an absolute path
          if not is_absolute_href(root_href):
              root_href = make_absolute_href(root_href, os.getcwd(), start_is_dir=True)
  
          def process_item(item: "Item_Type", _root_href: str) -> Callable[[], None]:
              item.resolve_links()
  
              new_self_href = _strategy.get_href(item, _root_href)
  
              def fn() -> None:
                  item.set_self_href(new_self_href)
  
              return fn
  
          def process_catalog(
              cat: Catalog, _root_href: str, is_root: bool
          ) -> List[Callable[[], None]]:
              setter_funcs: List[Callable[[], None]] = []
  
              cat.resolve_links()
  
              new_self_href = _strategy.get_href(cat, _root_href, is_root)
              new_root = os.path.dirname(new_self_href)
  
              for item in cat.get_items():
                  setter_funcs.append(process_item(item, new_root))
  
              for child in cat.get_children():
                  setter_funcs.extend(process_catalog(child, new_root, is_root=False))
  
              def fn() -> None:
                  cat.set_self_href(new_self_href)
  
              setter_funcs.append(fn)
  
              return setter_funcs
  
          # Collect functions that will actually mutate the objects.
          # Delay mutation as setting hrefs while walking the catalog
          # can result in bad links.
          setter_funcs = process_catalog(self, root_href, is_root=True)
  
          for fn in setter_funcs:
              fn()
  
      def generate_subcatalogs(
          self,
          template: str,
          defaults: Optional[Dict[str, Any]] = None,
          parent_ids: Optional[List[str]] = None,
      ) -> List["Catalog"]:
          """Walks through the catalog and generates subcatalogs
          for items based on the template string.
  
          See :class:`~pystac.layout.LayoutTemplate`
          for details on the construction of template strings. This template string
          will be applied to the items, and subcatalogs will be created that separate
          and organize the items based on template values.
  
          Args:
              template :   A template string that
                  can be consumed by a :class:`~pystac.layout.LayoutTemplate`
              defaults :  Default values for the template variables
                  that will be used if the property cannot be found on
                  the item.
              parent_ids : Optional list of the parent catalogs'
                  identifiers. If the bottom-most subcatalogs already match the
                  template, no subcatalog is added.
  
          Returns:
              [catalog]: List of new catalogs created
          """
          result: List[Catalog] = []
          parent_ids = parent_ids or list()
          parent_ids.append(self.id)
          for child in self.get_children():
              result.extend(
                  child.generate_subcatalogs(
                      template, defaults=defaults, parent_ids=parent_ids.copy()
                  )
              )
  
          layout_template = LayoutTemplate(template, defaults=defaults)
  
          keep_item_links: List[Link] = []
          item_links = [lk for lk in self.links if lk.rel == pystac.RelType.ITEM]
          for link in item_links:
              link.resolve_stac_object(root=self.get_root())
              item = cast(pystac.Item, link.target)
              subcat_ids = layout_template.substitute(item).split("/")
              id_iter = reversed(parent_ids)
              if all(
                  ["{}".format(id) == next(id_iter, None) for id in reversed(subcat_ids)]
              ):
                  # Skip items for which the sub-catalog structure already
                  # matches the template. The list of parent IDs can include more
                  # elements on the root side, so compare the reversed sequences.
                  keep_item_links.append(link)
                  continue
              curr_parent = self
              for subcat_id in subcat_ids:
                  subcat = curr_parent.get_child(subcat_id)
                  if subcat is None:
                      subcat_desc = "Catalog of items from {} with id {}".format(
                          curr_parent.id, subcat_id
                      )
                      subcat = pystac.Catalog(id=subcat_id, description=subcat_desc)
                      curr_parent.add_child(subcat)
                      result.append(subcat)
                  curr_parent = subcat
  
              # resolve collection link so when added back points to correct location
              col_link = item.get_single_link(pystac.RelType.COLLECTION)
              if col_link is not None:
                  col_link.resolve_stac_object()
  
              curr_parent.add_item(item)
  
          # keep only non-item links and item links that have not been moved elsewhere
          self.links = [
              lk for lk in self.links if lk.rel != pystac.RelType.ITEM
          ] + keep_item_links
  
          return result
  
      def save(
          self,
          catalog_type: Optional[CatalogType] = None,
          dest_href: Optional[str] = None,
          stac_io: Optional[pystac.StacIO] = None,
      ) -> None:
          """Save this catalog and all it's children/item to files determined by the object's
          self link HREF or a specified path.
  
          Args:
              catalog_type : The catalog type that dictates the structure of
                  the catalog to save. Use a member of :class:`~pystac.CatalogType`.
                  If not supplied, the catalog_type of this catalog will be used.
                  If that attribute is not set, an exception will be raised.
              dest_href : The location where the catalog is to be saved.
                  If not supplied, the catalog's self link HREF is used to determine
                  the location of the catalog file and children's files.
              stac_io : Optional instance of :class:`~pystac.StacIO` to use. If not
                  provided, will use the instance set while reading in the catalog,
                  or the default instance if this is not available.
          Note:
              If the catalog type is ``CatalogType.ABSOLUTE_PUBLISHED``,
              all self links will be included, and hierarchical links be absolute URLs.
              If the catalog type is ``CatalogType.RELATIVE_PUBLISHED``, this catalog's
              self link will be included, but no child catalog will have self links, and
              hierarchical links will be relative URLs
              If the catalog  type is ``CatalogType.SELF_CONTAINED``, no self links will
              be included and hierarchical links will be relative URLs.
          """
  
          root = self.get_root()
          if root is None:
              raise Exception("There is no root catalog")
  
          if catalog_type is not None:
              root.catalog_type = catalog_type
  
          items_include_self_link = root.catalog_type in [CatalogType.ABSOLUTE_PUBLISHED]
  
          for child_link in self.get_child_links():
              if child_link.is_resolved():
                  child = cast(Catalog, child_link.target)
                  if dest_href is not None:
                      rel_href = make_relative_href(child.self_href, self.self_href)
                      child_dest_href = make_absolute_href(
                          rel_href, dest_href, start_is_dir=True
                      )
                      child.save(
                          dest_href=os.path.dirname(child_dest_href),
                          stac_io=stac_io,
                      )
                  else:
                      child.save(stac_io=stac_io)
  
          for item_link in self.get_item_links():
              if item_link.is_resolved():
                  item = cast(pystac.Item, item_link.target)
                  if dest_href is not None:
                      rel_href = make_relative_href(item.self_href, self.self_href)
                      item_dest_href = make_absolute_href(
                          rel_href, dest_href, start_is_dir=True
                      )
                      item.save_object(
                          include_self_link=items_include_self_link,
                          dest_href=item_dest_href,
                          stac_io=stac_io,
                      )
                  else:
                      item.save_object(
                          include_self_link=items_include_self_link, stac_io=stac_io
                      )
  
          include_self_link = False
          # include a self link if this is the root catalog
          # or if ABSOLUTE_PUBLISHED catalog
          if root.catalog_type == CatalogType.ABSOLUTE_PUBLISHED:
              include_self_link = True
          elif root.catalog_type != CatalogType.SELF_CONTAINED:
              root_link = self.get_root_link()
              if root_link and root_link.get_absolute_href() == self.get_self_href():
                  include_self_link = True
  
          catalog_dest_href = None
          if dest_href is not None:
              rel_href = make_relative_href(self.self_href, self.self_href)
              catalog_dest_href = make_absolute_href(
                  rel_href, dest_href, start_is_dir=True
              )
          self.save_object(
              include_self_link=include_self_link,
              dest_href=catalog_dest_href,
              stac_io=stac_io,
          )
          if catalog_type is not None:
              self.catalog_type = catalog_type
  
      def walk(
          self,
      ) -> Iterable[Tuple["Catalog", Iterable["Catalog"], Iterable["Item_Type"]]]:
          """Walks through children and items of catalogs.
  
          For each catalog in the STAC's tree rooted at this catalog (including this
          catalog itself), it yields a 3-tuple (root, subcatalogs, items). The root in
          that 3-tuple refers to the current catalog being walked, the subcatalogs are any
          catalogs or collections for which the root is a parent, and items represents
          any items that have the root as a parent.
  
          This has similar functionality to Python's :func:`os.walk`.
  
          Returns:
             Generator[(Catalog, Generator[Catalog], Generator[Item])]: A generator that
             yields a 3-tuple (parent_catalog, children, items).
          """
          children = self.get_children()
          items = self.get_items()
  
          yield self, children, items
          for child in self.get_children():
              yield from child.walk()
  
      def validate_all(self) -> None:
          """Validates each catalog, collection contained within this catalog.
  
          Walks through the children and items of the catalog and validates each
          stac object.
  
          Raises:
              STACValidationError: Raises this error on any item that is invalid.
                  Will raise on the first invalid stac object encountered.
          """
          self.validate()
          for child in self.get_children():
              child.validate_all()
          for item in self.get_items():
              item.validate()
  
      def _object_links(self) -> List[Union[str, pystac.RelType]]:
          return [
              pystac.RelType.CHILD,
              pystac.RelType.ITEM,
              *pystac.EXTENSION_HOOKS.get_extended_object_links(self),
          ]
  
      def map_items(
          self,
          item_mapper: Callable[["Item_Type"], Union["Item_Type", List["Item_Type"]]],
      ) -> "Catalog":
          """Creates a copy of a catalog, with each item passed through the
          item_mapper function.
  
          Args:
              item_mapper :   A function that takes in an item, and returns
                  either an item or list of items. The item that is passed into the
                  item_mapper is a copy, so the method can mutate it safely.
  
          Returns:
              Catalog: A full copy of this catalog, with items manipulated according
              to the item_mapper function.
          """
  
          new_cat = self.full_copy()
  
          def process_catalog(catalog: Catalog) -> None:
              for child in catalog.get_children():
                  process_catalog(child)
  
              item_links: List[Link] = []
              for item_link in catalog.get_item_links():
                  item_link.resolve_stac_object(root=self.get_root())
                  mapped = item_mapper(cast(pystac.Item, item_link.target))
                  if mapped is None:
                      raise Exception("item_mapper cannot return None.")
                  if isinstance(mapped, pystac.Item):
                      item_link.target = mapped
                      item_links.append(item_link)
                  else:
                      for i in mapped:
                          new_link = item_link.clone()
                          new_link.target = i
                          item_links.append(new_link)
              catalog.clear_items()
              catalog.add_links(item_links)
  
          process_catalog(new_cat)
          return new_cat
  
      def map_assets(
          self,
          asset_mapper: Callable[
              [str, "Asset_Type"],
              Union["Asset_Type", Tuple[str, "Asset_Type"], Dict[str, "Asset_Type"]],
          ],
      ) -> "Catalog":
          """Creates a copy of a catalog, with each Asset for each Item passed
          through the asset_mapper function.
  
          Args:
              asset_mapper : A function that takes in an key and an Asset, and
                  returns either an Asset, a (key, Asset), or a dictionary of Assets with
                  unique keys. The Asset that is passed into the item_mapper is a copy,
                  so the method can mutate it safely.
  
          Returns:
              Catalog: A full copy of this catalog, with assets manipulated according
              to the asset_mapper function.
          """
  
          def apply_asset_mapper(
              tup: Tuple[str, "Asset_Type"]
          ) -> List[Tuple[str, pystac.Asset]]:
              k, v = tup
              result = asset_mapper(k, v)
              if result is None:
                  raise Exception("asset_mapper cannot return None.")
              if isinstance(result, pystac.Asset):
                  return [(k, result)]
              elif isinstance(result, tuple):
                  return [result]
              else:
                  assets = list(result.items())
                  if len(assets) < 1:
                      raise Exception("asset_mapper must return a non-empty list")
                  return assets
  
          def item_mapper(item: pystac.Item) -> pystac.Item:
              new_assets = [
                  x
                  for result in map(apply_asset_mapper, item.assets.items())
                  for x in result
              ]
              item.assets = dict(new_assets)
              return item
  
          return self.map_items(item_mapper)
  
      def describe(self, include_hrefs: bool = False, _indent: int = 0) -> None:
          """Prints out information about this Catalog and all contained
          STACObjects.
  
          Args:
              include_hrefs (bool) - If True, print out each object's self link
                  HREF along with the object ID.
          """
          s = "{}* {}".format(" " * _indent, self)
          if include_hrefs:
              s += " {}".format(self.get_self_href())
          print(s)
          for child in self.get_children():
              child.describe(include_hrefs=include_hrefs, _indent=_indent + 4)
          for item in self.get_items():
              s = "{}* {}".format(" " * (_indent + 2), item)
              if include_hrefs:
                  s += " {}".format(item.get_self_href())
              print(s)
  
      @classmethod
      def from_dict(
          cls,
          d: Dict[str, Any],
          href: Optional[str] = None,
          root: Optional["Catalog"] = None,
          migrate: bool = False,
          preserve_dict: bool = True,
      ) -> "Catalog":
          if migrate:
              info = identify_stac_object(d)
              d = migrate_to_latest(d, info)
  
          if not cls.matches_object_type(d):
              raise STACTypeError(f"{d} does not represent a {cls.__name__} instance")
  
          catalog_type = CatalogType.determine_type(d)
  
          if preserve_dict:
              d = deepcopy(d)
  
          id = d.pop("id")
          description = d.pop("description")
          title = d.pop("title", None)
          stac_extensions = d.pop("stac_extensions", None)
          links = d.pop("links")
  
          d.pop("stac_version")
  
          cat = cls(
              id=id,
              description=description,
              title=title,
              stac_extensions=stac_extensions,
              extra_fields=d,
              href=href,
              catalog_type=catalog_type or CatalogType.ABSOLUTE_PUBLISHED,
          )
  
          for link in links:
              if link["rel"] == pystac.RelType.ROOT:
                  # Remove the link that's generated in Catalog's constructor.
                  cat.remove_links(pystac.RelType.ROOT)
  
              if link["rel"] != pystac.RelType.SELF or href is None:
                  cat.add_link(Link.from_dict(link))
  
          if root:
              cat.set_root(root)
  
          return cat
  
      def full_copy(
          self, root: Optional["Catalog"] = None, parent: Optional["Catalog"] = None
      ) -> "Catalog":
          return cast(Catalog, super().full_copy(root, parent))
  
      @classmethod
      def from_file(cls, href: str, stac_io: Optional[pystac.StacIO] = None) -> "Catalog":
          if stac_io is None:
              stac_io = pystac.StacIO.default()
  
          result = super().from_file(href, stac_io)
          if not isinstance(result, Catalog):
              raise pystac.STACTypeError(f"{result} is not a {Catalog}.")
          result._stac_io = stac_io
  
          return result
  
      @classmethod
      def matches_object_type(cls, d: Dict[str, Any]) -> bool:
          return identify_stac_object_type(d) == STACObjectType.CATALOG
  