1 files changed, 66 insertions, 0 deletions
diff --git a/src/hydrilla/item_infos.py b/src/hydrilla/item_infos.py
index 9a87b40..0e10871 100644
--- a/src/hydrilla/item_infos.py
+++ b/src/hydrilla/item_infos.py
@@ -484,3 +484,69 @@ class CategorizedItemInfo(Categorizable, t.Generic[CategorizedType, CategoryKeyT
     def is_empty(self) -> bool:
         """...."""
         return len(self.items) == 0
+
+
+VersionedType = t.TypeVar('VersionedType', ResourceInfo, MappingInfo)
+
+class VersionedItemInfo(
+        CategorizedItemInfo[VersionedType, versions.VerTuple],
+        t.Generic[VersionedType]
+):
+    """Stores data of multiple versions of given resource/mapping."""
+    SelfType = t.TypeVar('SelfType', bound='VersionedItemInfo[VersionedType]')
+
+    def register(self: 'SelfType', item_info: VersionedType) -> 'SelfType':
+        """
+        Make item info queryable by version. Perform sanity checks for uuid.
+        """
+        return self._update(item_info.version, lambda old_info: item_info)
+
+    def unregister(self: 'SelfType', version: versions.VerTuple) -> 'SelfType':
+        """...."""
+        return self._update(version, lambda old_info: None)
+
+    @property
+    def newest_version(self) -> versions.VerTuple:
+        """...."""
+        assert not self.is_empty()
+
+        return max(self.items.keys())
+
+    @property
+    def newest_info(self) -> VersionedType:
+        """Find and return info of the newest version of item."""
+        return self.items[self.newest_version]
+
+    def get_by_ver(self, ver: t.Sequence[int]) -> t.Optional[VersionedType]:
+        """
+        Find and return info of the specified version of the item (or None if
+        absent).
+        """
+        return self.items.get(versions.normalize(ver))
+
+    def get_all(self) -> t.Iterable[VersionedType]:
+        """Generate item info for all its versions, from oldest to newest."""
+        return [self.items[version] for version in sorted(self.items.keys())]
+
+VersionedResourceInfo = VersionedItemInfo[ResourceInfo]
+VersionedMappingInfo  = VersionedItemInfo[MappingInfo]
+
+
+VersionedItemInfoMap     = Map[str, VersionedItemInfo]
+VersionedResourceInfoMap = Map[str, VersionedResourceInfo]
+VersionedMappingInfoMap  = Map[str, VersionedMappingInfo]
+
+def register_in_map(
+        map: Map[str, VersionedItemInfo[VersionedType]],
+        info: VersionedType
+) -> Map[str, VersionedItemInfo[VersionedType]]:
+    versioned_info = map.get(info.identifier, VersionedItemInfo())
+
+    return map.set(info.identifier, versioned_info.register(info))
+
+def all_map_infos(
+        map: Map[str, VersionedItemInfo[VersionedType]]
+) -> t.Iterator[VersionedType]:
+    for versioned_info in map.values():
+        for item_info in versioned_info.get_all():
+            yield item_info