music-kraken-core/music_kraken/objects/collection.py

164 lines
5.4 KiB
Python

from __future__ import annotations
from collections import defaultdict
from typing import TypeVar, Generic, Dict, Optional, Iterable, List, Iterator, Tuple, Generator, Union, Any
from .parents import OuterProxy
from ..utils import object_trace
T = TypeVar('T', bound=OuterProxy)
class Collection(Generic[T]):
__is_collection__ = True
_data: List[T]
_indexed_values: Dict[str, set]
_indexed_to_objects: Dict[any, list]
shallow_list = property(fget=lambda self: self.data)
def __init__(
self,
data: Optional[Iterable[T]] = None,
sync_on_append: Dict[str, Collection] = None,
append_object_to_attribute: Dict[str, T] = None,
extend_object_to_attribute: Dict[str, Collection] = None,
) -> None:
self._collection_for: dict = dict()
self._contains_ids = set()
self._data = []
# List of collection attributes that should be modified on append
# Key: collection attribute (str) of appended element
# Value: main collection to sync to
self.append_object_to_attribute: Dict[str, T] = append_object_to_attribute or {}
self.extend_object_to_attribute: Dict[str, Collection[T]] = extend_object_to_attribute or {}
self.sync_on_append: Dict[str, Collection] = sync_on_append or {}
self._id_to_index_values: Dict[int, set] = defaultdict(set)
# This is to cleanly unmap previously mapped items by their id
self._indexed_from_id: Dict[int, Dict[str, Any]] = defaultdict(dict)
# this is to keep track and look up the actual objects
self._indexed_values: Dict[str, Dict[Any, T]] = defaultdict(dict)
self.extend(data)
def __repr__(self) -> str:
return f"Collection({id(self)})"
def _map_element(self, __object: T, from_map: bool = False):
self._unmap_element(__object.id)
self._indexed_from_id[__object.id]["id"] = __object.id
self._indexed_values["id"][__object.id] = __object
for name, value in __object.indexing_values:
if value is None or value == __object._inner._default_values.get(name):
continue
self._indexed_values[name][value] = __object
self._indexed_from_id[__object.id][name] = value
def _unmap_element(self, __object: Union[T, int]):
obj_id = __object.id if isinstance(__object, OuterProxy) else __object
if obj_id not in self._indexed_from_id:
return
for name, value in self._indexed_from_id[obj_id].items():
if value in self._indexed_values[name]:
del self._indexed_values[name][value]
del self._indexed_from_id[obj_id]
def _find_object(self, __object: T) -> Optional[T]:
for name, value in __object.indexing_values:
if value in self._indexed_values[name]:
return self._indexed_values[name][value]
def append(self, __object: Optional[T], already_is_parent: bool = False, from_map: bool = False):
"""
If an object, that represents the same entity exists in a relevant collection,
merge into this object. (and remap)
Else append to this collection.
:param __object:
:param already_is_parent:
:param from_map:
:return:
"""
if __object is None:
return
existing_object = self._find_object(__object)
if existing_object is None:
# append
self._data.append(__object)
self._map_element(__object)
for collection_attribute, child_collection in self.extend_object_to_attribute.items():
__object.__getattribute__(collection_attribute).extend(child_collection)
for attribute, new_object in self.append_object_to_attribute.items():
__object.__getattribute__(attribute).append(new_object)
# only modify collections if the object actually has been appended
for attribute, a in self.sync_on_append.items():
b = __object.__getattribute__(attribute)
object_trace(f"Syncing [{a}{id(a)}] = [{b}{id(b)}]")
data_to_extend = b.data
a._collection_for.update(b._collection_for)
for synced_with, key in b._collection_for.items():
synced_with.__setattr__(key, a)
a.extend(data_to_extend)
else:
# merge only if the two objects are not the same
if existing_object.id == __object.id:
return
old_id = existing_object.id
existing_object.merge(__object)
if existing_object.id != old_id:
self._unmap_element(old_id)
self._map_element(existing_object)
def extend(self, __iterable: Optional[Generator[T, None, None]]):
if __iterable is None:
return
for __object in __iterable:
self.append(__object)
@property
def data(self) -> List[T]:
return list(self.__iter__())
def __len__(self) -> int:
return len(self._data)
@property
def empty(self) -> bool:
return self.__len__() <= 0
def __iter__(self) -> Iterator[T]:
yield from self._data
def __merge__(self, __other: Collection, override: bool = False):
self.extend(__other)
def __getitem__(self, item: int):
return self._data[item]