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

from __future__ import annotations

import random
from collections import defaultdict
from functools import lru_cache
from typing import Optional, Dict, Tuple, List, Type, Generic, Any, TypeVar, Set

from pathlib import Path
import inspect

from .metadata import Metadata
from ..utils import get_unix_time, object_trace
from ..utils.config import logging_settings, main_settings
from ..utils.shared import HIGHEST_ID
from ..utils.hacking import MetaClass

LOGGER = logging_settings["object_logger"]

P = TypeVar("P", bound="OuterProxy")


class InnerData:
    """
    This is the core class, which is used for every Data class.
    The attributes are set, and can be merged.

    The concept is, that the outer class proxies this class.
    If the data in the wrapper class has to be merged, then this class is just replaced and garbage collected.
    """

    _refers_to_instances: set = None

    def __init__(self, object_type, **kwargs):
        self._refers_to_instances = set()

        # collection : collection that is a collection of self
        self._is_collection_child: Dict[Collection, Collection] = {}
        self._is_collection_parent: Dict[Collection, Collection] = {}
        
        # initialize the default values
        self._default_values = {}
        for name, factory in object_type._default_factories.items():
            self._default_values[name] = factory()

        for key, value in kwargs.items():
            self.__setattr__(key, value)

    def __merge__(self, __other: InnerData, override: bool = False):
        """
        :param __other:
        :param override:
        :return:
        """

        for key, value in __other.__dict__.copy().items():
            # just set the other value if self doesn't already have it
            if key not in self.__dict__ or (key in self.__dict__ and self.__dict__[key] == self._default_values.get(key)):
                self.__setattr__(key, value)
                continue

            # if the object of value implemented __merge__, it merges
            existing = self.__getattribute__(key)
            if hasattr(type(existing), "__merge__"):
                existing.__merge__(value, override)
                continue

            # override the existing value if requested
            if override:
                self.__setattr__(key, value)


class OuterProxy:
    """
    Wraps the inner data, and provides apis, to naturally access those values.
    """

    _default_factories: dict = {}
    _outer_attribute: Set[str] = {"options", "metadata", "indexing_values", "option_string"}

    DOWNWARDS_COLLECTION_STRING_ATTRIBUTES = tuple()
    UPWARDS_COLLECTION_STRING_ATTRIBUTES = tuple()

    TITEL = "id"

    def __init__(self, _id: int = None, dynamic: bool = False, **kwargs):
        _automatic_id: bool = False

        if _id is None and not dynamic:
            """
            generates a random integer id
            the range is defined in the config
            """
            _id = random.randint(0, HIGHEST_ID)
            _automatic_id = True

        kwargs["automatic_id"] = _automatic_id
        kwargs["id"] = _id
        kwargs["dynamic"] = dynamic

        for name, factory in type(self)._default_factories.items():
            if kwargs.get(name, None) is None:
                kwargs[name] = factory()

        collection_data: Dict[str, list] = {}
        for name, value in kwargs.copy().items():
            if isinstance(value, list) and name.endswith("_list"):
                collection_name = name.replace("_list", "_collection")
                collection_data[collection_name] = value

                del kwargs[name]

        self._fetched_from: dict = {}
        self._inner: InnerData = InnerData(type(self), **kwargs)
        self._inner._refers_to_instances.add(self)

        object_trace(f"creating {type(self).__name__} [{self.title_string}]")
        self.__init_collections__()

        for name, data_list in collection_data.items():
            collection = self._inner.__getattribute__(name)
            collection.extend(data_list)

            self._inner.__setattr__(name, collection)

    def __init_collections__(self):
        pass

    def __getattribute__(self, __name: str) -> Any:
        """
        Returns the attribute of _inner if the attribute exists,
        else it returns the attribute of self.

        That the _inner gets checked first is essential for the type hints.
        :param __name:
        :return:
        """

        if __name.startswith("_") or __name in self._outer_attribute or __name.isupper():
            return object.__getattribute__(self, __name)

        _inner: InnerData = super().__getattribute__("_inner")
        try:
            return _inner.__getattribute__(__name)
        except AttributeError:
            return super().__getattribute__(__name)

    def __setattr__(self, __name, __value):
        if not __name.startswith("_") and hasattr(self, "_inner"):
            _inner: InnerData = super().__getattribute__("_inner")
            return _inner.__setattr__(__name, __value)

        return super().__setattr__(__name, __value)

    def _add_other_db_objects(self, object_type: Type[OuterProxy], object_list: List[OuterProxy]):
        pass

    def add_list_of_other_objects(self, object_list: List[OuterProxy]):
        d: Dict[Type[OuterProxy], List[OuterProxy]] = defaultdict(list)

        for db_object in object_list:
            d[type(db_object)].append(db_object)

        for key, value in d.items():
            self._add_other_db_objects(key, value)

    def __hash__(self):
        """
        :raise: IsDynamicException
        :return:
        """

        if self.dynamic:
            return id(self._inner)

        return self.id

    def __eq__(self, other: Any):
        return self.__hash__() == other.__hash__()

    def merge(self, __other: Optional[OuterProxy], override: bool = False):
        """
        1. merges the data of __other in self
        2. replaces the data of __other with the data of self

        :param __other:
        :param override:
        :return:
        """
        if __other is None:
            return

        object_trace(f"merging {type(self).__name__} [{self.title_string} | {self.id}] with {type(__other).__name__} [{__other.title_string} | {__other.id}] called by [{' | '.join(f'{s.function} {Path(s.filename).name}:{str(s.lineno)}' for s in inspect.stack()[1:4])}]")

        a = self
        b = __other

        if a.id == b.id:
            return
        
        # switch instances if more efficient
        if len(b._inner._refers_to_instances) > len(a._inner._refers_to_instances):
            a, b = b, a

        a._inner.__merge__(b._inner, override=override)
        for collection, child_collection in b._inner._is_collection_child.items():
            try:
                collection.children.remove(child_collection)
            except ValueError:
                pass
            
        for collection, parent_collection in b._inner._is_collection_parent.items():
            try:
                collection.parents.remove(parent_collection)
            except ValueError:
                pass
        
        old_inner = b._inner
        a._inner._refers_to_instances.update(b._inner._refers_to_instances)

        for instance in b._inner._refers_to_instances:
            instance._inner = a._inner

        del old_inner

    def __merge__(self, __other: Optional[OuterProxy], override: bool = False):
        self.merge(__other, override)

    def mark_as_fetched(self, *url_hash_list: List[str]):
        for url_hash in url_hash_list:
            self._fetched_from[url_hash] = {
                "time": get_unix_time(),
                "url": url_hash,
            }

    def already_fetched_from(self, url_hash: str) -> bool:
        res = self._fetched_from.get(url_hash, None)

        if res is None:
            return False

        return get_unix_time() - res["time"] < main_settings["refresh_after"]

    @property
    def metadata(self) -> Metadata:
        """
        This is an interface.
        :return:
        """
        return Metadata()

    @property
    def options(self) -> List[P]:
        return [self]

    @property
    def indexing_values(self) -> List[Tuple[str, object]]:
        """
        This is an interface.
        It is supposed to return a map of the name and values for all important attributes.
        This helps in comparing classes for equal data (e.g. being the same song but different attributes)

        TODO
        Rewrite this approach into a approach, that is centered around statistics, and not binaries.
        Instead of: one of this matches, it is the same
        This: If enough attributes are similar enough, they are the same

        Returns:
            List[Tuple[str, object]]: the first element in the tuple is the name of the attribute, the second the value.
        """

        return []

    @property
    @lru_cache()
    def all_collections(self):
        r = []

        for key in self._default_factories:
            val = self._inner.__getattribute__(key)
            if hasattr(val, "__is_collection__"):
                r.append(val)

        return r

    def __repr__(self):
        return f"{type(self).__name__}({', '.join(key + ': ' + str(val) for key, val in self.indexing_values)})"

    @property
    def title_string(self) -> str:
        return str(self.__getattribute__(self.TITEL))