""" This file provides the Django ABIDField and ABIDModel base model to inherit from. """ from typing import Any, Dict, Union, List, Set, cast from uuid import uuid4 from functools import partial from charidfield import CharIDField # type: ignore[import-untyped] from django.contrib import admin from django.core.exceptions import ValidationError, NON_FIELD_ERRORS from django.db import models from django.utils import timezone from django.db.utils import OperationalError from django.contrib.auth import get_user_model from django.urls import reverse_lazy from django_stubs_ext.db.models import TypedModelMeta from .abid import ( ABID, ABID_LEN, ABID_RAND_LEN, ABID_SUFFIX_LEN, DEFAULT_ABID_PREFIX, DEFAULT_ABID_URI_SALT, abid_part_from_prefix, abid_hashes_from_values, ts_from_abid, abid_part_from_ts, ) #################################################### # Database Field for typeid/ulid style IDs with a prefix, e.g. snp_01BJQMF54D093DXEAWZ6JYRPAQ ABIDField = partial( CharIDField, max_length=ABID_LEN, help_text="ABID-format identifier for this entity (e.g. snp_01BJQMF54D093DXEAWZ6JYRPAQ)", default=None, null=True, blank=True, db_index=True, unique=True, ) def get_or_create_system_user_pk(username='system'): """Get or create a system user with is_superuser=True to be the default owner for new DB rows""" User = get_user_model() # if only one user exists total, return that user if User.objects.filter(is_superuser=True).count() == 1: return User.objects.filter(is_superuser=True).values_list('pk', flat=True)[0] # otherwise, create a dedicated "system" user user, _was_created = User.objects.get_or_create(username=username, is_staff=True, is_superuser=True, defaults={'email': '', 'password': ''}) return user.pk class AutoDateTimeField(models.DateTimeField): # def pre_save(self, model_instance, add): # return timezone.now() pass class ABIDError(Exception): pass class ABIDModel(models.Model): """ Abstract Base Model for other models to depend on. Provides ArchiveBox ID (ABID) interface. """ abid_prefix: str = DEFAULT_ABID_PREFIX # e.g. 'tag_' abid_ts_src = 'self.created_at' # e.g. 'self.created_at' abid_uri_src = 'None' # e.g. 'self.uri' (MUST BE SET) abid_subtype_src = 'self.__class__.__name__' # e.g. 'self.extractor' abid_rand_src = 'self.id' # e.g. 'self.uuid' or 'self.id' abid_salt: str = DEFAULT_ABID_URI_SALT # combined with self.uri to anonymize hashes on a per-install basis (default is shared globally with all users, means everyone will hash ABC to -> 123 the same around the world, makes it easy to share ABIDs across installs and see if they are for the same URI. Change this if you dont want your hashes to be guessable / in the same hash space as all other users) abid_drift_allowed: bool = False # set to True to allow abid_field values to change after a fixed ABID has been issued (NOT RECOMMENDED: means values can drift out of sync from original ABID) # id = models.UUIDField(primary_key=True, default=None, null=False, editable=False, unique=True, verbose_name='ID') # abid = ABIDField(prefix=abid_prefix) # created_by = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, default=None, null=False) # created_at = AutoDateTimeField(default=None, null=False, db_index=True) # modified_at = models.DateTimeField(auto_now=True) _prefetched_objects_cache: Dict[str, Any] class Meta(TypedModelMeta): abstract = True @admin.display(description='Summary') def __str__(self) -> str: return f'[{self.abid or (self.abid_prefix + "NEW")}] {self.__class__.__name__} {eval(self.abid_uri_src)}' def __init__(self, *args: Any, **kwargs: Any) -> None: """Overriden __init__ method ensures we have a stable creation timestamp that fields can use within initialization code pre-saving to DB.""" super().__init__(*args, **kwargs) # pre-compute a stable timestamp of the obj init time (with abid.ts precision limit applied) for use when object is first created, # some other fields depend on a timestamp at creation time, and it's nice to have one common timestamp they can all share. # Used as an alternative to auto_now_add=True + auto_now=True which can produce two different times & requires saving to DB to get the TS. # (ordinarily fields cant depend on other fields until the obj is saved to db and recalled) self._init_timestamp = ts_from_abid(abid_part_from_ts(timezone.now())) def clean(self, abid_drift_allowed: bool | None=None) -> None: if self._state.adding: # only runs once when a new object is first saved to the DB # sets self.id, self.pk, self.created_by, self.created_at, self.modified_at self._previous_abid = None self.abid = str(self.issue_new_abid()) else: # otherwise if updating, make sure none of the field changes would invalidate existing ABID abid_diffs = self.ABID_FRESH_DIFFS if abid_diffs: # change has invalidated the existing ABID, raise a nice ValidationError pointing out which fields caused the issue keys_changed = ', '.join(diff['abid_src'] for diff in abid_diffs.values()) full_summary = ( f"This {self.__class__.__name__}(abid={str(self.ABID)}) was assigned a fixed, unique ID (ABID) based on its contents when it was created. " + f"\nYou must reduce your changes to not affect these fields [{keys_changed}], or create a new {self.__class__.__name__} object instead." ) change_error = ValidationError({ **{ # url: ValidationError('Cannot update self.url= https://example.com/old -> https://example.com/new ...') diff['abid_src'].replace('self.', '') if (diff['old_val'] != diff['new_val']) and hasattr(self, diff['abid_src'].replace('self.', '')) else NON_FIELD_ERRORS : ValidationError( 'Cannot update %(abid_src)s= "%(old_val)s" -> "%(new_val)s" (would alter %(model)s.ABID.%(key)s=%(old_hash)s to %(new_hash)s)', code='ABIDConflict', params=diff, ) for diff in abid_diffs.values() }, NON_FIELD_ERRORS: ValidationError(full_summary), }) allowed_to_invalidate_abid = self.abid_drift_allowed if (abid_drift_allowed is None) else abid_drift_allowed if allowed_to_invalidate_abid: print(f'\n#### WARNING: Change allowed despite it invalidating the ABID of an existing record ({self.__class__.__name__}.abid_drift_allowed={self.abid_drift_allowed})!', self.abid) print(change_error) print('--------------------------------------------------------------------------------------------------') else: print(f'\n#### ERROR: Change blocked because it would invalidate ABID of an existing record ({self.__class__.__name__}.abid_drift_allowed={self.abid_drift_allowed})', self.abid) print(change_error) print('--------------------------------------------------------------------------------------------------') raise change_error def save(self, *args: Any, abid_drift_allowed: bool | None=None, **kwargs: Any) -> None: """Overriden save method ensures new ABID is generated while a new object is first saving.""" self.clean(abid_drift_allowed=abid_drift_allowed) return super().save(*args, **kwargs) @classmethod def id_from_abid(cls, abid: str) -> str: return str(cls.objects.only('pk').get(abid=cls.abid_prefix + str(abid).split('_', 1)[-1]).pk) @property def ABID_SOURCES(self) -> Dict[str, str]: """"Get the dict of fresh ABID component values based on the live object's properties.""" assert self.abid_prefix return { 'prefix': 'self.abid_prefix', # defined as static class vars at build time 'ts': self.abid_ts_src, 'uri': self.abid_uri_src, 'subtype': self.abid_subtype_src, 'rand': self.abid_rand_src, 'salt': 'self.abid_salt', # defined as static class vars at build time } @property def ABID_FRESH_VALUES(self) -> Dict[str, Any]: """"Get the dict of fresh ABID component values based on the live object's properties.""" abid_sources = self.ABID_SOURCES assert all(src != 'None' for src in abid_sources.values()) return { 'prefix': eval(abid_sources['prefix']), 'ts': eval(abid_sources['ts']), 'uri': eval(abid_sources['uri']), 'subtype': eval(abid_sources['subtype']), 'rand': eval(abid_sources['rand']), 'salt': eval(abid_sources['salt']), } @property def ABID_FRESH_HASHES(self) -> Dict[str, str]: """"Get the dict of fresh ABID component hashes based on the live object's properties.""" abid_values = self.ABID_FRESH_VALUES assert all(val for val in abid_values.values()) return abid_hashes_from_values( prefix=abid_values['prefix'], ts=abid_values['ts'], uri=abid_values['uri'], subtype=abid_values['subtype'], rand=abid_values['rand'], salt=abid_values['salt'], ) @property def ABID_FRESH_DIFFS(self) -> Dict[str, Dict[str, Any]]: """Get the dict of discrepancies between the existing saved ABID and a new fresh ABID computed based on the live object.""" existing_abid = self.ABID existing_values = {} if self._state.adding else self.__class__.objects.get(pk=self.pk).ABID_FRESH_VALUES abid_sources = self.ABID_SOURCES fresh_values = self.ABID_FRESH_VALUES fresh_hashes = self.ABID_FRESH_HASHES return { key: { 'key': key, 'model': self.__class__.__name__, 'pk': self.pk, 'abid_src': abid_sources[key], 'old_val': existing_values.get(key, None), 'old_hash': getattr(existing_abid, key), 'new_val': fresh_values[key], 'new_hash': new_hash, 'summary': f'{abid_sources[key]}= "{existing_values.get(key, None)}" -> "{fresh_values[key]}" (would alter {self.__class__.__name__.lower()}.ABID.{key}={getattr(existing_abid, key)} to {new_hash})', } for key, new_hash in fresh_hashes.items() if getattr(existing_abid, key) != new_hash } def issue_new_abid(self, overwrite=False) -> ABID: """ Issue a new ABID based on the current object's properties, can only be called once on new objects (before they are saved to DB). """ if not overwrite: assert self._state.adding, 'Can only issue new ABID when model._state.adding is True' assert eval(self.abid_uri_src), f'Can only issue new ABID if self.abid_uri_src is defined ({self.abid_uri_src}={eval(self.abid_uri_src)})' # Setup Field defaults to be ready for ABID generation self.abid = None self.id = self.id or uuid4() self.pk = self.id self.created_at = self.created_at or self._init_timestamp # cut off precision to match precision of TS component self.modified_at = self.modified_at or self.created_at self.created_by_id = (hasattr(self, 'created_by_id') and self.created_by_id) or get_or_create_system_user_pk() # Compute fresh ABID values & hashes based on object's live properties abid_fresh_values = self.ABID_FRESH_VALUES assert all(abid_fresh_values.values()), f'All ABID_FRESH_VALUES must be set {abid_fresh_values}' abid_fresh_hashes = self.ABID_FRESH_HASHES assert all(abid_fresh_hashes.values()), f'All ABID_FRESH_HASHES must be able to be generated {abid_fresh_hashes}' new_abid = ABID(**abid_fresh_hashes) assert new_abid.ulid and new_abid.uuid and new_abid.typeid, f'Failed to calculate {abid_fresh_values["prefix"]}_ABID for {self.__class__.__name__}' return new_abid @property def ABID(self) -> ABID: """ Get the object's existing ABID (from self.abid if it's already saved to DB, otherwise generated fresh) e.g. -> ABID(ts='01HX9FPYTR', uri='E4A5CCD9', subtype='00', rand='ZYEBQE') """ if self.abid: return ABID.parse(cast(str, self.abid)) return self.issue_new_abid() # These are all example helpers to make it easy to access alternate formats of the ABID.*, only add them if you actually need them # @property # def UUID(self) -> UUID: # """ # Get a uuid.UUID (v4) representation of the object's ABID. # """ # return self.ABID.uuid # @property # def uuid(self) -> str: # """ # Get a str uuid.UUID (v4) representation of the object's ABID. # """ # return str(self.ABID.uuid) # @property # def ULID(self) -> ULID: # """ # Get a ulid.ULID representation of the object's ABID. # """ # return self.ABID.ulid # @property # def TypeID(self) -> TypeID: # """ # Get a typeid.TypeID (stripe-style) representation of the object's ABID. # """ # return self.ABID.typeid @property def api_url(self) -> str: """ Compute the REST API URL to access this object. e.g. /api/v1/core/snapshot/snp_01BJQMF54D093DXEAWZ6JYRP """ return reverse_lazy('api-1:get_any', args=[self.abid]) # + f'?api_key={get_or_create_api_token(request.user)}' @property def api_docs_url(self) -> str: """ Compute the REST API Documentation URL to learn about accessing this object. e.g. /api/v1/docs#/Core%20Models/api_v1_core_get_snapshots """ return f'/api/v1/docs#/{self._meta.app_label.title()}%20Models/api_v1_{self._meta.app_label}_get_{self._meta.db_table}' @property def admin_change_url(self) -> str: return f"/admin/{self._meta.app_label}/{self._meta.model_name}/{self.pk}/change/" def get_absolute_url(self): return self.api_docs_url class ModelWithHealthStats(models.Model): num_uses_failed = models.PositiveIntegerField(default=0) num_uses_succeeded = models.PositiveIntegerField(default=0) class Meta: abstract = True def record_health_failure(self) -> None: self.num_uses_failed += 1 self.save() def record_health_success(self) -> None: self.num_uses_succeeded += 1 self.save() def reset_health(self) -> None: # move all the failures to successes when resetting so we dont lose track of the total count self.num_uses_succeeded = self.num_uses_failed + self.num_uses_succeeded self.num_uses_failed = 0 self.save() @property def health(self) -> int: total_uses = max((self.num_uses_failed + self.num_uses_succeeded, 1)) success_pct = (self.num_uses_succeeded / total_uses) * 100 return round(success_pct) #################################################### # Django helpers def find_all_abid_prefixes() -> Dict[str, type[models.Model]]: """ Return the mapping of all ABID prefixes to their models. e.g. {'tag_': core.models.Tag, 'snp_': core.models.Snapshot, ...} """ import django.apps prefix_map = {} for model in django.apps.apps.get_models(): abid_prefix = getattr(model, 'abid_prefix', None) if abid_prefix: prefix_map[abid_prefix] = model return prefix_map def find_prefix_for_abid(abid: ABID) -> str: """ Find the correct prefix for a given ABID that may have be missing a prefix (slow). e.g. ABID('obj_01BJQMF54D093DXEAWZ6JYRPAQ') -> 'snp_' """ # if existing abid prefix is correct, lookup is easy model = find_model_from_abid(abid) if model: assert issubclass(model, ABIDModel) return model.abid_prefix # prefix might be obj_ or missing, fuzzy-search to find any object that matches return find_obj_from_abid_rand(abid)[0].abid_prefix def find_model_from_abid_prefix(prefix: str) -> type[ABIDModel] | None: """ Return the Django Model that corresponds to a given ABID prefix. e.g. 'tag_' -> core.models.Tag """ prefix = abid_part_from_prefix(prefix) import django.apps for model in django.apps.apps.get_models(): if not issubclass(model, ABIDModel): continue # skip non-ABID-enabled models if not hasattr(model, 'objects'): continue # skip abstract models if (model.abid_prefix == prefix): return model return None def find_model_from_abid(abid: ABID) -> type[models.Model] | None: """ Shortcut for find_model_from_abid_prefix(abid.prefix) """ return find_model_from_abid_prefix(abid.prefix) def find_obj_from_abid_rand(rand: Union[ABID, str], model=None) -> List[ABIDModel]: """ Find an object corresponding to an ABID by exhaustively searching using its random suffix (slow). e.g. 'obj_....................JYRPAQ' -> Snapshot('snp_01BJQMF54D093DXEAWZ6JYRPAQ') Honestly should only be used for debugging, no reason to expose this ability to users. """ # convert str to ABID if necessary if isinstance(rand, ABID): abid: ABID = rand else: rand = str(rand) if len(rand) < ABID_SUFFIX_LEN: padding_needed = ABID_SUFFIX_LEN - len(rand) rand = ('0'*padding_needed) + rand abid = ABID.parse(rand) import django.apps partial_matches: List[ABIDModel] = [] models_to_try = cast(Set[type[models.Model]], set(filter(bool, ( model, find_model_from_abid(abid), *django.apps.apps.get_models(), )))) # print(abid, abid.rand, abid.uuid, models_to_try) for model in models_to_try: if not issubclass(model, ABIDModel): continue # skip Models that arent ABID-enabled if not hasattr(model, 'objects'): continue # skip abstract Models assert hasattr(model, 'objects') # force-fix for type hint nit about missing manager https://github.com/typeddjango/django-stubs/issues/1684 # continue on to try fuzzy searching by randomness portion derived from uuid field try: qs = [] if hasattr(model, 'abid'): qs = model.objects.filter(abid__endswith=abid.rand) elif hasattr(model, 'uuid'): qs = model.objects.filter(uuid__endswith=str(abid.uuid)[-ABID_RAND_LEN:]) elif hasattr(model, 'id'): # NOTE: this only works on SQLite where every column is a string # other DB backends like postgres dont let you do __endswith if this is a BigAutoInteger field # try to search for uuid=...-2354352 # try to search for id=...2354352 # try to search for id=2354352 qs = model.objects.filter( models.Q(id__endswith=str(abid.uuid)[-ABID_RAND_LEN:]) | models.Q(id__endswith=abid.rand) | models.Q(id__startswith=str(int(abid.rand)) if abid.rand.isdigit() else abid.rand) ) for obj in qs: if abid in (str(obj.ABID), str(obj.id), str(obj.pk), str(obj.abid)): # found exact match, no need to keep iterating return [obj] partial_matches.append(obj) except OperationalError as err: print(f'[!] WARNING: Got error while trying to iterate through QuerySet for {model}:', err, '\n') return partial_matches def find_obj_from_abid(abid: ABID, model=None, fuzzy=False) -> Any: """ Find an object with a given ABID by filtering possible models for a matching abid/uuid/id (fast). e.g. 'snp_01BJQMF54D093DXEAWZ6JYRPAQ' -> Snapshot('snp_01BJQMF54D093DXEAWZ6JYRPAQ') """ model = model or find_model_from_abid(abid) assert model, f'Could not find model that could match this ABID type: {abid}' try: if hasattr(model, 'abid'): return model.objects.get(abid__endswith=abid.suffix) if hasattr(model, 'uuid'): return model.objects.get(uuid=abid.uuid) return model.objects.get(id=abid.uuid) except model.DoesNotExist: # if the model has an abid field then it shouldve matched, pointless to fuzzy search in that case if hasattr(model, 'abid') or (not fuzzy): raise # continue on to try fuzzy searching by randomness portion derived from uuid field match_by_rand = find_obj_from_abid_rand(abid, model=model) if match_by_rand: if match_by_rand[0].abid_prefix != abid.prefix: print(f'[!] WARNING: fetched object {match_by_rand} even though prefix {abid.prefix} doesnt match!', abid, '\n') return match_by_rand raise model.DoesNotExist