import abc
import hashlib
import json
import logging
import os
import secrets
from abc import abstractmethod
from collections import defaultdict
from datetime import datetime
from typing import Union, List, Optional, Dict, Tuple, Set, Any
from uuid import uuid4

import joblib
import numpy as np
from django.conf import settings as s
from django.contrib.auth.models import AbstractUser
from django.contrib.contenttypes.fields import GenericRelation, GenericForeignKey
from django.contrib.contenttypes.models import ContentType
from django.contrib.postgres.fields import ArrayField
from django.db import models, transaction
from django.db.models import JSONField, Count, Q, QuerySet
from django.utils import timezone
from django.utils.functional import cached_property
from envipy_additional_information import EnviPyModel
from model_utils.models import TimeStampedModel
from polymorphic.models import PolymorphicModel
from sklearn.metrics import precision_score, recall_score, jaccard_score
from sklearn.model_selection import ShuffleSplit

from utilities.chem import FormatConverter, ProductSet, PredictionResult, IndigoUtils
from utilities.ml import Dataset, ApplicabilityDomainPCA, EnsembleClassifierChain, RelativeReasoning

logger = logging.getLogger(__name__)


##########################
# User/Groups/Permission #
##########################

class User(AbstractUser):
    email = models.EmailField(unique=True)
    uuid = models.UUIDField(null=False, blank=False, verbose_name='UUID of this object', unique=True, default=uuid4)
    url = models.TextField(blank=False, null=True, verbose_name='URL', unique=True)
    default_package = models.ForeignKey('epdb.Package', verbose_name='Default Package', null=True,
                                        on_delete=models.SET_NULL)
    default_group = models.ForeignKey('Group', verbose_name='Default Group', null=True, blank=False,
                                      on_delete=models.SET_NULL, related_name='default_group')
    default_setting = models.ForeignKey('epdb.Setting', on_delete=models.SET_NULL,
                                        verbose_name='The users default settings', null=True, blank=False)

    USERNAME_FIELD = "email"
    REQUIRED_FIELDS = ['username']

    def save(self, *args, **kwargs):
        if not self.url:
            self.url = self._url()

        super().save(*args, **kwargs)

    def _url(self):
        return '{}/user/{}'.format(s.SERVER_URL, self.uuid)

    def prediction_settings(self):
        if self.default_setting is None:
            self.default_setting = Setting.objects.get(global_default=True)
            self.save()
        return self.default_setting


class APIToken(TimeStampedModel):
    """
    API authentication token for users.

    Provides secure token-based authentication with expiration support.
    """
    hashed_key = models.CharField(
        max_length=128,
        unique=True,
        help_text="SHA-256 hash of the token key"
    )

    user = models.ForeignKey(
        User,
        on_delete=models.CASCADE,
        related_name='api_tokens',
        help_text="User who owns this token"
    )

    expires_at = models.DateTimeField(
        null=True,
        blank=True,
        help_text="Token expiration time (null for no expiration)"
    )

    name = models.CharField(
        max_length=100,
        help_text="Descriptive name for this token"
    )

    is_active = models.BooleanField(
        default=True,
        help_text="Whether this token is active"
    )

    class Meta:
        db_table = 'epdb_api_token'
        verbose_name = 'API Token'
        verbose_name_plural = 'API Tokens'
        ordering = ['-created']

    def __str__(self) -> str:
        return f"{self.name} ({self.user.username})"

    def is_valid(self) -> bool:
        """Check if token is valid and not expired."""
        if not self.is_active:
            return False

        if self.expires_at and timezone.now() > self.expires_at:
            return False

        return True

    @classmethod
    def create_token(cls, user: User, name: str, expires_days: Optional[int] = None) -> Tuple['APIToken', str]:
        """
        Create a new API token for a user.

        Args:
            user: User to create token for
            name: Descriptive name for the token
            expires_days: Number of days until expiration (None for no expiration)

        Returns:
            Tuple of (token_instance, raw_key)
        """
        raw_key = secrets.token_urlsafe(32)
        hashed_key = hashlib.sha256(raw_key.encode()).hexdigest()

        expires_at = None
        if expires_days:
            expires_at = timezone.now() + timezone.timedelta(days=expires_days)

        token = cls.objects.create(
            user=user,
            name=name,
            hashed_key=hashed_key,
            expires_at=expires_at
        )

        return token, raw_key

    @classmethod
    def authenticate(cls, raw_key: str) -> Optional[User]:
        """
        Authenticate a user using an API token.

        Args:
            raw_key: Raw token key

        Returns:
            User if token is valid, None otherwise
        """
        hashed_key = hashlib.sha256(raw_key.encode()).hexdigest()

        try:
            token = cls.objects.select_related('user').get(hashed_key=hashed_key)
            if token.is_valid():
                return token.user
        except cls.DoesNotExist:
            pass

        return None


class Group(TimeStampedModel):
    uuid = models.UUIDField(null=False, blank=False, verbose_name='UUID of this object', unique=True, default=uuid4)
    url = models.TextField(blank=False, null=True, verbose_name='URL', unique=True)
    name = models.TextField(blank=False, null=False, verbose_name='Group name')
    owner = models.ForeignKey("User", verbose_name='Group Owner', on_delete=models.CASCADE)
    public = models.BooleanField(verbose_name='Public Group', default=False)
    description = models.TextField(blank=False, null=False, verbose_name='Descriptions', default='no description')
    user_member = models.ManyToManyField("User", verbose_name='User members', related_name='users_in_group')
    group_member = models.ManyToManyField("Group", verbose_name='Group member', related_name='groups_in_group', blank=True)

    def __str__(self):
        return f"{self.name} (pk={self.pk})"

    def save(self, *args, **kwargs):
        if not self.url:
            self.url = self._url()

        super().save(*args, **kwargs)

    def _url(self):
        return '{}/group/{}'.format(s.SERVER_URL, self.uuid)


class Permission(TimeStampedModel):
    READ = ('read', 'Read')
    WRITE = ('write', 'Write')
    ALL = ('all', 'All')
    PERMS = [
        READ,
        WRITE,
        ALL
    ]
    permission = models.CharField(max_length=32, choices=PERMS, null=False)

    def has_read(self):
        return self.permission in [p[0] for p in self.PERMS]

    def has_write(self):
        return self.permission in [self.WRITE[0], self.ALL[0]]

    def has_all(self):
        return self.permission == self.ALL[0]

    class Meta:
        abstract: True


class UserPackagePermission(Permission):
    uuid = models.UUIDField(null=False, blank=False, verbose_name='UUID of this object', primary_key=True,
                            default=uuid4)
    user = models.ForeignKey('User', verbose_name='Permission to', on_delete=models.CASCADE)
    package = models.ForeignKey('epdb.Package', verbose_name='Permission on', on_delete=models.CASCADE)

    class Meta:
        unique_together = [('package', 'user')]

    def __str__(self):
        return f"User: {self.user} has Permission: {self.permission}  on Package: {self.package}"


class GroupPackagePermission(Permission):
    uuid = models.UUIDField(null=False, blank=False, verbose_name='UUID of this object', primary_key=True,
                            default=uuid4)
    group = models.ForeignKey('Group', verbose_name='Permission to', on_delete=models.CASCADE)
    package = models.ForeignKey('epdb.Package', verbose_name='Permission on', on_delete=models.CASCADE)

    class Meta:
        unique_together = [('package', 'group')]

    def __str__(self):
        return f"Group: {self.group} has Permission: {self.permission}  on Package: {self.package}"


############################
# External IDs / Databases #
############################
class ExternalDatabase(TimeStampedModel):
    uuid = models.UUIDField(default=uuid4, editable=False, unique=True)
    name = models.CharField(max_length=100, unique=True, verbose_name="Database Name")
    full_name = models.CharField(max_length=255, blank=True, verbose_name="Full Database Name")
    description = models.TextField(blank=True, verbose_name="Description")
    base_url = models.URLField(blank=True, null=True, verbose_name="Base URL")
    url_pattern = models.CharField(
        max_length=500,
        blank=True,
        verbose_name="URL Pattern",
        help_text="URL pattern with {id} placeholder, e.g., 'https://pubchem.ncbi.nlm.nih.gov/compound/{id}'"
    )
    is_active = models.BooleanField(default=True, verbose_name="Is Active")

    class Meta:
        db_table = 'epdb_external_database'
        verbose_name = 'External Database'
        verbose_name_plural = 'External Databases'
        ordering = ['name']

    def __str__(self):
        return self.full_name or self.name

    def get_url_for_identifier(self, identifier_value):
        if self.url_pattern and '{id}' in self.url_pattern:
            return self.url_pattern.format(id=identifier_value)
        return None

    @staticmethod
    def get_databases():
        return {
            'compound': [
                {
                    'database': ExternalDatabase.objects.get(name='PubChem Compound'),
                    'placeholder': 'PubChem Compound ID e.g. 12345',
                }, {
                    'database': ExternalDatabase.objects.get(name='PubChem Substance'),
                    'placeholder': 'PubChem Substance ID e.g. 12345',
                }, {
                    'database': ExternalDatabase.objects.get(name='KEGG Reaction'),
                    'placeholder': 'KEGG ID including entity Prefix e.g. C12345',
                }, {
                    'database': ExternalDatabase.objects.get(name='ChEBI'),
                    'placeholder': 'ChEBI ID without prefix e.g. 12345',
                },
            ],
            'structure': [
                {
                    'database': ExternalDatabase.objects.get(name='PubChem Compound'),
                    'placeholder': 'PubChem Compound ID e.g. 12345',
                }, {
                    'database': ExternalDatabase.objects.get(name='PubChem Substance'),
                    'placeholder': 'PubChem Substance ID e.g. 12345',
                }, {
                    'database': ExternalDatabase.objects.get(name='KEGG Reaction'),
                    'placeholder': 'KEGG ID including entity Prefix e.g. C12345',
                }, {
                    'database': ExternalDatabase.objects.get(name='ChEBI'),
                    'placeholder': 'ChEBI ID without prefix e.g. 12345',
                },
            ],
            'reaction': [
                {
                    'database': ExternalDatabase.objects.get(name='KEGG Reaction'),
                    'placeholder': 'KEGG ID including entity Prefix e.g. C12345',
                }, {
                    'database': ExternalDatabase.objects.get(name='RHEA'),
                    'placeholder': 'RHEA ID without Prefix e.g. 12345',
                }, {
                    'database': ExternalDatabase.objects.get(name='UniProt'),
                    'placeholder': 'Query ID for UniPro e.g. rhea:12345',
                }
            ]
        }


class ExternalIdentifier(TimeStampedModel):
    uuid = models.UUIDField(default=uuid4, editable=False, unique=True)

    # Generic foreign key to link to any model
    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
    object_id = models.IntegerField()
    content_object = GenericForeignKey('content_type', 'object_id')

    database = models.ForeignKey(
        ExternalDatabase,
        on_delete=models.CASCADE,
        verbose_name="External Database"
    )
    identifier_value = models.CharField(max_length=255, verbose_name="Identifier Value")
    url = models.URLField(blank=True, null=True, verbose_name="Direct URL")
    is_primary = models.BooleanField(
        default=False,
        verbose_name="Is Primary",
        help_text="Mark this as the primary identifier for this database"
    )

    class Meta:
        db_table = 'epdb_external_identifier'
        verbose_name = 'External Identifier'
        verbose_name_plural = 'External Identifiers'
        unique_together = [('content_type', 'object_id', 'database', 'identifier_value')]
        indexes = [
            models.Index(fields=['content_type', 'object_id']),
            models.Index(fields=['database', 'identifier_value']),
        ]

    def __str__(self):
        return f"{self.database.name}: {self.identifier_value}"

    @property
    def external_url(self):
        if self.url:
            return self.url
        return self.database.get_url_for_identifier(self.identifier_value)

    def save(self, *args, **kwargs):
        if not self.url and self.database.url_pattern:
            self.url = self.database.get_url_for_identifier(self.identifier_value)
        super().save(*args, **kwargs)


class ExternalIdentifierMixin(models.Model):
    class Meta:
        abstract = True

    def get_external_identifiers(self):
        return self.external_identifiers.all()

    def get_external_identifier(self, database_name):
        return self.external_identifiers.filter(database__name=database_name)

    def add_external_identifier(self, database_name, identifier_value, url=None, is_primary=False):
        database, created = ExternalDatabase.objects.get_or_create(name=database_name)

        if is_primary:
            self.external_identifiers.filter(database=database, is_primary=True).update(is_primary=False)

        external_id, created = ExternalIdentifier.objects.get_or_create(
            content_type=ContentType.objects.get_for_model(self),
            object_id=self.pk,
            database=database,
            identifier_value=identifier_value,
            defaults={
                'url': url,
                'is_primary': is_primary
            }
        )
        return external_id

    def remove_external_identifier(self, database_name, identifier_value):
        self.external_identifiers.filter(
            database__name=database_name,
            identifier_value=identifier_value
        ).delete()


class ChemicalIdentifierMixin(ExternalIdentifierMixin):

    class Meta:
        abstract = True

    @property
    def pubchem_compound_id(self):
        identifier = self.get_external_identifier('PubChem Compound')
        return identifier.identifier_value if identifier else None

    @property
    def pubchem_substance_id(self):
        identifier = self.get_external_identifier('PubChem Substance')
        return identifier.identifier_value if identifier else None

    @property
    def chebi_id(self):
        identifier = self.get_external_identifier('ChEBI')
        return identifier.identifier_value if identifier else None

    @property
    def cas_number(self):
        identifier = self.get_external_identifier('CAS')
        return identifier.identifier_value if identifier else None

    def add_pubchem_compound_id(self, compound_id, is_primary=True):
        return self.add_external_identifier(
            'PubChem Compound',
            compound_id,
            f'https://pubchem.ncbi.nlm.nih.gov/compound/{compound_id}',
            is_primary
        )

    def add_pubchem_substance_id(self, substance_id):
        return self.add_external_identifier(
            'PubChem Substance',
            substance_id,
            f'https://pubchem.ncbi.nlm.nih.gov/substance/{substance_id}'
        )

    def add_chebi_id(self, chebi_id, is_primary=False):
        clean_id = chebi_id.replace('CHEBI:', '')
        return self.add_external_identifier(
            'ChEBI',
            clean_id,
            f'https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:{clean_id}',
            is_primary
        )

    def add_cas_number(self, cas_number):
        return self.add_external_identifier('CAS', cas_number)

    def get_pubchem_identifiers(self):
        return self.get_external_identifier('PubChem Compound') or self.get_external_identifier('PubChem Substance')

    def get_pubchem_compound_identifiers(self):
        return self.get_external_identifier('PubChem Compound')

    def get_pubchem_substance_identifiers(self):
        return self.get_external_identifier('PubChem Substance')

    def get_chebi_identifiers(self):
        return self.get_external_identifier('ChEBI')

    def get_cas_identifiers(self):
        return self.get_external_identifier('CAS')

class ReactionIdentifierMixin(ExternalIdentifierMixin):

    class Meta:
        abstract = True

    @property
    def rhea_id(self):
        identifier = self.get_external_identifier('RHEA')
        return identifier.identifier_value if identifier else None

    @property
    def kegg_reaction_id(self):
        identifier = self.get_external_identifier('KEGG Reaction')
        return identifier.identifier_value if identifier else None

    @property
    def metacyc_reaction_id(self):
        identifier = self.get_external_identifier('MetaCyc')
        return identifier.identifier_value if identifier else None

    def add_rhea_id(self, rhea_id, is_primary=True):
        return self.add_external_identifier(
            'RHEA',
            rhea_id,
            f'https://www.rhea-db.org/rhea/{rhea_id}',
            is_primary
        )

    def add_uniprot_id(self, uniprot_id, is_primary=True):
        return self.add_external_identifier(
            'UniProt',
            uniprot_id,
            f'https://www.uniprot.org/uniprotkb?query="{uniprot_id}"',
            is_primary
        )

    def add_kegg_reaction_id(self, kegg_id):
        return self.add_external_identifier(
            'KEGG Reaction',
            kegg_id,
            f'https://www.genome.jp/entry/reaction+{kegg_id}'
        )

    def add_metacyc_reaction_id(self, metacyc_id):
        return self.add_external_identifier('MetaCyc', metacyc_id)

    def get_rhea_identifiers(self):
        return self.get_external_identifier('RHEA')

    def get_uniprot_identifiers(self):
        return self.get_external_identifier('UniProt')


##############
# EP Objects #
##############
class EnviPathModel(TimeStampedModel):
    uuid = models.UUIDField(null=False, blank=False, verbose_name='UUID of this object', unique=True,
                            default=uuid4)
    name = models.TextField(blank=False, null=False, verbose_name='Name', default='no name')
    description = models.TextField(blank=False, null=False, verbose_name='Descriptions', default='no description')

    url = models.TextField(blank=False, null=True, verbose_name='URL', unique=True)

    kv = JSONField(null=True, blank=True, default=dict)

    def save(self, *args, **kwargs):
        if not self.url:
            self.url = self._url()

        super().save(*args, **kwargs)

    @abc.abstractmethod
    def _url(self):
        pass

    def simple_json(self, include_description=False):
        res = {
            'url': self.url,
            'uuid': str(self.uuid),
            'name': self.name,
        }

        if include_description:
            res['description'] = self.description

        return res

    def get_v(self, k, default=None):
        if self.kv:
            return self.kv.get(k, default)
        return default

    class Meta:
        abstract = True

    def __str__(self):
        return f"{self.name} (pk={self.pk})"


class AliasMixin(models.Model):
    aliases = ArrayField(
        models.TextField(blank=False, null=False),
        verbose_name='Aliases', default=list
    )

    @transaction.atomic
    def add_alias(self, new_alias, set_as_default=False):
        if set_as_default:
            self.aliases.append(self.name)
            self.name = new_alias

            if new_alias in self.aliases:
                self.aliases.remove(new_alias)
        else:
            if new_alias not in self.aliases:
                self.aliases.append(new_alias)

        self.aliases = sorted(list(set(self.aliases)), key=lambda x: x.lower())
        self.save()

    class Meta:
        abstract = True


class ScenarioMixin(models.Model):
    scenarios = models.ManyToManyField("epdb.Scenario", verbose_name='Attached Scenarios')

    @transaction.atomic
    def set_scenarios(self, scenarios: List['Scenario']):
        self.scenarios.clear()
        self.save()

        for s in scenarios:
            self.scenarios.add(s)

        self.save()

    class Meta:
        abstract = True


class License(models.Model):
    link = models.URLField(blank=False, null=False, verbose_name='link')
    image_link = models.URLField(blank=False, null=False, verbose_name='Image link')


class Package(EnviPathModel):
    reviewed = models.BooleanField(verbose_name='Reviewstatus', default=False)
    license = models.ForeignKey('epdb.License', on_delete=models.SET_NULL, blank=True, null=True,
                                verbose_name='License')

    def delete(self, *args, **kwargs):
        # explicitly handle related Rules
        for r in self.rules.all():
            r.delete()
        super().delete(*args, **kwargs)

    def __str__(self):
        return f"{self.name} (pk={self.pk})"

    @property
    def compounds(self) -> QuerySet:
        return self.compound_set.all()

    @property
    def rules(self) -> QuerySet:
        return self.rule_set.all()

    @property
    def reactions(self) -> QuerySet:
        return self.reaction_set.all()

    @property
    def pathways(self) -> QuerySet:
        return self.pathway_set.all()

    @property
    def scenarios(self) -> QuerySet:
        return self.scenario_set.all()

    @property
    def models(self) -> QuerySet:
        return self.epmodel_set.all()

    def _url(self):
        return '{}/package/{}'.format(s.SERVER_URL, self.uuid)

    def get_applicable_rules(self) -> List['Rule']:
        """
        Returns a ordered set of rules where the following applies:
        1. All Composite will be added to result
        2. All SimpleRules will be added if theres no CompositeRule present using the SimpleRule
        Ordering is based on "url" field.
        """
        rules = []
        rule_qs = self.rules

        reflected_simple_rules = set()

        for r in rule_qs:
            if isinstance(r, ParallelRule) or isinstance(r, SequentialRule):
                rules.append(r)
                for sr in r.simple_rules.all():
                    reflected_simple_rules.add(sr)

        for r in rule_qs:
            if isinstance(r, SimpleAmbitRule) or isinstance(r, SimpleRDKitRule):
                if r not in reflected_simple_rules:
                    rules.append(r)

        rules = sorted(rules, key=lambda x: x.url)
        return rules


class Compound(EnviPathModel, AliasMixin, ScenarioMixin, ChemicalIdentifierMixin):
    package = models.ForeignKey('epdb.Package', verbose_name='Package', on_delete=models.CASCADE, db_index=True)
    default_structure = models.ForeignKey('CompoundStructure', verbose_name='Default Structure',
                                          related_name='compound_default_structure',
                                          on_delete=models.CASCADE, null=True)

    external_identifiers = GenericRelation('ExternalIdentifier')

    @property
    def structures(self) -> QuerySet:
        return CompoundStructure.objects.filter(compound=self)

    @property
    def normalized_structure(self) -> 'CompoundStructure' :
        return CompoundStructure.objects.get(compound=self, normalized_structure=True)

    def _url(self):
        return '{}/compound/{}'.format(self.package.url, self.uuid)

    @transaction.atomic
    def set_default_structure(self, cs: 'CompoundStructure'):
        if cs.compound != self:
            raise ValueError("Attempt to set a CompoundStructure stored in a different compound as default")

        self.default_structure = cs
        self.save()

    @property
    def related_pathways(self):
        pathways = Node.objects.filter(node_labels__in=[self.default_structure]).values_list('pathway', flat=True)
        return Pathway.objects.filter(package=self.package, id__in=set(pathways)).order_by('name')

    @property
    def related_reactions(self):
        return (
                Reaction.objects.filter(package=self.package, educts__in=[self.default_structure])
                |
                Reaction.objects.filter(package=self.package, products__in=[self.default_structure])
        ).order_by('name')

    @staticmethod
    @transaction.atomic
    def create(package: Package, smiles: str, name: str = None, description: str = None, *args, **kwargs) -> 'Compound':

        if smiles is None or smiles.strip() == '':
            raise ValueError('SMILES is required')

        smiles = smiles.strip()

        parsed = FormatConverter.from_smiles(smiles)
        if parsed is None:
            raise ValueError('Given SMILES is invalid')

        standardized_smiles = FormatConverter.standardize(smiles)

        # Check if we find a direct match for a given SMILES
        if CompoundStructure.objects.filter(smiles=smiles, compound__package=package).exists():
            return CompoundStructure.objects.get(smiles=smiles, compound__package=package).compound

        # Check if we can find the standardized one
        if CompoundStructure.objects.filter(smiles=standardized_smiles, compound__package=package).exists():
            # TODO should we add a structure?
            return CompoundStructure.objects.get(smiles=standardized_smiles, compound__package=package).compound

        # Generate Compound
        c = Compound()
        c.package = package

        if name is None or name.strip() == '':
            name = f"Compound {Compound.objects.filter(package=package).count() + 1}"

        c.name = name

        # We have a default here only set the value if it carries some payload
        if description is not None and description.strip() != '':
            c.description = description.strip()

        c.save()

        is_standardized = standardized_smiles == smiles

        if not is_standardized:
            _ = CompoundStructure.create(c, standardized_smiles, name='Normalized structure of {}'.format(name),
                                         description='{} (in its normalized form)'.format(description),
                                         normalized_structure=True)

        cs = CompoundStructure.create(c, smiles, name=name, description=description,
                                      normalized_structure=is_standardized)

        c.default_structure = cs
        c.save()

        return c

    @transaction.atomic
    def add_structure(self, smiles: str, name: str = None, description: str = None, default_structure: bool = False,
                      *args, **kwargs) -> 'CompoundStructure':

        if smiles is None or smiles == '':
            raise ValueError('SMILES is required')

        smiles = smiles.strip()

        parsed = FormatConverter.from_smiles(smiles)
        if parsed is None:
            raise ValueError('Given SMILES is invalid')

        standardized_smiles = FormatConverter.standardize(smiles)

        is_standardized = standardized_smiles == smiles

        if self.normalized_structure.smiles != standardized_smiles:
            raise ValueError('The standardized SMILES does not match the compounds standardized one!')

        if is_standardized:
            CompoundStructure.objects.get(smiles__in=smiles, compound__package=self.package)

        # Check if we find a direct match for a given SMILES and/or its standardized SMILES
        if CompoundStructure.objects.filter(smiles__in=smiles, compound__package=self.package).exists():
            return CompoundStructure.objects.get(smiles__in=smiles, compound__package=self.package)

        cs = CompoundStructure.create(self, smiles, name=name, description=description,
                                      normalized_structure=is_standardized)

        if default_structure:
            self.default_structure = cs
            self.save()

        return cs

    @transaction.atomic
    def copy(self, target: 'Package', mapping: Dict):
        if self in mapping:
            return mapping[self]

        new_compound = Compound.objects.create(
            package=target,
            name=self.name,
            description=self.description,
            kv=self.kv.copy() if self.kv else {}
        )
        mapping[self] = new_compound

        # Copy compound structures
        for structure in self.structures.all():
            if structure not in mapping:
                new_structure = CompoundStructure.objects.create(
                    compound=new_compound,
                    smiles=structure.smiles,
                    canonical_smiles=structure.canonical_smiles,
                    inchikey=structure.inchikey,
                    normalized_structure=structure.normalized_structure,
                    name=structure.name,
                    description=structure.description,
                    kv=structure.kv.copy() if structure.kv else {}
                )
                mapping[structure] = new_structure

                # Copy external identifiers for structure
                for ext_id in structure.external_identifiers.all():
                    ExternalIdentifier.objects.create(
                        content_object=new_structure,
                        database=ext_id.database,
                        identifier_value=ext_id.identifier_value,
                        url=ext_id.url,
                        is_primary=ext_id.is_primary
                    )

        if self.default_structure:
            new_compound.default_structure = mapping.get(self.default_structure)
            new_compound.save()

        for a in self.aliases:
            new_compound.add_alias(a)
            new_compound.save()

        # Copy external identifiers for compound
        for ext_id in self.external_identifiers.all():
            ExternalIdentifier.objects.create(
                content_object=new_compound,
                database=ext_id.database,
                identifier_value=ext_id.identifier_value,
                url=ext_id.url,
                is_primary=ext_id.is_primary
            )

        return new_compound

    class Meta:
        unique_together = [('uuid', 'package')]


class CompoundStructure(EnviPathModel, AliasMixin, ScenarioMixin, ChemicalIdentifierMixin):
    compound = models.ForeignKey('epdb.Compound', on_delete=models.CASCADE, db_index=True)
    smiles = models.TextField(blank=False, null=False, verbose_name='SMILES')
    canonical_smiles = models.TextField(blank=False, null=False, verbose_name='Canonical SMILES')
    inchikey = models.TextField(max_length=27, blank=False, null=False, verbose_name="InChIKey")
    normalized_structure = models.BooleanField(null=False, blank=False, default=False)

    external_identifiers = GenericRelation('ExternalIdentifier')

    def save(self, *args, **kwargs):
        # Compute these fields only on initial save call
        if self.pk is None:
            try:
                # Generate canonical SMILES
                self.canonical_smiles = FormatConverter.canonicalize(self.smiles)
                # Generate InChIKey
                self.inchikey = FormatConverter.InChIKey(self.smiles)
            except Exception as e:
                logger.error(f"Could compute canonical SMILES/InChIKey from {self.smiles}, error: {e}")

        super().save(*args, **kwargs)

    def _url(self):
        return '{}/structure/{}'.format(self.compound.url, self.uuid)

    @staticmethod
    @transaction.atomic
    def create(compound: Compound, smiles: str, name: str = None, description: str = None, *args, **kwargs):
        if CompoundStructure.objects.filter(compound=compound, smiles=smiles).exists():
            return CompoundStructure.objects.get(compound=compound, smiles=smiles)

        if compound.pk is None:
            raise ValueError("Unpersisted Compound! Persist compound first!")

        cs = CompoundStructure()
        if name is not None:
            cs.name = name

        if description is not None:
            cs.description = description

        cs.smiles = smiles
        cs.compound = compound

        if 'normalized_structure' in kwargs:
            cs.normalized_structure = kwargs['normalized_structure']

        cs.save()

        return cs

    @transaction.atomic
    def copy(self, target: 'Package', mapping: Dict):
        if self in mapping:
            return mapping[self]

        self.compound.copy(target, mapping)
        return mapping[self]

    @property
    def as_svg(self, width: int = 800, height: int = 400):
        return IndigoUtils.mol_to_svg(self.smiles, width=width, height=height)

    @property
    def related_pathways(self):
        pathways = Node.objects.filter(node_labels__in=[self]).values_list('pathway', flat=True)
        return Pathway.objects.filter(package=self.compound.package, id__in=set(pathways)).order_by('name')

    @property
    def related_reactions(self):
        return (
                Reaction.objects.filter(package=self.compound.package, educts__in=[self])
                |
                Reaction.objects.filter(package=self.compound.package, products__in=[self])
        ).order_by('name')

    @property
    def is_default_structure(self):
        return self.compound.default_structure == self


class Rule(PolymorphicModel, EnviPathModel, AliasMixin, ScenarioMixin):
    package = models.ForeignKey('epdb.Package', verbose_name='Package', on_delete=models.CASCADE, db_index=True)

    # # https://github.com/django-polymorphic/django-polymorphic/issues/229
    # _non_polymorphic = models.Manager()
    #
    # class Meta:
    #     base_manager_name = '_non_polymorphic'

    @abc.abstractmethod
    def apply(self, *args, **kwargs):
        pass

    @staticmethod
    def cls_for_type(rule_type: str):
        if rule_type == 'SimpleAmbitRule':
            return SimpleAmbitRule
        elif rule_type == 'SimpleRDKitRule':
            return SimpleRDKitRule
        elif rule_type == 'ParallelRule':
            return ParallelRule
        elif rule_type == 'SequentialRule':
            return SequentialRule
        else:
            raise ValueError(f'{rule_type} is unknown!')

    @staticmethod
    @transaction.atomic
    def create(rule_type: str, *args, **kwargs):
        cls = Rule.cls_for_type(rule_type)
        return cls.create(*args, **kwargs)


    @transaction.atomic
    def copy(self, target: 'Package', mapping: Dict):
        """Copy a rule to the target package."""
        if self in mapping:
            return mapping[self]

        # Get the specific rule type and copy accordingly
        rule_type = type(self)

        if rule_type == SimpleAmbitRule:
            new_rule = SimpleAmbitRule.objects.create(
                package=target,
                name=self.name,
                description=self.description,
                smirks=self.smirks,
                reactant_filter_smarts=self.reactant_filter_smarts,
                product_filter_smarts=self.product_filter_smarts,
                kv=self.kv.copy() if self.kv else {}
            )
        elif rule_type == SimpleRDKitRule:
            new_rule = SimpleRDKitRule.objects.create(
                package=target,
                name=self.name,
                description=self.description,
                reaction_smarts=self.reaction_smarts,
                kv=self.kv.copy() if self.kv else {}
            )
        elif rule_type == ParallelRule:
            new_rule = ParallelRule.objects.create(
                package=target,
                name=self.name,
                description=self.description,
                kv=self.kv.copy() if self.kv else {}
            )
            # Copy simple rules relationships
            for simple_rule in self.simple_rules.all():
                copied_simple_rule = simple_rule.copy(target, mapping)
                new_rule.simple_rules.add(copied_simple_rule)
        elif rule_type == SequentialRule:
            raise ValueError("SequentialRule copy not implemented!")
        else:
            raise ValueError(f"Unknown rule type: {rule_type}")

        mapping[self] = new_rule

        return new_rule


class SimpleRule(Rule):
    pass


#
#
class SimpleAmbitRule(SimpleRule):
    smirks = models.TextField(blank=False, null=False, verbose_name='SMIRKS')
    reactant_filter_smarts = models.TextField(null=True, verbose_name='Reactant Filter SMARTS')
    product_filter_smarts = models.TextField(null=True, verbose_name='Product Filter SMARTS')

    @staticmethod
    @transaction.atomic
    def create(package: Package, name: str = None, description: str = None, smirks: str = None,
               reactant_filter_smarts: str = None, product_filter_smarts: str = None):

        if smirks is None or smirks.strip() == '':
            raise ValueError('SMIRKS is required!')

        smirks = smirks.strip()

        if not FormatConverter.is_valid_smirks(smirks):
            raise ValueError(f'SMIRKS "{smirks}" is invalid!')

        query = SimpleAmbitRule.objects.filter(package=package, smirks=smirks)

        if reactant_filter_smarts is not None and reactant_filter_smarts.strip() != '':
            query = query.filter(reactant_filter_smarts=reactant_filter_smarts)

        if product_filter_smarts is not None and product_filter_smarts.strip() != '':
            query = query.filter(product_filter_smarts=product_filter_smarts)

        if query.exists():
            if query.count() > 1:
                logger.error(f'More than one rule matched this one! {query}')
            return query.first()

        r = SimpleAmbitRule()
        r.package = package

        if name is None or name.strip() == '':
            name = f'Rule {Rule.objects.filter(package=package).count() + 1}'

        r.name = name

        if description is not None and description.strip() != '':
            r.description = description

        r.smirks = smirks

        if reactant_filter_smarts is not None and reactant_filter_smarts.strip() != '':
            r.reactant_filter_smarts = reactant_filter_smarts

        if product_filter_smarts is not None and product_filter_smarts.strip() != '':
            r.product_filter_smarts = product_filter_smarts

        r.save()
        return r

    def _url(self):
        return '{}/simple-ambit-rule/{}'.format(self.package.url, self.uuid)

    def apply(self, smiles):
        return FormatConverter.apply(smiles, self.smirks)

    @property
    def reactants_smarts(self):
        return self.smirks.split('>>')[0]

    @property
    def products_smarts(self):
        return self.smirks.split('>>')[1]

    @property
    def related_reactions(self):
        qs = Package.objects.filter(reviewed=True)
        return self.reaction_rule.filter(package__in=qs).order_by('name')

    @property
    def related_pathways(self):
        return Pathway.objects.filter(
            id__in=Edge.objects.filter(edge_label__in=self.related_reactions).values('pathway_id')).order_by('name')

    @property
    def as_svg(self):
        return IndigoUtils.smirks_to_svg(self.smirks, True, width=800, height=400)


class SimpleRDKitRule(SimpleRule):
    reaction_smarts = models.TextField(blank=False, null=False, verbose_name='SMIRKS')

    def apply(self, smiles):
        return FormatConverter.apply(smiles, self.reaction_smarts)

    def _url(self):
        return '{}/simple-rdkit-rule/{}'.format(self.package.url, self.uuid)


#
#
class ParallelRule(Rule):
    simple_rules = models.ManyToManyField('epdb.SimpleRule', verbose_name='Simple rules')

    def _url(self):
        return '{}/parallel-rule/{}'.format(self.package.url, self.uuid)

    @cached_property
    def srs(self) -> QuerySet:
        return self.simple_rules.all()

    def apply(self, structure):
        res = list()
        for simple_rule in self.srs:
            res.extend(simple_rule.apply(structure))

        return list(set(res))

    @property
    def reactants_smarts(self) -> Set[str]:
        res = set()

        for sr in self.srs:
            for part in sr.reactants_smarts.split('.'):
                res.add(part)

        return res

    @property
    def products_smarts(self) -> Set[str]:
        res = set()

        for sr in self.srs:
            for part in sr.products_smarts.split('.'):
                res.add(part)

        return res



class SequentialRule(Rule):
    simple_rules = models.ManyToManyField('epdb.SimpleRule', verbose_name='Simple rules',
                                          through='SequentialRuleOrdering')

    def _url(self):
        return '{}/sequential-rule/{}'.format(self.compound.url, self.uuid)

    @property
    def srs(self):
        return self.simple_rules.all()

    def apply(self, structure):
        # TODO determine levels or see java implementation
        res = set()
        for simple_rule in self.srs:
            res.union(set(simple_rule.apply(structure)))
        return res


class SequentialRuleOrdering(models.Model):
    sequential_rule = models.ForeignKey(SequentialRule, on_delete=models.CASCADE)
    simple_rule = models.ForeignKey(SimpleRule, on_delete=models.CASCADE)
    order_index = models.IntegerField(null=False, blank=False)


class Reaction(EnviPathModel, AliasMixin, ScenarioMixin, ReactionIdentifierMixin):
    package = models.ForeignKey('epdb.Package', verbose_name='Package', on_delete=models.CASCADE, db_index=True)
    educts = models.ManyToManyField('epdb.CompoundStructure', verbose_name='Educts', related_name='reaction_educts')
    products = models.ManyToManyField('epdb.CompoundStructure', verbose_name='Products',
                                      related_name='reaction_products')
    rules = models.ManyToManyField('epdb.Rule', verbose_name='Rule', related_name='reaction_rule')
    multi_step = models.BooleanField(verbose_name='Multistep Reaction')
    medline_references = ArrayField(
        models.TextField(blank=False, null=False), null=True,
        verbose_name='Medline References'
    )

    external_identifiers = GenericRelation('ExternalIdentifier')

    def _url(self):
        return '{}/reaction/{}'.format(self.package.url, self.uuid)

    @staticmethod
    @transaction.atomic
    def create(package: Package, name: str = None, description: str = None,
               educts: Union[List[str], List[CompoundStructure]] = None,
               products: Union[List[str], List[CompoundStructure]] = None,
               rules: Union[Rule | List[Rule]] = None, multi_step: bool = True):

        _educts = []
        _products = []

        # Determine if we receive smiles or compoundstructures
        if all(isinstance(x, str) for x in educts + products):
            for educt in educts:
                c = Compound.create(package, educt)
                _educts.append(c.default_structure)

            for product in products:
                c = Compound.create(package, product)
                _products.append(c.default_structure)

        elif all(isinstance(x, CompoundStructure) for x in educts + products):
            _educts += educts
            _products += products

        else:
            raise ValueError("Found mixed types for educts and/or products!")

        if len(_educts) == 0 or len(_products) == 0:
            raise ValueError("No educts or products specified!")

        if rules is None:
            rules = []

        if isinstance(rules, Rule):
            rules = [rules]

        query = Reaction.objects.annotate(
            educt_count=Count('educts', filter=Q(educts__in=_educts), distinct=True),
            product_count=Count('products', filter=Q(products__in=_products), distinct=True),
        )

        # The annotate/filter wont work if rules is an empty list
        if rules:
            query = query.annotate(
                rule_count=Count('rules', filter=Q(rules__in=rules), distinct=True)
            ).filter(rule_count=len(rules))
        else:
            query = query.annotate(
                rule_count=Count('rules', distinct=True)
            ).filter(rule_count=0)

        existing_reaction_qs = query.filter(
            educt_count=len(_educts),
            product_count=len(_products),
            multi_step=multi_step,
            package=package
        )

        if existing_reaction_qs.exists():
            if existing_reaction_qs.count() > 1:
                logger.error(f'Found more than one reaction for given input! {existing_reaction_qs}')
            return existing_reaction_qs.first()

        r = Reaction()
        r.package = package

        if name is not None and name.strip() != '':
            r.name = name

        if description is not None and name.strip() != '':
            r.description = description

        r.multi_step = multi_step

        r.save()

        if rules:
            for rule in rules:
                r.rules.add(rule)

        for educt in _educts:
            r.educts.add(educt)

        for product in _products:
            r.products.add(product)

        r.save()
        return r

    @transaction.atomic
    def copy(self, target: 'Package', mapping: Dict ) -> 'Reaction':
        """Copy a reaction to the target package."""
        if self in mapping:
            return mapping[self]

        # Create new reaction
        new_reaction = Reaction.objects.create(
            package=target,
            name=self.name,
            description=self.description,
            multi_step=self.multi_step,
            medline_references=self.medline_references,
            kv=self.kv.copy() if self.kv else {}
        )
        mapping[self] = new_reaction

        # Copy educts (reactant compounds)
        for educt in self.educts.all():
            copied_educt = educt.copy(target, mapping)
            new_reaction.educts.add(copied_educt)

        # Copy products
        for product in self.products.all():
            copied_product = product.copy(target, mapping)
            new_reaction.products.add(copied_product)

        # Copy rules
        for rule in self.rules.all():
            copied_rule = rule.copy(target, mapping)
            new_reaction.rules.add(copied_rule)

        # Copy external identifiers
        for ext_id in self.external_identifiers.all():
            ExternalIdentifier.objects.create(
                content_object=new_reaction,
                database=ext_id.database,
                identifier_value=ext_id.identifier_value,
                url=ext_id.url,
                is_primary=ext_id.is_primary
            )

        return new_reaction

    def smirks(self):
        return f"{'.'.join([cs.smiles for cs in self.educts.all()])}>>{'.'.join([cs.smiles for cs in self.products.all()])}"

    @property
    def as_svg(self):
        return IndigoUtils.smirks_to_svg(self.smirks(), False, width=800, height=400)

    @property
    def related_pathways(self):
        return Pathway.objects.filter(
            id__in=Edge.objects.filter(edge_label=self).values('pathway_id')).order_by('name')


class Pathway(EnviPathModel, AliasMixin, ScenarioMixin):
    package = models.ForeignKey('epdb.Package', verbose_name='Package', on_delete=models.CASCADE, db_index=True)
    setting = models.ForeignKey('epdb.Setting', verbose_name='Setting', on_delete=models.CASCADE, null=True, blank=True)

    @property
    def root_nodes(self):
        # sames as return Node.objects.filter(pathway=self, depth=0) but will utilize
        # potentially prefetched node_set
        return self.node_set.all().filter(pathway=self, depth=0)

    @property
    def nodes(self):
        # same as Node.objects.filter(pathway=self) but will utilize
        # potentially prefetched node_set
        return self.node_set.all()

    def get_node(self, node_url):
        for n in self.nodes:
            if n.url == node_url:
                return n
        return None

    @property
    def edges(self):
        # same as Edge.objects.filter(pathway=self) but will utilize
        # potentially prefetched edge_set
        return self.edge_set.all()

    def _url(self):
        return '{}/pathway/{}'.format(self.package.url, self.uuid)

    # Mode
    def is_built(self):
        return self.kv.get('mode', 'build') == 'build'

    def is_predicted(self):
        return self.kv.get('mode', 'build') == 'predicted'

    def is_incremental(self):
        return self.kv.get('mode', 'build') == 'incremental'

    # Status
    def status(self):
        return self.kv.get('status', 'completed')

    def completed(self):
        return self.status() == 'completed'

    def running(self):
        return self.status() == 'running'

    def failed(self):
        return self.status() == 'failed'

    def d3_json(self):
        # Ideally it would be something like this but
        # to reduce crossing in edges do a DFS
        # nodes = [n.d3_json() for n in self.nodes]

        nodes = []
        processed = set()

        queue = list()
        for n in self.root_nodes:
            queue.append(n)

        # Add unconnected nodes
        for n in self.nodes:
            if len(n.out_edges.all()) == 0:
                if n not in queue:
                    queue.append(n)

        while len(queue):
            current = queue.pop()
            processed.add(current)

            nodes.append(current.d3_json())

            for e in self.edges:
                if current in e.start_nodes.all():
                    for prod in e.end_nodes.all():
                        if prod not in queue and prod not in processed:
                            queue.append(prod)

        # We shouldn't lose or make up nodes...
        assert len(nodes) == len(self.nodes)
        logger.debug(f"{self.name}: Num Nodes {len(nodes)} vs. DB Nodes {len(self.nodes)}")

        links = [e.d3_json() for e in self.edges]

        # D3 links Nodes based on indices in nodes array
        node_url_to_idx = dict()
        for i, n in enumerate(nodes):
            n['id'] = i
            node_url_to_idx[n['url']] = i

        adjusted_links = []
        for link in links:
            # Check if we'll need pseudo nodes
            if len(link['end_node_urls']) > 1:
                start_depth = nodes[node_url_to_idx[link['start_node_urls'][0]]]['depth']
                pseudo_idx = len(nodes)
                pseudo_node = {
                    "depth": start_depth + 0.5,
                    "pseudo": True,
                    "id": pseudo_idx,
                }
                nodes.append(pseudo_node)

                # add links start -> pseudo
                new_link = {
                    'name': link['name'],
                    'id': link['id'],
                    'url': link['url'],
                    'image': link['image'],
                    'reaction': link['reaction'],
                    'reaction_probability': link['reaction_probability'],
                    'scenarios': link['scenarios'],
                    'source': node_url_to_idx[link['start_node_urls'][0]],
                    'target': pseudo_idx,
                    'app_domain': link.get('app_domain', None)
                }
                adjusted_links.append(new_link)

                # add n links pseudo -> end
                for target in link['end_node_urls']:
                    new_link = {
                        'name': link['name'],
                        'id': link['id'],
                        'url': link['url'],
                        'image': link['image'],
                        'reaction': link['reaction'],
                        'reaction_probability': link['reaction_probability'],
                        'scenarios': link['scenarios'],
                        'source': pseudo_idx,
                        'target': node_url_to_idx[target],
                        'app_domain': link.get('app_domain', None)
                    }
                    adjusted_links.append(new_link)

            else:
                link['source'] = node_url_to_idx[link['start_node_urls'][0]]
                link['target'] = node_url_to_idx[link['end_node_urls'][0]]
                adjusted_links.append(link)

        res = {
            "aliases": [],
            "completed": "true",
            "description": self.description,
            "id": self.url,
            "isIncremental": self.kv.get('mode') == 'incremental',
            "isPredicted": self.kv.get('mode') == 'predicted',
            "lastModified": self.modified.strftime('%Y-%m-%d %H:%M:%S'),
            "pathwayName": self.name,
            "reviewStatus": "reviewed" if self.package.reviewed else 'unreviewed',
            "scenarios": [],
            "upToDate": True,
            "links": adjusted_links,
            "nodes": nodes,
            "modified": self.modified.strftime('%Y-%m-%d %H:%M:%S'),
            "status": self.status(),
        }

        return json.dumps(res)

    def to_csv(self) -> str:
        import csv
        import io

        rows = []
        rows.append([
            'SMILES',
            'name',
            'depth',
            'probability',
            'rule_names',
            'rule_ids',
            'parent_smiles',
        ])
        for n in self.nodes.order_by('depth'):
            cs = n.default_node_label
            row = [cs.smiles, cs.name, n.depth]

            edges = self.edges.filter(end_nodes__in=[n])
            if len(edges):
                for e in edges:
                    _row = row.copy()
                    _row.append(e.kv.get('probability'))
                    _row.append(','.join([r.name for r in e.edge_label.rules.all()]))
                    _row.append(','.join([r.url for r in e.edge_label.rules.all()]))
                    _row.append(e.start_nodes.all()[0].default_node_label.smiles)
                    rows.append(_row)
            else:
                row += [None, None, None, None]
                rows.append(row)

        buffer = io.StringIO()

        writer = csv.writer(buffer)
        writer.writerows(rows)

        buffer.seek(0)

        return buffer.getvalue()

    @staticmethod
    @transaction.atomic
    def create(package: 'Package', smiles: str, name: Optional[str] = None, description: Optional[str] = None):
        pw = Pathway()
        pw.package = package

        if name is None or name.strip() == '':
            name = f"Pathway {Pathway.objects.filter(package=package).count() + 1}"

        pw.name = name

        if description is not None and description.strip() != '':
            pw.description = description

        pw.save()
        try:
            # create root node
            Node.create(pw, smiles, 0)
        except ValueError as e:
            # Node creation failed, most likely due to an invalid smiles
            # delete this pathway...
            pw.delete()
            raise e

        return pw

    @transaction.atomic
    def copy(self, target: 'Package', mapping: Dict) -> 'Pathway':

        if self in mapping:
            return mapping[self]

        # Start copying the pathway
        new_pathway = Pathway.objects.create(
            package=target,
            name=self.name,
            description=self.description,
            setting=self.setting, # TODO copy settings?
            kv=self.kv.copy() if self.kv else {}
        )

        # # Copy aliases if they exist
        # if hasattr(self, 'aliases'):
        #     new_pathway.aliases.set(self.aliases.all())
        #
        # # Copy scenarios if they exist
        # if hasattr(self, 'scenarios'):
        #     new_pathway.scenarios.set(self.scenarios.all())

        # Copy all nodes first
        for node in self.nodes.all():
            # Copy the compound structure for the node label
            copied_structure = None
            if node.default_node_label:
                copied_compound = node.default_node_label.compound.copy(target, mapping)
                # Find the corresponding structure in the copied compound
                for structure in copied_compound.structures.all():
                    if structure.smiles == node.default_node_label.smiles:
                        copied_structure = structure
                        break

            new_node = Node.objects.create(
                pathway=new_pathway,
                default_node_label=copied_structure,
                depth=node.depth,
                name=node.name,
                description=node.description,
                kv=node.kv.copy() if node.kv else {}
            )
            mapping[node] = new_node

            # Copy node labels (many-to-many relationship)
            for label in node.node_labels.all():
                copied_label_compound = label.compound.copy(target, mapping)
                for structure in copied_label_compound.structures.all():
                    if structure.smiles == label.smiles:
                        new_node.node_labels.add(structure)
                        break

        # Copy all edges
        for edge in self.edges.all():
            # Copy the reaction for edge label if it exists
            copied_reaction = None
            if edge.edge_label:
                copied_reaction = edge.edge_label.copy(target, mapping)

            new_edge = Edge.objects.create(
                pathway=new_pathway,
                edge_label=copied_reaction,
                name=edge.name,
                description=edge.description,
                kv=edge.kv.copy() if edge.kv else {}
            )

            # Copy start and end nodes relationships
            for start_node in edge.start_nodes.all():
                if start_node in mapping:
                    new_edge.start_nodes.add(mapping[start_node])

            for end_node in edge.end_nodes.all():
                if end_node in mapping:
                    new_edge.end_nodes.add(mapping[end_node])

        mapping[self] = new_pathway

        return new_pathway

    @transaction.atomic
    def add_node(self, smiles: str, name: Optional[str] = None, description: Optional[str] = None, depth: Optional[int] = 0):
        return Node.create(self, smiles, depth, name=name, description=description)

    @transaction.atomic
    def add_edge(self, start_nodes: List['Node'], end_nodes: List['Node'], rule: Optional['Rule'] = None,
                 name: Optional[str] = None, description: Optional[str] = None):
        return Edge.create(self, start_nodes, end_nodes, rule, name=name, description=description)


class Node(EnviPathModel, AliasMixin, ScenarioMixin):
    pathway = models.ForeignKey('epdb.Pathway', verbose_name='belongs to', on_delete=models.CASCADE, db_index=True)
    default_node_label = models.ForeignKey('epdb.CompoundStructure', verbose_name='Default Node Label',
                                           on_delete=models.CASCADE, related_name='default_node_structure')
    node_labels = models.ManyToManyField('epdb.CompoundStructure', verbose_name='All Node Labels',
                                         related_name='node_structures')
    out_edges = models.ManyToManyField('epdb.Edge', verbose_name='Outgoing Edges')
    depth = models.IntegerField(verbose_name='Node depth', null=False, blank=False)

    def _url(self):
        return '{}/node/{}'.format(self.pathway.url, self.uuid)

    def d3_json(self):
        app_domain_data = self.get_app_domain_assessment_data()

        return {
            "depth": self.depth,
            "url": self.url,
            "node_label_id": self.default_node_label.url,
            "image": f"{self.url}?image=svg",
            "image_svg": IndigoUtils.mol_to_svg(self.default_node_label.smiles, width=40, height=40),
            "name": self.default_node_label.name,
            "smiles": self.default_node_label.smiles,
            "scenarios": [{'name': s.name, 'url': s.url} for s in self.scenarios.all()],
            "app_domain": {
                'inside_app_domain': app_domain_data['assessment']['inside_app_domain'] if app_domain_data else None,
                'uncovered_functional_groups': False,
            }
        }

    @staticmethod
    def create(pathway: 'Pathway', smiles: str, depth: int, name: Optional[str] = None,
               description: Optional[str] = None):
        c = Compound.create(pathway.package, smiles, name=name, description=description)

        if Node.objects.filter(pathway=pathway, default_node_label=c.default_structure).exists():
            return Node.objects.get(pathway=pathway, default_node_label=c.default_structure)

        n = Node()
        n.pathway = pathway
        n.depth = depth

        n.default_node_label = c.default_structure
        n.save()

        n.node_labels.add(c.default_structure)
        n.save()

        return n

    @property
    def as_svg(self):
        return IndigoUtils.mol_to_svg(self.default_node_label.smiles)

    def get_app_domain_assessment_data(self):
        data = self.kv.get('app_domain_assessment', None)

        if data:
            rule_ids = defaultdict(list)
            for e in Edge.objects.filter(start_nodes__in=[self]):
                for r in e.edge_label.rules.all():
                    rule_ids[str(r.uuid)].append(e.simple_json())

            for t in data['assessment']['transformations']:
                if t['rule']['uuid'] in rule_ids:
                    t['is_predicted'] = True
                    t['edges'] = rule_ids[t['rule']['uuid']]

        return data

    def simple_json(self, include_description=False):
        res = super().simple_json()
        name = res.get('name', None)
        if name == 'no name':
            res['name'] = self.default_node_label.name

        return res


class Edge(EnviPathModel, AliasMixin, ScenarioMixin):
    pathway = models.ForeignKey('epdb.Pathway', verbose_name='belongs to', on_delete=models.CASCADE, db_index=True)
    edge_label = models.ForeignKey('epdb.Reaction', verbose_name='Edge label', null=True, on_delete=models.SET_NULL)
    start_nodes = models.ManyToManyField('epdb.Node', verbose_name='Start Nodes', related_name='edge_educts')
    end_nodes = models.ManyToManyField('epdb.Node', verbose_name='End Nodes', related_name='edge_products')

    def _url(self):
        return '{}/edge/{}'.format(self.pathway.url, self.uuid)

    def d3_json(self):
        edge_json = {
            'name': self.name,
            'id': self.url,
            'url': self.url,
            'image': self.url + '?image=svg',
            'reaction': {'name': self.edge_label.name, 'url': self.edge_label.url} if self.edge_label else None,
            'reaction_probability': self.kv.get('probability'),
            'start_node_urls': [x.url for x in self.start_nodes.all()],
            'end_node_urls': [x.url for x in self.end_nodes.all()],
            "scenarios": [{'name': s.name, 'url': s.url} for s in self.scenarios.all()],
        }

        for n in self.start_nodes.all():
            app_domain_data = n.get_app_domain_assessment_data()

            if app_domain_data:
                for t in app_domain_data['assessment']['transformations']:
                    if 'edges' in t:
                        for e in t['edges']:
                            if e['uuid'] == str(self.uuid):
                                passes_app_domain = (
                                                            t['local_compatibility'] >= app_domain_data['ad_params'][
                                                        'local_compatibility_threshold']
                                                    ) and (
                                                            t['reliability'] >= app_domain_data['ad_params'][
                                                        'reliability_threshold']
                                                    )

                                edge_json['app_domain'] = {
                                    'passes_app_domain': passes_app_domain,
                                    'local_compatibility': t['local_compatibility'],
                                    'local_compatibility_threshold': app_domain_data['ad_params'][
                                        'local_compatibility_threshold'],
                                    'reliability': t['reliability'],
                                    'reliability_threshold': app_domain_data['ad_params']['reliability_threshold'],
                                    'times_triggered': t['times_triggered'],
                                }

                                break

        return edge_json

    @staticmethod
    def create(pathway, start_nodes: List[Node], end_nodes: List[Node], rule: Optional[Rule] = None,
               name: Optional[str] = None,
               description: Optional[str] = None):
        e = Edge()
        e.pathway = pathway
        e.save()

        for node in start_nodes:
            e.start_nodes.add(node)

        for node in end_nodes:
            e.end_nodes.add(node)

        if name is None:
            name = f'Reaction {pathway.package.reactions.count() + 1}'

        if description is None:
            description = s.DEFAULT_VALUES['description']

        r = Reaction.create(pathway.package, name=name, description=description,
                            educts=[n.default_node_label for n in e.start_nodes.all()],
                            products=[n.default_node_label for n in e.end_nodes.all()],
                            rules=rule, multi_step=False
                            )

        e.edge_label = r
        e.save()
        return e

    @property
    def as_svg(self):
        return self.edge_label.as_svg if self.edge_label else None

    def simple_json(self, include_description=False):
        res = super().simple_json()
        name = res.get('name', None)
        if name == 'no name':
            res['name'] = self.edge_label.name

        return res


class EPModel(PolymorphicModel, EnviPathModel):
    package = models.ForeignKey('epdb.Package', verbose_name='Package', on_delete=models.CASCADE, db_index=True)

    def _url(self):
        return '{}/model/{}'.format(self.package.url, self.uuid)


class PackageBasedModel(EPModel):
    rule_packages = models.ManyToManyField("Package", verbose_name="Rule Packages",
                                           related_name="%(app_label)s_%(class)s_rule_packages")
    data_packages = models.ManyToManyField("Package", verbose_name="Data Packages",
                                           related_name="%(app_label)s_%(class)s_data_packages")
    eval_packages = models.ManyToManyField("Package", verbose_name="Evaluation Packages",
                                           related_name="%(app_label)s_%(class)s_eval_packages")
    threshold = models.FloatField(null=False, blank=False, default=0.5)
    eval_results = JSONField(null=True, blank=True, default=dict)
    app_domain = models.ForeignKey('epdb.ApplicabilityDomain', on_delete=models.SET_NULL, null=True, blank=True,
                                   default=None)
    multigen_eval = models.BooleanField(null=False, blank=False, default=False)

    INITIAL = "INITIAL"
    INITIALIZING = "INITIALIZING"
    BUILDING = "BUILDING"
    BUILT_NOT_EVALUATED = "BUILT_NOT_EVALUATED"
    EVALUATING = "EVALUATING"
    FINISHED = "FINISHED"
    ERROR = "ERROR"
    PROGRESS_STATUS_CHOICES = {
        INITIAL: "Initial",
        INITIALIZING: "Model is initializing.",
        BUILDING: "Model is building.",
        BUILT_NOT_EVALUATED: "Model is built and can be used for predictions, Model is not evaluated yet.",
        EVALUATING: "Model is evaluating",
        FINISHED: "Model has finished building and evaluation.",
        ERROR: "Model has failed."
    }
    model_status = models.CharField(blank=False, null=False, choices=PROGRESS_STATUS_CHOICES, default=INITIAL)

    def status(self):
        return self.PROGRESS_STATUS_CHOICES[self.model_status]

    def ready_for_prediction(self) -> bool:
        return self.model_status in [self.BUILT_NOT_EVALUATED, self.EVALUATING, self.FINISHED]

    @property
    def pr_curve(self):
        if self.model_status != self.FINISHED:
            raise ValueError(f"Expected {self.FINISHED} but model is in status {self.model_status}")

        res = []

        thresholds = self.eval_results['average_precision_per_threshold'].keys()

        for t in thresholds:
            res.append({
                'precision': self.eval_results['average_precision_per_threshold'][t],
                'recall': self.eval_results['average_recall_per_threshold'][t],
                'threshold': float(t)
            })

        return res

    @cached_property
    def applicable_rules(self) -> List['Rule']:
        """
        Returns a ordered set of rules where the following applies:
        1. All Composite will be added to result
        2. All SimpleRules will be added if theres no CompositeRule present using the SimpleRule
        Ordering is based on "url" field.
        """
        rules = []
        rule_qs = Rule.objects.none()
        for package in self.rule_packages.all():
            rule_qs |= package.rules

        rule_qs = rule_qs.distinct()

        reflected_simple_rules = set()

        for r in rule_qs:
            if isinstance(r, ParallelRule) or isinstance(r, SequentialRule):
                rules.append(r)
                for sr in r.simple_rules.all():
                    reflected_simple_rules.add(sr)

        for r in rule_qs:
            if isinstance(r, SimpleAmbitRule) or isinstance(r, SimpleRDKitRule):
                if r not in reflected_simple_rules:
                    rules.append(r)

        rules = sorted(rules, key=lambda x: x.url)

        return rules

    def _get_excludes(self):
        # TODO
        return []

    def _get_reactions(self) -> QuerySet:
        return Reaction.objects.filter(package__in=self.data_packages.all()).distinct()

    def build_dataset(self):
        self.model_status = self.INITIALIZING
        self.save()

        start = datetime.now()

        applicable_rules = self.applicable_rules
        reactions = list(self._get_reactions())
        ds = Dataset.generate_dataset(reactions, applicable_rules, educts_only=True)

        end = datetime.now()
        logger.debug(f"build_dataset took {(end - start).total_seconds()} seconds")

        f = os.path.join(s.MODEL_DIR, f"{self.uuid}_ds.pkl")
        ds.save(f)
        return ds

    def load_dataset(self) -> 'Dataset':
        ds_path = os.path.join(s.MODEL_DIR, f"{self.uuid}_ds.pkl")
        return Dataset.load(ds_path)

    def retrain(self):
        self.build_dataset()
        self.build_model()

    def rebuild(self):
        self.build_model()

    @abstractmethod
    def _fit_model(self, ds: Dataset):
        pass

    @abstractmethod
    def _model_args(self) -> Dict[str, Any]:
        pass

    def build_model(self):
        self.model_status = self.BUILDING
        self.save()

        ds = self.load_dataset()

        mod = self._fit_model(ds)

        f = os.path.join(s.MODEL_DIR, f"{self.uuid}_mod.pkl")
        joblib.dump(mod, f)

        if self.app_domain is not None:
            logger.debug("Building applicability domain...")
            self.app_domain.build()
            logger.debug("Done building applicability domain.")

        self.model_status = self.BUILT_NOT_EVALUATED
        self.save()

    def evaluate_model(self):

        if self.model_status != self.BUILT_NOT_EVALUATED:
            raise ValueError(f"Can't evaluate a model in state {self.model_status}!")

        self.model_status = self.EVALUATING
        self.save()

        def train_func(X, y, train_index, model_kwargs):
            clz = model_kwargs.pop('clz')
            if clz == 'RuleBaseRelativeReasoning':
                mod = RelativeReasoning(
                    **model_kwargs
                )
            else:
                mod = EnsembleClassifierChain(
                    **model_kwargs
                )

            if train_index is not None:
                X, y = X[train_index], y[train_index]

            mod.fit(X, y)
            return mod

        def evaluate_sg(model, X, y, test_index, threshold):
            X_test = X[test_index]
            y_test = y[test_index]

            y_pred = model.predict_proba(X_test)
            y_thresholded = (y_pred >= threshold).astype(int)

            # Flatten them to get rid of np.nan
            y_test = np.asarray(y_test).flatten()
            y_pred = np.asarray(y_pred).flatten()
            y_thresholded = np.asarray(y_thresholded).flatten()

            mask = ~np.isnan(y_test)
            y_test_filtered = y_test[mask]
            y_pred_filtered = y_pred[mask]
            y_thresholded_filtered = y_thresholded[mask]

            acc = jaccard_score(y_test_filtered, y_thresholded_filtered, zero_division=0)

            prec, rec = dict(), dict()

            for t in np.arange(0, 1.05, 0.05):
                temp_thresholded = (y_pred_filtered >= t).astype(int)
                prec[f"{t:.2f}"] = precision_score(y_test_filtered, temp_thresholded, zero_division=0)
                rec[f"{t:.2f}"] = recall_score(y_test_filtered, temp_thresholded, zero_division=0)

            return acc, prec, rec

        def evaluate_mg(model, pathways: Union[QuerySet['Pathway']| List['Pathway']], threshold):
            thresholds = np.arange(0.1, 1.1, 0.1)

            precision = {f"{t:.2f}": [] for t in thresholds}
            recall = {f"{t:.2f}": [] for t in thresholds}

            # Note: only one root compound supported at this time
            root_compounds = [[p.default_node_label.smiles for p in p.root_nodes][0] for p in pathways]

            # As we need a Model Instance in our setting, get a fresh copy from db, overwrite the serialized mode and
            # pass it to the setting used in prediction
            if isinstance(self, MLRelativeReasoning):
                mod = MLRelativeReasoning.objects.get(pk=self.pk)
            elif isinstance(self, RuleBasedRelativeReasoning):
                mod = RuleBasedRelativeReasoning.objects.get(pk=self.pk)

            mod.model = model

            s = Setting()
            s.model = mod
            s.model_threshold = thresholds.min()
            s.max_depth = 10
            s.max_nodes = 50

            from epdb.logic import SPathway
            from utilities.ml import multigen_eval

            pred_pathways = []
            for i, root in enumerate(root_compounds):
                logger.debug(f"Evaluating pathway {i + 1} of {len(root_compounds)}...")

                spw = SPathway(root_nodes=root, prediction_setting=s)
                level = 0

                while not spw.done:
                    spw.predict_step(from_depth=level)
                    level += 1

                pred_pathways.append(spw)

            mg_acc = 0.0
            for t in thresholds:
                for true, pred in zip(test_pathways, pred_pathways):
                    acc, pre, rec = multigen_eval(true, pred, t)
                    if abs(t - threshold) < 0.01:
                        mg_acc = acc
                    precision[f"{t:.2f}"].append(pre)
                    recall[f"{t:.2f}"].append(rec)

            precision = {k: sum(v) / len(v) if len(v) > 0 else 0 for k, v in precision.items()}
            recall = {k: sum(v) / len(v) if len(v) > 0 else 0 for k, v in recall.items()}
            return mg_acc, precision, recall

        ds = self.load_dataset()

        if isinstance(self, RuleBasedRelativeReasoning):
            X = np.array(ds.X(exclude_id_col=False, na_replacement=None))
            y = np.array(ds.y(na_replacement=np.nan))
        else:
            X = np.array(ds.X(na_replacement=np.nan))
            y = np.array(ds.y(na_replacement=np.nan))

        n_splits = 20

        shuff = ShuffleSplit(n_splits=n_splits, test_size=0.25, random_state=42)
        splits = list(shuff.split(X))

        from joblib import Parallel, delayed
        models = Parallel(n_jobs=10)(delayed(train_func)(X, y, train_index, self._model_args()) for train_index, _ in splits)
        evaluations = Parallel(n_jobs=10)(delayed(evaluate_sg)(model, X, y, test_index, self.threshold)
                                          for model, (_, test_index) in zip(models, splits))

        def compute_averages(data):
            num_items = len(data)
            avg_first_item = sum(item[0] for item in data) / num_items

            sum_dict2 = defaultdict(float)
            sum_dict3 = defaultdict(float)

            for _, dict2, dict3 in data:
                for key in dict2:
                    sum_dict2[key] += dict2[key]
                for key in dict3:
                    sum_dict3[key] += dict3[key]

            avg_dict2 = {key: val / num_items for key, val in sum_dict2.items()}
            avg_dict3 = {key: val / num_items for key, val in sum_dict3.items()}

            return {
                "average_accuracy": float(avg_first_item),
                "average_precision_per_threshold": avg_dict2,
                "average_recall_per_threshold": avg_dict3
            }

        self.eval_results = compute_averages(evaluations)

        if self.multigen_eval:

            # We have to consider 2 cases here:
            # 1. No eval packages provided -> Split Train data X times and train and evaluate model
            # 2. eval packages provided -> Use the already built model and do evaluation on the set provided.

            if self.eval_packages.count() > 0:
                pathway_qs = Pathway.objects.filter(package__in=self.eval_packages.all()).distinct()
                evaluate_mg(self.model, pathway_qs, self.threshold)
                return

            pathway_qs = Pathway.objects.prefetch_related(
                'node_set',
                'node_set__out_edges',
                'node_set__default_node_label',
                'node_set__scenarios',
                'edge_set',
                'edge_set__start_nodes',
                'edge_set__end_nodes',
                'edge_set__edge_label',
                'edge_set__scenarios'
            ).filter(package__in=self.data_packages.all()).distinct()

            pathways = []
            for pathway in pathway_qs:
                # There is one pathway with no root compounds, so this check is required
                if len(pathway.root_nodes) > 0:
                    pathways.append(pathway)
                else:
                    logging.warning(f"No root compound in pathway {pathway.name}, excluding from multigen evaluation")

            # build lookup reaction -> {uuid1, uuid2} for overlap check
            reaction_to_educts = defaultdict(set)
            for pathway in pathways:
                for reaction in pathway.edges:
                    for e in reaction.edge_label.educts.all():
                        reaction_to_educts[str(reaction.edge_label.uuid)].add(str(e.uuid))

            # build lookup to avoid recalculation of features, labels
            id_to_index = {uuid: i for i, uuid in enumerate(ds[:, 0])}

            # Compute splits of the collected pathway
            splits = []
            for train, test in ShuffleSplit(n_splits=n_splits, test_size=0.25, random_state=42).split(pathways):
                train_pathways = [pathways[i] for i in train]
                test_pathways = [pathways[i] for i in test]

                # Collect structures from test pathways
                test_educts = set()
                for pathway in test_pathways:
                    for reaction in pathway.edges:
                        test_educts.update(reaction_to_educts[str(reaction.edge_label.uuid)])

                split_ids = []
                overlap = 0
                # Collect indices of the structures contained in train pathways iff they're not present in any of
                # the test pathways
                for pathway in train_pathways:
                    for reaction in pathway.edges:
                        for educt in reaction_to_educts[str(reaction.edge_label.uuid)]:
                            # Ensure compounds in the training set do not appear in the test set
                            if educt not in test_educts:
                                if educt in id_to_index:
                                    split_ids.append(id_to_index[str(educt)])
                                try:
                                    split_ids.append(id_to_index[str(educt)])
                                except KeyError:
                                    logger.debug(f"Couldn't find features in X for compound {educt}")
                            else:
                                overlap += 1

                logging.debug(
                    f"{overlap} compounds had to be removed from multigen split due to overlap within pathways")

                # Get the rows from the dataset corresponding to compounds in the training set pathways
                split_x, split_y = X[split_ids], y[split_ids]
                splits.append([(split_x, split_y), test_pathways])


            # Build model on subsets obtained by pathway split
            trained_models = Parallel(n_jobs=10)(
                delayed(train_func)(split_x, split_y, np.arange(split_x.shape[0]), self._model_args()) for (split_x, split_y), _ in splits
            )

            # Parallelizing multigen evaluate would be non-trivial, potentially possible but requires a lot of work
            multi_ret_vals = Parallel(n_jobs=1)(
                delayed(evaluate_mg)(model, test_pathways, self.threshold) for model, (_, test_pathways) in
                zip(trained_models, splits)
            )


            self.eval_results.update({f"multigen_{k}": v for k, v in compute_averages(multi_ret_vals).items()})

        self.model_status = self.FINISHED
        self.save()

    @staticmethod
    def combine_products_and_probs(rules: List['Rule'], probabilities, products):
        res = []
        for rule, p, smis in zip(rules, probabilities, products):
            res.append(PredictionResult(smis, p, rule))
        return res

    class Meta:
        abstract = True


class RuleBasedRelativeReasoning(PackageBasedModel):
    min_count = models.IntegerField(null=False, blank=False, default=10)
    max_count = models.IntegerField(null=False, blank=False, default=0)

    @staticmethod
    @transaction.atomic
    def create(package: 'Package', rule_packages: List['Package'], data_packages: List['Package'],
               eval_packages: List['Package'], threshold: float = 0.5, min_count: int = 10, max_count: int = 0,
               name: 'str' = None, description: str = None):

        rbrr = RuleBasedRelativeReasoning()
        rbrr.package = package

        if name is None or name.strip() == '':
            name = f"RuleBasedRelativeReasoning {RuleBasedRelativeReasoning.objects.filter(package=package).count() + 1}"

        rbrr.name = name

        if description is not None and description.strip() != '':
            rbrr.description = description

        if threshold is None or (threshold <= 0 or 1 <= threshold):
            raise ValueError("Threshold must be a float between 0 and 1.")

        rbrr.threshold = threshold

        if min_count is None or min_count < 1:
            raise ValueError("Minimum count must be an int greater than equal 1.")

        rbrr.min_count = min_count

        if max_count is None or max_count > min_count:
            raise ValueError("Maximum count must be an int and must not be less than min_count.")

        if max_count is None:
            raise ValueError("Maximum count must be at least 0.")

        if len(rule_packages) == 0:
            raise ValueError("At least one rule package must be provided.")

        rbrr.save()

        for p in rule_packages:
            rbrr.rule_packages.add(p)

        if data_packages:
            for p in data_packages:
                rbrr.data_packages.add(p)
        else:
            for p in rule_packages:
                rbrr.data_packages.add(p)

        if eval_packages:
            for p in eval_packages:
                rbrr.eval_packages.add(p)

        rbrr.save()

        return rbrr

    def _fit_model(self, ds: Dataset):
        X, y = ds.X(exclude_id_col=False, na_replacement=None), ds.y(na_replacement=None)
        model = RelativeReasoning(
            start_index= ds.triggered()[0],
            end_index= ds.triggered()[1],
        )
        model.fit(X, y)
        return model

    def _model_args(self):
        ds = self.load_dataset()
        return {
            'clz': 'RuleBaseRelativeReasoning',
            'start_index': ds.triggered()[0],
            'end_index': ds.triggered()[1],
        }

    @cached_property
    def model(self) -> 'RelativeReasoning':
        mod = joblib.load(os.path.join(s.MODEL_DIR, f'{self.uuid}_mod.pkl'))
        return mod

    def predict(self, smiles) -> List['PredictionResult']:
        start = datetime.now()
        ds = self.load_dataset()
        classify_ds, classify_prods = ds.classification_dataset([smiles], self.applicable_rules)

        mod = self.model
        pred = mod.predict(classify_ds.X(exclude_id_col=False, na_replacement=None))

        res = RuleBasedRelativeReasoning.combine_products_and_probs(self.applicable_rules, pred[0], classify_prods[0])

        end = datetime.now()
        logger.info(f"Full predict took {(end - start).total_seconds()}s")
        return res


class MLRelativeReasoning(PackageBasedModel):

    @staticmethod
    @transaction.atomic
    def create(package: 'Package', rule_packages: List['Package'],
               data_packages: List['Package'], eval_packages: List['Package'], threshold: float = 0.5,
               name: 'str' = None, description: str = None, build_app_domain: bool = False,
               app_domain_num_neighbours: int = None, app_domain_reliability_threshold: float = None,
               app_domain_local_compatibility_threshold: float = None):

        mlrr = MLRelativeReasoning()
        mlrr.package = package

        if name is None or name.strip() == '':
            name = f"MLRelativeReasoning {MLRelativeReasoning.objects.filter(package=package).count() + 1}"

        mlrr.name = name

        if description is not None and description.strip() != '':
            mlrr.description = description

        if threshold is None or (threshold <= 0 or 1 <= threshold):
            raise ValueError("Threshold must be a float between 0 and 1.")

        mlrr.threshold = threshold

        if len(rule_packages) == 0:
            raise ValueError("At least one rule package must be provided.")

        mlrr.save()

        for p in rule_packages:
            mlrr.rule_packages.add(p)

        if data_packages:
            for p in data_packages:
                mlrr.data_packages.add(p)
        else:
            for p in rule_packages:
                mlrr.data_packages.add(p)

        if eval_packages:
            for p in eval_packages:
                mlrr.eval_packages.add(p)

        if build_app_domain:
            ad = ApplicabilityDomain.create(mlrr, app_domain_num_neighbours, app_domain_reliability_threshold,
                                            app_domain_local_compatibility_threshold)
            mlrr.app_domain = ad

        mlrr.save()

        return mlrr

    def _fit_model(self, ds: Dataset):
        X, y = ds.X(na_replacement=np.nan), ds.y(na_replacement=np.nan)

        model = EnsembleClassifierChain(
            **s.DEFAULT_MODEL_PARAMS
        )
        model.fit(X, y)
        return model

    def _model_args(self):
        return {
            'clz': 'MLRelativeReasoning',
            **s.DEFAULT_MODEL_PARAMS,
        }

    @cached_property
    def model(self) -> 'EnsembleClassifierChain':
        mod = joblib.load(os.path.join(s.MODEL_DIR, f'{self.uuid}_mod.pkl'))
        mod.base_clf.n_jobs = -1
        return mod

    def predict(self, smiles) -> List['PredictionResult']:
        start = datetime.now()
        ds = self.load_dataset()
        classify_ds, classify_prods = ds.classification_dataset([smiles], self.applicable_rules)
        pred = self.model.predict_proba(classify_ds.X())

        res = MLRelativeReasoning.combine_products_and_probs(self.applicable_rules, pred[0], classify_prods[0])

        end = datetime.now()
        logger.info(f"Full predict took {(end - start).total_seconds()}s")
        return res


class ApplicabilityDomain(EnviPathModel):
    model = models.ForeignKey(MLRelativeReasoning, on_delete=models.CASCADE)

    num_neighbours = models.IntegerField(blank=False, null=False, default=5)
    reliability_threshold = models.FloatField(blank=False, null=False, default=0.5)
    local_compatibilty_threshold = models.FloatField(blank=False, null=False, default=0.5)

    functional_groups = models.JSONField(blank=True, null=True, default=dict)

    @staticmethod
    @transaction.atomic
    def create(mlrr: MLRelativeReasoning, num_neighbours: int = 5, reliability_threshold: float = 0.5,
               local_compatibility_threshold: float = 0.5):
        ad = ApplicabilityDomain()
        ad.model = mlrr
        # ad.uuid = mlrr.uuid
        ad.name = f"AD for {mlrr.name}"
        ad.num_neighbours = num_neighbours
        ad.reliability_threshold = reliability_threshold
        ad.local_compatibilty_threshold = local_compatibility_threshold
        ad.save()
        return ad

    @cached_property
    def pca(self) -> ApplicabilityDomainPCA:
        pca = joblib.load(os.path.join(s.MODEL_DIR, f'{self.model.uuid}_pca.pkl'))
        return pca

    @cached_property
    def training_set_probs(self):
        return joblib.load(os.path.join(s.MODEL_DIR, f"{self.model.uuid}_train_probs.pkl"))

    def build(self):
        ds = self.model.load_dataset()

        start = datetime.now()

        # Get Trainingset probs and dump them as they're required when using the app domain
        probs = self.model.model.predict_proba(ds.X())
        f = os.path.join(s.MODEL_DIR, f"{self.model.uuid}_train_probs.pkl")
        joblib.dump(probs, f)

        ad = ApplicabilityDomainPCA(num_neighbours=self.num_neighbours)
        ad.build(ds)

        # Collect functional Groups together with their counts for reactivity center highlighting
        functional_groups_counts = defaultdict(int)
        for cs in CompoundStructure.objects.filter(compound__package__in=self.model.data_packages.all()):
            for fg in FormatConverter.get_functional_groups(cs.smiles):
                functional_groups_counts[fg] += 1

        self.functional_groups = dict(functional_groups_counts)
        self.save()

        end = datetime.now()
        logger.debug(f"fitting app domain pca took {(end - start).total_seconds()} seconds")

        f = os.path.join(s.MODEL_DIR, f"{self.model.uuid}_pca.pkl")
        joblib.dump(ad, f)

    def assess(self, structure: Union[str, 'CompoundStructure']):
        ds = self.model.load_dataset()

        if isinstance(structure, CompoundStructure):
            smiles = structure.smiles
        else:
            smiles = structure

        assessment_ds, assessment_prods = ds.classification_dataset([structure], self.model.applicable_rules)

        # qualified_neighbours_per_rule is a nested dictionary structured as:
        #   {
        #       assessment_structure_index: {
        #           rule_index: [training_structure_indices_with_same_triggered_reaction]
        #       }
        #   }
        #
        # For each structure in the assessment dataset and each rule (represented by a trigger feature),
        # it identifies all training structures that have the same trigger reaction activated (i.e., value 1).
        # This is used to find "qualified neighbours" — training examples that share the same triggered feature
        # with a given assessment structure under a particular rule.
        qualified_neighbours_per_rule: Dict[int, Dict[int, List[int]]] = defaultdict(lambda: defaultdict(list))

        for rule_idx, feature_index in enumerate(range(*assessment_ds.triggered())):
            feature = ds.columns[feature_index]
            if feature.startswith('trig_'):
                # TODO unroll loop
                for i, cx in enumerate(assessment_ds.X(exclude_id_col=False)):
                    if int(cx[feature_index]) == 1:
                        for j, tx in enumerate(ds.X(exclude_id_col=False)):
                            if int(tx[feature_index]) == 1:
                                qualified_neighbours_per_rule[i][rule_idx].append(j)

        probs = self.training_set_probs
        # preds = self.model.model.predict_proba(assessment_ds.X())
        preds = self.model.combine_products_and_probs(self.model.applicable_rules,
                                                      self.model.model.predict_proba(assessment_ds.X())[0],
                                                      assessment_prods[0])

        assessments = list()

        # loop through our assessment dataset
        for i, instance in enumerate(assessment_ds):

            rule_reliabilities = dict()
            local_compatibilities = dict()
            neighbours_per_rule = dict()
            neighbor_probs_per_rule = dict()

            # loop through rule indices together with the collected neighbours indices from train dataset
            for rule_idx, vals in qualified_neighbours_per_rule[i].items():

                # collect the train dataset instances and store it along with the index (a.k.a. row number) of the
                # train dataset
                train_instances = []
                for v in vals:
                    train_instances.append((v, ds.at(v)))

                # sf is a tuple with start/end index of the features
                sf = ds.struct_features()

                # compute tanimoto distance for all neighbours
                # result ist a list of tuples with train index and computed distance
                dists = self._compute_distances(
                    instance.X()[0][sf[0]:sf[1]],
                    [ti[1].X()[0][sf[0]:sf[1]] for ti in train_instances]
                )

                dists_with_index = list()
                for ti, dist in zip(train_instances, dists):
                    dists_with_index.append((ti[0], dist[1]))

                #  sort them in a descending way and take at most `self.num_neighbours`
                dists_with_index = sorted(dists_with_index, key=lambda x: x[1], reverse=True)
                dists_with_index = dists_with_index[:self.num_neighbours]

                # compute average distance
                rule_reliabilities[rule_idx] = sum([d[1] for d in dists_with_index]) / len(dists_with_index) if len(
                    dists_with_index) > 0 else 0.0

                # for local_compatibility we'll need the datasets for the indices having the highest similarity
                neighbour_datasets = [(d[0], ds.at(d[0])) for d in dists_with_index]
                local_compatibilities[rule_idx] = self._compute_compatibility(rule_idx, probs, neighbour_datasets)
                neighbours_per_rule[rule_idx] = [CompoundStructure.objects.get(uuid=ds[1].structure_id()) for ds in
                                                 neighbour_datasets]
                neighbor_probs_per_rule[rule_idx] = [probs[d[0]][rule_idx] for d in dists_with_index]

            ad_res = {
                'ad_params': {
                    'uuid': str(self.uuid),
                    'model': self.model.simple_json(),
                    'num_neighbours': self.num_neighbours,
                    'reliability_threshold': self.reliability_threshold,
                    'local_compatibility_threshold': self.local_compatibilty_threshold,
                },
                'assessment': {
                    'smiles': smiles,
                    'inside_app_domain': self.pca.is_applicable(instance)[0],
                }
            }

            transformations = list()
            for rule_idx in rule_reliabilities.keys():
                rule = Rule.objects.get(uuid=instance.columns[instance.observed()[0] + rule_idx].replace('obs_', ''))

                rule_data = rule.simple_json()
                rule_data['image'] = f"{rule.url}?image=svg"

                neighbors = []
                for n, n_prob in zip(neighbours_per_rule[rule_idx], neighbor_probs_per_rule[rule_idx]):
                    neighbor = n.simple_json()
                    neighbor['image'] = f"{n.url}?image=svg"
                    neighbor['smiles'] = n.smiles
                    neighbor['related_pathways'] = [
                        pw.simple_json() for pw in Pathway.objects.filter(
                            node__default_node_label=n,
                            package__in=self.model.data_packages.all()
                        ).distinct()
                    ]
                    neighbor['probability'] = n_prob

                    neighbors.append(neighbor)

                transformation = {
                    'rule': rule_data,
                    'reliability': rule_reliabilities[rule_idx],
                    # We're setting it here to False, as we don't know whether "assess" is called during pathway
                    # prediction or from Model Page. For persisted Nodes this field will be overwritten at runtime
                    'is_predicted': False,
                    'local_compatibility': local_compatibilities[rule_idx],
                    'probability': preds[rule_idx].probability,
                    'transformation_products': [x.product_set for x in preds[rule_idx].product_sets],
                    'times_triggered': ds.times_triggered(str(rule.uuid)),
                    'neighbors': neighbors,
                }

                transformations.append(transformation)

            ad_res['assessment']['transformations'] = transformations

            assessments.append(ad_res)

        return assessments

    @staticmethod
    def _compute_distances(classify_instance: List[int], train_instances: List[List[int]]):
        from utilities.ml import tanimoto_distance
        distances = [(i, tanimoto_distance(classify_instance, train)) for i, train in
                     enumerate(train_instances)]
        return distances

    @staticmethod
    def _compute_compatibility(rule_idx: int, preds, neighbours: List[Tuple[int, 'Dataset']]):
        tp, tn, fp, fn = 0.0, 0.0, 0.0, 0.0
        accuracy = 0.0

        for n in neighbours:
            obs = n[1].y()[0][rule_idx]
            pred = preds[n[0]][rule_idx]
            if obs and pred:
                tp += 1
            elif not obs and pred:
                fp += 1
            elif obs and not pred:
                fn += 1
            else:
                tn += 1
            # Jaccard Index
            if tp + tn > 0.0:
                accuracy = (tp + tn) / (tp + tn + fp + fn)

        return accuracy



class EnviFormer(EPModel):
    threshold = models.FloatField(null=False, blank=False, default=0.5)

    @staticmethod
    @transaction.atomic
    def create(package, name, description, threshold):
        mod = EnviFormer()
        mod.package = package
        mod.name = name
        mod.description = description
        mod.threshold = threshold
        mod.save()

        return mod

    @cached_property
    def model(self):
        mod = getattr(s, 'ENVIFORMER_INSTANCE', None)
        logger.info(f"Model from settings {hash(mod)}")
        return mod

    def predict(self, smiles) -> List['PredictionResult']:
        # example = {
        #     'C#N': 0.46326889595136767,
        #     'C#C': 0.04981685951409509,
        # }
        from rdkit import Chem
        m = Chem.MolFromSmiles(smiles)
        Chem.Kekulize(m)
        kek = Chem.MolToSmiles(m, kekuleSmiles=True)
        logger.info(f"Submitting {kek} to {hash(self.model)}")
        products = self.model.predict(kek)
        logger.info(f"Got results {products}")

        res = []
        for smi, prob in products.items():
            res.append(PredictionResult([ProductSet([smi])], prob, None))

        return res

    @cached_property
    def applicable_rules(self):
        return []

    def status(self):
        return "Model is built and can be used for predictions, Model is not evaluated yet."

    def ready_for_prediction(self) -> bool:
        return True


class PluginModel(EPModel):
    pass


class Scenario(EnviPathModel):
    package = models.ForeignKey('epdb.Package', verbose_name='Package', on_delete=models.CASCADE, db_index=True)
    scenario_date = models.CharField(max_length=256, null=False, blank=False, default='No date')
    scenario_type = models.CharField(max_length=256, null=False, blank=False, default='Not specified')

    # for Referring Scenarios this property will be filled
    parent = models.ForeignKey('self', on_delete=models.CASCADE, default=None, null=True)

    additional_information = models.JSONField(verbose_name='Additional Information')

    def _url(self):
        return '{}/scenario/{}'.format(self.package.url, self.uuid)

    @staticmethod
    @transaction.atomic
    def create(package: 'Package', name:str, description:str, scenario_date:str, scenario_type:str, additional_information: List['EnviPyModel']):
        s = Scenario()
        s.package = package

        if name is None or name.strip() == '':
            name = f"Scenario {Scenario.objects.filter(package=package).count() + 1}"

        s.name = name

        if description is not None and description.strip() != '':
            s.description = description

        if scenario_date is not None and scenario_date.strip() != '':
            s.scenario_date = scenario_date

        if scenario_type is not None and scenario_type.strip() != '':
            s.scenario_type = scenario_type

        add_inf = defaultdict(list)

        for info in additional_information:
            cls_name = info.__class__.__name__
            ai_data = json.loads(info.model_dump_json())
            ai_data['uuid'] = f"{uuid4()}"
            add_inf[cls_name].append(ai_data)


        s.additional_information = add_inf

        s.save()

        return s

    @transaction.atomic
    def add_additional_information(self, data: 'EnviPyModel'):
        cls_name = data.__class__.__name__
        ai_data = json.loads(data.model_dump_json())
        ai_data['uuid'] = f"{uuid4()}"

        if cls_name not in self.additional_information:
            self.additional_information[cls_name] = []

        self.additional_information[cls_name].append(ai_data)
        self.save()


    @transaction.atomic
    def remove_additional_information(self, ai_uuid):
        found_type = None
        found_idx = -1

        for k, vals in self.additional_information.items():
            for i, v in enumerate(vals):
                if v['uuid'] == ai_uuid:
                    found_type = k
                    found_idx = i
                    break

        if found_type is not None and found_idx >= 0:
            if len(self.additional_information[found_type]) == 1:
                del self.additional_information[k]
            else:
                self.additional_information[k].pop(found_idx)
            self.save()
        else:
            raise ValueError(f"Could not find additional information with uuid {ai_uuid}")

    @transaction.atomic
    def set_additional_information(self, data: Dict[str, 'EnviPyModel']):
        new_ais = defaultdict(list)
        for k, vals in data.items():
            for v in vals:
                ai_data = json.loads(v.model_dump_json())
                if hasattr(v, 'uuid'):
                    ai_data['uuid'] = str(v.uuid)
                else:
                    ai_data['uuid'] = str(uuid4())

                new_ais[k].append(ai_data)

        self.additional_information = new_ais
        self.save()

    def get_additional_information(self):
        from envipy_additional_information import NAME_MAPPING

        for k, vals in self.additional_information.items():
            if k == 'enzyme':
                continue

            for v in vals:
                # Per default additional fields are ignored
                MAPPING = {c.__name__: c for c in NAME_MAPPING.values()}
                inst = MAPPING[k](**v)
                # Add uuid to uniquely identify objects for manipulation
                if 'uuid' in v:
                    inst.__dict__['uuid'] = v['uuid']

                yield inst


class UserSettingPermission(Permission):
    uuid = models.UUIDField(null=False, blank=False, verbose_name='UUID of this object', primary_key=True,
                            default=uuid4)
    user = models.ForeignKey('User', verbose_name='Permission to', on_delete=models.CASCADE)
    setting = models.ForeignKey('epdb.Setting', verbose_name='Permission on', on_delete=models.CASCADE)

    class Meta:
        unique_together = [('setting', 'user')]

    def __str__(self):
        return f"User: {self.user} has Permission: {self.permission} on Setting: {self.setting}"


class Setting(EnviPathModel):
    public = models.BooleanField(null=False, blank=False, default=False)
    global_default = models.BooleanField(null=False, blank=False, default=False)

    max_depth = models.IntegerField(null=False, blank=False, verbose_name='Setting Max Depth', default=5)
    max_nodes = models.IntegerField(null=False, blank=False, verbose_name='Setting Max Number of Nodes', default=30)

    rule_packages = models.ManyToManyField("Package", verbose_name="Setting Rule Packages",
                                           related_name="setting_rule_packages", blank=True)
    model = models.ForeignKey('EPModel', verbose_name='Setting EPModel', on_delete=models.SET_NULL, null=True,
                              blank=True)
    model_threshold = models.FloatField(null=True, blank=True, verbose_name='Setting Model Threshold', default=0.25)

    def _url(self):
        return '{}/setting/{}'.format(s.SERVER_URL, self.uuid)

    @cached_property
    def applicable_rules(self):
        """
        Returns a ordered set of rules where the following applies:
        1. All Composite will be added to result
        2. All SimpleRules will be added if theres no CompositeRule present using the SimpleRule
        Ordering is based on "url" field.
        """
        rules = []
        rule_qs = Rule.objects.none()
        for package in self.rule_packages.all():
            rule_qs |= package.rules

        rule_qs = rule_qs.distinct()

        reflected_simple_rules = set()

        for r in rule_qs:
            if isinstance(r, ParallelRule) or isinstance(r, SequentialRule):
                rules.append(r)
                for sr in r.simple_rules.all():
                    reflected_simple_rules.add(sr)

        for r in rule_qs:
            if isinstance(r, SimpleAmbitRule) or isinstance(r, SimpleRDKitRule):
                if r not in reflected_simple_rules:
                    rules.append(r)

        rules = sorted(rules, key=lambda x: x.url)
        return rules

    def expand(self, pathway, current_node):
        """Decision Method whether to expand on a certain Node or not"""
        if pathway.num_nodes() >= self.max_nodes:
            logger.info(f"Pathway has {pathway.num_nodes()} which exceeds the limit of {self.max_nodes}")
            return []

        if pathway.depth() >= self.max_depth:
            logger.info(f"Pathway has reached depth {pathway.depth()} which exceeds the limit of {self.max_depth}")
            return []

        transformations = []
        if self.model is not None:
            pred_results = self.model.predict(current_node.smiles)
            for pred_result in pred_results:
                if pred_result.probability >= self.model_threshold:
                    transformations.append(pred_result)
        else:
            for rule in self.applicable_rules:
                tmp_products = rule.apply(current_node.smiles)
                if tmp_products:
                    transformations.append(PredictionResult(tmp_products, 1.0, rule))

        return transformations

    @transaction.atomic
    def make_global_default(self):
        # Flag all others as global_default False to ensure there's only a single global_default
        Setting.objects.all().update(global_default=False)
        if not self.public:
            self.public = True
        self.global_default = True
        self.save()