Portal/rsconcept/backend/apps/oss/models/ChangeManager.py

''' Models: Change propagation manager. '''
from typing import Optional, cast

from cctext import extract_entities
from rest_framework.serializers import ValidationError

from apps.library.models import LibraryItem
from apps.rsform.graph import Graph
from apps.rsform.models import (
    DELETED_ALIAS,
    INSERT_LAST,
    Constituenta,
    CstType,
    RSForm,
    extract_globals,
    replace_entities,
    replace_globals
)

from .Inheritance import Inheritance
from .Operation import Operation, OperationType
from .OperationSchema import OperationSchema
from .Substitution import Substitution

CstMapping = dict[str, Optional[Constituenta]]
CstSubstitution = list[tuple[Constituenta, Constituenta]]


class ChangeManager:
    ''' Change propagation wrapper for OSS. '''

    def __init__(self, model: LibraryItem):
        self.oss = OperationSchema(model)
        self.cache = OssCache(self.oss)

    def after_create_cst(self, cst_list: list[Constituenta], source: RSForm) -> None:
        ''' Trigger cascade resolutions when new constituent is created. '''
        self.cache.insert(source)
        inserted_aliases = [cst.alias for cst in cst_list]
        depend_aliases: set[str] = set()
        for new_cst in cst_list:
            depend_aliases.update(new_cst.extract_references())
        depend_aliases.difference_update(inserted_aliases)
        alias_mapping: CstMapping = {}
        for alias in depend_aliases:
            cst = source.cache.by_alias.get(alias)
            if cst is not None:
                alias_mapping[alias] = cst
        operation = self.cache.get_operation(source)
        self._cascade_create_cst(cst_list, operation, alias_mapping)

    def after_change_cst_type(self, target: Constituenta, source: RSForm) -> None:
        ''' Trigger cascade resolutions when constituenta type is changed. '''
        self.cache.insert(source)
        operation = self.cache.get_operation(source)
        self._cascade_change_cst_type(target.pk, target.cst_type, operation)

    def after_update_cst(self, target: Constituenta, data: dict, old_data: dict, source: RSForm) -> None:
        ''' Trigger cascade resolutions when constituenta data is changed. '''
        self.cache.insert(source)
        operation = self.cache.get_operation(source)
        depend_aliases = self._extract_data_references(data, old_data)
        alias_mapping: CstMapping = {}
        for alias in depend_aliases:
            cst = source.cache.by_alias.get(alias)
            if cst is not None:
                alias_mapping[alias] = cst
        self._cascade_update_cst(target.pk, operation, data, old_data, alias_mapping)

    def before_delete(self, target: list[Constituenta], source: RSForm) -> None:
        ''' Trigger cascade resolutions before constituents are deleted. '''
        self.cache.insert(source)
        operation = self.cache.get_operation(source)
        self._cascade_before_delete(target, operation)

    def before_substitute(self, substitutions: CstSubstitution, source: RSForm) -> None:
        ''' Trigger cascade resolutions before constituents are substituted. '''
        self.cache.insert(source)
        operation = self.cache.get_operation(source)
        self._cascade_before_substitute(substitutions, operation)

    def _cascade_create_cst(self, cst_list: list[Constituenta], operation: Operation, mapping: CstMapping) -> None:
        children = self.cache.graph.outputs[operation.pk]
        if len(children) == 0:
            return
        source_schema = self.cache.get_schema(operation)
        assert source_schema is not None
        for child_id in children:
            child_operation = self.cache.operation_by_id[child_id]
            child_schema = self.cache.get_schema(child_operation)
            if child_schema is None:
                continue

            # TODO: update substitutions for diamond synthesis (if needed)

            self.cache.ensure_loaded()
            new_mapping = self._transform_mapping(mapping, child_operation, child_schema)
            alias_mapping = ChangeManager._produce_alias_mapping(new_mapping)
            insert_where = self._determine_insert_position(cst_list[0], child_operation, source_schema, child_schema)
            new_cst_list = child_schema.insert_copy(cst_list, insert_where, alias_mapping)
            for index, cst in enumerate(new_cst_list):
                new_inheritance = Inheritance.objects.create(
                    operation=child_operation,
                    child=cst,
                    parent=cst_list[index]
                )
                self.cache.insert_inheritance(new_inheritance)
            new_mapping = {alias_mapping[alias]: cst for alias, cst in new_mapping.items()}
            self._cascade_create_cst(new_cst_list, child_operation, new_mapping)

    def _cascade_change_cst_type(self, cst_id: int, ctype: CstType, operation: Operation) -> None:
        children = self.cache.graph.outputs[operation.pk]
        if len(children) == 0:
            return
        self.cache.ensure_loaded()
        for child_id in children:
            child_operation = self.cache.operation_by_id[child_id]
            successor_id = self.cache.get_inheritor(cst_id, child_id)
            if successor_id is None:
                continue
            child_schema = self.cache.get_schema(child_operation)
            if child_schema is not None and child_schema.change_cst_type(successor_id, ctype):
                self._cascade_change_cst_type(successor_id, ctype, child_operation)

    # pylint: disable=too-many-arguments
    def _cascade_update_cst(
        self,
        cst_id: int, operation: Operation,
        data: dict, old_data: dict,
        mapping: CstMapping
    ) -> None:
        children = self.cache.graph.outputs[operation.pk]
        if len(children) == 0:
            return
        self.cache.ensure_loaded()
        for child_id in children:
            child_operation = self.cache.operation_by_id[child_id]
            successor_id = self.cache.get_inheritor(cst_id, child_id)
            if successor_id is None:
                continue
            child_schema = self.cache.get_schema(child_operation)
            assert child_schema is not None
            new_mapping = self._transform_mapping(mapping, child_operation, child_schema)
            alias_mapping = ChangeManager._produce_alias_mapping(new_mapping)
            successor = child_schema.cache.by_id.get(successor_id)
            if successor is None:
                continue
            new_data = self._prepare_update_data(successor, data, old_data, alias_mapping)
            if len(new_data) == 0:
                continue
            new_old_data = child_schema.update_cst(successor, new_data)
            if len(new_old_data) == 0:
                continue
            new_mapping = {alias_mapping[alias]: cst for alias, cst in new_mapping.items()}
            self._cascade_update_cst(successor_id, child_operation, new_data, new_old_data, new_mapping)

    def _cascade_before_delete(self, target: list[Constituenta], operation: Operation) -> None:
        children = self.cache.graph.outputs[operation.pk]
        if len(children) == 0:
            return
        self.cache.ensure_loaded()
        for child_id in children:
            child_operation = self.cache.operation_by_id[child_id]
            child_schema = self.cache.get_schema(child_operation)
            if child_schema is None:
                continue
            self._undo_substitutions_cst(target, child_operation, child_schema)
            child_target_ids = self.cache.get_inheritors_list([cst.pk for cst in target], child_id)
            child_target_cst = [child_schema.cache.by_id[cst_id] for cst_id in child_target_ids]
            self._cascade_before_delete(child_target_cst, child_operation)
            if len(child_target_cst) > 0:
                self.cache.remove_cst(child_target_ids, child_id)
                child_schema.delete_cst(child_target_cst)

    def _cascade_before_substitute(self, substitutions: CstSubstitution, operation: Operation) -> None:
        children = self.cache.graph.outputs[operation.pk]
        if len(children) == 0:
            return
        self.cache.ensure_loaded()
        for child_id in children:
            child_operation = self.cache.operation_by_id[child_id]
            child_schema = self.cache.get_schema(child_operation)
            if child_schema is None:
                continue
            new_substitutions = self._transform_substitutions(substitutions, child_id, child_schema)
            if len(new_substitutions) == 0:
                continue
            self._cascade_before_substitute(new_substitutions, child_operation)
            child_schema.substitute(new_substitutions)

    def _cascade_partial_mapping(
        self,
        mapping: CstMapping,
        target: list[int],
        operation: Operation,
        schema: RSForm
    ) -> None:
        alias_mapping = ChangeManager._produce_alias_mapping(mapping)
        schema.apply_partial_mapping(alias_mapping, target)
        children = self.cache.graph.outputs[operation.pk]
        if len(children) == 0:
            return
        self.cache.ensure_loaded()
        for child_id in children:
            child_operation = self.cache.operation_by_id[child_id]
            child_schema = self.cache.get_schema(child_operation)
            if child_schema is None:
                continue
            new_mapping = self._transform_mapping(mapping, child_operation, child_schema)
            if not new_mapping:
                continue
            new_target = self.cache.get_inheritors_list(target, child_id)
            if len(new_target) == 0:
                continue
            self._cascade_partial_mapping(new_mapping, new_target, child_operation, child_schema)

    @staticmethod
    def _produce_alias_mapping(mapping: CstMapping) -> dict[str, str]:
        result: dict[str, str] = {}
        for alias, cst in mapping.items():
            if cst is None:
                result[alias] = DELETED_ALIAS
            else:
                result[alias] = cst.alias
        return result

    def _transform_mapping(self, mapping: CstMapping, operation: Operation, schema: RSForm) -> CstMapping:
        if len(mapping) == 0:
            return mapping
        result: CstMapping = {}
        for alias, cst in mapping.items():
            if cst is None:
                result[alias] = None
                continue
            successor_id = self.cache.get_successor(cst.pk, operation.pk)
            if successor_id is None:
                continue
            successor = schema.cache.by_id.get(successor_id)
            if successor is None:
                continue
            result[alias] = successor
        return result

    def _determine_insert_position(
        self, prototype: Constituenta,
        operation: Operation,
        source: RSForm,
        destination: RSForm
    ) -> int:
        ''' Determine insert_after for new constituenta. '''
        if prototype.order == 1:
            return 1
        prev_cst = source.cache.constituents[prototype.order - 2]
        inherited_prev_id = self.cache.get_successor(prev_cst.pk, operation.pk)
        if inherited_prev_id is None:
            return INSERT_LAST
        prev_cst = destination.cache.by_id[inherited_prev_id]
        return cast(int, prev_cst.order) + 1

    def _extract_data_references(self, data: dict, old_data: dict) -> set[str]:
        result: set[str] = set()
        if 'definition_formal' in data:
            result.update(extract_globals(data['definition_formal']))
            result.update(extract_globals(old_data['definition_formal']))
        if 'term_raw' in data:
            result.update(extract_entities(data['term_raw']))
            result.update(extract_entities(old_data['term_raw']))
        if 'definition_raw' in data:
            result.update(extract_entities(data['definition_raw']))
            result.update(extract_entities(old_data['definition_raw']))
        return result

    def _prepare_update_data(self, cst: Constituenta, data: dict, old_data: dict, mapping: dict[str, str]) -> dict:
        new_data = {}
        if 'term_forms' in data:
            if old_data['term_forms'] == cst.term_forms:
                new_data['term_forms'] = data['term_forms']
        if 'convention' in data:
            if old_data['convention'] == cst.convention:
                new_data['convention'] = data['convention']
        if 'definition_formal' in data:
            new_data['definition_formal'] = replace_globals(data['definition_formal'], mapping)
        if 'term_raw' in data:
            if replace_entities(old_data['term_raw'], mapping) == cst.term_raw:
                new_data['term_raw'] = replace_entities(data['term_raw'], mapping)
        if 'definition_raw' in data:
            if replace_entities(old_data['definition_raw'], mapping) == cst.definition_raw:
                new_data['definition_raw'] = replace_entities(data['definition_raw'], mapping)
        return new_data

    def _transform_substitutions(
        self,
        target: CstSubstitution,
        operation: int,
        schema: RSForm
    ) -> CstSubstitution:
        result: CstSubstitution = []
        for current_sub in target:
            sub_replaced = False
            new_substitution_id = self.cache.get_inheritor(current_sub[1].pk, operation)
            if new_substitution_id is None:
                for sub in self.cache.substitutions[operation]:
                    if sub.original_id == current_sub[1].pk:
                        sub_replaced = True
                        new_substitution_id = self.cache.get_inheritor(sub.original_id, operation)
                        break

            new_original_id = self.cache.get_inheritor(current_sub[0].pk, operation)
            original_replaced = False
            if new_original_id is None:
                for sub in self.cache.substitutions[operation]:
                    if sub.original_id == current_sub[0].pk:
                        original_replaced = True
                        sub.original_id = current_sub[1].pk
                        sub.save()
                        new_original_id = new_substitution_id
                        new_substitution_id = self.cache.get_inheritor(sub.substitution_id, operation)
                        break

            if sub_replaced and original_replaced:
                raise ValidationError({'propagation': 'Substitution breaks OSS substitutions.'})

            for sub in self.cache.substitutions[operation]:
                if sub.substitution_id == current_sub[0].pk:
                    sub.substitution_id = current_sub[1].pk
                    sub.save()

            if new_original_id is not None and new_substitution_id is not None:
                result.append((schema.cache.by_id[new_original_id], schema.cache.by_id[new_substitution_id]))
        return result

    def _undo_substitutions_cst(self, target: list[Constituenta], operation: Operation, schema: RSForm) -> None:
        target_ids = [cst.pk for cst in target]
        to_process = []
        for sub in self.cache.substitutions[operation.pk]:
            if sub.original_id in target_ids or sub.substitution_id in target_ids:
                to_process.append(sub)
        for sub in to_process:
            self._undo_substitution(sub, schema, target_ids)

    def _undo_substitution(self, target: Substitution, schema: RSForm, ignore_parents: list[int]) -> None:
        operation = self.cache.operation_by_id[target.operation_id]
        original_schema, _, original_cst, substitution_cst = self.cache.unfold_sub(target)

        dependant = []
        for cst_id in original_schema.get_dependant([original_cst.pk]):
            if cst_id not in ignore_parents:
                inheritor_id = self.cache.get_inheritor(cst_id, operation.pk)
                if inheritor_id is not None:
                    dependant.append(inheritor_id)

        self.cache.substitutions[operation.pk].remove(target)
        target.delete()

        new_original: Optional[Constituenta] = None
        if original_cst.pk not in ignore_parents:
            full_cst = Constituenta.objects.get(pk=original_cst.pk)
            self.after_create_cst([full_cst], original_schema)
            new_original_id = self.cache.get_inheritor(original_cst.pk, operation.pk)
            assert new_original_id is not None
            new_original = schema.cache.by_id[new_original_id]
        if len(dependant) == 0:
            return

        substitution_id = self.cache.get_inheritor(substitution_cst.pk, operation.pk)
        assert substitution_id is not None
        substitution_inheritor = schema.cache.by_id[substitution_id]
        mapping = {cast(str, substitution_inheritor.alias): new_original}
        self._cascade_partial_mapping(mapping, dependant, operation, schema)


class OssCache:
    ''' Cache for OSS data. '''

    def __init__(self, oss: OperationSchema):
        self._oss = oss
        self._schemas: list[RSForm] = []
        self._schema_by_id: dict[int, RSForm] = {}

        self.operations = list(oss.operations().only('result_id'))
        self.operation_by_id = {operation.pk: operation for operation in self.operations}
        self.graph = Graph[int]()
        for operation in self.operations:
            self.graph.add_node(operation.pk)
        for argument in self._oss.arguments().only('operation_id', 'argument_id'):
            self.graph.add_edge(argument.argument_id, argument.operation_id)

        self.is_loaded = False
        self.substitutions: dict[int, list[Substitution]] = {}
        self.inheritance: dict[int, list[Inheritance]] = {}

    def insert(self, schema: RSForm) -> None:
        ''' Insert new schema. '''
        if not self._schema_by_id.get(schema.model.pk):
            schema.cache.ensure_loaded()
            self._insert_new(schema)

    def get_schema(self, operation: Operation) -> Optional[RSForm]:
        ''' Get schema by Operation. '''
        if operation.result_id is None:
            return None
        if operation.result_id in self._schema_by_id:
            return self._schema_by_id[operation.result_id]
        else:
            schema = RSForm.from_id(operation.result_id)
            schema.cache.ensure_loaded()
            self._insert_new(schema)
            return schema

    def get_operation(self, schema: RSForm) -> Operation:
        ''' Get operation by schema. '''
        for operation in self.operations:
            if operation.result_id == schema.model.pk:
                return operation
        raise ValueError(f'Operation for schema {schema.model.pk} not found')

    def ensure_loaded(self) -> None:
        ''' Ensure propagation of changes. '''
        if self.is_loaded:
            return
        self.is_loaded = True
        for operation in self.operations:
            if operation.operation_type != OperationType.INPUT:
                self.inheritance[operation.pk] = []
                self.substitutions[operation.pk] = []
        for sub in self._oss.substitutions().only('operation_id', 'original_id', 'substitution_id'):
            self.substitutions[sub.operation_id].append(sub)
        for item in self._oss.inheritance().only('operation_id', 'parent_id', 'child_id'):
            self.inheritance[item.operation_id].append(item)

    def get_inheritor(self, parent_cst: int, operation: int) -> Optional[int]:
        ''' Get child for parent inside target RSFrom. '''
        for item in self.inheritance[operation]:
            if item.parent_id == parent_cst:
                return item.child_id
        return None

    def get_inheritors_list(self, target: list[int], operation: int) -> list[int]:
        ''' Get child for parent inside target RSFrom. '''
        result = []
        for item in self.inheritance[operation]:
            if item.parent_id in target:
                result.append(item.child_id)
        return result

    def get_successor(self, parent_cst: int, operation: int) -> Optional[int]:
        ''' Get child for parent inside target RSFrom including substitutions. '''
        for sub in self.substitutions[operation]:
            if sub.original_id == parent_cst:
                return self.get_inheritor(sub.substitution_id, operation)
        return self.get_inheritor(parent_cst, operation)


    def insert_inheritance(self, inheritance: Inheritance) -> None:
        ''' Insert new inheritance. '''
        self.inheritance[inheritance.operation_id].append(inheritance)

    def insert_substitution(self, sub: Substitution) -> None:
        ''' Insert new inheritance. '''
        self.substitutions[sub.operation_id].append(sub)

    def remove_cst(self, target: list[int], operation: int) -> None:
        ''' Remove constituents from operation. '''
        subs_to_delete = [
            sub for sub in self.substitutions[operation]
            if sub.original_id in target or sub.substitution_id in target
        ]
        for sub in subs_to_delete:
            self.substitutions[operation].remove(sub)
        inherit_to_delete = [item for item in self.inheritance[operation] if item.child_id in target]
        for item in inherit_to_delete:
            self.inheritance[operation].remove(item)

    def unfold_sub(self, sub: Substitution) -> tuple[RSForm, RSForm, Constituenta, Constituenta]:
        operation = self.operation_by_id[sub.operation_id]
        parents = self.graph.inputs[operation.pk]
        original_cst = None
        substitution_cst = None
        original_schema = None
        substitution_schema = None
        for parent_id in parents:
            parent_schema = self.get_schema(self.operation_by_id[parent_id])
            if parent_schema is None:
                continue
            if sub.original_id in parent_schema.cache.by_id:
                original_schema = parent_schema
                original_cst = original_schema.cache.by_id[sub.original_id]
            if sub.substitution_id in parent_schema.cache.by_id:
                substitution_schema = parent_schema
                substitution_cst = substitution_schema.cache.by_id[sub.substitution_id]
        if original_schema is None or substitution_schema is None or original_cst is None or substitution_cst is None:
            raise ValueError(f'Parent schema for Substitution-{sub.pk} not found.')
        return original_schema, substitution_schema, original_cst, substitution_cst

    def _insert_new(self, schema: RSForm) -> None:
        self._schemas.append(schema)
        self._schema_by_id[schema.model.pk] = schema