"""Local entity-reader compatibility adapter for the legacy Zep consumer shape."""

from __future__ import annotations

from dataclasses import dataclass, field
from typing import Any, Optional

from .memory_repository import SqlAlchemyMemoryRepository


@dataclass
class LocalEntityNode:
    uuid: str
    name: str
    labels: list[str]
    summary: str
    attributes: dict[str, Any]
    related_edges: list[dict[str, Any]] = field(default_factory=list)
    related_nodes: list[dict[str, Any]] = field(default_factory=list)

    def to_dict(self) -> dict[str, Any]:
        return {
            "uuid": self.uuid,
            "name": self.name,
            "labels": self.labels,
            "summary": self.summary,
            "attributes": self.attributes,
            "related_edges": self.related_edges,
            "related_nodes": self.related_nodes,
        }

    def get_entity_type(self) -> Optional[str]:
        return next((label for label in self.labels if label not in {"Entity", "Node"}), None)


@dataclass
class LocalFilteredEntities:
    entities: list[LocalEntityNode]
    entity_types: set[str]
    total_count: int
    filtered_count: int

    def to_dict(self) -> dict[str, Any]:
        return {
            "entities": [entity.to_dict() for entity in self.entities],
            "entity_types": sorted(self.entity_types),
            "total_count": self.total_count,
            "filtered_count": self.filtered_count,
        }


class LocalEntityReader:
    def __init__(
        self,
        session_or_repository,
        *,
        organization_id: str | None = None,
        graph_id: str | None = None,
        owns_session: bool = False,
    ):
        self.owns_session = False
        if isinstance(session_or_repository, SqlAlchemyMemoryRepository):
            self.repository = session_or_repository
        else:
            if organization_id is None or graph_id is None:
                raise ValueError("memory_reader_scope_required")
            self.repository = SqlAlchemyMemoryRepository(
                session_or_repository,
                organization_id=organization_id,
                graph_id=graph_id,
            )
            self.owns_session = owns_session

    def _validate_graph_id(self, graph_id: str | None = None) -> None:
        if graph_id is not None and graph_id != self.repository.graph_id:
            raise ValueError("memory_graph_scope_conflict")

    def close(self) -> None:
        if self.owns_session:
            self.repository.session.close()
            self.owns_session = False

    @staticmethod
    def _node_dict(node) -> dict[str, Any]:
        return {
            "uuid": node.id,
            "name": node.canonical_name,
            "labels": list(node.labels or []),
            "summary": node.summary or "",
            "attributes": dict(node.attributes or {}),
        }

    def _entity(self, node, *, enrich_with_edges: bool = True) -> LocalEntityNode:
        related_edges: list[dict[str, Any]] = []
        related_nodes: list[dict[str, Any]] = []
        if enrich_with_edges:
            all_nodes = {item.id: item for item in self.repository.list_nodes()}
            for edge in self.repository.get_node_edges(node.id):
                source = all_nodes.get(edge.source_node_id)
                target = all_nodes.get(edge.target_node_id)
                if edge.source_node_id == node.id:
                    related_edges.append(
                        {
                            "direction": "outgoing",
                            "edge_name": edge.relation,
                            "fact": edge.fact,
                            "target_node_uuid": edge.target_node_id,
                        }
                    )
                    related_node = target
                else:
                    related_edges.append(
                        {
                            "direction": "incoming",
                            "edge_name": edge.relation,
                            "fact": edge.fact,
                            "source_node_uuid": edge.source_node_id,
                        }
                    )
                    related_node = source
                if related_node is not None:
                    related_nodes.append(
                        {
                            "uuid": related_node.id,
                            "name": related_node.canonical_name,
                            "labels": list(related_node.labels or []),
                            "summary": related_node.summary or "",
                        }
                    )
        return LocalEntityNode(
            uuid=node.id,
            name=node.canonical_name,
            labels=list(node.labels or []),
            summary=node.summary or "",
            attributes=dict(node.attributes or {}),
            related_edges=related_edges,
            related_nodes=related_nodes,
        )

    def get_all_nodes(self, graph_id: str | None = None) -> list[dict[str, Any]]:
        self._validate_graph_id(graph_id)
        return [self._node_dict(node) for node in self.repository.list_nodes()]

    def get_all_edges(self, graph_id: str | None = None) -> list[dict[str, Any]]:
        self._validate_graph_id(graph_id)
        return [
            {
                "uuid": edge.id,
                "name": edge.relation,
                "fact": edge.fact,
                "source_node_uuid": edge.source_node_id,
                "target_node_uuid": edge.target_node_id,
                "attributes": dict(edge.attributes or {}),
            }
            for edge in self.repository.list_edges()
        ]

    def filter_defined_entities(
        self,
        graph_id: str | None = None,
        *,
        defined_entity_types: Optional[list[str]] = None,
        enrich_with_edges: bool = True,
    ) -> LocalFilteredEntities:
        self._validate_graph_id(graph_id)
        nodes = self.repository.list_nodes()
        allowed = set(defined_entity_types or [])
        entity_types: set[str] = set()
        entities: list[LocalEntityNode] = []
        for node in nodes:
            custom_labels = [label for label in node.labels or [] if label not in {"Entity", "Node"}]
            if not custom_labels:
                continue
            if defined_entity_types:
                matching_labels = [label for label in custom_labels if label in allowed]
                if not matching_labels:
                    continue
                entity_type = matching_labels[0]
            else:
                entity_type = custom_labels[0]
            entity_types.add(entity_type)
            entities.append(self._entity(node, enrich_with_edges=enrich_with_edges))
        return LocalFilteredEntities(
            entities=entities,
            entity_types=entity_types,
            total_count=len(nodes),
            filtered_count=len(entities),
        )

    def get_entity_with_context(
        self,
        graph_id_or_entity_uuid: str | None = None,
        entity_uuid: str | None = None,
        *,
        graph_id: str | None = None,
    ) -> Optional[LocalEntityNode]:
        requested_graph_id = graph_id
        if entity_uuid is not None and requested_graph_id is None:
            requested_graph_id = graph_id_or_entity_uuid
        self._validate_graph_id(requested_graph_id)
        node_id = entity_uuid or graph_id_or_entity_uuid
        if not node_id:
            raise ValueError("memory_entity_id_required")
        node = self.repository.get_node(node_id)
        return self._entity(node, enrich_with_edges=True) if node is not None else None

    def get_entities_by_type(
        self,
        graph_id_or_entity_type: str | None = None,
        entity_type: str | None = None,
        *,
        graph_id: str | None = None,
        enrich_with_edges: bool = True,
    ) -> list[LocalEntityNode]:
        requested_graph_id = graph_id
        if entity_type is not None and requested_graph_id is None:
            requested_graph_id = graph_id_or_entity_type
        self._validate_graph_id(requested_graph_id)
        selected_type = entity_type or graph_id_or_entity_type
        if not selected_type:
            raise ValueError("memory_entity_type_required")
        return [
            self._entity(node, enrich_with_edges=enrich_with_edges)
            for node in self.repository.list_nodes()
            if selected_type in (node.labels or [])
        ]


def make_local_entity_reader_factory(session_factory, *, organization_id: str):
    """Create per-worker readers; each reader owns and closes its own session."""
    if not isinstance(organization_id, str) or not organization_id.strip():
        raise ValueError("memory_reader_organization_required")

    def factory(graph_id: str) -> LocalEntityReader:
        return LocalEntityReader(
            session_factory(),
            organization_id=organization_id,
            graph_id=graph_id,
            owns_session=True,
        )

    return factory