"""InMemoryGraphDB — NetworkX-backed property graph for testing."""

from __future__ import annotations

import logging

import networkx as nx

from aucourt_ingest.storage.graph_db import (
    GraphDB, GraphNode, GraphRelationship,
    _node_id, _rel_id,
)

logger = logging.getLogger(__name__)


class InMemoryGraphDB:
    """In-memory graph using NetworkX. No external dependencies beyond networkx.

    Suitable for testing and standalone use. Production should use Neo4jGraphDB.
    """

    def __init__(self):
        self._g = nx.MultiDiGraph()
        self._nodes: dict[str, GraphNode] = {}
        self._rels: dict[str, GraphRelationship] = {}

    async def create_node(self, label: str, properties: dict) -> str:
        node_id = _node_id(label, properties)
        if node_id not in self._nodes:
            self._nodes[node_id] = GraphNode(node_id, label, properties.copy())
            self._g.add_node(node_id, label=label, **properties)
        else:
            # Update existing node properties
            existing = self._nodes[node_id]
            existing.properties.update(properties)
            for k, v in properties.items():
                self._g.nodes[node_id][k] = v
        return node_id

    async def create_relationship(self, from_id: str, to_id: str,
                                   rel_type: str, properties: dict | None = None) -> str:
        rel_id = _rel_id(from_id, to_id, rel_type)
        props = properties or {}
        rel = GraphRelationship(rel_id, from_id, to_id, rel_type, props)
        self._rels[rel_id] = rel
        self._g.add_edge(from_id, to_id, key=rel_type, **props)
        return rel_id

    async def get_node(self, node_id: str) -> GraphNode | None:
        return self._nodes.get(node_id)

    async def get_relationships(self, node_id: str,
                                   rel_type: str | None = None,
                                   direction: str = "outgoing") -> list[GraphRelationship]:
        results = []
        if direction in ("outgoing", "both"):
            for u, v, k in self._g.out_edges(node_id, keys=True):
                rel = self._rels.get(_rel_id(u, v, k))
                if rel and (rel_type is None or rel.rel_type == rel_type):
                    results.append(rel)
        if direction in ("incoming", "both"):
            for u, v, k in self._g.in_edges(node_id, keys=True):
                rel = self._rels.get(_rel_id(u, v, k))
                if rel and (rel_type is None or rel.rel_type == rel_type):
                    if rel.rel_id not in {r.rel_id for r in results}:
                        results.append(rel)
        return results

    async def query_nodes(self, label: str = None,
                           properties: dict | None = None) -> list[GraphNode]:
        results = []
        for node_id, node in self._nodes.items():
            if label and node.label != label:
                continue
            if properties:
                if not all(node.properties.get(k) == v for k, v in properties.items()):
                    continue
            results.append(node)
        return results

    async def node_count(self, label: str | None = None) -> int:
        if label:
            return sum(1 for n in self._nodes.values() if n.label == label)
        return len(self._nodes)

    async def relationship_count(self, rel_type: str | None = None) -> int:
        if rel_type:
            return sum(1 for r in self._rels.values() if r.rel_type == rel_type)
        return len(self._rels)

    async def neighbors(self, node_id: str, rel_type: str | None = None,
                        direction: str = "outgoing") -> list[str]:
        """Get adjacent node IDs."""
        rels = await self.get_relationships(node_id, rel_type, direction)
        return [r.to_id if r.from_id == node_id else r.from_id for r in rels]

    async def shortest_path(self, from_id: str, to_id: str) -> list[str] | None:
        """Find shortest path between two nodes. Returns node ID list or None."""
        try:
            path = nx.shortest_path(self._g, from_id, to_id)
            return list(path) if path else None
        except (nx.NetworkXNoPath, nx.NodeNotFound):
            return None

    async def close(self, destroy: bool = True):
        """Clear graph data. Set destroy=False to keep data (e.g. for tests)."""
        if destroy:
            self._g.clear()
            self._nodes.clear()
            self._rels.clear()