"""Actual Neo4j rollback after DELETE and partial replacement; isolated scopes."""
import os
import uuid

import pytest

from tools.graphrag import build_graphrag as builder
from tools.graphrag.graph_db import create_neo4j_driver, get_neo4j_settings

pytestmark = pytest.mark.skipif(os.getenv('RUN_NEO4J_TESTS') != '1', reason='Requires local Neo4j.')


@pytest.fixture
def managed_graph(monkeypatch):
    scope = 'atomic-rebuild-' + uuid.uuid4().hex
    monkeypatch.setattr(builder, 'GRAPH_SCOPE', scope)
    settings = get_neo4j_settings()
    with create_neo4j_driver(settings) as driver, driver.session(database=settings.database) as session:
        session.run('CREATE (:Person {id:$id, name:"Original", graph_scope:$scope})',
                    id=scope+'old', scope=scope).consume()
        session.run('CREATE (:IndexState {id:$scope, metadata_json:$metadata})',
                    scope=scope, metadata='{"version":"old"}').consume()
        try:
            yield session, scope
        finally:
            session.run('MATCH (n) WHERE n.graph_scope=$scope DETACH DELETE n', scope=scope).consume()
            session.run('MATCH (s:IndexState {id:$scope}) DELETE s', scope=scope).consume()


def replacement(scope):
    payload = {key: [] for key in [*builder.NODE_QUERIES, *builder.RELATIONSHIP_QUERIES]}
    payload['people'] = [{'id': scope+'new', 'name': 'Replacement', 'graph_scope': scope}]
    payload['documents'] = [{'path': scope+'/p.md', 'graph_scope': scope}]
    payload['person_documents'] = [{'person_id': scope+'new', 'document_path': scope+'/p.md'}]
    return payload


def test_failed_replacement_restores_deleted_graph_and_version(managed_graph):
    session, scope = managed_graph
    payload = replacement(scope)
    payload['documents'].append({'path': None, 'graph_scope': scope})
    with pytest.raises(Exception):
        with session.begin_transaction() as tx:
            builder.write_graph_transaction(tx, payload, version={'version': 'new'})
            tx.commit()
    rows = session.run('MATCH (n) WHERE n.graph_scope=$scope RETURN n.name AS name', scope=scope).data()
    assert rows == [{'name': 'Original'}]
    assert builder.graph_version(session) == {'version': 'old'}


def test_successful_replacement_commits_graph_and_version_together(managed_graph):
    session, scope = managed_graph
    payload = replacement(scope); version = {'version': 'new', 'git_revision': 'new-commit'}
    for _ in range(2):
        with session.begin_transaction() as tx:
            builder.write_graph_transaction(tx, payload, version=version)
            tx.commit()
        assert builder.graph_version(session) == version
        nodes, relationships = builder.graph_counts(session)
        assert dict(nodes) == {'Person': 1, 'Document': 1}
        assert dict(relationships) == {'HAS_DOCUMENT': 1}