"""Helper methods for querying neo4j."""

from participant.connectors import neo4j
from participant.utils.convert import node_to_dict


def get_node(query, **kwargs):
    """Get a node by running a query."""
    return _single_node_query(query, **kwargs)


def create_node(query, **kwargs):
    """Create a node by running a query."""
    return _single_node_query(query, **kwargs)


def update_node(query, **kwargs):
    """Update a node by running a query."""
    return _single_node_query(query, **kwargs)


def get_nodes(query, **kwargs):
    """Get multiple nodes by running a query."""
    with neo4j.db_session() as session:

        results = session.run(query, **kwargs)

    data = []
    if results is not None:
        for record in results:
            data.append(node_to_dict(record.get('node')))

    return data


def get_records(query, **kwargs):
    """Get multiple records by running a query.

    Use when the query is selecting specific fields/attributes, not
    nodes.

    """
    with neo4j.db_session() as session:
        results = session.run(query, **kwargs)

    data = []
    if results is not None:
        for record in results:
            data.append(node_to_dict(record))

    return data


def get_nodes_and_relationship(query, **kwargs):
    """Get multiple nodes and their relationship by running a query."""
    with neo4j.db_session() as session:

        results = session.run(query, **kwargs)

    data = []
    if results is not None:
        for record in results.data():
            node = node_to_dict(record.get('node'))
            relationship = node_to_dict(record.get('r')[0])
            data.append((node, relationship))

    return data


def create_relationship(query, **kwargs):
    """Create a relationship by running a query."""
    return _single_relationship_query(query, **kwargs)


def update_relationship(query, **kwargs):
    """Update a relationship by running a query."""
    return _single_relationship_query(query, **kwargs)


def delete_relationship(query, **kwargs):
    """Delete a relationship by running a query."""
    return _single_relationship_query(query, **kwargs)


def _single_node_query(query, **kwargs):
    """Update a node by running a query."""
    with neo4j.db_session() as session:

        result = session.run(query, **kwargs).single()

    if not result or not result.get('node'):
        return None
    return result.get('node')


def _single_relationship_query(query, **kwargs):
    """Update a relationship by running a query."""
    with neo4j.db_session() as session:
        result = session.run(query, **kwargs).single()

    if not result or not result.get('r'):
        return None

    formatted_result = {
        'type': result['r'].type,
        'properties': [],
    }

    for key, value in result['r'].items():
        formatted_result['properties'].append(
            {
                'name': key,
                'value': value,
            }
        )

    return formatted_result