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"""This module allows to connect to a Neo4j database."""

from airflow.hooks.base import BaseHook
from airflow.models import Connection
from neo4j import GraphDatabase, Neo4jDriver, Result


class Neo4jHook(BaseHook):
    """
    Interact with Neo4j.

    Performs a connection to Neo4j and runs the query.
    """

    conn_name_attr = "neo4j_conn_id"
    default_conn_name = "neo4j_default"
    conn_type = "neo4j"
    hook_name = "Neo4j"

    def __init__(self, conn_id: str = default_conn_name, *args, **kwargs) -> None:
        super().__init__(*args, **kwargs)
        self.neo4j_conn_id = conn_id
        self.connection = kwargs.pop("connection", None)
        self.client = None
        self.extras = None
        self.uri = None

    def get_conn(self) -> Neo4jDriver:
        """
        Function that initiates a new Neo4j connection
        with username, password and database schema.
        """
        self.connection = self.get_connection(self.neo4j_conn_id)
        self.extras = self.connection.extra_dejson.copy()

        self.uri = self.get_uri(self.connection)
        self.log.info("URI: %s", self.uri)

        if self.client is not None:
            return self.client

        is_encrypted = self.connection.extra_dejson.get("encrypted", False)

        self.client = GraphDatabase.driver(
            self.uri,
            auth=(self.connection.login, self.connection.password),
            encrypted=is_encrypted,
        )

        return self.client

    def get_uri(self, conn: Connection) -> str:
        """
        Build the uri based on extras
        - Default - uses bolt scheme(bolt://)
        - neo4j_scheme - neo4j://
        - certs_self_signed - neo4j+ssc://
        - certs_trusted_ca - neo4j+s://
        :param conn: connection object.
        :return: uri
        """
        use_neo4j_scheme = conn.extra_dejson.get("neo4j_scheme", False)
        scheme = "neo4j" if use_neo4j_scheme else "bolt"

        # Self signed certificates
        ssc = conn.extra_dejson.get("certs_self_signed", False)

        # Only certificates signed by CA.
        trusted_ca = conn.extra_dejson.get("certs_trusted_ca", False)
        encryption_scheme = ""

        if ssc:
            encryption_scheme = "+ssc"
        elif trusted_ca:
            encryption_scheme = "+s"

        return "{scheme}{encryption_scheme}://{host}:{port}".format(
            scheme=scheme,
            encryption_scheme=encryption_scheme,
            host=conn.host,
            port="7687" if conn.port is None else f"{conn.port}",
        )

    def run(self, query) -> Result:
        """
        Function to create a neo4j session
        and execute the query in the session.


        :param query: Neo4j query
        :return: Result
        """
        driver = self.get_conn()
        if not self.connection.schema:
            with driver.session() as session:
                result = session.run(query)
        else:
            with driver.session(database=self.connection.schema) as session:
                result = session.run(query)
        return result