"""Handle connection to auth database."""
import sqlite3
import logging
import contextlib
from typing import Any, Protocol, Callable, Iterator

import traceback

from flask import current_app

from .protocols import DbCursor

class DbConnection(Protocol):
    """Type annotation for a generic database connection object."""
    def cursor(self) -> Any:
        """A cursor object"""

    def commit(self) -> Any:
        """Commit the transaction."""

    def rollback(self) -> Any:
        """Rollback the transaction."""

@contextlib.contextmanager
def connection(db_path: str, row_factory: Callable = sqlite3.Row) -> Iterator[DbConnection]:
    """Create the connection to the auth database."""
    logging.debug("SQLite3 DB Path: '%s'.", db_path)
    conn = sqlite3.connect(db_path)
    conn.row_factory = row_factory
    conn.set_trace_callback(logging.debug)
    conn.execute("PRAGMA foreign_keys = ON")
    try:
        yield conn
    except sqlite3.Error as exc:
        conn.rollback()
        logging.debug(traceback.format_exc())
        raise exc
    finally:
        conn.commit()
        conn.close()

@contextlib.contextmanager
def cursor(conn: DbConnection) -> Iterator[DbCursor]:
    """Get a cursor from the given connection to the auth database."""
    cur = conn.cursor()
    try:
        yield cur
        conn.commit()
    except sqlite3.Error as exc:
        conn.rollback()
        logging.debug(traceback.format_exc())
        raise exc
    finally:
        cur.close()

def with_db_connection(func: Callable[[DbConnection], Any]) -> Any:
    """
    Takes a function of one argument `func`, whose one argument is a database
    connection.
    """
    db_uri = current_app.config["AUTH_DB"]
    with connection(db_uri) as conn:
        return func(conn)