import os
import sqlite3
import thread

threaddbs = {}


def get_db_connection(conn, name=''):
    """returns an sqlite3 connection to a persistent database"""

    if not name:
        name = '{}.db'.format(conn.name)

    threadid = thread.get_ident()
    if name in threaddbs and threadid in threaddbs[name]:
        return threaddbs[name][threadid]
    filename = os.path.join(bot.persist_dir, name)

    db = sqlite3.connect(filename, timeout=10)
    if name in threaddbs:
        threaddbs[name][threadid] = db
    else:
        threaddbs[name] = {threadid: db}
    return db

bot.get_db_connection = get_db_connection