import mysql.connector
import pydapper
import logging
import json
import os

connection_pool = None

def initPool():
    try:
        global connection_pool

        config_path = './src/server/BreCal/connection_data.json'
        print (os.getcwd())
        if not os.path.exists(config_path):
            print ('cannot find ' + config_path)
            exit(1)

        f = open(config_path);
        connection_data = json.load(f)

        connection_pool = mysql.connector.connect(**connection_data)

        commands = pydapper.using(connection_pool)
        data = commands.query_single("SELECT id from `user`")
        print("DB connection successful")

    except mysql.connector.PoolError as e:
        logging.error(f"Failed to create connection pool: {e}")
        print(e)
    except e:
        print(e)