import json
import sys
from datetime import datetime

from mysql.connector.pooling import MySQLConnectionPool

# Get keys from config file
with open(sys.argv[1]) as file:
    KEYS = json.load(file)

DATETIME_STRING_FORMAT = '%Y-%m-%dT%H:%M:%S'
CONNECTION_POOL = None


def init_connection_pool(user, password, database, host, port):
    global CONNECTION_POOL
    CONNECTION_POOL = MySQLConnectionPool(pool_name="opendcpool", pool_size=5,
                                          user=user, password=password, database=database, host=host, port=port)


def execute(statement, t):
    """Open a database connection and execute the statement."""

    # Connect to the database
    connection = CONNECTION_POOL.get_connection()
    cursor = connection.cursor()

    # Execute the statement
    cursor.execute(statement, t)

    # Get the id
    cursor.execute('SELECT last_insert_id();')
    row_id = cursor.fetchone()[0]

    # Disconnect from the database
    connection.commit()
    connection.close()

    # Return the id
    return row_id


def fetchone(statement, t=None):
    """Open a database connection and return the first row matched by the SELECT statement."""

    # Connect to the database
    connection = CONNECTION_POOL.get_connection()
    cursor = connection.cursor()

    # Execute the SELECT statement

    if t is not None:
        cursor.execute(statement, t)
    else:
        cursor.execute(statement)

    value = cursor.fetchone()

    # Disconnect from the database and return
    connection.close()
    return value


def fetchall(statement, t=None):
    """Open a database connection and return all rows matched by the SELECT statement."""

    # Connect to the database
    connection = CONNECTION_POOL.get_connection()
    cursor = connection.cursor()

    # Execute the SELECT statement

    if t is not None:
        cursor.execute(statement, t)
    else:
        cursor.execute(statement)

    values = cursor.fetchall()

    # Disconnect from the database and return
    connection.close()
    return values


def datetime_to_string(datetime_to_convert):
    """Return a database-compatible string representation of the given datetime object."""

    return datetime_to_convert.strftime(DATETIME_STRING_FORMAT)


def string_to_datetime(string_to_convert):
    """Return a datetime corresponding to the given string representation."""

    return datetime.strptime(string_to_convert, DATETIME_STRING_FORMAT)