DatabaseConnection

"""
This is a wrapper over the database. It is responsible
for setting up the connection and executing querys

"""
__author__ = 'Ionut'
__version__ = '1.0'

import redis


class Database():
    """
    This is a singleton class that can be used
    to communicate with the database

    """
    _connection = None

    def __init__(self):
        """
        Responsible for connecting to the database
        if a connection is not already present

        """
        if Database._connection is None:
            Database._connection = self._connect()

    def _connect(self):
        """
        Connects to the database

        """
        while True:
            connection = redis.StrictRedis()
            if self._test_connection(connection) == 0:
                break
        return connection

    def _test_connection(self, connection):
        """
        Checks if the connection the the redis database
        was successfull

        """
        try:
            connection.set('test', 'test')
        except redis.ConnectionError:
            return -1
        return 0

    def get_connection(self):
        """
        Returns an object that can be used to interact
        with the database

        """
        return self._connection