Wrapper for pymongo to integrate nicer into Django with failover stuff, forked for python3

mongodb.py

"""
MONGODB = {
    'default': {
        'NAME': env('MONGODB_DEFAULT_DATABASE', default='scanvis'),  # Default database to connect to
        'URI': env('MONGODB_URI', default='mongodb://localhost:27017/')
    }
}
"""
from django.conf import settings
from pymongo import MongoClient

__all__ = ("clients", "client", "db")


class DatabaseConfigDoesNotExist(Exception):
    pass


class ClientWrapper(object):

    def __init__(self, client, default=None):
        self._client = client
        self._databases = {}
        self._default = default

    def __getattr__(self, alias):
        if self._default and alias == "default":
            alias = self._default

        if alias in self._databases:
            return self._databases[alias]

        database = self._client[alias]
        self._databases[alias] = database

        return database

    def __str__(self):
        return "<ClientWrapper %s>" % self._client.__str__()


class MongoHandler:

    def __init__(self, databases):
        self.databases = databases
        self.clients = {}

    def __getitem__(self, alias):
        if alias in self.clients:
            return self.clients[alias]

        if alias not in self.databases:
            raise DatabaseConfigDoesNotExist(
                "The database %s config doesn't exist" % alias
            )
        client = MongoClient(self.databases[alias]["URI"])
        self.clients[alias] = ClientWrapper(client, self.databases[alias]["NAME"])
        return self.clients[alias]


clients = MongoHandler(settings.MONGODB)
client = clients["default"]

db = client.default