NewProvider creates a new Provider that connects to Mongo using uri, and uses the specified db.

NewProviderFromViper creates a new Provider, configured using Viper.

MoodsCollection is the name of Mood objects collection in Mongo.

Namespace is the package namespace, used for configuring environment variables, etc.

ErrInvalidID is returned when an hex ID could not be converted into an ObjectID.

A MoodService is an implementation of api.MoodService that uses Mongo as the underlying data store.

A Provider provides various services that use Mongo as an underlying data store.