/// <summary>
        /// Creates a new collection.
        /// </summary>
        /// <param name="client">The DocumentDB client instance.</param>
        /// <param name="database">The Database where this DocumentCollection exists / will be created</param>
        /// <param name="collectionId">The id of the DocumentCollection to search for, or create.</param>
        /// <param name="collectionSpec">The spec/template to create collections from.</param>
        /// <returns>The created DocumentCollection object</returns>
        public static async Task <DocumentCollection> CreateNewCollection(
            DocumentClient client,
            Database database,
            string collectionId,
            DocumentCollectionSpec collectionSpec)
        {
            DocumentCollection collectionDefinition = new DocumentCollection {
                Id = collectionId
            };

            if (collectionSpec != null)
            {
                CopyIndexingPolicy(collectionSpec, collectionDefinition);
            }

            DocumentCollection collection = await CreateDocumentCollectionWithRetriesAsync(
                client,
                database,
                collectionDefinition,
                (collectionSpec != null)?collectionSpec.OfferType : null);

            if (collectionSpec != null)
            {
                await RegisterScripts(client, collectionSpec, collection);
            }

            return(collection);
        }
        /// <summary>
        /// Registers the stored procedures, triggers and UDFs in the collection spec/template.
        /// </summary>
        /// <param name="client">The DocumentDB client.</param>
        /// <param name="collectionSpec">The collection spec/template.</param>
        /// <param name="collection">The collection.</param>
        /// <returns>The Task object for asynchronous execution.</returns>
        public static async Task RegisterScripts(DocumentClient client, DocumentCollectionSpec collectionSpec, DocumentCollection collection)
        {
            if (collectionSpec.StoredProcedures != null)
            {
                foreach (StoredProcedure sproc in collectionSpec.StoredProcedures)
                {
                    await client.CreateStoredProcedureAsync(collection.SelfLink, sproc);
                }
            }

            if (collectionSpec.Triggers != null)
            {
                foreach (Trigger trigger in collectionSpec.Triggers)
                {
                    await client.CreateTriggerAsync(collection.SelfLink, trigger);
                }
            }

            if (collectionSpec.UserDefinedFunctions != null)
            {
                foreach (UserDefinedFunction udf in collectionSpec.UserDefinedFunctions)
                {
                    await client.CreateUserDefinedFunctionAsync(collection.SelfLink, udf);
                }
            }
        }
        /// <summary>
        /// Get a DocumentCollection by id, or create a new one if one with the id provided doesn't exist.
        /// </summary>
        /// <param name="client">The DocumentDB client instance.</param>
        /// <param name="database">The Database where this DocumentCollection exists / will be created</param>
        /// <param name="collectionId">The id of the DocumentCollection to search for, or create.</param>
        /// <param name="collectionSpec">The spec/template to create collections from.</param>
        /// <returns>The matched, or created, DocumentCollection object</returns>
        public static async Task <DocumentCollection> GetCollectionAsync(
            DocumentClient client,
            Database database,
            string collectionId,
            DocumentCollectionSpec collectionSpec)
        {
            DocumentCollection collection = client.CreateDocumentCollectionQuery(database.SelfLink)
                                            .Where(c => c.Id == collectionId).ToArray().FirstOrDefault();

            if (collection == null)
            {
                collection = await CreateNewCollection(client, database, collectionId, collectionSpec);
            }

            return(collection);
        }
        /// <summary>
        /// Copies the indexing policy from the collection spec.
        /// </summary>
        /// <param name="collectionSpec">The collection spec/template</param>
        /// <param name="collectionDefinition">The collection definition to create.</param>
        public static void CopyIndexingPolicy(DocumentCollectionSpec collectionSpec, DocumentCollection collectionDefinition)
        {
            if (collectionSpec.IndexingPolicy != null)
            {
                collectionDefinition.IndexingPolicy.Automatic    = collectionSpec.IndexingPolicy.Automatic;
                collectionDefinition.IndexingPolicy.IndexingMode = collectionSpec.IndexingPolicy.IndexingMode;

                if (collectionSpec.IndexingPolicy.IncludedPaths != null)
                {
                    foreach (IncludedPath path in collectionSpec.IndexingPolicy.IncludedPaths)
                    {
                        collectionDefinition.IndexingPolicy.IncludedPaths.Add(path);
                    }
                }

                if (collectionSpec.IndexingPolicy.ExcludedPaths != null)
                {
                    foreach (ExcludedPath path in collectionSpec.IndexingPolicy.ExcludedPaths)
                    {
                        collectionDefinition.IndexingPolicy.ExcludedPaths.Add(path);
                    }
                }
            }
        }